bluuebunny/crossref_metadata_2025 huggingface dataset:
Growing a Nontraditional Accounting Firm: Warren and Associates
Authors: Bagranoff Nancy A. , Turner Leslie D.
Published: April 2008

This case presents the history of a small CPA firm that is a value-added reseller (VAR) providing IT consulting services to mid-sized and small business clients. Since this firm does not provide audit, compilation and review, or tax services, it provides a view of a CPA firm that is different from the traditional audit and tax organization. The main question posed is determining the best growth strategy for this CPA firm. To answer this question, you must research and evaluate consulting opportunities related to Sections 302 and 404 of the Sarbanes-Oxley Act, as well as several of the recently developed AICPA services such as WebTrust, SysTrust™, and ElderCare. The research that you do will provide a deeper understanding of the role of accountants as consultants. The case affords an excellent opportunity to stimulate class discussion or presentations about the nature of CPA services beyond audit and tax services.
Firm Performance Effects in Relation to the Implementation and Use of Enterprise Resource Planning Systems
Authors: Nicolaou Andreas I.
Published: April 2008

Research indicates that successful adoption of information technology to support business strategy can help organizations gain superior financial performance. The recent wave of enterprise-wide resource planning systems adoptions is a significant commitment of resources and may affect almost all business processes. This study examines the effect of adoption of enterprise systems on a firm's long-term financial performance. A large-scale data identification and collection method compared the financial data of 247 firms adopting enterprise wide systems with a matched control group of firms cross-sectionally and longitudinally before and after adoption. A number of implementation characteristics were also measured and their effects assessed. The results show that firms adopting enterprise systems exhibit higher differential performance only after two years of continued use. Furthermore, controlling for implementation characteristics as vendor choice, implementation goal, modules implemented, and implementation time period, helped explain the financial performance effects of enterprise resource planning system use. These results provide important insights that complement extant research findings and also raise future research issues.
Bias Due to Visual Illusion in the Graphical Presentation of Accounting Information
Authors: Amer T. S.
Published: April 2008

Graphical displays of information are among the most common decision aids available. Recent research has focused on how graphs that have been prepared without following key preparation guidelines impact decision making. This paper adds to the literature by demonstrating that visual illusion may bias decision makers who view data from the graph, even if the graphs are prepared according to key-preparation guidelines. The investigation of a visual illusion (i.e., an unintended consequence even in a correctly depicted graph) contrasts with prior studies in accounting that have typically examined manipulated graphs (i.e., intentionally distorted, incorrectly depicted graphs). A laboratory study incorporated a 2×2 design to examine the effects of the so-called “Poggendorff illusion” and the possible mitigating effect of adding horizontal gridlines. It shows that decision makers may systematically underestimate or overestimate the values displayed on line graphs. In addition, this research suggests that the bias can be moderated by including horizontal gridlines on line graphs. Adding horizontal gridlines also reduces the variance in some values decision makers view in graphs. The results have both theoretical and practical implications for information display.
New Roles for AIS Courses: A Surprising Finding from a Case Study
Authors: Fordham David R.
Published: April 2008

To meet the growing need for accountants familiar with information systems, many colleges and universities have added a concentration in Accounting Information Systems (AIS) to their accounting programs. While there is general—albeit not universal—agreement on the “core concepts” for the primary AIS course, there is no such consensus on what topics should be covered by supplemental AIS coursework. This paper begins by describing the efforts of one university to create, and then revise, an AIS curriculum. During the review process, the faculty made a surprising discovery: the roles of the AIS content in the professional and career development of the alumni were completely different from the roles expected. Consideration of these new roles might assist other institutions in improving their programs.
Tolerance for Ambiguity and IT Competency among Accountants
Authors: Lamberton Barbara , Fedorowicz Jane , Roohani Saeed J.
Published: April 2008

The accounting profession must attract and retain individuals with the interest, attitudes, and competencies demanded by the marketplace. This paper examines the influence of tolerance for ambiguity, computer anxiety, and gender on interest in acquiring IT competency among 123 accounting and AIS majors. In comparison to individuals majoring in accounting, the AIS majors were more tolerant of ambiguity (p = .025) and had slightly more positive attitudes toward computers. However, neither computer anxiety (p = .112) nor gender (p = .915) explained major selection. The results suggest the accountants with strong interests in IT are more comfortable with ill-defined, ambiguous problem-solving situations. The study implies that tolerance for ambiguity, a characteristic increasingly valued by the profession, should be considered in the classroom and in hiring decisions.
A Service-Learning Course in Accounting Information Systems
Authors: Rose Jacob M. , Rose Anna M. , Norman Carolyn Strand
Published: April 2008

This study reports the results of a quasi-experiment involving 90 master of accounting students. The students participated in one of three course types: full-immersion service learning with a supporting textbook, full-immersion service learning without a supporting textbook, or nonservice learning using case-based projects with deliverables identical to those in the service-learning courses. Results indicate that full-immersion service learning increased student satisfaction, student perceptions of ability, self-confidence in chosen careers, desire to study accounting information systems, and performance on complex data modeling tasks. The only performance decrement noted was in performance on a topic that was loosely related to the service-learning project. These results should be of interest to faculty and administrators who might be contemplating the value of integrating service learning in the accounting curriculum.
New York State Agencies: A Case Study for Analyzing the Process of Legacy System Migration: Part I
Authors: Fisher Ingrid , Bradford Marianne
Published: April 2008

The first of a two-part case, Part I explains the problems the NY State Government encountered when updating and converting a large-scale legacy information system (IS). The case illustrates the complexities of legacy system migration under legal constraints. Systems issues include: (1) the role of strategic planning for IS, (2) the importance of stakeholder analysis when changing systems, (3) organizational approaches to systems implementation and (4) business process analysis. This case is appropriate for use in either an undergraduate or graduate Accounting Information Systems course and offers a flexible approach to adoption, ranging from comprehensive adoption of all topics in both parts to specific topics within either part.
The Effect of Incentives on Knowledge Sharing in Computer-Mediated Communication: An Experimental Investigation
Authors: Taylor Eileen Z.
Published: April 2008

Do financial incentives increase knowledge sharing in a computermediated environment? Thirty-six accounting students assigned to groups with different financial incentives (group, piece-rate, or tournament) searched for errors in accounting-related spreadsheets, with access to an online chat room they could use for helping others. The dependent variable was the amount of knowledge the students shared with others. Quantitative and qualitative data suggest that the group financial incentives inspired more knowledge sharing than did either tournament or piece-rate. Results suggest that managers should carefully consider incentive structures in computer-based systems because incentives potentially affect knowledge sharing.
The Moderating Effect of Context on the Market Reaction to IT Investments
Authors: Oh Wonseok , Ki m Joung W. , Richardson Vernon J.
Published: April 2008

This paper examines the moderating effects of firm and IT characteristics on the market reaction to IT investment announcements. A special emphasis has been placed on the potential interaction effects of these two types of variables, since the previous event studies have paid limited attention to the possibility that they interact and jointly alter investors' perceptions in relation to IT investment announcements. Very recently, several authors have noted the importance of interaction effects on theory development for IS research. Their assessments are particularly relevant to IT-value event studies, since the market reaction to IT investment announcements involves a complex process shaped by the interaction of firm and IT characteristics. Based on the previous studies in IS, finance, and accounting, a firm's growth potential and uncertainty are used as proxies to represent firm characteristics, while IT strategic role and asset-specificity of IT are chosen as the variables reflecting IT characteristics. Three other variables (discloser information, firm size, and industry) are included to control for their effects. We develop eight hypotheses based on the examinations of the main and interaction effects of firm and IT characteristic variables on the shareholder's reaction to IT investment announcements.

The results of the main effects indicate that a firm's growth prospects, uncertainty, the strategic role of IT, and discloser information are significantly related to cumulative abnormal returns (CARs), while no significant effect was observed for asset-specificity of IT resources. Interestingly, however, interaction effects reveal that the stock market reacts with a discount to announcements of IT investments that are characterized as highly asset-specific in the presence of uncertainty. In addition, the market reacts more favorably to investments with a transformational IT strategic role when the firm faces greater uncertainty. One of our main contributions in this study is to provide a finer level of granularity with regard to the market reaction to IT investments by considering the interaction as well as the main effects of firm and IT characteristics.
An Introduction to the Clinical Case Representation Paradigm for Information Systems Research
Authors: Lehmann Constance M. , Heagy Cynthia D.
Published: April 2008

The purpose of this paper is to explain how the use of the Clinical Case Representation Paradigm (CCRP) in accounting information systems (IS) research has the potential to enrich our knowledge of expertise development in IS. The CCRP has been tested extensively in the medical literature, improving the previous novice-expert research by introducing a stage theory of expertise development, which analyzes novice, intermediate, and expert-level judgment and decision making. We propose the use of this paradigm in IS research and provide suggestions for its application using data collected from IS professionals and AIS students.

Our results are similar to those found in other CCRP studies in that the more experienced professionals had more concise problem representations, included more inferences (i.e., indicating encapsulated knowledge), and matched the canonical representation and solution more closely. Interestingly, evidence of solution quality was found at the intermediate level. We indicate the limitations of our application of the CCRP and make suggestions for further research projects.
Policy-Level Specifications in REA Enterprise Information Systems
Authors: Geerts Guido L. , McCarthy William E.
Published: April 2008

The Resource-Event-Agent (REA) enterprise model is a widely accepted framework for the design of the accountability infrastructure of enterprise information systems. Policy-level specifications define constraints and guidelines under which an enterprise operates, and they are an extension to the REA enterprise model, adding the “what should, could, or must be” to the “what is.” This paper aims both at comprehensive understanding of policy-level definitions as part of REA enterprise systems and at understanding of the semantic constructs that enable such definitions. We first explore two distinctive semantic abstractions essential to policy-level specifications: typification and grouping. The typification abstraction links instances of an object class to concepts for which they are concrete realizations, while the grouping abstraction aggregates objects into collections. We next present a number of patterns for the semantic modeling of policies. Following, we look at policy-level applications for REA enterprise information systems. We explore type and grouping definitions for the REA primitives (resource, event, agent) and discuss enterprise applications for three different kinds of policy definitions: knowledge-intensive descriptions, validation rules, and target descriptions. Our discussion of specific enterprise applications includes internal control applications (e.g., limit checks), variance analysis based on standard specifi-cations (e.g., bills of materials), and budgeting applications.
Chondroitin-4-Sulphate Reduced Oxidative Injury in Caerulein-Induced Pancreatitis in Mice: The Involvement of NF-κB Translocation and Apoptosis Activation
Authors: Campo Giuseppe M. , Avenoso Angela , Campo Salvatore , Nastasi Giancarlo , Traina Paola , D’Ascola Angela , Calatroni Alberto
Published: April 2008

Activation of nuclear factor κB (NF-κB) and caspases may greatly amplify inflammation and cell damage in addition to that directly exerted by free radicals. Since reactive oxygen species (ROS) are involved in acute pancreatitis, we studied whether the administration of chondroitin-4-sulphate (C4S), in addition to its antioxidant activity, was able to modulate NF-κB and caspase activation in an experimental model of caerulein-induced acute pancreatitis in mice. Hyperstimulating doses of caerulein (50 μg/ kg), five injections per mouse given at hourly intervals produced the following: high serum lipase and amylase activity; lipid peroxidation, evaluated by 8-isoprostane concentrations; loss of antioxidant defenses such as glutathione reductase (GR) activity; NF-κB activation and loss of cytoplasmic IκBα protein; increases in tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), caspase-3, and caspase-7 gene expression and their related protein; accumulation and activation of neutrophils in the damaged tissue, evaluated by elastase (ELA) determination; and pancreatic injury, evaluated by histologic analysis. Pretreatment of mice with different doses of C4S, given 1 hr before caerulein injections and 1 and 2 hrs after the last caerulein injection, reduced lipid peroxidation, inhibited NF-κB translocation and cytoplasmic IκBα protein loss, decreased TNF-α, IL-6, and caspase gene expression and their related protein levels, limited endogenous antioxidant depletion, and reduced tissue neutrophils accumulation and tissue damage. Since molecules with antioxidant activity can block NF-κB and apoptosis activation, we suggest that C4S administration is able to block NF-κB and caspase activation by reducing the oxidative burst.
Lack of association between the angiotensin-converting enzyme gene (I/D) polymorphism and diabetic nephropathy in Tunisian type 2 diabetic patients
Authors: Arfa Imen , Abid Abdelmajid , Nouira Sonia , Elloumi-Zghal Houda , Malouche Dhafer , Mannai Imen , Zorgati Mohamed Majdi , Ben Alaya Nissaf , Rebai Ahmed , Zouari Béchir , Ben Ammar Slim , Ben Rayana Mohamed Chiheb , Hmida Slama , Blousa-Chabchoub Samira , Abdelhak Sonia
Published: April 2008

Objective. The aim of the present study was to investigate whether the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism is associated with diabetic nephropathy and type 2 diabetes in the Tunisian population.

Design. A case-control study was conducted among 141 unrelated type 2 diabetic patients with (90 patients) or without nephropathy (51 patients) and 103 non-diabetic controls with normal fasting blood glucose. Genotyping was performed using a nested polymerase chain reaction amplification in order to identify correctly heterozygous individuals.

Results. The distribution of DD, ID and II genotypes did not significantly differ between type 2 diabetic patients with or without nephropathy (DD: 44%; ID: 46%; II: 10% vs. DD: 41%; ID: 47 %; II: 12%, respectively).There was also no significant statistical difference between the genotype distribution and allele frequencies of the (I/D) polymorphism in all type 2 diabetic subjects compared to non-diabetic controls with normal fasting blood glucose (DD: 43%; ID: 46%; II: 11% vs. DD: 37%; ID: 48% ;II: 15%, respectively).

Conclusions. In the present preliminary study, the (I/D) polymorphis within the ACE gene is likely not associated with diabetic nephropathy nor with type 2 diabetes in the Tunisian studied population.
Review: Concomitant calcium entry blockade and inhibition of the renin-angiotensin system: a rational and effective means for treating hypertension
Authors: Gojanovic Boris , Feihl François , Liaudet Lucas , Waeber Bernard
Published: April 2008

Pharmacological treatment of hypertension is effective in preventing cardiovascular and renal complications. Calcium antagonists (CAs) and blockers of the renin-angiotensin system [angiotensin-converting enzyme (ACE) inhibitors and angiotensin II antagonists (ARBs)] are widely used today to initiate antihypertensive treatment but, when given as monotherapy, do not suffice in most patients to normalise blood pressure (BP). Combining a CA and either an ACE-inhibitor or an ARB considerably increases the antihypertensive efficacy, but not at the expense of a deterioration of tolerability. Several fixed-dose combinations are available (CA + ACE-inhibitors: amlodipine + benazepril, felodipine + ramipril, verapamil + trandolapril; CA + ARB: amlodipine + valsartan). They are expected not only to improve BP control, but also to facilitate long-term adherence with ON antihypertensive therapy, thereby providing renal damage caused by high BP. maximal protection against the cardiovascular and renal damage caused by high BP.
The Directional Peeling Effect of Nanostructured Rigiflex Molds on Liquid‐Crystal Devices: Liquid‐Crystal Alignment and Optical Properties
Authors: Kim Jong Bok , Lim Ju Ri , Park Jin Seol , Ahn Han Jin , Lee Min Jung , Jo Sung Jin , Kim Mihee , Kang Daeseung , Lee Se Jong , Kim Youn Sang , Baik Hong Koo
Published: April 2008

We report a new strategy, the directional peeling of a rigiflex mold with a nanostructure, to overcome several problems with general patterning techniques for liquid‐crystal (LC) alignment. These include difficulty in generating the pretilt angle and in controlling the LC rising‐up direction, formation of local domains, and weak optical properties. The directional peeling of the rigiflex mold results in pretilt‐angle formation and controls the LC rising‐up direction. In addition, a nanostructure with small spacing aligns the LC with a high order parameter because of a strong confinement effect and suppresses diffraction due to its small spacing. Eventually, the nanostructure achieves improvements in the optical properties. In summary, while recent patterning techniques for LC alignment only solve one problem, the directional peeling of the rigiflex mold with a nanostructure simultaneously overcomes several problems with LC alignment and optical properties.
An Efficient Radical Procedure for the Halogenation and Chalcogenation of B‐Alkylcatecholboranes
Authors: Schaffner Arnaud‐Pierre , Montermini Florian , Pozzi Davide , Darmency Vincent , Scanlan Eoin Martin , Renaud Philippe
Published: April 2008

An efficient formal anti‐Markovnikov addition of HX (X=Cl, Br, I, SR and SeR) to olefins under mild reaction conditions is described. The procedure is based on the hydroboration of alkenes with catecholborane. The conversion of the intermediate B‐alkylcatecholboranes to the corresponding halides, sulfides and selenides is based on a common process, i.e., generation of a radical from the alkylborane followed by abstraction of a heteroatom from an aromatic sulfonyl reagent. The efficiency of these radical reactions is remarkable. The mildness of the reaction conditions is well illustrated by the preparation of iodoalkanes. Despite the notorious reactivity of iodoalkanes under radical reaction conditions, no product degradation was observed.
Dimethylzinc‐Mediated, Oxidatively Promoted Reformatsky Reaction of Ethyl Iodoacetate with Aldehydes and Ketones
Authors: Cozzi Pier Giorgio , Mignogna Alessandro , Vicennati Paola
Published: April 2008

A practical and general Reformatsky reaction, promoted by oxidants and mediated by dimethylzinc, is described. The reaction is fast and runs at 0 °C with aldehydes and ketones, under mild reaction conditions. Preliminary results obtained for the enantioselective version show that inexpensive chiral amino alcohols could be used in the challenging formation of enantioenriched quaternary stereogenic centers.
Enantioselective Olefin Epoxidation using Axially Chiral Biaryl Azepinium Salts as Catalysts. Rapid in‐situ Screening and Origin of the Stereocontrol
Authors: Novikov Roman , Bernardinelli Gérald , Lacour Jérôme
Published: April 2008

To unravel the origin of the stereocontrol in epoxidation reactions of unfunctionalized alkenes by diastereomeric biaryl oxaziridinium salts, two series of novel iminium cations were prepared. These moieties combine (Ra)‐dimethylbiphenyl or (Ra)‐5,5′,6,6′,7,7′,8,8′‐octahydrobinaphthyl cores with chiral exocyclic appendages derived from commercially available (S)‐ or (R)‐3,3‐dimethylbutan‐2‐amine and (S)‐ or (R)‐1‐phenylpropan‐1‐amine. Under biphasic enantioselective olefin epoxidation conditions, in‐situ generated bromide salts of these derivatives have displayed similar or better asymmetric efficiency than the classical binaphthyl derivatives. A structural analysis was performed in search of a correlation between the origin of the stereocontrol/level of enantioselectivity in the products, and dihedral angles around the biaryl twist of the catalysts.
Brønsted Acid‐Catalyzed Three‐Component Hosomi–Sakurai Reactions
Authors: Kampen Daniela , Ladépêche Arnaud , Claßen Gerrit , List Benjamin
Published: April 2008

Aldehydes react with silyl ethers or the corresponding alcohols and allylsilanes in the presence of catalytic amounts of 2,4‐dinitrobenzenesulfonic acid (DNBA) to provide a wide range of homoallylic ethers in moderate to high yields.
Reduced dose of lenograstim is as efficacious as standard dose of filgrastim for peripheral blood stem cell mobilization and transplantation: A randomized study in patients undergoing autologous peripheral stem cell transplantation
Authors: Ataergin Selmin , Arpaci Fikret , Turan Mustafa , Solchaga Luis , Cetin Turker , Ozturk Mustafa , Ozet Ahmet , Komurcu Seref , Ozturk Bekir
Published: April 2008

In vitro studies have demonstrated a 27% increased efficacy of lenograstim over filgrastim. However, equal doses of 10 μg/kg/day of filgrastim and lenograstim have been recommended for mobilization of CD34+ cells without associated chemotherapy. In this study, we investigated whether a 25% reduced dose of lenograstim at 7.5 μg/kg/day is equavalent to 10 μg/kg/day filgrastim for autologous peripheral blood stem cell (PBSC) mobilization and transplantation. A total of 40 consecutive patients were randomized to either filgrastim (n = 20) or lenograstim (n = 20). The two cohorts were similar in regard to disease, sex, body weight, body surface area, conditioning regimens, previous chemotherapy cycles and radiotherapy. Each growth factor was administered for 4 consecutive days. The first PBSC apheresis was done on the 5th day. In the posttransplant period, the same G‐CSF was given at 5 μg/kg/day until leukocyte engraftment. Successful mobilization was achieved in 95% of patients. Successful mobilization with the first apheresis, was achieved in 10/20 (50%) patients in the filgrastim group versus 9/20 (46%) patients in the lenograstim group. No significant difference was seen in the median number of CD34+cells mobilized, as well as the median number of apheresis, median volume of apheresis, percentage of CD34+ cells, and CD34+ cell number. Leukocyte and platelet engraftments, the number of days requiring G‐CSF and parenteral antibiotics, the number of transfusions were similar in both groups in the posttransplant period. Lenograstim 7.5 μg/kg/day is as efficious as filgrastim 10 μg/kg/day for autologous PBSC mobilization and transplantation. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Compound heterozygosity for two MSH6 mutations in a patient with early onset colorectal cancer, vitiligo and systemic lupus erythematosus
Authors: Rahner Nils , Höefler Gerald , Högenauer Christoph , Lackner Caroline , Steinke Verena , Sengteller Marlies , Friedl Waltraut , Aretz Stefan , Propping Peter , Mangold Elisabeth , Walldorf Constanze
Published: April 2008

Lynch syndrome (hereditary non‐polyposis colorectal cancer, HNPCC) is an autosomal dominant condition caused by heterozygous germline mutations in the DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6, or PMS2. Rare cases have been reported of an inherited bi‐allelic deficiency of MMR genes, associated with multiple café‐au‐lait spots, early onset CNS tumors, hematological malignancies, and early onset gastrointestinal neoplasia. We report on a patient with vitiligo in segments of the integument who developed systemic lupus erythematosus (SLE) at the age of 16, and four synchronous colorectal cancers at age 17 years. Examination of the colorectal cancer tissue showed high microsatellite instability (MSI‐H) and an exclusive loss of expression of the MSH6 protein. Immunohistochemical analysis of normal colon tissue also showed loss of MSH6, pointing to a bi‐allelic MSH6 mutation. Sequencing of the MSH6 gene showed the two germline mutations; c.1806_1809delAAAG;p.Glu604LeufsX5 and c.3226C > T;p.Arg1076Cys. We confirmed that the two mutations are on two different alleles by allele‐specific PCR. To our knowledge, neither parent is clinically affected. They did not wish to be tested for the mutations identified in their daughter. These data suggest that bi‐allelic mutations of one of the MMR genes should be considered in patients who develop early‐onset multiple HNPCC‐associated tumors and autoimmune disorders, even in absence of either hematological malignancies or brain tumors. © 2008 Wiley‐Liss, Inc.
No major role for the EMX2 gene in schizencephaly
Authors: Merello Elisa , Swanson Eric , De Marco Patrizia , Akhter Murtaza , Striano Pasquale , Rossi Andrea , Cama Armando , Leventer Richard J. , Guerrini Renzo , Capra Valeria , Dobyns William B.
Published: April 2008

Schizencephaly (SCH) is a rare disorder of cerebral cortical development, characterized by full thickness clefts spanning the wall of the cerebral hemispheres that are lined and surrounded by polymicrogyric cortex. Based on pathological analysis, SCH was originally considered to have multiple causes including infectious and vascular injuries, and toxic agents. However, a few reports of familial SCH have suggested a possible genetic etiology. Ten years ago two articles identified EMX2 as the first causative gene for human SCH in 13 of 18 patients, although for several putative mutations no pathogenic role was demonstrated. Here, we reinterpret the original articles as showing a significantly lower mutational rate (17%) than originally reported (72%), and provide results of EMX2 sequencing in 39 new SCH patients, detecting no pathogenic mutations. We conclude that the reported association between SCH and EMX2 mutations is not adequately supported by current data, and that diagnostic testing of EMX2 is not justified, as any results would be uninterpretable. © 2008 Wiley‐Liss, Inc.
Synthesis and characterization of aromatic/aliphatic co‐polyureas
Authors: Li Xue‐lian , Chen Da‐jun
Published: April 2008

In the present work, a series of aromatic/aliphatic co‐polyureas have been synthesized from 4,4‐diphenylmethane diisocyanate (MDI), m‐phenylene diamine (m‐PDA), and 1,6‐diaminohexane (HDA) in DMAc by a two‐stage solution polymerization route. Characterizations of the polyurea products have been carried out by 1H‐nuclear magnetic resonance (NMR) and Fourier transform infrared (FT‐IR) spectroscopic techniques. Thermal properties of the polyurea samples have been investigated by differential scanning calorimetry and thermogravimetric analysis. The mechanical properties of the polyurea samples have been measured. The results show that the polyurea samples with the expected structure have been synthesized. The results of DSC analysis show the glass transition temperatures of the co‐polyurea samples decrease with the increase of HDA content, and fit the Fox equation well. TGA data of the polyurea samples indicate that thermal stability of the aromatic polyurea is better than that of the co‐polyureas. The thermal degradation activation energies of the co‐polyureas are ∼60–70 kJ/mol. The results of mechanical measurement show that the initial modulus and tensile strength of the co‐polyurea samples decrease with the increase of HDA content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Dispersion of nanoclay into polypropylene with carbon dioxide in the presence of maleated polypropylene
Authors: Nguyen Quang T. , Baird Donald G.
Published: April 2008

The effect of maleic anhydride grafted polypropylene (PP‐g‐MA) on the mechanical and rheological properties of polypropylene (PP)–clay nanocomposites prepared with nanoclay expanded with CO2 and direct melt blending was studied. The results from the studies of the mechanical properties, rheological properties, and transmission electron microscopy show that when PP‐g‐MA was combined with the technique that used CO2, greater enhancements in the mechanical properties and degree of dispersion of nanoclay in PP were observed. Furthermore, yieldlike behavior in the viscosity and a tail in the low‐frequency behavior of the elastic modulus was attributed to the reaction of PP‐g‐MA with the nanoclay surface and not exfoliation. A fairly well‐dispersed morphology was observed for concentrations as high 6.8 wt % clay when the clay was expanded and mixed with CO2. At this concentration, mechanical properties such as yield strength and modulus increased by as much as 13 and 69%, respectively, relative to the pure PP. Furthermore, the modulus of the composite samples prepared with PP‐g‐MA and CO2 was some 15% higher than that of samples prepared by direct melt compounding (without the use of CO2). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of a novel star polymer consisting of a dendritic polyamidoamine core and polystyrene arms and its self‐assembly to form large multimolecular micelles
Authors: Zhao Yili , Song Yantao , Jiang Wei , Zhang Bao , Li Yapeng , Sha Ke , Wang Shuwei , Chen Liang , Ma Lina , Wang Jingyuan
Published: April 2008

This work is focused on the synthesis and self‐assembly of novel dendritic star polymers with a dendritic polyamidoamine core and many linear polystyrene arms. The polymers can synchronously form unimolecular micelles (ca. 10 nm) and large multimolecular micelles (ca. 100 nm) in selected solvents (tetrahydrofuran/methanol) at room temperature. Atomic force microscopy, scanning electron microscopy, and dynamic light scattering measurements have provided direct evidence that the large micelles are a kind of multimicelle aggregate with the basic building units of unimolecular micelles. Accordingly, a possible self‐assembly process is put forward, and a new aggregate model, termed multimicelle aggregate, is suggested to explain the formation of the large micelles. In the multimicelle aggregate model, the large micelles are the aggregates of small micelles associated by intermicellar interactions such as hydrogen bonds and p–p stacking interactions. It is the first demonstration of the self‐assembly mechanism for the large multimolecular micelles generated from the solution self‐assembly of dendritic star polymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effects of reactive melt mixing on the morphology and thermal behavior of linear low‐density polyethylene/rubber blends
Authors: Penco Maurizio , Sciucca Stefania Della , Passaglia Elisa , Giordani Guido , Coiai Serena , Di Landro Luca
Published: April 2008

Linear low‐density polyethylene (LLDPE)/polybutadiene (PB) and LLDPE/poly(styrene‐b‐butadiene‐b‐styrene) (SBS) binary blends were prepared by simple melt mixing or by reactive blending in the presence of a free‐radical initiator, and for comparison, pure LLDPE was treated under the same conditions with a comparable free‐radical initiator concentration. The effect of the reactive melt mixing on the morphology of the blends was studied with transmission electron microscopy, and the corresponding particle size distributions were analyzed and compared to highlight the effects of the crosslinking and grafting phenomena. Thermal properties of the obtained materials were investigated with differential scanning calorimetry and dynamic mechanical thermal analysis (DMTA). In particular, the effect of the reactive mixing parameters on the amorphous phase mobility was investigated. The influence of the chemical modification on the crystallization behavior of LLDPE, neat and blended with PB and SBS, was also studied with dynamic and isothermal differential scanning calorimetry tests, and the isothermal thermograms were analyzed in light of the Avrami equation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A comparative study of the cure characteristics, processability, mechanical properties, ageing, and morphology of rice husk ash, silica and carbon black filled 75 : 25 NR/EPDM blends
Authors: Arayapranee Wanvimon , Rempel Garry L.
Published: April 2008

The performance of rice husk ash (RHA), obtained by burning rice husks, as a filler for natural rubber (NR)/ethylene–propylene–diene monomer (EPDM) blends was investigated. For comparison purposes, two commercial reinforcing fillers, silica and carbon black were also used. A fixed 75 : 25 blend ratio (wt %) of NR and EPDM was prepared using a two‐stage conventional mixing procedure. Filler loading was varied from 0 to 60 parts per hundred of resin (phr) at 15 phr intervals. The results indicated that RHA offers processing advantages over silica and carbon black. The use of RHA as an additional filler provided almost no improvement in the tensile strength and abrasion resistance of the 75 : 25 NR/EPDM blends. The ozone resistance of the blends was inferior to those obtained from the addition of RHA. However, RHA was better in resilience property than that of silica and carbon black. Scanning electron micrographs revealed that the dispersion of RHA filler in the rubber matrix is discontinuous, which in turn generates weak structure when compared with carbon black and silica. According to these observations, RHA could be used as a diluent filler for the 75 : 25 NR/EPDM blend, while silica and carbon black can be used as a reinforcing filler. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Study on the structure of mangrove polyflavonoid tannins with MALDI‐TOF mass spectrometry
Authors: Oo C. W. , Pizzi A. , Pasch H. , Kassim M. J.
Published: April 2008

Matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry is a suitable method for examining polyflavonoid tannin oligomers as it is capable to determine aspects of their oligomeric structure and characteristics, which are otherwise too difficult to determine by other techniques. It has been possible to determine by MALDI‐TOF for Rhizophora apiculata mangrove polyflvonoid tannins that: (i) procyanidins oligomers formed by catechin/epicatechin, epigallocatechin, and epicatechin gallate monomers are present in great proportions; (ii) oligomers, up to nonamers, in which the repeating unit at 528–529 Da is a catechin gallate dimer that has lost both the gallic acid residues and an hydroxy group which are the predominant species; (iii) oligomers of the two types covalently linked to each other also occur. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and Anticancer Activity of New 1‐Substituted‐6H‐pyrido[4,3‐b]carbazole Derivatives
Authors: Tylińska Beata , Jasztold‐Howorko Ryszard , Mastalarz Henryk , Szczaurska‐Nowak Katarzyna , Wietrzyk Joanna
Published: April 2008

This study examines the synthesis and cytostatic activity of new 5,6‐dimethyl‐1‐substituted‐6H‐pyrido[4,3‐b]carbazole derivatives. Their structures were confirmed by 1H‐NMR and elemental analysis. Seven of the new compounds were tested by the SRB method in vitro against human lung cancer (A549) and human kidney cancer (A498) cell lines. Biological tests indicated remarkable cytostatic effects of four compounds tested in comparison with ellipticine and cisplatin as reference drugs. One particular compound 3c was about four times more active on A498 than ellipticine with similar activity on the A549 cell line, and outperformed cisplatin activity on both tumor cell lines.
Investigations Concerning the Correlation of COX‐1 Inhibitory and Hydroxyl Radical Scavenging Activity
Authors: Scholz Michael , Ulbrich Holger , Mattern Andreas , Kramb Jan‐Peter , Kiefer Werner , Dannhardt Gerd
Published: April 2008

The aim was to study the COX‐1 inhibiting efficacy in context with hydroxyl radical scavenging properties of compounds bearing a carboxylic acid and ester function, respectively. In general, the acids are more potent radical scavengers than the corresponding esters but there is no clear correlation with their COX‐1 inhibiting potencies. A feasible scavenging mechanism of carboxylic acids is discussed.
The vortical response to penetrative convection and the associated gravity‐wave generation
Authors: Lane Todd P.
Published: April 2008

This study documents the vortical motions that arise due to penetrative convective updraughts. Using an idealized axisymmetric model of dry thermals it is shown that in a stable environment the baroclinic generation of vorticity forms a circulation that opposes updraught overshoot and manifests the first signature of gravity waves emanating from the thermal. Continued baroclinic generation of vorticity of oscillating sign completes the first full wavelength and populates the wave packet. These examples provide an alternate description of the generation of gravity waves by penetrative convection and provide further insight into the morphology of the wave source Copyright © 2008 Royal Meteorological Society
Hydrological aspects of meteorological verification
Authors: Pappenberger F. , Scipal K. , Buizza R.
Published: April 2008

All major weather forecast centres verify meteorological forecasts as a normal part of their operational duties, with verifications usually based on variables and methods of meteorological relevance. These forecasts are then often used to drive hydrological models, and this article demonstrates that a considerable gap exists between current meteorological practice and hydrological needs. This article discusses this gap in terms of the type of variables; the domain and resolution; the importance of choosing appropriate thresholds; and the smoothing and accumulation period. A list of recommendations for a user‐focused evaluation is given in the conclusions. We suggest that the meteorological community, and specifically the forecast centres, should consider making these adjustments and producing additional products suitable for hydrological applications. Copyright © 2008 Royal Meteorological Society
Percutaneous treatment of an iatrogenic cardiac fistula
Authors: Patterson Mark S. , Vaina Sophia , Serruys Patrick W.
Published: April 2008

Coronary fistulae, defined as communications between coronary arteries and cardiac chambers or veins, are uncommon. We present a case where a fistula was inadvertently caused by the surgical anastomosis of an arterial coronary artery bypass graft to a coronary vein. This produced two coronary problems, the unrevascularized Cx territory and a coronary arteriovenous fistula, and left the patient with symptoms. Each of these problems was addressed in a tailored percutaneous intervention by deploying ostial and distal stents to revascularize the Cx, followed by coils to block the distal section of the graft. © 2008 Wiley‐Liss, Inc.
Low gradient aortic stenosis: Assessment, treatment, and outcome
Authors: Higgins James R. , Arimie Raluca , Currier Jesse
Published: April 2008

Aortic stenosis is a commonly encountered valvular disorder in the treatment of cardiovascular disease. Generally, symptomatic patients who undergo valve replacement experience a vast reduction in symptoms and a great improvement in survival. A subset of symptomatic patients in whom management is less clear are those with a small transvalvular gradient and low cardiac output, or low gradient aortic stenosis. The assessment, treatment, and outcome of this unique group of patients will be reviewed. © 2008 Wiley‐Liss, Inc.
Oxidative Homolysis of a Nitrosylchromium Complex
Authors: Song Wenjing , Bakac Andreja
Published: April 2008

Metal(III)–polypyridine complexes [M(NN)3]3+ (M=Ru or Fe; NN=bipyridine (bpy), phenanthroline (phen), or 4,7‐dimethylphenanthroline (Me2‐phen)) oxidize the nitrosylpentaaquachromium(III) ion, [CraqNO]2+, with an overall 4:1 stoichiometry, 4 [Ru(bpy)3]3++[CraqNO]2++2 H2O→4 [Ru(bpy)3]2++[Craq]3++NO3−+4 H+. The kinetics follow a mixed second‐order rate law, −d[[M(NN)3]3+]/dt=nk[[M(NN)3]3+][[CraqNO]2+], in which k represents the rate constant for the initial one‐electron transfer step, and n=2–4 depending on reaction conditions and relative rates of the first and subsequent steps. With [CraqNO]2+ in excess, the values of nk are 283 M−1 s−1 ([Ru(bpy)3]3+), 7.4 ([Ru(Me2‐phen)3]3+), and 5.8 ([Fe(phen)3]3+). In the proposed mechanism, the one‐electron oxidation of [CraqNO]2+ releases NO, which is further oxidized to nitrite, k=1.04×106 M−1 s−1, 6.17×104, and 1.12×104 with the three respective oxidants. Further oxidation yields the observed nitrate. The kinetics of the first step show a strong correlation with thermodynamic driving force. Parallels were drawn with oxidative homolysis of a superoxochromium(III) ion, [CraqOO]2+, to gain insight into relative oxidizability of coordinated NO and O2, and to address the question of the “oxidation state” of coordinated NO in [CraqNO]2+.
On the Way to Selective PARP‐2 Inhibitors. Design, Synthesis, and Preliminary Evaluation of a Series of Isoquinolinone Derivatives
Authors: Pellicciari Roberto , Camaioni Emidio , Costantino Gabriele , Formentini Laura , Sabbatini Paola , Venturoni Francesco , Eren Gökçen , Bellocchi Daniele , Chiarugi Alberto , Moroni Flavio
Published: April 2008

PARP‐1 and PARP‐2 are members of the family of poly(ADP‐ribose)polymerases, which are involved in the maintenance of genomic integrity under conditions of genotoxic stimuli. The different roles of the two isoforms under pathophysiological conditions have not yet been fully clarified, and this is partially due to the lack of selective inhibitors. We report herein the synthesis and preliminary pharmacological evaluation of a large series of isoquinolinone derivatives as PARP‐1/PARP‐2 inhibitors. Among them, we identified the 5‐benzoyloxyisoquinolin‐1(2 H)‐one derivative as the most selective PARP‐2 inhibitor reported so far, with a PARP‐2/PARP‐1 selectivity index greater than 60.
Competitive Activation of CH and CX Bonds in Reactions of Pt+ with CH3X (X=F,Cl): Experiment and Theory
Authors: Zhao Xiang , Hopkinson Alan C. , Bohme Diethard K.
Published: April 2008

The reactions of Pt+ with CH3X (X=F, Cl) are studied experimentally by employing an inductively coupled plasma/selected‐ion flow tube tandem mass spectrometer and theoretically by density functional theory. Dehydrogenation and HX elimination are found to be the primary reaction channels in the remarkably different ratios of 95:5 and 60:40 in the fast reactions of Pt+ with CH3F and CH3Cl, respectively. The observed kinetics are consistent with quantum chemistry calculations, which indicate that both channels in the reaction with CH3F are exothermic with ground‐state Pt+(2D), but that HF elimination is prohibited kinetically because of a transition state that lies above the reactant entrance. The observed HF‐elimination channel is attributed to a slow reaction of CH3F with excited‐state Pt+(4F) for which calculations predict a small barrier. The calculations also show that both the HCl‐elimination and dehydrogenation channels observed with CH3Cl are thermodynamically and kinetically allowed, although the state‐specific product distributions could not be ascertained experimentally. Further CH3F addition is observed with the primary products to produce PtCH2+(CH3F)1,2 and PtCHF+(CH3F)1,2. With CH3Cl, sequential HCl elimination is observed with PtCH2+ to form PtCnH2n+ with n=2, 3, which then add CH3Cl sequentially to form PtC2H4+(CH3Cl)1–3 and PtC3H6+(CH3Cl)1,2. Also, sequential addition is observed for PtCHCl+ to form PtCHCl+(CH3Cl)1,2.
Understanding the Supramolecular Self‐Assembly of the Fullerene Derivative PCBM on Gold Surfaces
Authors: Wang Yang , Alcamí Manuel , Martín Fernando
Published: April 2008

We report a DFT study on the self‐assembly of the fullerene derivative PCBM on the Au(111) surface. Recent STM experiments (Angew. Chem. 2007, 119, 8020–8023[1]) show a coverage‐dependent transition of the adsorption and self‐assembly of PCBM on this surface. To understand the origin of this observation, we compute the geometries and relative energies of ten PCBM dimers and four tetramers. The calculations show that the self‐assembly of PCBM at high coverage is mainly controlled by hydrogen bonding between the PCBM tails. Due to the large size of the fullerene cage, the hydrogen bonds are formed far away from the surface; hence they are very similar to those found in the gas phase. This picture successfully explains the observed site‐insensitive adsorption at high coverage and the 2D arrangement of PCBM on the surface.
Syntheses, Characterization and Catalytic Application of Palladacycles Containing Phosphane or Phosphane Oxide Functionalities
Authors: Peng Kuo‐Fu , Chen Ming‐Tsz , Huang Chi‐An , Chen Chi‐Tien
Published: April 2008

The preparation of ligand precursors PhN=C(CMe2)(NPh)C=N(CH2)2PPh2 (1) and PhN=C(CMe2)(NPh)C=N(CH2)2P(O)Ph2 (2) are described. Treatment of 1 or 2 with 1 mol equiv. Pd(OAc)2 affords orthometallated palladium(II) complexes [PhN=C(CMe2)(N‐η1‐Ph)C=N(CH2)2PPh2]Pd(OAc) (3) as a mononuclear complex or {[PhN=C(CMe2)(N‐η1‐Ph)C=N(CH2)2P(O)Ph2]Pd(OAc)}2 (4) as an acetate‐bridged dinuclear complex, respectively. Reaction of 3 with excess LiCl in methanol affords a mononuclear palladium(II) complex [PhN=C(CMe2)(N‐η1‐Ph)C=N(CH2)2PPh2]PdCl (5). The crystal and molecular structures are reported for compounds 3–5. Application of these novel palladacyclic complexes to the Suzuki and Heck reactions with aryl halide substrates was examined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)