bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computational and Experimental Studies on the Mechanism of the Photochemical Carbonylation of Group 6 Fischer Carbene Complexes
Authors: Fernández Israel , Sierra Miguel A. , Gómez‐Gallego Mar , Mancheño María J. , Cossío Fernando P. 
Published: July 2005

AbstractThe photocarbonylation reaction of Group 6 Fischer carbene complexes has been studied by DFT and experimental procedures. The process occurs by intersystem crossing (ISC) from the lowest excited singlet state (S1) to the lowest triplet state (T1), the latter structure being decisive for the outcome of the reaction. Methylenepentacarbonylchromium(0) complexes, alkoxypentacarbonylchromium(0)carbene complexes, and alkoxyphosphinetetracarbonylchromium(0) carbene complexes have coordinatively unsaturated chromacyclopropanone T1 structures with a biradical character. The evolution of the metallacyclopropanone species occurs by a jump (spin inversion) to the S0 hypersurface by coordination of a molecule of the solvent, leading to ketene‐derived products in the presence of ketenophiles or reverting to the starting carbene complex in their absence. The T1 excited states obtained from methylenephosphinetetracarbonylchromium(0) complexes and pentacarbonyltungsten(0)carbene complexes are unable to produce the carbonylation. The reaction with ketenophiles is favored in coordinating solvents, which has been tested experimentally in the reaction of alkoxypentacarbonylchromium(0) complexes and imines.
DFT Calculations of the Electric Field Gradient at the Tin Nucleus as a Support of Structural Interpretation by 119Sn Mössbauer Spectroscopy
Authors: Barone Giampaolo , Silvestri Arturo , Ruisi Giuseppe , La Manna Gianfranco 
Published: July 2005

AbstractDFT calculations, using an all‐electron basis set and with full geometry optimization, were performed on 34 SnII and SnIV compounds of known structure and 119Sn Mössbauer parameters, to obtain the theoretical values of the electric field gradient components, Vxx, Vyy, and Vzz, at the tin nucleus. These were used to determine the quantity V=Vzz${\bigg[}$1+${{1\over 3}}$${\bigg(}$${{V{_{xx}}- V{_{yy}}\over V{_{zz}}}}$${\bigg)}$2${\bigg]}$1/2, for each investigated compound, which is related to the quadrupole splitting (ΔE) parameter according to ΔE=1/2eQV, where e is the electronic charge and Q is the quadrupole moment of the tin nucleus. The linear fitting of the correlation plot of the experimental ΔE, versus the corresponding calculated V values, produced a slope that is equal to 0.93±0.03 and a correlation coefficient R=0.982. The value of Q obtained, 15.2±4.4 fm2, is in agreement with that previously experimentally determined or calculated by analogous procedures. The calculation method is able to establish the sign of the electric field gradient component Vzz, in agreement with the sign of ΔE determined experimentally by Mössbauer–Zeeman spectroscopy. The calculated structural parameters are in good agreement with the corresponding experimental data, determined by X‐ray crystallography in the solid state, with average structural deviations of about 3 % for bond lengths and angles in the tin environment. Calculated values of ΔE were obtained from the calibration fitting constant and from the values of V. By comparing experimental and calculated ΔE parameters, the structure assignment of configurational isomers was successful in two test cases, in agreement with the experimental X‐ray crystallographic structures. These results indicate that the method can be used as a tool to support the routine structure interpretation of tin compounds by 119Sn Mössbauer spectroscopy.
Motility of Catalytic Nanoparticles through Self‐Generated Forces
Authors: Paxton Walter F. , Sen Ayusman , Mallouk Thomas E. 
Published: July 2005

AbstractSmall‐scale synthetic motors capable of generating their own motive forces by exploiting the chemical free energy of their environment represent an important step in developing practical nanomachines. Catalytic particles are capable of generating concentration and other gradients that can be used to self‐propel small objects. However, the autonomous movement of catalytic nanoparticles by self‐generated forces is a relatively unexplored area in colloid and interfacial chemistry. This paper explores the potential of catalytically self‐generated forces for propulsion of small objects through fluids.
Understanding of the Mode of Action of FeIII–EDDHA as Iron Chlorosis Corrector Based on Its Photochemical and Redox Behavior
Authors: Gómez‐Gallego Mar , Pellico Daniel , Ramírez‐López Pedro , Mancheño María J. , Romano Santiago , de la Torre María C. , Sierra Miguel A. 
Published: July 2005

AbstractThe very low reduction potential of the chelate FeIII–EDDHA (EDDHA= ethylenediamine N,N′‐bis(2‐hydroxy)phenylacetic acid) makes it unreactive in photochemically or chemically induced electron transfer processes. The lack of reactivity of this complex toward light invalidates photodegradation as an alternative mechanism for environmental elimination. However, in spite of its low reduction potential, the biological reduction of FeIII–EDDHA is very effective. Based on electrochemical measurements, it is proposed that FeIII–EDDHA itself is not the substrate of the enzyme ferric chelate reductase. Likely, at the more acidic pH in the vicinity of the roots, the ferric chelate in a closed form (FeL−) could generate a vacant coordination site that leads to an open hexacoordinate species (FeHL) where the reduction of the metal by the enzyme takes place.
Linear and Branched Phospha[n]triangulanes
Authors: Slootweg J. Chris , de Kanter Frans J. J. , Schakel Marius , Lutz Martin , Spek Anthony L. , Kozhushkov Sergei I. , de Meijere Armin , Lammertsma Koop 
Published: August 2005

AbstractNovel, highly stable, linear and branched mono‐ and diphospha[n]triangulanes were synthesized in high yields by the CuCl‐catalyzed phosphinidene addition to spirocyclopropanated methylenecyclopropanes and bicyclopropylidenes. The effect of spirofusion on the electronic properties of these esthetically attractive phosphacycles is apparent from X‐ray single crystal structure analyses, which reveals a tightening of the phosphirane ring on additional spirocyclopropanation, and from the NMR features that show deshielded chemical shifts for the ring‐phosphorus and ‐carbon atoms. Steric factors play a role in the addition reaction when the substrate alkene carries a second sphere of spirocyclopropane rings and causes the formation of 2‐phosphabicyclo[3.2.0]heptenes in small amounts. These by‐products most probably result from addition of the [PhP(Cl)W(CO)5]‐Cu‐L (L=alkene or solvent) reagent to the spirocyclopropanated bicyclopropylidene to give an intermediate σ‐complex, which subsequently, facilitated by steric factors, undergoes a cyclopropylcarbinyl to cyclobutyl ring expansion followed by a [1,3]‐sigmatropic shift.
Diastereoselective Atom Transfer Radical Cyclization Reactions of Unsaturated α‐Bromo Oxazolidinone Imides Catalyzed by Lewis Acids.
Authors: Yang Dan , Zheng Bao‐Fu , Gu Shen , Chan Philip W. H. , Zhu Nian‐Yong 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Chiral Ru‐Based Complexes for Asymmetric Olefin Metathesis: Enhancement of Catalyst Activity Through Steric and Electronic Modifications.
Authors: Van Veldhuizen Joshua J. , Gillingham Dennis G. , Garber Steven B. , Kataoka Osamu , Hoveyda Amir H. 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
A Stereoselective Approach to Both 3,4‐trans‐Disubstituted Pyrrolidin‐2‐ones and Pyrrolidines. A Convenient Synthesis of (3R,4R)‐4‐Benzyl‐3‐pyrrolidinecarboxylic Acid.
Authors: Galeazzi Roberta , Martelli Gianluca , Mobbili Giovanna , Orena Mario , Panagiotaki Maria 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Ruthenium‐Catalyzed C—H/CO/Olefin Coupling Reaction of N‐Arylpyrazoles. Extraordinary Reactivity of N‐Arylpyrazoles Toward Carbonylation at C—H Bonds.
Authors: Asaumi Taku , Chatani Naoto , Matsuo Takuya , Kakiuchi Fumitoshi , Murai Shinji 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Multi‐Substituted Pyrazoles Utilizing the N‐Alkylated 3‐Hydroxy‐3‐propargyl‐ or Allenylisoindolines.
Authors: Choi Yong Hyun , Kim Kyung Soon , Lee Sangku , Jeong Tae‐Sook , Lee Hee‐Yoon , Kim Yong Hae , Lee Woo Song 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Conjugates of Oligo(2′‐O‐Methylribonucleotides) with Minor Groove Binders as New Sequence‐Specific Agents Recognizing Both Grooves of Double‐Stranded DNA
Authors: Novopashina D. , Sinyakov A. , Ryabinin V. , Venyaminova A. , Boutorine A. 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Life‐Prolonging Effect of Immunocell BAK (BRM‐Activated Killer) Therapy for Advanced Solid Cancer Patients: Prognostic Significance of Serum Immunosuppressive Acidic Protein Levels
Authors: Ebina Takusaburo , Ogama Naoko , Shimanuki Hiroko , Kubota Tomoka , Isono Noriko 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
The Formation and Thermal Decomposition of 4‐Hydroperoxy‐2‐hydroxy‐3,4‐6‐triisopropylcyclohexa‐2,5‐dienone.
Authors: Abakumov G. A. , Vavilina N. N. , Kurskii Yu. A. , Nevodchikov V. I. , Cherkasov V. K. , Shavyrin A. S. 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Regio‐ and Enantioselective Copper‐Catalyzed Addition of Dialkylzinc Reagents to Cyclic 2‐Alkenyl Aziridines.
Authors: Gini Francesca , Del Moro Federica , Macchia Franco , Pineschi Mauro 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Highly Enantioselective Cr(Salen)‐Catalyzed Reaction of 2‐(Trimethylsilyloxy)furan and Aldehydes. Effect of Alcohol on Enantioselectivity.
Authors: Onitsuka Satoaki , Matsuoka Yuko , Irie Ryo , Katsuki Tsutomu 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Halogenation of Aromatic Compounds by N‐Chloro‐, N‐Bromo‐, and N‐Iodosuccinimide.
Authors: Tanemura Kiyoshi , Suzuki Tsuneo , Nishida Yoko , Satsumabayashi Koko , Horaguchi Takaaki 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Alkyl‐Substituted Dipyrrylmethenes and Their Oxa‐ and Thia‐Analogues: “Structure—Solvation Properties” Correlations.
Authors: Semeikin A. S. , Berezin M. B. , Chernova O. M. , Antina E. V. , Syrbu S. A. , Lyubimova T. V. , Kutepov A. M. 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Naringenin Derivatives as anti‐Atherogenic Agents.
Authors: Lee Sangku , Lee Chul‐Ho , Moon Surk‐Sik , Kim Eungsoo , Kim Chul‐Tae , Kim Bang‐Hyun , Bok Song‐Hae , Jeong Tae‐Sook 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
The Use of Triisopropylsilyl‐oxymethyl (TOM) in the Synthesis of anti‐Telomerase 2‐5A Antisense Compound RBI 011
Authors: Cramer Hagen , Rhea Rachele , Okicki Jim , Yirava Karen , Silverman Robert 
Published: July 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Fixed dose‐rate gemcitabine infusion as first‐line treatment for advanced‐stage carcinoma of the pancreas and biliary tree
Authors: Gelibter Alain , Malaguti Paola , Di Cosimo Serena , Bria Emilio , Ruggeri Enzo Maria , Carlini Paolo , Carboni Fabio , Ettorre Giuseppe Maria , Pellicciotta Mario , Giannarelli Diana , Terzoli Edmondo , Cognetti Francesco , Milella Michele 
Published: August 2005

AbstractBACKGROUNDGemcitabine infusion at the fixed dose rate of 10 mg/m2 per minute (FDR‐gemcitabine) has pharmacokinetic advantages and may result in improved therapeutic efficacy.METHODSBetween April 2002 and September 2003, 40 patients with advanced‐stage pancreatic adenocarcinoma (PDAC; n = 27) or biliary tree carcinoma (BTC; n = 13) were treated with weekly FDR‐gemcitabine (1000 mg/m2). The primary end point was the response rate. The secondary end points were progression‐free and overall survival (PFS and OS), tumor marker response, and clinical benefit response (CBR).RESULTSThe overall response rate (ORR) on an intent‐to‐treat basis was 15% (95% confidence interval [95% CI], 4–26%). A positive CBR was obtained in 14 of 29 (48%) patients. Seventeen of 25 (68%) patients had a reduction in carbohydrate antigen 19‐9 (CA 19‐9) of > 25%. The median time to treatment failure and the median PFS were 17 weeks (95% CI, 13–22 weeks) and 19 weeks (95% CI, 15–23 weeks), respectively. The median OS was 40 weeks (95% CI, 36–45 weeks) and the 1‐year actuarial survival rate was 25.8%. Multivariate analysis showed that a performance status score of 0–1 at study entry and locally advanced disease were the only independent predictors of longer PFS and OS, whereas a reduction in CA 19‐9 serum levels > 75% was an independent predictor of longer PFS, but had no impact on OS. Toxicity was mild with Grade 3–4 neutropenia (according to the National Cancer Institute‐Common Toxicity Criteria [version 2.0]) in 18 of 427 treatment weeks (4.2%), and Grade 3 anemia and thrombocytopenia in 6 of 427 treatment weeks (1.4%) and 9 of 427 treatment weeks (2.1%), respectively, and asymptomatic Grade 3–4 transaminase elevation in 21 of 427 treatment weeks (4.9%).CONCLUSIONSFDR‐gemcitabine at the weekly dose of 1000 mg/m2 demonstrated promising activity, despite negligible toxicity, in patients with advanced‐stage PDAC and BTC. Cancer 2005. © 2005 American Cancer Society.
Caspase 8 is absent or low in many ex vivo gliomas
Authors: Ashley David M. , Riffkin Christopher D. , Muscat Andrea M. , Knight Melissa J. , Kaye Andrew H. , Novak Ulrike , Hawkins Christine J. 
Published: August 2005

AbstractBACKGROUNDBetter treatments are required urgently for patients with malignant glioma, which currently is incurable. Death ligands, such as tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL), may offer promise for the treatment high‐grade glioma if such ligands induce apoptotic signaling in vivo in glioma cells. Caspase 8 is required for death ligand signaling, and its levels may influence the sensitivity of glioma cells to death ligands. It also may act as a tumor suppressor protein. The authors analyzed caspase 8 expression levels in ex vivo glioma specimens and explored potential mechanisms of its regulation.METHODSEleven glioblastomas, 5 anaplastic astrocytomas, and 3 low‐grade astrocytomas were studied. The levels of caspase 8, caspase 10, cellular FLICE inhibitory protein (c‐FLIP), and signal transducer and activator of transcription (STAT)‐1 were assayed using quantitative immunoblotting. Caspase 8 mRNA was measured by Northern blot analysis. The methylation status of the caspase 8 gene was determined by bisulfate modification of genomic DNA, cloning, and sequencing. Statistical analyses were performed using nonparametric (Spearman) correlations.RESULTSSome ex vivo glioma samples lacked detectable caspase 8, with many expressing barely detectable levels. No tumors expressed significant amounts of caspase 10 or c‐FLIP. A strong association was found between caspase 8 mRNA and protein levels. Neither expression of the transcription factor STAT‐1 nor caspase 8 gene methylation correlated with caspase 8 levels.CONCLUSIONSThe absence of caspase 8 protein in many resected glioma samples implied that many patients with glioma may not benefit from death ligand‐based treatments, unless caspase 8 (or caspase 10) protein expression can be elevated. Demethylating agents are unlikely to boost caspase 8 levels in glioma cells, but treatments that increase caspase 8 mRNA levels may up‐regulate expression of the protein. Cancer 2005. © 2005 American Cancer Society.
Nodular fasciitis of parotid region: A pitfall in the diagnosis of pleomorphic adenomas on fine‐needle aspiration cytology
Authors: Saad Reda S. , Takei Hidehiro , Lipscomb Jane , Ruiz Bernardo 
Published: August 2005

AbstractFine‐needle aspiration cytology (FNAC) is routinely employed for the preoperative diagnosis of salivary gland lesions. Although most cases show morphologic features characteristic of specific entities, some lesions can be diagnostically challenging. We report two parotid aspirates, initially diagnosed as pleomorphic adenoma on FNA. The patients, a 33‐yr‐old white man, and a 24‐yr‐old white woman, presented with indurated lesions arising in the parotid gland region. The aspirates from both patients were markedly hypercellular. Smears showed a mixture of spindle cells with a well‐demarcated cytoplasm showing occasional long cytoplasmic process; and cells with abundant cytoplasm with round to oval eccentric nuclei, giving the impression of plasmacytoid cells of pleomorphic adenoma. The nuclear chromatin was evenly distributed and finely granular with one or two occasional small nucleoli. Intermingled with the tumor cells were scattered neutrophils, eosinophils, and macrophages. Aggregates of spindle cells were also seen embedded in a mucoid background with occasional small tufts of a fibrillar mucoid stroma. These fibrillar tufts were magenta red in the Diff‐Quik stain, giving the impression of matrix of pleomorphic adenoma. Both cases were later diagnosed on histologic examination as nodular fasciitis. Nodular fasciitis should be considered in the differential diagnosis of a mass arising in association with the parotid gland. Diagn. Cytopathol. 2005;33:191–194. © 2005 Wiley‐Liss, Inc.
Trichomonas vaginalis P16 Immunoreactivity in cervicovaginal Pap tests: A diagnostic pitfall
Authors: Pantanowitz Liron , Florence Roxanne R. , Goulart Robert A. , Otis Christopher N. 
Published: August 2005

AbstractDetection of p16 is emerging as a useful biomarker for Human Papillomavirus (HPV)‐related dysplastic and malignant lesions of the cervix, and as such has potential application to cervicovaginal Papanicolaou (Pap) specimens. While evaluating p16 immunocytochemistry in our laboratory we observed one Pap test in which Trichomonas vaginalis stained positively for p16. We therefore proceeded to determine the frequency of T. vaginalis immunoreactivity for p16 in 10 consecutive, satisfactory, liquid‐based Pap tests diagnosed as negative for intraepithelial lesion or malignancy in which T. vaginalis was present. For each case, a ThinPrep™ slide prepared from residual vial material was immunostained with p16. In an additional case, a prepared cell block was stained with p16. T. vaginalis were consistently p16 positive. We document, for the first time, p16 immunoreactivity of T. vaginalis that, on a Pap slide and cell block, may be morphologically misinterpreted as small dysplastic or malignant epithelial cells. The presence of this parasite in Pap tests may also potentially hinder the use of p16 as an adjunct to liquid‐based cervical screening cytology. Diagn. Cytopathol. 2005;33:210–213. © 2005 Wiley‐Liss, Inc.
Steady filtration problems with seawater intrusion: macro‐hybrid penalized finite element approximations
Authors: Alduncin Gonzalo , Esquivel‐Avila Jorge , Vera‐Guzman Norberto 
Published: August 2005

AbstractMacro‐hybrid penalized finite element approximations are studied for steady filtration problems with seawater intrusion. On the basis of nonoverlapping domain decompositions with vertical interfaces, sections of coastal aquifers are decomposed into subsystems with simpler geometries and small scales, interconnected via transmission conditions of pressure and flux continuity. Corresponding local penalized formulations are derived from the global penalized variational formulation of the two‐free boundary flow problem, with continuity transmission conditions modelled variationally in a dual sense. Then, macro‐hybrid finite element approximations are derived for the system, defined on independent subdomain grids. Parallel relaxation penalty‐duality algorithms are proposed from fixed‐point problem characterizations. Numerical experiments exemplify the macro‐hybrid penalized theory, showing a good agreement with previous primal conforming penalized finite element approximations (Comput. Methods Appl. Mech. Engng. 2000; 190:609–624). Copyright © 2005 John Wiley & Sons, Ltd.
Evaluation of adaptive mesh refinement and coarsening for the computation of compressible flows on unstructured meshes
Authors: Walter Miguel A. T. , Abdu Aline A. Q. , Figueira da Silva Luís Fernando , Azevedo João Luiz F. 
Published: August 2005

AbstractThe compressible gas flows of interest to aerospace applications often involve situations where shock and expansion waves are present. Decreasing the characteristic dimension of the computational cells in the vicinity of shock waves improves the quality of the computed flows. This reduction in size may be accomplished by the use of mesh adaption procedures. In this paper an analysis is presented of an adaptive mesh scheme developed for an unstructured mesh finite volume upwind computer code. This scheme is tailored to refine or coarsen the computational mesh where gradients of the flow properties are respectively high or low. The refinement and coarsening procedures are applied to the classical gas dynamic problems of the stabilization of shock waves by solid bodies. In particular, situations where oblique shock waves interact with an expansion fan and where bow shocks arise around solid bodies are considered. The effectiveness of the scheme in reducing the computational time, while increasing the solution accuracy, is assessed. It is shown that the refinement procedure alone leads to a number of computational cells which is 20% larger than when alternate passes of refinement and coarsening are used. Accordingly, a reduction of computational time of the same order of magnitude is obtained. Copyright © 2005 John Wiley & Sons, Ltd.
Transforming growth factor‐β‐regulated gene transcription and protein expression in human GFAP‐negative lamina cribrosa cells
Authors: Kirwan Ruaidhrí P. , Leonard Martin O. , Murphy Madeline , Clark Abbot F. , O'Brien Colm J. 
Published: August 2005

AbstractPrimary open‐angle glaucoma (POAG) is a progressive optic neuropathy, which is a major cause of worldwide visual impairment and blindness. Pathological hallmarks of the glaucomatous optic nerve head (ONH) include retinal ganglion cell axon loss and extracellular matrix (ECM) remodeling of the lamina cribrosa layer. Transforming growth factor‐β (TGF‐β) is an important pro‐fibrotic modulator of ECM metabolism, whose levels are elevated in human POAG lamina cribrosa tissue compared with non‐glaucomatous controls. We hypothesize that in POAG, lamina cribrosa (LC) glial cells respond to elevated TGF‐β, producing a remodeled ONH ECM. Using Affymetrix microarrays, we report the first study examining the effect of TGF‐β1 on global gene expression profiles in glial fibrillary acidic acid (GFAP)‐negative LC glial cells in vitro. Prominent among the differentially expressed genes were those with established fibrogenic potential, including CTGF, collagen I, elastin, thrombospondin, decorin, biglycan, and fibromodulin. Independent TaqMan and Sybr Green quantitative PCR analysis significantly validated genes involved in regulation of cell proliferation (platelet‐derived growth factor [PDGF‐α]), angiogenesis (vascular endothelial growth factor [VEGF]), ECM accumulation and degradation (CTGF, IL‐11, and ADAMT‐S5), and growth factor binding (ESM‐1). Bioinformatic analysis of the ESM‐1 promoter identified putative Smad and Runx transcription factor binding sites, and luciferase assays confirmed that TGF‐β1 drives transcription of the ESM‐1 gene. TGF‐β1 induces expression and release of ECM components in LC cells, which may be important in regulating matrix remodeling in the lamina cribrosa. In disease states such as POAG, the LC cell may represent an important pro‐fibrotic cell type and an attractive target for novel therapeutic strategies. © 2005 Wiley‐Liss, Inc.