bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, characterization, and soil biodegradation study of polyamides derived from the novel bioactive diacid monomer 5‐(2‐phthalimidoethanesulfonamido) isophthalic acid
Authors: Karimi Zarchi Mohammad Ali , Tayefi Mohammad , Tirgir Farhang , Sabzalian Mohammad R. 
Published: March 2011

AbstractA new bioactive diacid monomer, 5‐(2‐phthalimidoethanesulfonamido) isophthalic acid (6), was synthesized in three steps. This monomer can be regarded as biologically active aromatic diacid and may be used in the design of biodegradable and biological materials. This monomer was polymerized with several aromatic diamines by step‐growth polymerization to give a series of biodegradable and highly thermally stable polyamides (PAs) with good yield (70–82%) and moderate inherent viscosity between 0.38–0.68 dL/g in a system of triphenylphosphite/pyridine/N‐methyl‐2‐pyrolidone/CaCl2. The new aromatic diacid 6 and all of the PAs derived from this diacid and aromatic diamines were characterized by Fourier transform infrared, 1H‐NMR, 13C‐NMR, and elemental analysis techniques. The thermal stability of the PAs was determined by thermogravimetric analysis and differential scanning calorimetry techniques under a nitrogen atmosphere, and we found that they were moderately stable. The soil biodegradability behavior of 6 and all of the PAs derived from this diacid and aromatic diamines were investigated in culture media, and we found that the synthesized diacid 6 and all of the PAs were biodegradable under a natural environmental. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and degradation of sorbitol‐based polymers
Authors: Pasupuleti Sasikiran , Madras Giridhar 
Published: March 2011

AbstractA new class of biodegradable copolyesters was synthesized by the catalyst‐free melt condensation of sorbitol with citric acid, tartaric acid, and sebacic acid. The resulting polymers were designated as poly(sorbitol citric sebacate) [p(SCS)] and poly(sorbitol tartaric sebacate) [p(STS)]. The synthesized polymers were characterized by Fourier transform infrared spectroscopy, 1H‐NMR spectroscopy, and differential scanning calorimetry analysis. Porous spongelike scaffolds were prepared with a salt‐leaching technique and characterized with scanning electron microscopy. Tensile testing of the p(SCS) and p(STS) polymers showed that they exhibited a wide range of mechanical properties. The Young's modulus and tensile strengths of the polymers ranged from 1.06 ± 0.12 to 462.65 ± 34.21 MPa and from 0.45 ± 0.04 to 20.32 ± 2.54 MPa, respectively. In vitro degradation studies were performed on disc‐shaped polymer samples. The half‐life of the polymers ranged from 0.54 to 38.52 days. The percentage hydration of the polymers was in the range 9.36 ± 1.26 to 78.25 ± 1.91, with sol contents of 2–14%. At any given polymer composition, the Young's modulus and tensile strength of p(SCS) was higher than that of p(STS), whereas the degradation rates of p(SCS) was lower than that of p(STS). This was attributed to the structural difference between the citric and tartaric monomers and to the degree of crosslinking. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of vanadium pentoxide on the mechanical, thermal, and electrical properties of poly(vinyl alcohol)/vanadium pentoxide nanocomposites
Authors: Wacharawichanant Sirirat , Wutanasiri Nareerut , Srifong Paveena , Meesangpan Usarat , Thongyai Supakanok 
Published: March 2011

AbstractIn this study, we examined the effect of vanadium pentoxide (V2O5) on the mechanical, thermal, and morphological properties of poly(vinyl alcohol) (PVA)/V2O5 nanocomposites. The PVA/V2O5 nanocomposites were prepared by solution mixing, followed by film casting. The results show that the Young's moduli of the resulting nanocomposites films were higher than the pure PVA modulus with increasing V2O5 content, and it reached a maximum point at about 0.4 wt % V2O5 content at 8.55 GPa. The tensile strength and stress at break increased with increasing V2O5 content. The addition of V2O5 did not affect the melting temperature. The crystallization temperatures of PVA were significantly changed with increasing V2O5 content. The 5% weight loss degradation temperature of the nanocomposites was measured by thermogravimetric analysis. The degradation temperatures of the V2O5 nanocomposites increased with increasing filler content and were higher than the degradation temperature of pure PVA; this showed a lower thermal stability compared to those of the nanocomposites. The results show that the thermal stability increased with the incorporation of V2O5 nanoparticles. The dielectric constant of PVA had a tendency to improve when the dispersion of particles was effective. The morphology of the surfaces the nanocomposites was examined by scanning electron microscopy. We observed that the dispersion of the V2O5 nanoparticles was relatively good; only few aggregations existed after the addition of the V2O5 nanoparticles at greater than 0.4 wt %. In perspective, the addition of 0.4 wt % V2O5 nanoparticles into PVA maximized the mechanical, thermal, and electrical properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Studies on the Amidoximation of Polyacrylonitrile Films: Influence of Synthesis Conditions
Authors: Mishra Abhishek , Sharma Shiromani , Gupta Bhuvanesh 
Published: March 2011

AbstractChemical transformation of acrylic membranes with hydroxylamine hydrochloride (HA) was carried out to introduce amidoxime groups. It was found that the reaction conditions, such as reaction time, HA concentration and temperature influence the amidoxime content, significantly. A sharp enhancement in the amidoximation at 80°C was observed. The FTIR studies showed a significant loss of nitrile groups during amidoximation process. Optimum conditions for the amidoximation process were investigated. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Investigation in thermal endurance of polyesterimide used in electrical machines
Authors: Nedjar M. 
Published: March 2011

AbstractThe purpose of this investigation is to evaluate thermal lifetime of polyesterimide using Weibull statistics. Thermal aging was performed on twisted pair specimens of copper wire insulated by a polyesterimide layer. The study shows that breakdown voltage varies versus aging time. Its increase is allotted to a crosslinking inducing a diminution of mean‐free path of charge carriers leading thereby to a mobility decrease, whereas its decrease is attributed to the viscosity diminution expressing a weakening of molecular bonds and a mobility increase of charge carriers. Shape parameter changes in function of aging time. Its increase is ascribed to an arrangement of the molecular structure, whereas its decrease is due to an augmentation in the size of defects. The thermal endurance graph is a straight line indicating that the degradation is governed by a first‐order chemical reaction. Activation energy and temperature index were determined. The degradation is governed by the dissolution of copper into the polymer and accelerates its degradation occurring at the polyesterimide–copper interface. Oxygen can diffuse into the insulation and attack copper resulting in the formation of copper oxide. The degradation is caused by the scission of imide and ester bonds. The process is followed by a change in color and a presence of cracks. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effects of rice straw fiber morphology and content on the mechanical and thermal properties of rice straw fiber‐high density polyethylene composites
Authors: Ming‐Zhu Pan , Chang‐Tong Mei , Xu‐Bing Zhou , Yun‐Lei Pu 
Published: March 2011

AbstractRice straw fiber‐high density polyethylene (HDPE) composites were prepared to investigate the effects of rice straw fiber morphology (rice straw refined fiber, rice straw pellet, rice straw strand), fiber content (20 and 40 wt %), and maleic anhydride polyethylene (MAPE) concentration (5 wt %) on the mechanical and thermal properties of the rice straw fiber‐HDPE composites in this study. Rice straw refined fiber exhibited more variability in length and width, and have a higher aspect ratio of 16.3. Compared to the composites filled of rice straw pellet, the composites made of the refined fiber and strand had a slightly higher tensile strength and lower tensile elongation at break. The tensile and flexural strength of the composites increased slightly with increasing rice straw fiber content up to 40 wt %, while the tensile elongation at break decreased. With addition MAPE, the composites filled with 20 wt % rice straw fiber showed an increase in tensile, flexural and impact strength and a decrease in tensile elongation at break. Differential scanning calorimetry showed that the fiber addition and morphology had no appreciable effect on the crystallization temperature of the composites but decreased the crystallinity. The scanning electron microscopy observation on the fracture surface of the composites indicated that introduction of MAPE to the system resulted in promotion in fiber dispersion, and an increase in interfacial bonding strength. Fiber breakage occurred significantly in the composites filled with refined fiber and strand after extruding and injection processing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Herbal drug incorporated antibacterial nanofibrous mat fabricated by electrospinning: An excellent matrix for wound dressings
Authors: Suganya S. , Senthil Ram T. , Lakshmi B. S. , Giridev V. R. 
Published: March 2011

AbstractNano‐components and nano‐systems for health care and medical applications are the focus of many research projects worldwide. Nanofibrous membranes are highly soft materials with high surface‐to‐volume ratios, and therefore can serve as excellent carriers for therapeutic agents that are antibacterial or accelerate wound healing. PCL/PVP Nanofiber mat containing chloroform: methanol (4:1) crude bark extract of Tecomella undulata, a medicinal plant widely known for its traditional medical applications including its wound healing ability, were prepared and evaluated for their antibacterial properties. With good drug stability and high drug‐loading efficacy, the incorporation of herbal extract in the polymer media did not appear to influence the morphology of the resulting fibers, as both the drug‐free and the drug‐loaded nanofibers remained unaltered, microscopically. Activity was tested against standard strains of Pseudomonas aeruginosa MTCC 2297, Staphylococcus aureus ATCC 933, Escherichia coli (IP‐406006). Extract loaded PCL/PVP nanofiber mat were able to inhibit the growth of the bacterial strains which indicate that it could act not only as a drug delivery system but also in the treatment of wound healing or dermal bacterial infections thereby proving a potential application for use as a wound dressing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Polyaniline‐Intercalated Molybdenum Oxide Nanocomposites: Simultaneous Synthesis and their Enhanced Application for Supercapacitor
Authors: Zheng Lei , Xu Yang , Jin Dong , Xie Yi 
Published: March 2011

AbstractA new and universal synthetic strategy to hybridize metal oxides and conduct polymer nanocomposites has been proposed in this work. The simultaneous reaction process, which includes the generation of metal oxide layers, the oxidation polymerization of monomers, and the in situ formation of polymer–metal oxides sandwich structure is successfully realized and results in the unique hybrid polyaniline (PANI)‐intercalated molybdenum oxide nanocomposites. The peroxomolybdate proved to play a dual role as the precursor of the inorganic hosts and the oxidizing agent for polymerization. The as‐obtained hybrid nanocomposites present a flexible lamellar structure by oriented assembly of conductive PANI chains in the MoO3 interlayer, and thus inherit excellent electrical performance and possess the potential of active electrode materials for electrochemical energy storage. Such uniform lamellar structure together with the anticipated high conductivity of the hybrid PANI/MoO3 nanocomposites afford high specific capacitance and good stability during the charge–discharge cycling for supercapacitor application.
Diode‐Like I–V Characteristics of a Nonplanar Polyaromatic Compound: a Spectroscopic Study of Isolated and Stacked Dibenzo[g,p]chrysene
Authors: Lee Shern‐Long , Huang Min‐Jie , Chen Chun‐hsien , Wang Cheng‐I , Liu Rai‐Shung 
Published: March 2011

AbstractIn this scanning‐tunneling‐microscopy/spectroscopy study (STM/STS), samples of isolated and close‐packed dibenzo[g,p]chrysene (DBC), a nonplanar polyaromatic compound, are used as model systems to demonstrate the effect of intermolecular interactions on the electronic structures. For dropcast films, DBC molecules adopt an edge‐on orientation in a close‐packed structure on graphite. Isolated DBC molecules are prepared on graphite from a DBC‐coated STM tip by a ca. 7 V/10 μs pulse. STS spectra for both isolated‐ and close‐packed DBC molecules exhibit diode‐like I–V curves in which the latter shows a turn‐on voltage (0.47 V) smaller than that of the former (0.91 V). The diode‐like behaviors are attributed to the more‐facile tunneling of electrons through the HOMO of DBC than through the LUMO. The reduced turn‐on voltage for the films is ascribed to the diminished HOMO–LUMO gap based on the results of DFT (density functional theory) simulations for the energy‐level couplings of π‐stacked DBC molecules.
The Effect of the Buffering Capacity of the Supporting Electrolyte on the Electrochemical Oxidation of Dopamine and 4‐Methylcatechol in Aqueous and Nonaqueous Solvents
Authors: Chen Shanshan , Tai Kah Yieng , Webster Richard D. 
Published: March 2011

AbstractDopamine was electrochemically oxidized in aqueous solutions and in the organic solvents N,N‐dimethyl‐formamide and dimethylsulfoxide containing varying amounts of supporting electrolyte and water, to form dopamine ortho‐quinone. It was found that the electrochemical oxidation mechanism in water and in organic solvents was strongly influenced by the buffering properties of the supporting electrolyte. In aqueous solutions close to pH 7, where buffers were not used, the protons released during the oxidation process were able to sufficiently change the localized pH at the electrode surface to reduce the deprotonation rate of dopamine ortho‐quinone, thereby slowing the conversion into leucoaminochrome. In N,N‐dimethylformamide and dimethylsulfoxide solutions, in the absence of buffers, dopamine was oxidized to dopamine ortho‐quinone that survived without further reaction for several minutes at 25 °C. The voltammetric data obtained in the organic solvents were made more complicated by the presence of HCl in commercial sources of dopamine, which also underwent an oxidation process.
Effect of injury on S1 dorsal root ganglia in an experimental model of neuropathic faecal incontinence
Authors: Peirce C , O'Herlihy C , O'Connell P R , Jones J F X 
Published: March 2011

AbstractBackgroundAn experimental model of neuropathic faecal incontinence has recently been established. This study aimed to quantify and compare the effect of crush and compression injury on first-order sensory neurones of the inferior rectal nerve (IRN) using a nuclear marker of axonal injury, activating transcription factor (ATF) 3.MethodsEighteen Wistar rats were allocated to three groups: an unoperated control group, an IRN crush group (positive control) and a retrouterine balloon compression group. Five days after surgery, all animals were anaesthetized and perfused with fixative, and S1 dorsal root ganglia (DRG) were harvested. The tissue was sampled and neuronal nuclear ATF-3 expression calculated.ResultsEstimated total S1 DRG ATF-3 nuclear labelling was higher in the nerve crush (median (interquartile range) 171 (60–824) cells) and balloon compression (59 (20–274) cells) groups, compared with that in the unoperated control group (9 (3–24) cells) (P = 0·001 and P = 0·008 respectively). In all groups, most neurones displaying the marker of injury were of the C-fibre class.ConclusionThis study confirmed the presence of axonal injury in a pelvic compression model of obstetric injury. C-fibre afferent pathways appeared to be most vulnerable. Neuromodulation may function through augmentation of residual C-fibre pathways.
Impact of endoscopic assessment and treatment on operative and non-operative management of acute oesophageal perforation
Authors: Kuppusamy M K , Felisky C , Kozarek R A , Schembre D , Ross A , Gan I , Irani S , Low D E 
Published: March 2011

Abstract

Background
Surgeons have not typically utilized an endoscopic approach for diagnosis and management of acute oesophageal perforation, mainly due to fears of increased mediastinal contamination. This study assessed the evolution of endoscopic approaches and their effect on outcomes over time in acute oesophageal perforation.

Methods
All patients with documented acute oesophageal perforation between 1990 and 2009 were enrolled prospectively in an Institutional Review Board-approved database.

Results
Of 81 patients who presented during the study period, 52 had upper gastrointestinal endoscopy for diagnosis alone (12 patients; 23 per cent) or as a component of acute management (40 patients; 77 per cent). Use of endoscopy increased from four of 13 patients in the first 5 years of the study to 20 of 24 patients in the final 5 years. Endoscopy was used in conjunction with surgery in 28 patients, of whom 21 underwent primary repair, three had resection, and one a diversion; 12 patients in this group had hybrid operations (combination of surgical and endoscopic management). Primary endoscopic treatment was used in 15 patients (29 per cent), most commonly involving stent placement (7). Of those having endoscopy, complication rates improved (from 3 of 4 to 8 of 20 patients), as did mean length of stay (from 21·8 to 13·4 days) between the initial and final 5 years of the study. There were two deaths (4 per cent). Of 21 patients who had both endoscopic assessment and management in the operating room, endoscopy identified additional pathology in ten, leading to a change in management plan in five patients.

Conclusion
Endoscopy is a safe and important component of the management of acute oesophageal perforation. It provides additional information that modifies treatment, and its wider use should result in improved outcomes.
Doing Research with Imprisoned Adult Male Child Sexual Abusers: Reflecting on the Challenges
Authors: Roberts Susan 
Published: March 2011

Much research has been undertaken within the prison environment, particularly in relation to sexual offenders. Yet, little attention has been paid to the task of doing research with imprisoned adult male child sexual abusers. This is a personal account of the experiences of a female researcher and the issues which emerged as part of the process of undertaking a qualitative, descriptive research study with 101 imprisoned adult males convicted of sexual offences against children. Consideration is given to the challenges which presented prior to and during the fieldwork phase; the means by which these were dealt with; the impact of the data collection process on the researcher; and the part played by gender in that. Copyright © 2011 John Wiley & Sons, Ltd.‘This is a personal account of the experiences of a female researcher’
Good Practice in Social Care for Refugee and Asylum‐seeking Children
Authors: Newbigging Karen , Thomas Nigel 
Published: March 2011

This article seeks to identify key components of good practice in social care services for safeguarding refugee and asylum‐seeking children. It is based on a wider research study, conducted in England, Wales and Northern Ireland, which aimed to identify indicators and examples of good practice in social care for asylum seekers and refugees (both adults and children). Methods included a systematic literature review, focus groups with asylum seekers and refugees, and a survey of voluntary and statutory agencies. This paper reflects on the findings as they relate to children, including both unaccompanied children and those in families, with particular attention to safeguarding issues, and identifies key components of good practice from a synthesis of the findings. The primary component identified is a clear commitment to seeing the wellbeing of children and young people as the primary focus of practice, rather than the demands of immigration policy. Others include provision of safe and appropriate accommodation, support for engagement in appropriate education and leisure pursuits, attention to emotional well‐being, good support and information for families, and inclusion of families and communities in the safeguarding agenda. The research showed that the needs of unaccompanied asylum‐seeking children and young people tend to be more visible than those living with their families, and that more research is needed, particularly in relation to the latter group. Copyright © 2011 John Wiley & Sons, Ltd.‘The wellbeing of children and young people as the primary focus of practice, rather than the demands of immigration policy’
Protein kinase B/Akt may regulate G2/M transition in the fertilized mouse egg by changing the localization of p21Cip1/WAF1
Authors: Wu Di‐Di , Feng Chen , Xu Xiao‐Yan , Xiao Jian‐Ying , Liu Chao , Meng Jun , Wang En‐Hua , Yu Bing‐Zhi 
Published: March 2011

AbstractProtein kinase B (PKB, also called Akt) is known as a serine/threonine protein kinase. Some studies indicate that the Akt signalling pathway strongly promotes G2/M transition in mammalian cell cycle progression, but the mechanism remains to be clarified, especially in the fertilized mouse egg. Here, we report that the expression of Akt at both the protein and mRNA level was highest in G2 phase, accompanied by a peak of Akt activity. In addition, the subcellular localization of p21Cip1/WAF1 has been proposed to be critical in the cell cycle. Hence, we detected the expression and localization of p21Cip1/WAF1 after injecting fertilized mouse eggs with Akt mRNA. In one‐cell stage fertilized embryos microinjected with mRNA coding for a constitutively active myristoylated Akt (myr‐Akt), p21Cip1/WAF1 was retained in the cytoplasm. Microinjection of mRNA of kinase‐deficient Akt(Akt‐KD) resulted in nuclear localization of p21Cip1/WAF1. Meanwhile, microinjection of different types of Akt mRNA affected the phosphorylation status of p21Cip1/WAF1. However, there was no obvious difference in the protein expression of p21Cip1/WAF1. Therefore, Akt controls the cell cycle by changing the subcellular localization of p21Cip1/WAF1, most likely by affecting the phosphorylation status of p21Cip1/WAF1. Copyright © 2011 John Wiley & Sons, Ltd.
Comparing EndoPAT and BIOPAC measurement of vascular responses to mental stress
Authors: Martin Elizabeth A. , Nelson Rebecca E. , Felmlee‐Devine M. Donna , Brown Troy E. , Lerman Amir 
Published: March 2011

AbstractThere are currently no comparison measurements of stress‐induced changes in vascular function during acute mental stress tests to measurements made by BIOPAC MP150 systems technology, a standard polygraph device used to detect deception during polygraph examinations in military or law enforcement applications. Vascular responses to reactive hyperaemia and acute mental stress in 25 healthy subjects were measured by both peripheral arterial tonometry (EndoPAT) and a blood pressure cuff attached to a pressure transducer (BIOPAC) and compared. Reactive hyperaemia was performed at baseline and following three acute mental stress tests. There was no difference in vascular reactivity at baseline and following acute mental stress, as measured by EndoPAT or BIOPAC systems (p > 0·05). Mental stress ratios measured by EndoPAT were significantly different than those measured by BIOPAC (p < 0·01). These data suggest that EndoPAT measurements of vascular responses to acute mental stress may be more specific and sensitive than measurements using the BIOPAC system. Copyright © 2011 John Wiley & Sons, Ltd.