bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cobalt‐Catalyzed C–N Bond‐Forming Reaction between Chloronitrobenzenes and Secondary Amines
Authors: Toma Gabriel , Yamaguchi Ryohei 
Published: October 2010

AbstractCyclic secondary amines react with mono‐ or dichloronitrobenzene in the presence of a catalytic amount of cobalt(II) chloride. Phosphane ligands are beneficial for the reaction, although the bite‐angle effect was not strong. The nitro‐substituted tertiary amines formed are important as bioactive compounds and can also be intermediates for the synthesis of substituted anilines. This work represents the first cobalt‐catalyzed approach to C–N bond‐forming reactions involving aromatic chlorides and cyclic secondary amines. The reaction is ortho‐ and para‐selective, with meta‐substituted halides being unreactive in this procedure.
An Efficient Synthesis of Polysubstituted Naphthalene Derivatives by Gold‐Catalyzed Cyclization of 1‐Arylalka‐2,3‐dienyl Acetates
Authors: Kong Wangqing , Fu Chunling , Ma Shengming 
Published: October 2010

AbstractAn efficient synthetic strategy to generate differently polysubstituted naphthalenes and iodonaphthalenes through a gold‐catalyzed cyclization reaction of 1‐arylalka‐2,3‐dienyl acetates was described. Due to the substituent loading capability of both the aromatic ring and the allene moiety, different substituents may be introduced to the different locations of the naphthalenes. A possible mechanism of the reaction involving the formation of alkenyl and naphthyl Au species was proposed on the basis of the mechanistic study.Iodination of the gold species afforded iodonaphthalenes, which are useful building blocks to introduce molecular complexity and diversity by coupling reactions.
Highly Sensitive and Selective Voltammetric Sensor Fullerene Modified Glassy Carbon Electrode for Determination of Cefitizoxime in Solubilized System
Authors: Jain Rajeev , Rather Jahangir Ahmad , Dwivedi Ashish , Vikas  
Published: October 2010

AbstractThe usefulness of fullerene modified glassy carbon electrode in mediating the reduction of cefitizoxime in solubilized system has been demonstrated. Due to the unique structure and extraordinary properties, fullerene shows higher catalytic efficiency towards cefitizoxime reduction. The kinetic parameters, electron transfer coefficient (α) and rate constant (K0) across the modified electrode are 0.37 and 0.1081/s respectively. The proposed square‐wave voltammetric method is linear over the concentration range 1.2–10.3 µg/mL. The limit of detection (LOD) is found 0.27 ng/mL. High sensitivity and selectivity together with low detection limit of the electrode response make it suitable for the determination of cefitizoxime.
Ultrasensitive Simultaneous Quantification of Nanomolar Level of Cd and Zn by Cathodic Adsorptive Stripping Voltammetry in Some Real Samples
Authors: Abbasi Shahryar , Farmany Abbas , Mortazavi Seyede Shima 
Published: October 2010

AbstractA novel, simple and sensitive adsorptive stripping voltammetry method was developed for simultaneous determination of Cd and Zn using N‐Nitrozo‐N‐phenylhydroxylamine (Cupferron) as a selective complexing agent. Cadmium and zinc metals gave peaks that were distinctly separated by 450–1200 mV, allowing their determination over a wide range of concentrations. The influence of pH and the nature of supporting electrolytes, concentration of ligand, preconcentration time and applied potential were investigated. The detection limits were 0.058 ng/mL for Zn and 0.092 ng/mL for Cd, and the RSD at a concentration level of 50 ppb, were 1.8–2.1 % for both zinc and cadmium, respectively. The method was applied to the determination of cadmium and zinc in blood, drug, food and water samples with the satisfactory results.
Online immunoaffinity assay‐CE using magnetic nanobeads for the determination of anti‐Helicobacter pylori IgG in human serum
Authors: Stege Patricia W. , Raba Julio , Messina Germán A. 
Published: October 2010

AbstractAbout two‐thirds of the world's population is infected with Helicobacter pylori (H. pylori). This Gram‐negative bacterium is the most important etiological agent of chronic active type B gastritis and peptic ulcer diseases. Conventional methods such as gastric biopsy, ELISA and culture, require a long time for the determination of H. pylori infections. Moreover, the antibodies in human serum sample are capable to react immunologically with the purified H. pylori antigens immobilized on different kinds of support like magnetic nanobeads. In this study, we have developed an online immunoaffinity assay‐CE to determine the concentration of anti‐H. pylori IgG using magnetic nanobeads as a support of the immunological affinity ligands and an LIF as a detector. The separation was performed in 0.1 M glycine–HCl, pH 2, as the background electrolyte. The linear calibration curve to predict the concentration of H. pylori‐specific immunoglobulin G antibodies in serum was produced within the range of 0.12–100 U/mL. The linear regression equation was i=492.86+96.03×Canti‐H. pylori, with the linear regression coefficient r2=0.999. The LOD calculated by fluorescence detection procedure was of 0.06 U/mL. The whole assay was done in no more than 35 min and it was entirely automatized. The development of immunoaffinity assay‐CE in this study demonstrates that there is a large possibility to introduce nanotechnology in several fields with significant advantages over the classic methodologies. Our proposition comprises the diagnosis and screening field.
The use of novel ionic liquid‐in‐water microemulsion without the addition of organic solvents in a capillary electrophoretic system
Authors: Cao Jun , Qu Haibin , Cheng Yiyu 
Published: October 2010

AbstractIn this work, a new ionic liquid‐in‐water (IL/W) microemulsion without requiring toxic organic solvents was investigated as a pseudostationary phase (PSP) in CE. As observed during the IL/W microemulsion system, a fast and an efficient separation of eight phenolic acids was achieved using 1‐butyl‐3‐methylimidazolivmhexa fluorophosphate (bmimPF6) as oil drops, Tween 20 as the surfactant, and borate as the BGE. The effects of oil phase, surfactant, buffer and pH on the separation were explored in detail to evaluate the novel PSP. In contrast, the detection efficiency of these same analytes was markedly decreased using oil‐in‐water (O/W) MEEKC. We have also validated the practicality of the IL/W microemulsion method by quantitative determination of acidic compounds in pharmaceutical injection. The results obtained indicated that an additional association between the IL cations and analytes tested seemed to play a prominent role in the separation mechanism exhibited by this novel PSP compared with the conventional O/W MEEKC.
Determination of inorganic ions in mineral water by gradient elution moving boundary electrophoresis
Authors: Flanigan Paul M. , Ross David , Shackman Jonathan G. 
Published: October 2010

AbstractA sensitive method was developed for the determination of the major inorganic ions in commercial mineral waters using gradient elution moving boundary electrophoresis with capacitively coupled contactless conductivity detection. This application was the first to demonstrate the separation of cations and anions simultaneously using gradient elution moving boundary electrophoresis. Seven ionic analytes (calcium, chloride, magnesium, nitrate, potassium, sodium, and sulfate) were separated in less than 7 min with detection values in the low μmol/L to sub‐μmol/L range. Calculated values of the major ions in three commercial mineral waters were compared to reported values with good correlation. In another application, phosphate and arsenate were separated in less than 2 min with limits of detection of 300 and 140 nmol/L, respectively. For all standard analyses, the RSD for migration times and peak areas were under 3%.
Risk factors for dementia in patients over 65 with diabetes
Authors: Parikh Niraj M. , Morgan Robert O. , Kunik Mark E. , Chen Hua , Aparasu Rajender R. , Yadav Ravi K. , Schulz Paul E. , Johnson Michael L. 
Published: October 2010

AbstractObjectiveThis study identified factors in patients with diabetes associated with risk of developing dementia.Research Design and MethodsThis retrospective, longitudinal study used a national cohort of US Veterans with diabetes 65 years or older to examine incidence of dementia over 2 years. A multivariable Cox regression model was used to estimate risk of developing dementia associated with sociodemographic factors, use of diabetes medications, and duration of diabetes.ResultsIn all, 377 838 patients (average age, 75.53 ± 6.07 years) were studied. Over the 2 year follow‐up, 14 580 (3.85%) were diagnosed with dementia. Major risk factors for dementia were age >75 years (75–85 years, hazard ratio [HR] 2.092, 95% confidence interval [CI] 2.017–2.169; ≥85 years, HR 3.468, CI 3.274–3.672), race black versus white, HR 1.218, CI 1.164–1.274), Southern residence (HR = 1.181, CI 1.133–1.232), and diabetes duration (HR for 5 years or more, 1.428, CI 1.357–1.504). There was a reduced HR for dementia with use of an oral hypoglycemic agent (HR 0.940, CI 0.909–0.972) and HMG‐CoA reductase inhibitors (HR, 0.875, CI 0.846–0.906). There was no change in HR with insulin use (HR 1.024, CI 0.983–1.067).ConclusionsSeveral important factors were identified that are associated with increased dementia risk, and two factors were identified that are associated with reduced risk. It will be important to ascertain whether risk‐factor modification reduces the HR for dementia in persons with diabetes, and to further examine effects of medication use for comorbid conditions. Copyright © 2010 John Wiley & Sons, Ltd.
Does a mandatory telemedicine call prior to visiting a physician reduce costs or simply attract good risks?
Authors: Grandchamp Chantal , Gardiol Lucien 
Published: October 2010

SUMMARYThis paper aims to estimate empirically the efficiency of a Swiss telemedicine service introduced in 2003. We used claims' data gathered by a major Swiss health insurer, over a period of 6 years and involving 160 000 insured adults.In Switzerland, health insurance is mandatory, but everyone has the option of choosing between a managed care plan and a fee‐for‐service plan. This paper focuses on a conventional fee‐for‐service plan including a mandatory access to a telemedicine service; the insured are obliged to phone this medical call centre before visiting a physician. This type of plan generates much lower average health expenditures than a conventional insurance plan. Reasons for this may include selection, incentive effects or efficiency.In our sample, about 90% of the difference in health expenditure can be explained by selection and incentive effects. The remaining 10% of savings due to the efficiency of the telemedicine service amount to about SFr 150 per year per insured, of which approximately 60% is saved by the insurer and 40% by the insured. Although the efficiency effect is greater than the cost of the plan, the big winners are the insured who not only save monetary and non‐monetary costs but also benefit from reduced premiums. Copyright © 2010 John Wiley & Sons, Ltd.
Can epigenetics solve the case of the midwife toad?—a comment on Vargas
Authors: Svardal Hannes 
Published: October 2010

AbstractIn a recent article in this journal, A. O. Vargas (2009. J Exp Zool B (Mol Dev Evol) 312:667–678) suggests to interpret the controversial midwife toad experiments of the early 20th century zoologist Paul Kammerer in the context of epigenetic inheritance. For information on Kammerer's work he resorts to a popular science book (Kammerer, '24. The Inheritance of Acquired Characteristics). However, the study of Kammerer's original publications reveals that there are substantial misunderstandings in Vargas' treatment of the subject. While Vargas' general idea—invoking epigenetic effects as an explanation of Kammerer's findings—remains attractive, at least two key aspects of his model need to be revised. Clarification of these issues is an important prerequisite for any experimental design with the aim to (dis)prove Kammerer and to establish a (potential) epigenetic basis of his observations about the mating behavior in midwife toads. J. Exp. Zool. (Mol. Dev. Evol.) 314B:625–628, 2010. © 2010 Wiley‐Liss, Inc.
Platelet‐rich plasma (PRP) impairs the craniofacial bone repair associated with its elevated TGF‐β levels and modulates the co‐expression between collagen III and α‐smooth muscle actin
Authors: Giovanini Allan Fernando , Gonzaga Carla Castiglia , Zielak João Cesar , Deliberador Tatiana Miranda , Kuczera Juliane , Göringher Isabella , de Oliveira Filho Marco Antonio , Baratto‐Filho Flares , Urban Cícero Andrade 
Published: October 2010

AbstractTransforming growth factor‐β (TGF‐β) is considered the main inducer of both the α‐smooth muscle actin (α‐SMA) phenotype and collagen synthesis and deposition and plays a significant role in the tissue repair and the development of fibrosis. Since the PRP constitutes an important source of TGF‐β and its efficacy on the craniofacial bone repair remains controversy, the aim of this study was to evaluate the effect of PRP in the presence of levels of TGF‐β on PRP samples, as well as in the presence of collagen III and α‐SMA+ cells, while comparing these results by means of a histomorphometric analysis of the bone matrix and fibrous deposition on the bone repair. Four bone defects of 16 mm2 were created on the calvarium of 21 rabbits. The surgical defects were treated with either particulate autograft, particulate autograft mixed with PRP and PRP alone. Animals were euthanized at 15, 30, and 45 days postoperative. Histomorphometric and immunohistochemical analyses were performed to assess repair time, as well as the expression of collagen III, and α‐SMA. The histomorphometric results demonstrated intensive deposition of fibrous tissue while hinder bone deposition occurred in PRP groups. These results coincided with higher values of the TGF‐β on the PRP sample, also larger occurrence of diffuse collagen III deposition and higher presence of α‐SMA+ cells spread among the fibrous tissue. Thus, the higher levels of TGF‐β associated with the both expression of collagen III and α‐SMA on defect treated with PRP suggest that its biomaterial induce an effect that can be considered similarly to a fibroproliferative disorder. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:457–463, 2011
ESI‐MS & MS/MS Analysis of Poly(2‐oxazoline)s with Different Side Groups
Authors: Altuntaş Esra , Kempe Kristian , Crecelius Anna , Hoogenboom Richard , Schubert Ulrich S. 
Published: October 2010

AbstractESI‐Q‐TOF MS has been used for the detailed characterization of various poly(2‐oxazoline)s with different side groups (i.e. methyl, ethyl, 1‐ethylpentyl, phenyl, o‐difluorophenyl and p‐tert‐butylphenyl) to evaluate this method as structural characterization tool for the detailed analysis of poly(2‐oxazoline)s. The results obtained provided an understanding of the fragmentation of poly(2‐oxazoline)s, revealing the elimination of small molecules such as ethene and hydrogen in their fragmentation patterns, which are partially dependent on the side groups. Also, a McLafferty rearrangement can be a possible fragmentation route for these polymers. In detail, side group elimination was only observed for poly(2‐alkyl‐2‐oxazoline)s, but not for poly(2‐aryl‐2‐oxazoline)s. magnified image
Novel Soluble Fluorene–Thienothiadiazole and Fluorene–Carbazole Copolymers for Optoelectronics
Authors: Cimrová Věra , Kmínek Ivan , Výprachtický Drahomír 
Published: October 2010

AbstractSummary: Optical, photophysical, electrochemical and photoelectrical properties of novel soluble low‐bandgap fluorene – thienothiadiazole based copolymers (CHTF and CDTF) and luminescent fluorene – carbazole copolymers, (CFCzE and CFCZA) were studied. Fluorene – thienothiadiazole copolymers exhibit in thin films long‐wavelength absorption with maxima at 750 – 785 nm and possess low bandgap, high electron affinity and exhibit reversible electrochromic behaviour. Therefore they are of interest for electrochromic and photovoltaic applications. Spectroelectrochemical study was performed and optical switching was demonstrated. Photovoltaic devices with bulk heterojunction made of blends of copolymers and fullerene derivative [60]PCBM were prepared. The power conversion efficiency was 2–3%. On the other hand, the fluorene‐carbazole copolymers exhibit blue photoluminescence with high quantum efficiency in solution and also in thin films. Light‐emitting devices with intensive broad bluish‐green‐white emission were fabricated.
Functionalization Conditions of PLGA‐PEG‐PLGA Copolymer with Itaconic Anhydride
Authors: Michlovská Lenka , Vojtová Lucy , Mravcová Ludmila , Hermanová Soňa , Kučerík Jiří , Jančář Josef 
Published: October 2010

AbstractSummary: Biodegradable thermosensitive triblock copolymers based on poly(ethylene glycol) and poly(lactic‐co‐glycolic acid) (PLGA‐PEG‐PLGA) prepared via ring opening polymerization were modified by itaconic anhydride (ITA), which gives copolymer both reactive double bonds and functional carboxylic acid groups essential for the reaction with biological active material. Functionalization conditions comprising ITA purification, temperature, time and presence of solvent were optimized with the respect to amount of end‐capped ITA. Maximum of 76.6 mol. % of bonded ITA were reached via “one pot” reaction in a bulk at 110 °C after 1.5 h. ITA functionalization thermally stabilized the original copolymer by increasing the initial degradation temperature Td from 284 °C to 294 °C and changing the negative glass transition temperature (Tg = ‐1.8 °C) to positive one up to 2.4 °C. The novel functionalized macromonomer can be cross‐linked either chemically or physically in order to produce new functionalized hydrogel network applicable as biomedical material in tissue engineering.
Photopolymer for Optical Holography and Holographic Interferometry
Authors: Květoň M. , Lédl V. , Havránek A. , Fiala P. 
Published: October 2010

AbstractSummary: In our laboratory, we have continued in experimental study of acrylamide‐based photopolymer recording material. Our exposition and detection setup was used for real‐time measurements of a diffraction grating formation process. Based on the results of our measurements, the chemical composition of the material was modified to increase sensitivity, value of refractive index modulation and stability of the formed structure. Recently, the material has been successfully applied to holographic interferometry.
Synthesis and Characterization of Polypyrrole Nanoparticles and Their Nanocomposites with Poly(propylene)
Authors: Sevil Baytekin , Zuhal Küçükyavuz 
Published: October 2010

AbstractSummary: Conducting polypyrrole (PPy) nanoparticles were synthesized via microemulsion polymerization. PP/PPy nanocomposites were prepared by melt‐mixing of polypyrrole with polypropylene (PP) and processed with injection molding. Tensile tests have revealed that increasing amount of PPy increased the strength and the stiffness of the nanocomposite while limiting the elongation of PP. Thermal gravimetric analysis has showed that incorporation of PPy nanoparticles has improved the thermal stability of the nanocomposites. Increasing amount of PPy nanoparticles increases the conductivity of nonconductive PP up to 2,4.10−4 Scm−1. The same techniques were used to characterize nanocomposites containing 2% w dispersant. Composites prepared with dispersant have involved smaller dimension PPy nanoparticles and exhibited improvement in some mechanical and thermal properties.
Microwave‐Assisted Synthesis of Poly(ε‐caprolactone)‐block‐poly(ethylene glycol) and Poly(lactide)‐block‐poly(ethylene glycol)
Authors: Karagöz Ayşe , Dinçer Sevil 
Published: October 2010

AbstractSummary: This study reported the preparation and characterization of PCL‐b‐mPEG (poly(ε‐caprolactone)‐block‐poly(ethylene glycol)) and PLL‐b‐mPEG (poly(L‐lactide)‐block‐poly(ethylene glycol)) diblock copolymers by microwave heating and comparison of resulted products the ones with prepared by conventional heating. Diblock copolymers were synthesized successfully by the microwave‐assisted ROP in the presence of stannous octoate (SnOct2) as catalyst under nitrogen atmosphere in different monomer ratios. Structural and functional characterization of copolymers were performed by FTIR, 1H‐NMR and DSC. Molecular weight values were determined by GPC and also calculated from 1H‐NMR. According to the results, microwave irradiation allowed to obtain polymers with very narrow size distribution in very short reaction time. Similar polymers prepared by conventional heating were also synthesized for comparison. Molecular weight and conversion of polymers were increased by irradiation time. This change was continued until a certain time point after which no more increase was observed. It was concluded that microwave irradiation is a succesful method to obtain these diblock copolymers in very short reaction time and with a similar conversion obtained by conventional method.
Designer Self‐Assembling Peptide Materials for Diverse Applications
Authors: Hauser Charlotte A.E. , Zhang Shuguang 
Published: October 2010

AbstractSummary: Macromolecuar chemistry and polymer science have had an enormous impact in many areas of science, engineering, medicine and our daily life. It has not only changed our way of life forever, but also continuously to improve our living standard. Macromolecuar chemistry now also encompasses bioengineering, biomimetics, designer biological materials and nanobiotechnology. Here we summarize a few classes of short peptides that we discovered and invented with broad applications including 3D tissue cell culture, reparative and regenerative medicine, tissue engineering, slow drug release, stabilization of membrane proteins for develop nanobiotechnology and molecular devices. Molecular design using short peptides as new materials will play increasingly important role in biomedical research, nanobiotechnology, clinical science and medicine.
Syntheses of Conjugated Polymers for Photonics
Authors: Výprachtický Drahomír , Cimrová Věra , Kmínek Ivan , Pavlačková Petra 
Published: October 2010

AbstractSummary: By the Suzuki coupling reaction of 9,9‐dioctyl‐2,7‐bis(1,3,2‐dioxaborinan‐2‐yl)fluorene (I) and 3,5‐di‐tert‐butylphenyl 2,5‐dibromobenzenesulfonate (II) the alternating poly{[9,9‐dioctylfluoren‐2,7‐diyl]‐alt‐[2‐(3,5‐di‐tert‐butyl‐phenoxysulfonyl)‐1,4‐phenylene]} (III) was synthesized. Alkaline hydrolysis of III gave a conjugated polyelectrolyte carrying sulfonic acid groups (IV). Monomers 2,5‐dibromo‐3‐[2‐(pyren‐1‐yl)vinyl]thiophene and 2,5‐dibromo‐3‐[2‐(quinolin‐4‐yl)vinyl)thiophene were prepared and copolymerized with I to afford poly{[9,9‐dioctylfluoren‐2,7‐diyl]‐alt‐[3‐(2‐(pyren‐1‐yl)vinyl)thiophen‐2,5‐diyl]} (V) and poly{[9,9‐dioctylfluoren‐2,7‐diyl]‐alt‐[3‐(2‐(quinolin‐4‐yl)‐vinyl)thiophen‐2,5‐diyl] (VI), respectively. Conjugated backbone of V contains the conjugated pyrene unit in the side chain. Similarly the side chain of VI contains the conjugated quinoline structure unit which can be for instance protonated. By the Suzuki polycondensation reaction of I and of the prepared methyl 3‐(2,7‐dibromocarbazole‐9‐yl)propionate (VII) the new poly{[9,9‐dioctylfluorene‐2,7‐diyl]‐alt‐[9‐(2‐methoxycarbonylethyl)carbazole‐2,7‐diyl]} (VIII) was synthesized and characterized.