bluuebunny/crossref_metadata_2025 huggingface dataset:
Piano cycles of Italian composers of the late 19th – first half of the 20th century: on the problem of programming.
Authors: Maidanevich Tamara Leonidovna
Published: April 2024

The object of study in this article is the piano work of Italian composers of the late 19th – first half of the 20th centuries. The subject is programming in instrumental music, represented by the genre of the piano cycle. Based on the definition of programming and the classification of types, developed in the works of domestic musicologists M. Aranovsky, L. Kazantseva, Yu. Khokhlova, the author reveals the features of its implementation in the cycles of famous Italian composers F. Busoni, J. Malipiero, A. Casella, M. Castelnuovo-Tedesco, created during the historical period under study. Particular attention is paid to considering the issue of continuing the tradition of embodying programming in cycles, established by romantic composers, as well as identifying national features characteristic of Italian art as a whole. The article uses an integrated approach, including systemic-historical and comparative methods of analysis. The author also turned to the method of musical theoretical analysis. The novelty of the research lies in the development of one of the important and relevant areas of musicology associated with the synthesis of arts, within the framework of solving a specific problem: the implementation of various types of programming. The author’s special contribution to the development of this topic is the introduction into scientific circulation of new works of Italian masters that have not previously been studied, the consideration, using their example, of various types of programming in close connection with the tradition that has developed in European art, and the identification of ways to update it. The most important feature is the integrity of the cycles, which is formed at the emotional, figurative, stylistic, compositional, and tonal levels. A conclusion is drawn about the originality of the piano cycles of Italian composers, which is manifested in close connection with national art.
Do managers “feel” the group? Managers’ autonomic responses during a creative task
Authors: Balconi Michela , Angioletti Laura
Published: April 2024

This study aimed at assessing the psychophysiological correlates of managers, compared to a group of non-managers, during a creative problem-solving dynamic through the use of a psychophysiological method exploiting autonomic measures data collection. Individuals performed a realistic complex problem-solving task (RCPT), a modified version of the NASA Moon survival problem exercise, in two distinct conditions: individually or in groups of three participants. Two main patterns of findings were observed, specifically, for the managers’ group: first, electrodermal activity and cardiac variability indices increased during the group compared to individual condition; second, cardiovascular indices decreased in the above-mentioned condition. No statistically significant results were observed for the non-managers group. Results suggest that managers could be able to “feel”, even at a deeper and psycho-physiological level, which social condition (in this case, the group one) is more suitable for solving a complex problem in a creative way.
Investigating the impact of mindful breathing meditation on brain waves: a study on young adults
Authors: Vimal Cruz Meenalosini , Jamal Suhaima , Wahl Camden , Chakkaravarthy Sethuraman Sibi
Published: April 2024

Extensive evidence affirms meditation’s impact on both physical and mental well-being, consistently highlighting increased alpha power during meditation. This study investigates how mindful breathing meditation affects brain waves in young adults, using EEG data from 15 participants. Focusing on boosting alpha wave power, the study shows a significant postmeditation increase. Data was processed with Finite Impulse Filters, Independent Component Analysis, Short-term Fourier analysis, and power spectral density analysis. The results highlight substantial alpha wave changes pre- and post-meditation. Additionally, data was preprocessed for machine learning-based classifiers (Support Vector Machine, Logistic Regression, Decision Forest, and Naïve Bayes) to categorize brain waves into Delta, Theta, Low Alpha, High Alpha, Low Beta, and High Beta. Comparative analysis reveals the strong impact of mindful breathing meditation and binaural beats on brain wave patterns. This research enhances our understanding of meditation’s physiological effects on brain function, emphasizing its potential for improving mental well-being.
Inhibitory G proteins play multiple roles to polarize sensory hair cell morphogenesis
Authors: Jarysta Amandine , Tadenev Abigail L.D. , Day Matthew , Krawchuk Barry , Low Benjamin E. , Wiles Michael V. , Tarchini Basile
Published: April 2024

Inhibitory G alpha (GNAI or Gαi) proteins are critical for the polarized morphogenesis of sensory hair cells and for hearing. The extent and nature of their actual contributions remains unclear, however, as previous studies did not investigate all GNAI proteins and included non-physiological approaches. Pertussis toxin can downregulate functionally redundant GNAI1, GNAI2, GNAI3 and GNAO proteins, but may also induce unrelated defects. Here we directly and systematically determine the role(s) of each individual GNAI protein in mouse auditory hair cells. GNAI2 and GNAI3 are similarly polarized at the hair cell apex with their binding partner GPSM2, whereas GNAI1 and GNAO are not detected. In Gnai3 mutants, GNAI2 progressively fails to fully occupy the subcellular compartments where GNAI3 is missing. In contrast, GNAI3 can fully compensate for the loss of GNAI2 and is essential for hair bundle morphogenesis and auditory function. Simultaneous inactivation of Gnai2 and Gnai3 recapitulates for the first time two distinct types of defects only observed so far with pertussis toxin: 1) a delay or failure of the basal body to migrate off-center in prospective hair cells, and 2) a reversal in the orientation of some hair cell types. We conclude that GNAI proteins are critical for hair cells to break planar symmetry and to orient properly before GNAI2/3 regulate hair bundle morphogenesis with GPSM2.
ROCK and the actomyosin network control biomineral growth and morphology during sea urchin skeletogenesis
Authors: Hijaze Eman , Gildor Tsvia , Seidel Ronald , Layous Majed , Winter Mark , Bertinetti Luca , Politi Yael , Ben-Tabou de-Leon Smadar
Published: April 2024

Biomineralization had apparently evolved independently in different phyla, using distinct minerals, organic scaffolds, and gene regulatory networks (GRNs). However, diverse eukaryotes from unicellular organisms, through echinoderms to vertebrates, use the actomyosin network during biomineralization. Specifically, the actomyosin remodeling protein, Rho-associated coiled-coil kinase (ROCK) regulates cell differentiation and gene expression in vertebrates’ biomineralizing cells, yet, little is known on ROCK’s role in invertebrates’ biomineralization. Here, we reveal that ROCK controls the formation, growth, and morphology of the calcite spicules in the sea urchin larva. ROCK expression is elevated in the sea urchin skeletogenic cells downstream of the Vascular Endothelial Growth Factor (VEGF) signaling. ROCK inhibition leads to skeletal loss and disrupts skeletogenic gene expression. ROCK inhibition after spicule formation reduces the spicule elongation rate and induces ectopic spicule branching. Similar skeletogenic phenotypes are observed when ROCK is inhibited in a skeletogenic cell culture, indicating that these phenotypes are due to ROCK activity specifically in the skeletogenic cells. Reduced skeletal growth and enhanced branching are also observed under direct perturbations of the actomyosin network. We propose that ROCK and the actomyosin machinery were employed independently, downstream of distinct GRNs, to regulate biomineral growth and morphology in Eukaryotes.
STAT3 is a genetic modifier of TGF-beta induced EMT in KRAS mutant pancreatic cancer
Authors: D'Amico Stephen , Kirillov Varvara , Petrenko Oleksi , Reich Nancy C
Published: April 2024

Oncogenic mutations in KRAS are among the most common in cancer. Classical models suggest that loss of epithelial characteristics and the acquisition of mesenchymal traits are associated with cancer aggressiveness and therapy resistance. However, the mechanistic link between these phenotypes and mutant KRAS biology remains to be established. Here, we identify STAT3 as a genetic modifier of TGF-beta-induced epithelial to mesenchymal transition. Gene expression profiling of pancreatic cancer cells identifies more than 200 genes commonly regulated by STAT3 and oncogenic KRAS. Functional classification of the STAT3-responsive program reveals its major role in tumor maintenance and epithelial homeostasis. The signatures of STAT3-activated cell states can be projected onto human KRAS mutant tumors, suggesting that they faithfully reflect characteristics of human disease. These observations have implications for therapeutic intervention and tumor aggressiveness.
Transcriptome-wide analysis of the function of Ded1 in translation preinitiation complex assembly in a reconstituted in vitro system
Authors: Zhou Fujun , Bocetti Julie M , Hou Meizhen , Qin Daoming , Hinnebusch Alan G , Lorsch Jon R
Published: April 2024

We have developed a deep sequencing-based approach, Rec-Seq, that allows simultaneous monitoring of ribosomal 48S preinitiation complex (PIC) formation on every mRNA in the translatome in an in vitro reconstituted system. Rec-Seq isolates key early steps in translation initiation in the absence of all other cellular components and processes. Using this approach, we show that the DEAD-box ATPase Ded1 promotes 48S PIC formation on the start codons of >1000 native mRNAs, most of which have long, structured 5′-untranslated regions (5′UTRs). Remarkably, initiation measured in Rec-Seq was enhanced by Ded1 for most mRNAs previously shown to be highly Ded1-dependent by ribosome profiling of ded1 mutants in vivo, demonstrating that the core translation functions of the factor are recapitulated in the purified system. Our data do not support a model in which Ded1acts by reducing initiation at alternative start codons in 5′UTRs and instead indicate it functions by directly promoting mRNA recruitment to the 43S PIC and scanning to locate the main start codon. We also provide evidence that eIF4A, another essential DEAD-box initiation factor, is required for efficient PIC assembly on almost all mRNAs, regardless of their structural complexity, in contrast to the preferential stimulation by Ded1 of initiation on mRNAs with long, structured 5′UTRs.
Activating SRC/MAPK signaling via 5-HT1A receptor contributes to the effect of vilazodone on improving thrombocytopenia
Authors: Zhou Ling , Ni Chengyang , Liao Ruixue , Tang Xiaoqin , Yi Taian , Ran Mei , Huang Miao , Liao Rui , Zhou Xiaogang , Qin Dalian , Wang Long , Huang Feihong , Xie Xiang , Wan Ying , Luo Jiesi , Wang Yiwei , Wu Jianming
Published: April 2024

Thrombocytopenia caused by long-term radiotherapy and chemotherapy exists in cancer treatment. Previous research demonstrates that 5-Hydroxtrayptamine (5-HT) and its receptors induce the formation of megakaryocytes (MKs) and platelets. However, the relationships between 5-HT1A receptor (5-HTR1A) and MKs is unclear so far. We screened and investigated the mechanism of vilazodone as a 5-HTR1A partial agonist in promoting MK differentiation and evaluated its therapeutic effect in thrombocytopenia. We employed a drug screening model based on machine learning (ML) to screen the megakaryocytopoiesis activity of Vilazodone (VLZ). The effects of VLZ on megakaryocytopoiesis were verified in HEL and Meg-01 cells. Tg (itga2b: eGFP) zebrafish was performed to analyze the alterations in thrombopoiesis. Moreover, we established a thrombocytopenia mice model to investigate how VLZ administration accelerates platelet recovery and function. We carried out network pharmacology, Western blot, and immunofluorescence to demonstrate the potential targets and pathway of VLZ. VLZ has been predicted to have a potential biological action. Meanwhile, VLZ administration promotes MK differentiation and thrombopoiesis in cells and zebrafish models. Progressive experiments showed that VLZ has a potential therapeutic effect on radiation-induced thrombocytopenia in vivo. The network pharmacology and associated mechanism study indicated that SRC and MAPK signaling are both involved in the processes of megakaryopoiesis facilitated by VLZ. Furthermore, the expression of 5-HTR1A during megakaryocyte differentiation is closely related to the activation of SRC and MAPK. Our findings demonstrated that the expression of 5-HTR1A on MK, VLZ could bind to the 5-HTR1A receptor and further regulate the SRC/MAPK signaling pathway to facilitate megakaryocyte differentiation and platelet production, which provides new insights into the alternative therapeutic options for thrombocytopenia.
Cardiovascular Drugs
Authors: Kleemann Axel
Published: January 2008

The article contains sections titled:

1.General Survey2.Adrenergic blockers, peripheral3.Adrenergic stimulants, central4.Angiotensin Converting Enzyme (ACE) Inhibitors5.Angiotensin II Receptor Antagonists6.Antiarrhythmics6.1.Class I Antiarrhythmics6.2.Class II Antiarrhythmics6.3.Class III Antiarrhythmics6.4.Class IV Antiarrhythmics7.Anticoagulants7.1.Synthetic Anticoagulants7.2.Heparin and Low Molecular Weight Heparins (LMWHs)8.Antiplatelet Drugs9.Antilipidemic Agents (Lipid Regulating Drugs)9.1.Bile Acid Sequestrants9.2.Cholesterol Absorption Inhibitors9.3.Fibrates (Fibric Acid Derivatives)9.4.Nicotinic Acid and Derivatives9.5.HMG‐CoA Reductase Inhibitors (Statins)10.β‐Adrenergic Blocking Agents11.Calcium Channel Blockers (Calcium Antagonists)12.Diuretics12.1.Carbonic Anhydrase Inhibitors12.2.Loop Diuretics (High‐Ceiling Diuretics)12.3.Potassium‐Sparing Diuretics (Antikaliuretic Agents)12.4.Thiazides and Related Diuretics13.Cardiac Glycosides (Positive Cardiac Inotropes)14.Endothelin Receptor Antagonists15.Vasodilators15.1.Nitrates15.2.Direct‐Acting Vasodilators15.3.Other Vasodilators16.Vasopressors (Sympathomimetics)References
Estimation of Physical Properties
Authors: Onken Ulfert , Fischer Kai , Rarey Jürgen , Kleiber Michael
Published: January 2008

The article contains sections titled:

1.Introduction1.1.Scope1.2.Data Sources1.3.Theoretical and Empirical Methods2.Molecular and Macroscopic Properties2.1.Intermolecular Forces2.2.Theorem of Corresponding States2.3.Estimation of Critical Properties2.4.Other Characteristic Constants of Pure Compounds3.Thermal and Caloric Properties of Single‐Phase Systems3.1.Pressure–Volume–Temperature Behavior of Gases and Liquids3.1.1.Pure Gases3.1.2.Pure Liquids3.1.3.Mixtures3.1.3.1.Gas Mixtures3.1.3.2.Liquid Mixtures3.2.Caloric Properties3.2.1.Heat Capacity of Ideal Gases3.2.2.Heat Capacity of Pure Liquids3.2.3.Heat Capacity of Liquid Mixtures4.Phase Equilibria4.1.Pure Compounds4.1.1.Vapor Pressure, Boiling Point, and Melting Point4.1.2.Enthalpy of Vaporization4.2.Mixtures4.2.1.Vapor–Liquid Equilibria with Liquid‐Phase Activity Coefficients4.2.1.1.Basic Considerations4.2.1.2.Data Correlation: Binary and Multicomponent Mixtures of Nonelectrolytes4.2.1.3.Prediction of Equilibrium Data4.2.2.Vapor–Liquid and Gas–Liquid Equilibria with Equations of State4.2.2.1.Basic Considerations4.2.2.2.Data Correlation4.2.2.3.Prediction of Vapor‐Liquid and Gas‐Liquid Equilibria4.2.3.Liquid–Liquid Equilibria4.2.4.Solid–Liquid Equilibria5.Thermodynamic Data of Chemical Reactions5.1.Definitions5.1.1.Enthalpy of Reaction5.1.2.Gibbs Energy of Reaction and Chemical Equilibrium5.2.Group Contribution Methods for the Estimation of Enthalpy and Gibbs Energy of Formation5.3.Applications5.3.1.Enthalpy of Reaction5.3.2.Chemical Equilibrium6.Transport Properties of Pure Compounds and Mixtures6.1.Viscosity6.1.1.Viscosity of Pure Gases6.1.2.Viscosity of Gas Mixtures6.1.3.Viscosity of Pure Liquids6.1.4.Viscosity of Liquid Mixtures6.2.Thermal Conductivity6.2.1.Thermal Conductivity of Gases at Low Pressure6.2.2.Thermal Conductivity of Gases at High Pressure6.2.3.Thermal Conductivity of Gas Mixtures6.2.4.Thermal Conductivity of Liquids6.2.5.Thermal Conductivity of Liquid Mixtures6.3.Diffusion Coefficients6.3.1.Diffusion Coefficients of Gases at Low and Moderate Pressures6.3.2.Diffusion Coefficients of Liquids7.Surface Tension of Liquids7.1.Surface Tension of Pure Liquids7.2.Surface Tension of Liquid Mixtures
Reactive Distillation
Authors: Sakuth Michael , Reusch Dieter , Janowsky Ralf
Published: January 2008

The article contains sections titled:

1.Introduction2.Mathematical Modeling of Reactive Distillation Processes2.1.Equilibrium‐Based Models2.2.Rate‐Based Models3.Design of Reactive Distillation Processes3.1.Procedures for Process Design Studies3.2.Flow sheet for Process Development4.Industrial Applications4.1.Commercial Packing Structures4.2.Industrial Catalytic Distillation Processes
Concrete
Authors: Kropp Jörg
Published: January 2008

The article contains sections titled:

1.

Introduction

2.

Materials

2.1.

Cement

2.2.

Aggregates

2.3.

Water

2.4.

Admixtures

2.4.1.

Setting and Hardening Admixtures

2.4.2.

Workability Admixtures

2.4.3.

Porosity Admixtures

2.4.4.

Other Admixtures

2.4.5.

Fine‐grained Material and Polymers

3.

Production

3.1.

Definition of Concrete Properties

3.2.

Proportioning of Materials

3.3.

Production Process

4.

Fresh Concrete

4.1.

Workability

4.2.

Placement, Consolidation, and Finish

4.3.

Curing

4.4.

Special Methods

5.

Mechanical Properties

5.1.

Crack Development

5.2.

Strength

5.2.1.

Compressive Strength

5.2.2.

Tensile Strength

5.2.3.

Fracture Mechanics

5.3.

Deformation Characteristics

5.3.1.

Relationship of Stress to Strain

5.3.2.

Modulus of Elasticity and Poisson's Ratio

5.3.3.

Creep

5.3.4.

Shrinkage and Swelling

6.

Physical Properties

6.1.

Density

6.2.

Porosity

6.3.

Thermal Conductivity

6.4.

Electrical Conductivity

6.5.

Permeability

6.6.

Thermal Expansion

6.7.

Shielding Properties

7.

Durability

7.1.

Chemical Attack

7.2.

Physical Attack

7.3.

Corrosion of the Reinforcement

8.

Special Concretes

8.1.

Lightweight Concrete

8.2.

Heavyweight Concrete

8.3.

Massive Concrete

8.4.

Fiber‐Reinforced Concrete

8.5.

Polymer Concrete

9.

Mortar

Concrete is an artificial building material composed of granular aggregates embedded in a binder matrix of hydrated cement. Minor constituents can be added to improve the performance of concrete in the fresh or hardened state. Aside from plain concrete structures, concrete is reinforced with steel bars or prestressing steel tendons to withstand bending or tension forces. The assessment of environmental compatibility of cement in concrete or mortar considers all the phases of its life cycle. The mix design of concrete must take into account all requirements specified for the fresh and hardened concrete in a given application. Basic considerations as well as procedures are presented, test methods are described, and the properties of concrete are discussed. For the long‐term performance of concrete, the interactions with the environment by physical and chemical actions are discussed. Concluding sections deal with special types of concrete.
Bacteriorhodopsin, Chemistry of
Authors: Lanyi Janos K.
Published: January 2008

Thirty years of research with bacteriorhodopsin has provided answers to many questions about how protons are transported by transmembrane pumps. In this small seven‐transmembrane protein, absorption of light by the retinal chromophore initiates a reaction cycle in which the initial state recovers through multiple conformational changes of the retinal and the protein, and a proton is translocated stepwise from one side of the membrane to the other. Spectroscopy, extensive use of site‐specific mutations, and crystallography have defined the photocycle reactions in atomic detail and provide a step‐by‐step description of the proton transfers, the transient local and global perturbations in the protein and how they arise, and the energy flow through the system, which add up to the mechanism of the pump.
Nucleic Acid Enzymes (Ribozymes and Deoxyribozymes): In Vitro Selection and Application
Authors: Silverman Scott K.
Published: January 2008

Natural catalysts composed of RNA were discovered in the early 1980s. After this advance, it was logical to consider that artificial nucleic acid enzymes made from either RNA or DNA could be developed by recapitulating the basic evolutionary principles in the laboratory. In subsequent years, many artificial ribozymes and deoxyribozymes have indeed been identified by
in vitro
selection, and the scope of nucleic acid catalysis now encompasses a much wider range of chemical reactions than is found in nature. The study of artificial ribozymes and deoxyribozymes can provide fundamental insight into the functioning of natural catalytic nucleic acids. In addition, artificial nucleic acid enzymes are increasingly used in practical applications ranging from analytical chemistry to biology.
Enzyme Catalysis
Authors: Bommarius Andreas Sebastian , Riebel Bettina R.
Published: January 2008

Orginally published in: Biocatalysis. Andreas Sebastian Bommarius and Bettina R. Riebel. Copyright © 2004 Wiley‐VCH Verlag GmbH & Co. KGaA Weinheim. Print ISBN: 3‐527‐30344‐1

The sections in this article are

Introduction

Characterization of Enzyme Catalysis

Basis of the Activity of Enzymes: What is Enzyme Catalysis?

Enzyme Reaction in a Reaction Coordinate Diagram

Development of Enzyme Kinetics from Binding and Catalysis

Sources and Reasons for the Activity of Enzymes as Catalysts

Chronology of the Most Important Theories of Enzyme Activity

Origin of Enzymatic Activity: Derivation of the Kurz Equation

Consequences of the Kurz Equation

Efficiency of Enzyme Catalysis: Beyond Pauling's Postulate

Performance Criteria for Catalysts, Processes, and Process Routes

Basic Performance Criteria for a Catalyst: Activity, Selectivity and Stability of Enzymes

Activity

Selectivity

Stability

Performance Criteria for the Process

Product Yield

(Bio)catalyst Productivity

(Bio)catalyst Stability

Reactor Productivity

Links between Enzyme Reaction Performance Parameters

Rate Acceleration

Ratio between Catalytic Constantkcatand Deactivation Rate Constantkd

Relationship between Deactivation Rate Constantkdand Total Turnover Number TTN

Performance Criteria for Process Schemes, Atom Economy, and Environmental Quotient
Catechol‐O‐methyltransferase Val158Met polymorphism is associated with methylphenidate response in ADHD children
Authors: Kereszturi Eva , Tarnok Zsanett , Bognar Emese , Lakatos Krisztina , Farkas Luca , Gadoros Julia , Sasvari‐Szekely Maria , Nemoda Zsofia
Published: January 2008

Methylphenidate is the most frequently prescribed drug in the treatment of attention deficit hyperactivity disorder (ADHD) but it is not effective in every case. Therefore, identifying genetic and/or biological markers predicting drug‐response is increasingly important. Here we present a case‐control study and pharmacogenetic association analyses in ADHD investigating three dopaminergic polymorphisms. Previous studies suggested variable number of tandem repeats (VNTR) in the dopamine D4 receptor (DRD4) and the dopamine transporter (DAT1) genes as genetic risk factors for ADHD and as possible markers of methylphenidate response. Our results did not indicate substantial involvement of these two VNTRs in ADHD, however, both the case‐control and the pharmacogenetic analyses showed significant role of the high activity Val‐allele of cathecol‐O‐methyltransferase (COMT) Val158Met polymorphism in our ADHD population. The Val‐allele was more frequent in the ADHD group (n = 173) compared to the healthy population (P = 0.016). The categorical analysis of 90 responders versus 32 non‐responders showed an association between the Val‐allele or Val/Val genotype and good methylphenidate response (P = 0.009 and P = 0.034, respectively). Analyzing symptom severity as a continuous trait, significant interaction of COMT genotype and methylphenidate was found on the Hyperactivity‐Impulsivity scale (P = 0.044). Symptom severity scores of all three genotype groups decreased following methylphenidate administration (P < 0.001), however Val/Val homozygote children had significantly less severe symptoms than those with Met/Met genotype after treatment (P = 0.015). This interaction might reflect the regulatory effect of COMT dominated prefrontal dopamine transmission on subcortical dopamine systems, which are the actual site of methylphenidate action. © 2008 Wiley‐Liss, Inc.
Synthesis and characterization of some diorganotin(IV) complexes of Schiff bases derived from a non‐protein amino acid. Crystal structures of {HO2CC6H4[NC(H)}{C(CH3)CH(CH3)‐3‐OH]‐p} and its di‐n‐butyltin(IV) complex (nBu2Sn{O2CC6H4[NC(H)}{C(CH3)CH(CH3)‐3‐OH]‐p}2)
Authors: Basu Baul Tushar S. , Masharing Cheerfulman , Basu Smita , Pettinari Claudio , Rivarola Eleonora , Chantrapromma Suchada , Fun Hoong‐Kun
Published: January 2008

Diorganotin(IV) complexes R2Sn(LH)2 (R = Me, nBu) and {[nBu2Sn(LH)]2O}2 (LH = 4‐[(2Z)‐(3‐hydroxy‐1‐methyl‐2‐butenylidene)amino]benzoate and 4‐[{(E)‐1‐(2‐hydroxyphenyl)methylidene}mino]benzoate) have been reported. The complexes were characterized by elemental analysis, IR, NMR (1H, 13C, 119Sn) and 119mSn Mössbauer spectroscopy. Crystal structures of a ligand {HO2CC6H4[NC(H)}{C(CH3)CH(CH3)‐3‐OH]‐p} and one of its di‐n‐butyltin(IV) complexes (nBu2Sn{O2CC6H4[NC(H)}{C(CH3)CH(CH3)‐3‐OH]‐p}2) were determined. The spectroscopic data suggest that R2Sn(LH)2 complexes have skew‐trapezoidal bipyramidal structure while {[nBu2Sn(LH)]2O}2 complexes adopt a dimeric tetraorganodistannoxane structure in the solid state and undergo complex exchange processes in deuterochloroform solution, as revealed by 119Sn NMR spectroscopy. Copyright © 2008 John Wiley & Sons, Ltd.
Suzuki cross‐coupling reaction of aryl and heterocyclic bromides and aromatic polybromides on a Pd(II)‐hydrotalcite catalyst
Authors: Mora Manuel , Jiménez‐Sanchidrián César , Ruiz José Rafael
Published: January 2008

The Suzuki cross‐coupling reaction of various bromine‐containing substrates and phenylboronic acid in toluene at 90 °C on a Pd(AcO)2Py2 catalyst supported on an MgAl hydrotalcite, using K2CO3 as the base, was studied. The conversion and selectivity results obtained for many of the substrates were excellent and similar to those provided by more active or even homogeneous catalysts. The reactions of aryl polybromides and phenylboronic acid gave the corresponding polyaromatic compounds in variable yields depending on the particular substrate. Arylation occurred in a consecutive manner by substitution of the different Br atoms. ICP‐MS measurements of the palladium content of the catalyst performed prior to and after the reaction revealed that part of the metal is incorporated into the bulk solution; therefore, the catalytic process is not purely heterogeneous. Copyright © 2008 John Wiley & Sons, Ltd.
Stereospecific synthesis of a family of novel (E)‐2‐aryl‐1‐silylalka‐1,4‐dienes or (E)‐4‐aryl‐5‐silylpenta‐1,2,4‐trienes via a cross‐coupling of (Z)‐silyl(stannyl)ethenes with allyl halides or propargyl bromide
Authors: Sasaki Fumio , Endo Takanori , Noguchi Masanori , Kawai Kenji , Nakano Taichi
Published: January 2008

Stereospecific synthesis of a family of novel (E)‐2‐aryl‐1‐silylalka‐1,4‐dienes or (E)‐4‐aryl‐5‐silylpenta‐1,2,4‐trienes via a cross‐coupling of (Z)‐silyl(stannyl)ethenes with allyl halides or propargyl bromide is described. In the reaction with allyl bromide, either a Pd(dba)2CuI combination (dba, dibenzylideneacetone) in DMF or copper(I) iodide in DMSO–THF readily catalyzes or mediates the coupling reaction of (Z)‐silyl(stannyl)ethenes at room temperature, producing novel vinylsilanes bearing an allyl group β to silicon with cis‐disposition in good yields. Allyl chlorides as halides can be used in the CuI‐mediated reaction. CuI alone much more effectively mediates the cross‐coupling reaction with propargyl bromide in DMSO–THF at room temperature compared with a Pd(dba)2CuI combination catalysis in DMF, providing novel stereodefined vinylsilanes bearing an allenyl group β to silicon with cis‐disposition in good yields. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of hydrodynamics, interface capillarity and molecular kinetics on wetting and de‐wetting on small cylindrical surfaces
Authors: Karakashev Stoyan I. , Nguyen Anh V.
Published: January 2008

Wetting and de‐wetting phenomena control many natural and industrial processes. Both statics and dynamics of wetting and de‐wetting are still a subject of intensive research. This article presents a novel modelling approach combined with experimental validation for the wetting and de‐wetting processes taking place on small cylindrical surfaces, such as wires being vertically withdrawn from a pool of liquid under steady flow conditions and slow withdrawal velocity. In particular, both the contact hydrodynamics and interface molecular kinetics are combined to predict the gas‐liquid interface deformation, the dynamic contact angle, and the moving contact line. The nonlinear equations governing the meniscus deformation and molecular kinetics at the moving surface are numerically solved. The outcome of this study is directly relevant to a number of industrial applications, including metallurgical coating of wires. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Effect of solvent induced hydroxylation of cyanoethyl group on dye uptake of cotton fabrics
Authors: Subha A. Selva , Thambidurai S.
Published: January 2008

The present investigation deals with the dyeing behavior of solvent induced cyanoethylated cotton fabric. The modified cotton fabric was dyed by conventional method with commercial reactive dye (Drimarene Red). It is observed that acetone induced cyanoethylated samples exhibit higher color values than ethanol treated samples. The effect of nitrogen content on the dye uptake of modified fabric is assessed which shows a good correlation between them. It is obvious that crystallinity has a noticeable effect on the dye uptake of both solvent modified fabrics. For convenience and comparison, a set of samples are also dyed without addition of salt, alkali, and both. It is evident that even without addition of salt, alkali and both the samples exhibit a significant dye uptake. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Fibroin membrane preparation and stabilization by polyethylene glycol diglycidyl ether
Authors: Moonsri Piyarut , Watanesk Ruangsri , Watanesk Surasak , Niamsup Hataichanoke , Deming Richard L.
Published: January 2008

Membranes prepared by drying aqueous Bombyx mori silk fibroin (SF) solution and modified silk fibroin (MSF) solutions, prepared by adding the low molecular weight crosslinking agent, polyethylene glycol diglycidyl ether (PEGDE) MW 526, 0–10% w/w, were investigated by Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, and UV–vis spectroscopy. Weight gain in aqueous solutions and their mechanical properties (tensile strength, elongation, and Young's modulus) were then characterized. SEM measurements revealed greater porosity in MSF membranes. IR spectra showed transformation from the largely α‐helical/random coil structures in SF membranes to predominantly β‐sheet in MSF membranes. Results from UV–vis spectroscopy showed that the MSF membranes were largely insoluble within the pH range of 4–10. Water absorbability of the MSF membranes improved with increasing the amounts of cross‐linker, up to 4%. The MSF membranes showed greater pliability and tenacity, but lower tensile strength, with increasing PEGDE concentrations. In the wet condition, PEGDE levels up to 4% can improve both tensile strength and tenacity of the MSF membrane, but higher levels (up to 10%) did not significantly change these properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Solubility and diffusivity measurements in nitrogen–poly(vinyl acetate) and nitrogen–toluene–poly(vinyl acetate) systems with the differential pressure decay technique
Authors: Pourdarvish Reza , Danner Ronald P. , Duda J. Larry
Published: January 2008

In creating thin films of polymers by solution processing, a common problem is the undesirable formation of bubbles during the drying process. Practical experience shows that bubbles can be created well below the boiling point of the solvent. Also, it has been observed that the degassing of the polymer solutions results in reduced bubble formation, and this indicates a relationship between the presence of air and bubble formation. This work is based on the hypothesis that if the solubility of air in the polymer solution increases with the solvent concentration, then the solution can become supersaturated with air as the concentration of the solvent is reduced during the drying process. To test this hypothesis, knowledge of the thermodynamics of the mixture is required. This study concentrated on the system of poly(vinyl acetate), toluene, and nitrogen. A thermodynamic model to predict phase behavior of this system was developed. The solubility of nitrogen in poly(vinyl acetate) and poly(vinyl acetate)–toluene as a function of the toluene composition over wide ranges of temperatures and pressures was measured with the pressure decay technique. The group‐contribution lattice–fluid equation of state was employed to correlate the thermodynamic behavior of the binary and ternary systems. In addition, experiments were conducted to measure the diffusion coefficients of the nitrogen in poly(vinyl acetate). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
A formaldehyde‐free flame retardant wood particleboard system based on two‐component polyurethane adhesive
Authors: Tang Yong , Wang De‐Yi , Jing Xin‐Ke , Ge Xin‐Guo , Yang Bing , Wang Yu‐Zhong
Published: January 2008

To address the problem of formaldehyde‐free flame retardation of wood particleboard, a novel phosphorus‐containing compound, di(2,2‐dimethyl‐1,3‐propanediol phosphate) urea (DDPPU) was synthesized. DDPPU was used as flame retardant for wood particleboard. The flammability of treated wood particleboard systems consisted of wood particles, polyurethane (PU) adhesive, and different flame retardant formulations were investigated by limiting oxygen index (LOI). The results of LOI indicate that DDPPU could improve the flame retardancy of wood particleboard. However, when H3BO3 was used as the second flame retardant component and combined with DDPPU, the flame retardant wood particleboard could obtain the highest LOI value (46.0) in these experiments. Thermogravimetric analysis shows that treated wood particleboard can decrease the initial decomposition temperature, and that at higher temperatures the degradation rate are lower than the untreated wood particleboard. Furthermore, wood particleboard treated with DDPPU/H3BO3 has a higher yield of residue char at 600°C than that treated with other flame retardant systems. The ability of char formation of these samples agrees with the order of LOI values. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Side‐chain copolymers containing smectic monomer and chiral reagent—Synthesis and characterization
Authors: He Xiao‐Zhi , Zhang Bao‐Yan , Hu Jian‐She , Yao Dan‐Shu , Hu Zeng‐Fu
Published: January 2008

A series of new chiral side‐chain liquid‐crystalline polymers were prepared containing smectic‐nematic monomer and nonmesogenic chiral monomer. All polymers were synthesized by graft polymerization using polymethylhydrosiloxane as backbone. The mesomorphic properties were investigated by differential scanning calorimetry, polarizing optical microscopy, thermogravimetric analyses, and X‐ray diffraction measurements. The chemical structures of the monomers and polymers obtained were confirmed by Fourier transform infrared, proton nuclear magnetic resonance spectra (1H NMR). M1 showed smectic (SB, SC) and nematic phase on the heating and the cooling cycle. Polymers P0–P2 were in chiral smectic A phase, while P3–P5 were in cholesteric phase, P6 has bad LC properties, and P7 has no LC properties. Experimental results demonstrated that nonmesogenic chiral moiety and LC mesogenic with long carbochain offered the possibility of application because of its lower glass transition temperature, and the glass transition temperatures and isotropization temperatures and the ranges of the mesophase temperature reduced with increasing the contents of chiral agent. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Morphology and thermal properties of liquid crystal p‐PAEB/n‐propyl methacrylate copolymers
Authors: Gao Jungang , Wang Yong , Hou Guixiang , Liu Guodong
Published: January 2008

The copolymers of p‐phenylene di{4‐[2‐(allyloxy) ethoxy]benzoate} (p‐PAEB) with n‐propyl methacrylate (PMA) were synthesized. The liquid crystalline behavior and thermal properties of copolymers were studied by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), X‐ray diffractometer (XRD), and torsional braid analysis (TBA). The results of XRD, POM, and DSC demonstrate that the phase texture of copolymers is affected by the composition of liquid crystal units in copolymers. The POM and XRD reveal that liquid crystal monomer (p‐PAEB) and copolymers of p‐PAEB with PMA are all smectic phase texture. The dynamic mechanical properties of copolymers are investigated with TBA. The results indicate that the phase transition temperatures and dynamic mechanical loss peak temperature Tp of copolymers are affected by the composition of copolymers and liquid crystal cross networks. The maximal mechanical loss Tp is 114°C and is decreased with added PMA. The behaviors of phase transition are affected by the crosslinking density, and it is revisable for lightly crosslinking LC polymer networks, but it is nonreversible for the densely crosslinking of LC polymer networks. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of new polyamides containing p‐phenylenediacryloyl moieties in the main chain
Authors: Faghihi Khalil , Naghavi Howra
Published: January 2008

Six new polyamides 8a–f containing p‐phenylenediacryloyl moieties in the main chain were prepared by the direct polycondensation reaction of bis(p‐amidobenzoic acid)‐p‐phenylene diacrylic acid 6 with 1,4‐diphenylene diamine 7a, 1,3‐diamino toluene 7b, 1,5‐diamino naphthalene 7c, 4,4′‐diamino diphenyl ether 7d, 4,4′‐diamino diphenyl sulfone 7e, and 3,3′‐diamino diphenylsulfone 7f by using thionyl chloride, N‐methyl‐2‐pyrolidone, and pyridine as condensing agents. These new polymers 8a–f were obtained in high yield and inherent viscosity between 0.35–0.65 dL/g. The resulting polyamides were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis (TGA and DTG), solubility test, FTIR and UV–vis spectroscopy. Diacid acid 6 as a new monomer containing p‐phenylenediacryloyl moiety was synthesized by using a three‐step reaction. First, p‐phenylenediacrylic acid 3 was prepared by reaction of terephthal aldehyde 1 with malonic acid 2 in the presence of pyridine, then diacid 3 was converted to p‐phenylenediacryloyl chloride 4 by reaction with thionyl chloride. Finally, bis(p‐amidobenzoic acid)‐p‐phenylene diacrylic acid 6 was prepared by the condensation reaction of phenylenediacryloyl chloride 4 with p‐aminobenzoic acid 5. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Improvement of the surface properties of polycarbonate by organic–inorganic hybrid coatings
Authors: Fabbri Paola , Leonelli Cristina , Messori Massimo , Pilati Francesco , Toselli Maurizio , Veronesi Paolo , Morlat‐Thérias Sandrine , Rivaton Agnès , Gardette Jean Luc
Published: January 2008

Organic–inorganic hybrids (ceramers) were prepared through the sol–gel process with opportune alkoxysilane‐terminated polymer chains as the organic phase and tetraethoxysilane as the inorganic network precursor. The consolidation process, used to reach a high degree of crosslinking between the two phases, was carried out with either conventional oven heating or microwave irradiation. High conversion degrees were obtained with both treatments even when microwave postcuring turned out to be much faster than conventional heating(5–10 s vs 40 min). Scratch‐test and photooxidation investigations showed a significant improvement in scratch, yellowing, and photodegradation resistance for coated polycarbonate. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polyester polyols and polyurethanes from ricinoleic acid
Authors: Petrović Zoran S. , Cvetković Ivana , Hong DooPyo , Wan Xianmei , Zhang Wei , Abraham Tim , Malsam Jeff
Published: January 2008

Triols of molecular weights (MWs) 1000–4000, suitable for flexible foams, were prepared by transesterification of methyl esters of ricinoleic acid with trimethylol propane. These polyols were noncrystallizing, relatively low‐viscosity liquids. They were reacted with diphenylmethane diisocyanate (MDI) to obtain elastomers having glass transition temperatures below −60°C. Polymer networks from high‐MW polyols exhibited relatively high sol fractions suggesting that some cyclization occurred during polyol preparation. The low Shore hardness, relatively low strength and modest elongation of the elastomers were attributed to the specific structure of polyricinoleic chains and the presence of dangling chains, serving as plasticizers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of styrene/maleimide copolymer with 4‐[N‐ethyl‐N‐(2‐hydroxyethyl) amino]‐4′‐nitroazobenzene as side chain
Authors: Pu Hongting , Liu Ling , Jiang Weichun , Li Xinwan , Chen Jianping
Published: January 2008

Relatively low thermal stability of second‐order nonlinear optical (NLO) coefficient due to the relaxation of dipole orientation is a major problem limiting the practical application of these NLO polymers. NLO polymers with suitable Tg are always important for optical devices. In the present work a synthetic approach to styrene‐(N‐(4‐hydroxyphenyl) maleimide) copolymer (SHMI) with 4‐[N‐ethyl‐N‐(2‐hydroxyethyl) amino]‐4′‐nitroazobenzene (DR1) as side chain and chromophores has made it possible to efficiently prepare a NLO polymer. The copolymer with high Tg of 202°C has low relaxation of dipole orientation. The maximum optical loss at the optical communication wavelength is less than 0.9 dB. NLO coefficient r33 is 8.2 pm/V (1550 nm) and its maximum relaxation at room temperature is 18%. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Preparation and characterization of nanopigment‐poly(styrene‐co‐n‐butyl acrylate‐co‐methacrylic acid) composite particles by high speed homogenization‐assisted suspension polymerization
Authors: Widiyandari Hendri , Iskandar Ferry , Hagura Nobuhiro , Okuyama Kikuo
Published: January 2008

Composite particles of nanoblue pigment‐poly(styrene‐co‐n‐butyl acrylate‐co‐methacrylic acid) of controllable size were successfully prepared using high‐speed homogenization‐assisted suspension polymerization. This composite has potential application as a toner for high‐resolution printing. A nanosized hybrid blue pigment, with a monodispersed and uniform spherical shape, was employed for the production of composite particles. The effects of agitation speed, pigment concentration, and anionic surfactant concentration on the properties of the prepared composite particles were investigated. Agitation speed plays an important role in controlling particle size. The prepared composite particles have geometric mean diameters in the range of 4.4–7.4 μm with the geometric standard deviation ranging from 1.23 to 1.33. High‐speed homogenization during droplet formation is useful for a reduction in the size of the prepared composite particles. In addition, the appropriate surfactant concentration has a significant effect on the particles' morphology. However, the concentration of the nanopigment did not significantly change either particle morphology or particle size. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
New polyamides based on 2,5‐bis[(4‐carboxyanilino) carbonyl] pyridine and aromatic diamines: Synthesis and characterization
Authors: Faghihi Khalil , Mozaffari Zohreh
Published: January 2008

Seven new polyamides 6a–g were synthesized through the direct polycondensation reaction of 2,5‐bis[(4‐carboxyanilino) carbonyl] pyridine 4 with seven derivatives of aromatic diamines 5a–g in a medium consisting of N‐methyl‐2‐pyrrolidone, triphenyl phosphite, calcium chloride, and pyridine. The polycondensation reaction produced a series of novel polyamides containing pyridyl moiety in the main chain in high yield with inherent viscosities between 0.32–0.72 dL/g. The resulted polymers were fully characterized by means of FTIR spectroscopy, elemental analyses, inherent viscosity, and solubility tests. Thermal properties of these polymers were investigated by using thermal gravimetric analysis and differential thermal gravimetric. All the polymers were soluble at room temperature in polar solvents, such as N,N‐dimethyl acetamide, N,N‐dimethyl formamide, dimethyl sulfoxide, and N‐methyl‐2‐pyrrolidone. 2,5‐Bis[(4‐carboxyanilino) carbonyl] pyridine 4 as a new monomer containing pyridyl moiety was synthesized by using a two‐step reaction. At first 2,5‐pyridine dicarboxylic acid 1 was converted to 2,5‐pyridine dicarbonyl dichloride 2. Then diacid 4 was prepared by condensation reaction of diacid chloride 2 with p‐aminobenzoic acid 3. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Characterization of SiO2 and Al2O3 incorporated PVdF‐HFP based composite polymer electrolytes with LiPF3(CF3CF2)3
Authors: Aravindan V. , Vickraman P.
Published: January 2008

Lithium fluoroalkylphosphate (LiPF3(CF3 CF2)3) based composite polymer electrolytes (CPE) have been prepared in the matrix of polyvinylidenefluoride‐hexafluoropropylene(PVdF‐HFP), using solvent casting technique. The membranes were gelled with ethylene carbonate and diethyl carbonate as a plasticizer and nanosized SiO2 and nanoporous Al2O3 as fillers. These membranes were subjected to a.c. impedance, DSC, SEM, FTIR, and Fluorescence studies. The a.c. impedance studies and activation energy calculation reveal that 2.5 wt % fillers containing membranes only exhibit maximum conductivity for SiO2 (1.16 mS cm−1) and Al2O3 (0.98 mS cm−1), compared to fillers free membranes and beyond 2.5 wt % of such fillers the conductivity tends to decrease. The enhancement of conductivity has been explained in terms of Vogel‐Tamman‐Fulcher (VTF) theory. Molecular interactions by FTIR and local viscosity environment by fluorescence studies have been investigated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Investigation on the formation mechanisms of hydrogels made by combination of γ‐ray irradiation and freeze‐thawing
Authors: Yang Xiaomin , Liu Qi , Chen Xiliang , Zhu Zhiyong
Published: January 2008

Hydrogels based on poly(vinyl alcohol) (PVA)/water‐soluble chitosan (ws‐chitosan)/glycerol were prepared by γ‐ray irradiation, freeze‐thawing, and combination of γ‐ray irradiation and freeze‐thawing, respectively. The influence of freeze‐thawing cycles, the irradiation doses, and the sequence of freeze‐thawing and irradiation processes on the rheological, swelling, and thermal properties of these hydrogels was investigated to evaluate the formation mechanisms of hydrogels made by combination of irradiation and freeze‐thawing. For hydrogels made by freeze‐thawing followed by irradiation, the physical crosslinking is destroyed partially while chemical crosslinking is formed by irradiation. However, the chemical crosslinking density reduces with the increase of freeze‐thawing cycles. Hydrogels made by irradiation followed by freeze‐thawing bear less degree of physical crosslinking with the increase of irradiation dose for the increased chemical crosslinking density. It is found that these hydrogels own larger swelling capacity and better transparent appearance than those made by freeze‐thawing followed by irradiation. Moreover, the former hydrogels have larger mechanical strength than the latter at low freeze‐thawing cycles. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008