bluuebunny/crossref_metadata_2025_split huggingface dataset:
A convenient synthesis of 4‐trifluoromethyl‐4H‐[1,5,2]dioxazines and 4‐trifluoromethyl‐6H‐[1,2,5]oxadiazines
Authors: Kamitori Yasuhiro 
Published: May 2009

Abstract1,1,1‐Trifluoroalkane‐2,3‐dione 3‐oximes 1 easily obtainable from aldehyde dimethylhydrazones were reacted with several aldehydes and ketones in the presence of acetic acid to afford 4‐trifluoromethyl‐4H‐[1,5,2]dioxadines 3 in satisfactory yields. When the reaction was carried out in the presence of ammonium acetate, 4‐trifluoromethyl‐6H‐[1,2,5]oxadiazines were obtained in good yields.
8‐Methyl‐7‐substituted‐1,6‐naphthyridine‐3‐carboxylic acids as New 6‐desfluoroquinolone antibacterials
Authors: Sabatini Stefano , Cecchetti Violetta , Tabarrini Oriana , Fravolini Arnaldo 
Published: May 2009

Abstract1,6‐Naphthyridine‐8‐methyl‐7‐substituted‐3‐carboxylic acids were synthesized as new 6‐desfluoro‐quinolone antibacterials in which the usual fluorine atom at C‐6 position was replaced by an endocyclic nitrogen atom. Comparing the antibacterial activity of these 6‐azaquinolones with our previous 6‐amino and 6‐hydrogen counterparts, they resulted always less active. However, the presence of methyl group at C‐8 position ensure good Gram‐positive antibacterial activity, with minimum inhibitory concentrations values on the same order of ciprofloxacin for piperidinyl derivative 3d and tetrahydroisoquinolinyl derivative 3c.
Syntheses and reactions of 2,2′‐bisbenzimidazole systems
Authors: Von Glahn Benita , Kramer Walter , Neidlein Richard , Suschitzky Hans 
Published: May 2009

AbstractNucleophilic reactions of two 2,2′‐bisbenzimidazole systems, namely the bis(2H‐benzimidazole‐2‐ylidene) 2 and the dispiro[2H‐benzimidazole‐2,1′‐cyclohexane‐4′,2″‐2″H‐benzimidazole] 3, as well as the syntheses of new 2,2′‐bisbenzimidazoles are reported and their conversion into other heterocycles is described.
Thioamide derivatives of cannabinoids. A study of the influence of the thioamide function on regiochemistry in the synthesis of thioamide cannabinoids from 2,4‐dihydroxybenzothioamides
Authors: Sośnicki Jacek , Jagodziński Tadeusz , Królikowska Miroslawa 
Published: May 2009

AbstractSeveral thiocarbamoyl derivatives of cannabinoids were obtained in the collidine‐catalysed condensation of 2,4‐dihydroxybenzothioamides with citral and citronellal. The thioamide function was found to change the regioselective preferences of the reaction as compared with the known cannabinoid syntheses from hydroxyacetophenones. The experimental results and theoretical (FMO theory) considerations made it possible to advance the reaction mechanism. Convenient methods were developed for the synthesis of the starting 2,4‐dihydroxybenzothioamides from resorcinol and isothiocyanates in the presence of the boron trifluoride/acetic acid 1:2 complex or aluminum chloride in nitromethane.
Synthesis of oxidized 1,2,3‐thiadiazines by hydroperoxy‐induced ring enlargement of 2‐benzenesulfonylaminoisothiazolium salts
Authors: Kolberg Arne , Sieler Joachim , Schulze Bärbel 
Published: May 2009

AbstractOxidation of 2‐benzenesulfonylaminoisothiazolium salts 1, 2 and their imines 3, 4 with hydrogen peroxide gave 1,2,3‐thiadiazine 1‐oxides 5, 6, which were converted into the corresponding 1,2,3‐thiadiazine 1,1‐dioxides 7, 8 using m‐chloroperoxybenzoic acid. Oxidation of 5, 6 with hydrogen peroxide furnished isothiazol‐3(2H)‐one 1,1‐dioxides 9, 10 as ring contraction products.
Synthesis of 1,4,5,6‐tetrahydropyrazolo[3,4‐d]pyrido[3,2‐b]azepine
Authors: Albright J. Donald , Du Xuemei 
Published: May 2009

AbstractThe synthesis of 7,8‐dihydro‐5(6H)‐quinolinone (3) from commercially available 3‐amino‐2‐cyclohexen‐1‐one (1) and 3‐(dimethylamino)acrolein (4) in 23% yield avoids the preparation of propynal (2). Conversion of 5‐(4‐methylphenylsulfonyl)‐6,7,8,9‐tetrahydro‐5H‐pyrido[3,2‐b]azepine (12) to 6‐(4‐methylphenylsulfonyl)‐1,4,5,6‐tetrahydropyrazolo[3,4‐d]pyrido[3,2‐b]azepine (24) is described. Removal of the N‐(4‐methylphenylsulfonyl) group with 40% sulfuric acid in acetic acid gave the tricyclic azepine 26. Application of a similar series of reactions to 5‐(4‐nitrobenzoyl)‐6,7,8,9‐tetrahydro‐5H‐pyrido[3,2‐b]‐azepine (13) afforded 6‐(4‐nitrobenzoyl)‐1,4,5,6‐tetrahydropyrazolo[3,4‐d]pyrido[3,2‐b]azepine (25).
Mechanism of the formation of 1,2,4‐thiadiazoles by condensation of aromatic thioamides and of N‐substituted thioureas
Authors: Forlani Luciano , Lugli Andrea , Boga Carta , Corradi Anna Bonamartini , Sgarabotto Paolo 
Published: May 2009

AbstractThe condensation reaction of thiobenzamide, (as well as thionicotinamide and isothionicotinamide) in the presence of dimethyl sulfoxide and of an acid, affords 3,5‐diphenyl‐1,2,4‐thiadiazole. Under the same experimental conditions, N‐substituted thioureas are also condensed to 1,2,4‐thiadiazole derivatives; their structure is ascertained by spectroscopic properties and by X‐ray diffraction. Some information on the mechanism of thiadiazoles formation from both starting classes of compounds, thiobenzamides and N‐substituted thiourea, is collected and discussed.
Carbene and radical pathways in pyrolysis of benzisoxazolones and benzotriazoles
Authors: Prager Rolf H. , Baradarani Mehdi M. , Khalafy Jabbar 
Published: May 2009

AbstractA comparative study of the flash vacuum pyrolysis of a number of N‐alkyl and N‐acyl benzotriazoles and benzisoxazolones has confirmed that carbene derived pathways predominate at lower temperatures, and radical pathways at highter temperatures. Two new general unimolecular thermal reactions are also highlighted.
Preparation of 4‐substituted 3‐amino‐2‐chloropyridines, synthesis of a nevirapine analogue
Authors: Bakke J. M. , Riha J. 
Published: May 2009

AbstractA new method for preparing 3‐amino‐2‐chloropyridines with a substituent (methyl, phenyl, carbox‐amide, methoxycarbonyl, acetyl, benzoyl and cyano) at the 4‐position has been developed. An isoquinoline analogue of the reverse transcriptase inhibitor Nevirapine has been synthesized from the 4‐amino‐3‐chloroisoquinoline.
Synthesis of heterocyclic nitrogen derivatives from aryl‐1,4‐benzoquinones
Authors: Hassan Mamdouh A. , Fandy Ragab F. , El‐Amine Tark M. 
Published: May 2009

AbstractTreatment of 2‐aryl‐3,6‐bis(arylamino)‐1,4‐benzoquinones 2a‐h with different acid chlorides, namely acetyl, phenylacetyl and chloroacetyl chloride yields 3a,7a‐dihydropyrrolo[2,3‐f]indole‐2,6‐dione 3, 5‐(N‐phenylacetylarylamino)‐3‐phenylindole‐2,6‐dione 4 and 3‐chloro‐5‐(N‐chloroacetylarylamino)indole‐2,6‐dione 5 respectively. Stirring 2‐aryl‐1,4‐benzoquinones (1) with ethylenediamine and/or o‐phenyl‐enediamine in methylene chloride gives pyrazino[2,3‐g]quinoxalines derivative 6 and/or tetrapentacene derivative 7 respectively. The products 5‐aryl‐ and 6‐aryl‐1/H‐indazole‐4,7‐diones 8 and 9 were obtained in the 1,3‐dipolar cycloaddition of diazomethane to (1).
Synthesis of 11Z‐9‐demethyl‐9‐((3‐indolyl)methyl)retinal
Authors: Wada Akimori , Fujioka Naoko , Ito Masayoshi 
Published: May 2009

AbstractA convenient synthesis of 11Z‐9‐demethyl‐9‐((3‐indolyl)methyl)retinal, which has an amino acid residue of tryptophan at the 9 position in retinal, is described using a tricarbonyliron complex.
Density functional theory calculations and vibrational spectra of 2‐bromo‐4‐chloro phenol and 2‐chloro‐4‐nitro phenol
Authors: Krishnakumar V. , Jayamani N. , Mathammal R. , Parasuraman K. 
Published: May 2009

AbstractFTIR and FT Raman spectra of 2‐bromo‐4‐chloro phenol (BCP) and 2‐chloro‐4‐nitro phenol (CNP) were recorded in the region 4000–400 and 4000–50 cm−1, respectively. The molecular structure, geometry optimization, and vibrational wavenumbers were investigated. The spectra were interpreted with the aid of normal coordinate analysis based on density functional theory (DFT) using the standard B3LYP/6‐31G** method and basis set combination and was scaled using multiple scale factors, which yield good agreement between the observed and calculated wavenumbers. The results of the calculations are applied to simulate the infrared and Raman spectra of the title compounds, which showed excellent agreement with the observed spectra. Copyright © 2009 John Wiley & Sons, Ltd.
Fibrinogen Patterns and Activity on Substrates with Tailored Hydroxy Density
Authors: Rodríguez Hernández José Carlos , Rico Patricia , Moratal David , Monleón Pradas Manuel , Salmerón‐Sánchez Manuel 
Published: May 2009

AbstractThe influence of the surface fraction of OH groups on fibrinogen (FG) adsorption is investigated in copolymers of ethyl acrylate and hydroxy ethylacrylate. The amount of adsorbed FG, quantified by western‐blotting combined with image analysis of the corresponding bands, decreases as the hydrophilicity of the substrate increases. The influence of substrate wettability on FG conformation and distribution is observed by atomic force microscopy (AFM). The most hydrophobic substrate promotes FG fibrillogenesis, which leads to a fibrin‐like appearance in the absence of any thrombin. The degree of FG interconnection was quantified by calculating the fractal dimension of the adsorbed protein from image analysis of the AFM results. The biological activity of the adsorbed FG is correlated to cell adhesion on FG‐coated substrates.magnified image
Preparation of Size Tunable Amphiphilic Poly(amino acid) Nanoparticles
Authors: Kim Hyungjin , Akagi Takami , Akashi Mitsuru 
Published: May 2009

AbstractSize tunable amphiphilic NPs composed of poly(γ‐PGA) and hydrophobic amino acids, such as Phe or Trp, were prepared. To prepare these size‐regulated NPs, γ‐PGA‐g‐Phe or γ‐PGA‐g‐Trp dissolved in DMSO was added to various concentrations of NaCl solution. The γ‐PGA‐Phe and γ‐PGA‐Trp formed monodispersed NPs, and the size of NPs can be easily controlled by NaCl concentration. The different‐sized NPs showed the same structure. The encapsulation of protein into the different‐sized NPs was successfully achieved and the size of protein‐encapsulated γ‐PGA‐Phe NPs was increased when protein was encapsulated.magnified image
Emerging Concepts in the Pathophysiology of Type 2 Diabetes Mellitus
Authors: Surampudi Prasanth N. , John‐Kalarickal Jennifer , Fonseca Vivian A. 
Published: May 2009

AbstractType 2 diabetes mellitus is a multifactorial metabolic disorder. It is characterized by chronic hyperglycemia, insulin resistance, and a relative insulin secretion defect. The prevalence of type 2 diabetes mellitus has risen worldwide in large part because of an increase in obesity and sedentary lifestyles. The underlying pathophysiology and complications of type 2 diabetes mellitus are still being elucidated. Recent advances in diabetes research have helped us to gain a better understanding about insulin resistance and insulin secretion defects. The evolving understanding about the influence of the incretin effect, insulin signal transduction, adipose tissue, intra–islet cell communication, and inflammation is changing the way in which we view type 2 diabetes mellitus. This new understanding will eventually provide us with new treatment approaches to help patients who have type 2 diabetes mellitus. This article gives a review of the current and emerging concepts of the pathophysiology of type 2 diabetes mellitus. Mt Sinai J Med 76: 216–226, 2009. © 2009 Mount Sinai School of Medicine
Glycemic Targets for Patients with Type 2 Diabetes Mellitus
Authors: Hamnvik Ole‐Petter R. , McMahon Graham T. 
Published: May 2009

AbstractCardiovascular disease is the predominant cause of death in diabetic patients, and reducing the risk of cardiovascular disease in diabetics has recently been the focus of several highly publicized large trials, including ACCORD (Action To Control Cardiovascular Risk in Diabetes), ADVANCE (Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation), and VADT (Veterans Affairs Diabetes Trial). These studies randomized high‐risk diabetic patients into either intensive treatment or standard treatment. The glycemic control arm of ACCORD was terminated 17 months before the planned end of the study because of a finding of significantly increased all‐cause and cardiovascular mortality in the intensive treatment group. These findings were not duplicated in either ADVANCE or VADT. Multiple possible explanations have been brought forward, including a higher incidence of death from unrecognized hypoglycemia, effects due to increased exposure to particular antidiabetic medications, adverse effects of rapid correction of hyperglycemia, weight gain, and differences in baseline characteristics. None of these were validated in post hoc analyses of the trial data, and the cause of the increased mortality remains elusive. Subgroup analyses suggest that those who start off with better control of their diabetes or without preexisting cardiovascular disease may have the most to gain from tight glycemic control. Reducing the risk of macrovascular disease and death in diabetic patients requires not only attention to glucose control but also meticulous attention to control of nonglycemic risk factors, including hypertension, hyperlipidemia, smoking, lack of exercise, and unhealthy diet as well as timely prescription of medications with proven preventative benefits, such as aspirin and statins. Mt Sinai J Med 76:227–233, 2009. © 2009 Mount Sinai School of Medicine
A fast parametric assignment algorithm with applications in max‐algebra
Authors: Gassner Elisabeth , Klinz Bettina 
Published: May 2009

AbstractThis article presents a fast algorithm for a class of parametric assignment problems. Moreover, it is shown how this algorithm can be applied to a problem arising in the so‐called max‐algebra which results as an analogue of classical linear algebra by replacing the classical addition and multiplication by a ⊕ b = max(a,b) and a ⊗ b = a + b, respectively. An instance of the linear parametric assignment problem is given by a bipartite graph G = (U,V,E) with 2n vertices, m edges and affine‐linear parametric edge weights cλ(i,j) = c(i,j) − b(i,j)λ for (i,j) ∈ E. The task is to find an assignment with minimum weight with respect to the parametric weights cλ for all values of λ. We develop an algorithm which solves the special case for which b(i,j) ∈ {0, 1} for all (i,j) ∈ E in 𝒪(mn+n2 log n) time. Our algorithm can be extended to solve the special parametric assignment problem which arises in connection with computing the essential terms of the so‐called characteristic max‐polynomial. The resulting algorithm runs in 𝒪(n3) time and thus improves upon the best‐known algorithm for computing the characteristic max‐polynomial due to Burkard and Butkovič (Appl Math 130 (2003), 367–380) by a factor of n. © 2009 Wiley Periodicals, Inc. NETWORKS, 2010
On the complexity of resilient network design
Authors: Tomaszewski Artur , Pióro Michał , Żotkiewicz Mateusz 
Published: May 2009

AbstractIn this article we prove 𝒩𝒫‐hardness of two well‐known optimization problems related to the design of multicommodity flow networks with two different methods for providing network resiliency against failures: path diversity and flow restoration. Path diversity is a static mechanism that consists of using, for each demand, a number of paths and oversizing the flows assigned to these paths so that for any failure the total surviving flow is not less than the volume of the demand. By contrast, flow restoration is a dynamic mechanism that consists of reassigning the failed flows to backup paths when a failure occurs. Both mechanisms are of practical interest because although flow restoration is in general superior to path diversity in terms of the required amount of resource capacity, it might be too complicated to implement. By providing an appropriate reduction from the fractional graph coloring problem, we show that both problems are 𝒩𝒫‐hard in the general case of failure scenarios that admit simultaneous failures of multiple links. Finally, we discuss how to efficiently solve the two problems using path generation techniques. © 2009 Wiley Periodicals, Inc. NETWORKS, 2010
Improved outcome for Chinese children with acute promyelocytic leukemia: A comparison of two protocols
Authors: Luo Xue‐Qun , Ke Zhi‐Yong , Huang Li‐Bin , Guan Xiao‐Qing , Zhang Ying‐Chuan , Zhang Xiao‐Li 
Published: May 2009

AbstractObjectiveAcute promyelocytic leukemia (APL) is now highly curable, except in many developing countries. Introduction of current treatment strategies may improve the outcome for children with APL in these countries.MethodsThe diagnosis was based on the FAB classification and detection of PML‐RARα rearrangement. From December 1999 to September 2004, 16 eligible children were treated with an intensive in‐house protocol including high‐dose AraC and anthracycline. Subsequently, 14 cases were treated with a less intensive protocol modified from the PETHEMA LPA99.ResultsThe 3.5 years event‐free survival (EFS) was 37.5% (95% CI, 13.8–61.2%) for patients treated on initial protocol. The treatment failures were: six patients abandoned treatment (37.5%), two who died of intracranial hemorrhage at diagnosis (6.3%) and sepsis in remission (6.3%) respectively, and two who relapsed (12.5%). Those treated on modified PETHEMA had a 3.5 years EFS of 79.6% (95% CI, 52.9–106.3%). Treatment failures included: one who died of intracranial hemorrhage at diagnosis (7.1%) and one who relapsed (7.1%). The patients on modified PETHEMA had a significantly higher EFS (P = 0.012), lower frequency of sepsis during treatment (7.7% vs. 77.8%; P = 0.0015), and lower hospitalization cost (median US$ 4,700 vs. US$ 20,000; P < 0.0001) than those on in‐house protocol.ConclusionTreatment with the less intensive protocol based on the PETHEMA LPA99 study of childhood APL successfully reduced chemotherapy toxicity and lowered hospitalization costs without increasing relapses. This led to decreases in treatment‐related morbidity and the treatment abandonment rate, thus improving overall outcome. Pediatr Blood Cancer 2009;53:325–328. © 2009 Wiley‐Liss, Inc.
Modeling and Simulation of Fast Neutral Beam Sources for Materials Processing
Authors: Economou Demetre J. 
Published: May 2009

AbstractFast (kinetic energy of 10 to some 100 eV) neutral beams can be used for etching, deposition or surface modification, without charging damage that may occur in conventional plasma processing of materials. This paper provides an overview of the modeling and simulation approaches applicable to neutral beam sources. Neutral beam sources based on both volume and surface neutralization of ions are discussed, with emphasis on the latter.magnified image
Influence of Hydrogen Plasma on the Defect Passivation of Polycrystalline Si Thin Film Solar Cells
Authors: Gorka Benjamin , Rau Björn , Dogan Pinar , Becker Christiane , Ruske Florian , Gall Stefan , Rech Bernd 
Published: May 2009

AbstractHydrogen passivation (HP) of polycrystalline silicon (poly‐Si) thin film solar cells was performed in a parallel plate radio‐frequency (rf) plasma setup. The influence of hydrogen pressure p and electrode gap d on breakdown voltage Vbrk is presented showing that the minimum in Vbrk shifts with higher pressures towards higher p · d values. Cell test structures provided by CSG Solar AG were used to examine the influence of p and d on the open circuit voltage VOC. The highest VOC's were achieved for p · d values that correspond to a minimum in Vbrk. HP strongly improved the VOC. After the hydrogen plasma treatment the VOC improved significantly by a factor of 2 and amounted to 450 mV. Optimized parameters were then applied to different poly‐Si solar cells prepared by electron beam evaporation.
Plasma Enhanced Chemical Vapour Deposition of Nanostructured Fluorocarbon Surfaces
Authors: Sardella Eloisa , Intranuovo Francesca , Rossini Pasqua , Nardulli Marina , Gristina Roberto , d'Agostino Riccardo , Favia Pietro 
Published: May 2009

AbstractFluorocarbon coatings have drawn much attention in the biomedical field for their peculiar chemical and topographical characteristics. It is well known that topography and chemistry of a material surface can modulate different cellular responses, including adhesion, proliferation and expression of differentiated phenotypes. In this work, PECVD processes were run and micro/nanostructured fluorocarbon coatings were obtained by varying both gas feed (C3F6O and C3F6 feeds) and substrate position in an RF (13.56 MHz) reactor. The interesting results demonstrated that the cell behaviour can be dramatically influenced by surface topography of fluorine containing coatings.
H2/NH3 Plasma‐Grafting of PEEK‐WC‐PU Membrane to Improve their cyto‐Compatibility with Hepatocytes
Authors: Laera Stefania , Lopez Linda C. , De Bartolo Loredana , Morelli Sabrina , Salerno Simona , Piscioneri Antonella , Nardulli Marina , Gristina Roberto , d'Agostino Riccardo , Favia Pietro 
Published: May 2009

AbstractPlasma treatments in H2 and NH3 RF (13.56 MHz) glow discharges have been used for modifying the surface of PEEK‐WC‐PU membranes. Water contact angle (WCA) and X‐Ray photoelectron spectroscopy (XPS) analyses were performed to study the compositional changes of PEEK‐WC‐PU membranes after grafting. Cell culture experiments with human hepatocytes clearly show that grafting N‐containing groups improves the cyto‐compatibility of the membranes.
Microstructural, Mechanical and Tribological Properties of CrA1YN Coatings Deposited by Magnetron Sputtering
Authors: Brizuela Marta , García‐Luis Alberto , Corengia Pablo , González‐Santamaría Daniel , Muñoz Roberto , González Javier‐Jesús 
Published: May 2009

AbstractCrAlYN coatings were synthesized by reactive magnetron sputtering. The aim of this research is to study the influence of the nitrogen flow at constant total gas flows on the chemical, structural and tribo‐mechanical properties of the CrAlYN coatings. The nitrogen flow has an important effect on the deposition growth rate, the crystalline structure and the mechanical properties of the CrAlYN coatings. All the coatings present a NaCl fcc lattice structure but increase in the nitrogen flow changes the coating texture. Coatings morphology also changes from a columnar to an equiaxial structure. Coating hardness decreases with increase in the nitrogen flow. All the coatings studied showed a similar tribological behaviour with a mean friction coefficient against steel between 0.47 and 0.53 without showing a clear correlation with the coatings' mechanical properties.
Thermal Evolution of WC/C Nanostructured Coatings by Raman and In Situ XRD Analysis
Authors: Mrabet Said El , Abad Manuel David , López‐Cartes Carlos , Martínez‐Martínez Diego , Sánchez‐López Juan Carlos 
Published: May 2009

AbstractIn this work, a series of WC/C nanostructured films were deposited on silicon substrates by changing the ratio of sputtering power applied to graphite and WC magnetron sources (PC/PWC: 0, 0.1, 0.5, 1). The thermal stability of WC/C coatings was followed in situ by means of X‐ray diffraction measurements up to 1 100 °C in vacuum (10−1 Pa). Initially, the film microstructure is composed of nanocrystalline WC1−x and W2C phases. As the PC/PWC ratio increases the crystallinity decreases, and WC1−x becomes the predominant phase from PC/PWC = 0.1. The results show that the structural evolution with temperature of all studied layers depends essentially on their initial phase and chemical composition (determined by the synthesis conditions: ratio PC/PWC). The coating deposited at PC/PWC = 0 reveals a transformation of W2C phase into W and W3C phases at 400 °C. However, the samples with PC/PWC greater than 0 exhibits an improved thermal stability up to 600–700 °C where the WC1−x begins to transform into W2C and WC phases. At 900 °C, WC is the predominant phase, especially for those coatings prepared with higher ratios. Further annealing above 1 000 °C yields W as the foremost phase. The thermal behaviour was later studied by means of Raman spectroscopy measurements at certain temperatures where the main changes in phase composition were observed. Particularly, a fitting analysis was carried out on the D and G bands typical of disordered and amorphous carbon. The changes induced during heating are discussed in terms of the positions of D and G lines, and full width at half maximum (FWHM).