bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of novel soybean‐oil‐based thermosensitive amphiphilic polymers for drug delivery applications
Authors: Abdekhodaie Mohammad J , Liu Zengshe , Erhan Sevim Z , Wu Xiao Yu 
Published: May 2012

AbstractHydrolyzed polymers of soybean oil (HPSO) and of epoxidized soybean oil (HPESO) were developed previously. Owing to their natural food origin and biocompatibility, we exploited further their potential as a drug delivery system and pharmaceutical excipients. This work aimed to investigate self‐assembly, thermal transition, interaction with various drugs and surface activity of these novel amphiphilic polymers. The critical micelle concentration of HPSO and HPESO was determined by the surface tension method. The molecular interaction between HPESO and anticancer drug doxorubicin HCl was examined. The effect of the polymers on the solution contact angle and surface energy of compressed tablets of hydrophobic drugs ibuprofen and nifedipine was measured. The thermal transition temperatures Ttr (cloud points) of the polymers in aqueous solutions increased with increasing polymer concentration. HPSO exhibited lower Ttr than HPESO. The critical micelle concentration was found to be 0.05 mg mL−1 for HPSO and 0.08 mg mL−1 for HPESO. Strong molecular interactions between HPESO and doxorubicin were observed. Both polymers reduced the interfacial energy and contact angles of drug tablets with more effect on ibuprofen tablets with the use of HPSO. These results suggest that the novel soybean‐oil‐based amphiphilic polymers have great potential for drug delivery and pharmaceutical formulations. Copyright © 2012 Society of Chemical Industry
Polyaldehydes: homopolymers, block copolymers and promising applications
Authors: Köstler Stefan 
Published: May 2012

AbstractThis minireview gives a brief overview on the polymerization of higher aldehydes, discusses current applications of certain polyaldehydes, and points toward potential future applications of these interesting materials. Although it was discovered long ago that several aldehydes can be polymerized, the application potential of these polymers was largely overlooked. This is somewhat surprising as many polyaldehydes show interesting properties such as fast and complete depolymerization triggered by chemical or thermal stimuli. Such stimuli‐responsive polymers can be useful materials in many applications in for example nanotechnology or drug delivery. By incorporating polyaldehydes into functional block copolymers even more versatile materials can be created. The increasing number of recent research examples demonstrates the growing interest in polyaldehydes as smart materials and their potential for novel applications. Copyright © 2012 Society of Chemical Industry
Impact of photovoltaic orientation on its relative economic value in wholesale energy markets
Authors: Hummon Marissa , Denholm Paul , Margolis Robert 
Published: May 2012

ABSTRACTMost calculations of optimum photovoltaic (PV) performance focus on maximizing annual energy production. However, given the seasonally and daily time varying electricity demand and resulting variation in price, the PV orientation resulting in maximum energy yield may not yield the maximum economic benefit. With the use of historical solar irradiance and wholesale market prices for several locations in the USA, we evaluate the benefits of a variety of orientations for fixed and tracking PV arrays. We find that orienting fixed arrays slightly to the west of due south generally increases their economic value in the simulated systems because the reduced generation on an annual basis is more than offset by increased generation in high‐value hours in late summer afternoons. However, this effect is small, typically providing an increase in value from 1% to 5%. The economic value of adjusting the orientation semi‐annually (May 1st and September 1st) and monthly shows a modest increase in value from 3% to 5%. Several other implications of this analysis are also discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Examining the relations between reading fluency and reading comprehension for english language learners
Authors: Quirk Matthew , Beem Sofie 
Published: May 2012

AbstractThis study examined the relations between reading fluency and comprehension among elementary school students (N = 171) in Grades 2, 3, and 5, all of whom were designated as English language learners (ELL) at some point in their educational careers. Although the overall relation between reading fluency and comprehension (r = .56) was consistent with previous research using non‐ELL student samples, results also revealed a substantial number of students (55.5%) who exhibited a significant gap (SD, 0.67 ) between their scores on reading fluency and comprehension assessments. In addition, the prevalence of students with fluency/comprehension gaps varied significantly across grade and English language proficiency levels. The results suggested that, although reading fluency and comprehension are significantly related for ELL students, practitioners should be cautious when making identification and instructional decisions for ELL students based solely on oral reading fluency data. © 2012 Wiley Periodicals, Inc.
Telephone‐delivered health education and interpersonal counseling improve quality of life for Latinas with breast cancer and their supportive partners
Authors: Badger Terry A. , Segrin Chris , Hepworth Joseph T. , Pasvogel Alice , Weihs Karen , Lopez Ana Maria 
Published: May 2012

AbstractObjectiveThis study aims to test two telephone‐delivered interventions for their efficacy in improving quality of life (QOL) (psychological, physical, social, and spiritual) among Latinas with breast cancer and their family members or friends (labeled supportive partners in this study).MethodsLatinas with breast cancer and their supportive partners (SPs) were randomly assigned to one of two telephone delivered 8‐week interventions: (i) telephone interpersonal counseling (TIP‐C) or (ii) telephone health education (THE). QOL assessments were made at baseline, immediately after the 8‐week interventions ended, and at an 8‐week follow‐up. Seventy Latinas and their 70 SPs completed all assessments (36 in health education and 34 in counseling) and were included in the final analysis.ResultsBoth Latinas with breast cancer and their SPs had significant improvements in virtually all dimensions of QOL over the 16 weeks of the investigation. However, there was no evidence documenting the superiority of either intervention for improving QOL. Preliminary cost analysis found that the counseling intervention cost about $164.68 for one dyad compared with $107.03 for health education. The majority of participants reported benefit from the intervention and liked that the intervention was in Spanish, included SPs, and was delivered by telephone.ConclusionThe results of this study show that relatively brief, culturally appropriate, and highly accessible telephone‐delivered interventions that provide emotional and information support can bring about substantial improvements in QOL for both Latinas with breast cancer and their SPs. Copyright © 2012 John Wiley & Sons, Ltd.
A pilot training programme for health and social care professionals providing oncological and palliative care to lesbian, gay and bisexual patients in Ireland
Authors: Reygan Finn C. G. , D'Alton Paul 
Published: May 2012

AbstractObjectiveThe international literature points to the specific cancer risks and palliative care needs of lesbian, gay and bisexual (LGB) populations. However, with the exception of a programme in the USA, there is a lack of training internationally for health and social care professionals providing oncological and palliative care to LGB patients. In Ireland, a training project funded by the Irish Cancer Society, the Irish Hospice Foundation and the Health Service Executive developed a training pilot programme for health and social care professionals providing oncological and palliative care to LGB patients.MethodsOver 200 (N = 201) oncology and palliative care staff participated in 17 brief, 50‐min trainings in pilot sites. Evaluation of the training included self‐report questionnaires at the end of each training and an evaluation interview with one participant from each of the four sites.ResultsThe majority of participants reported that they would recommend the training to their colleagues, were interested in further training in the area and found the training useful for their practice. They also reported becoming more familiar with LGB‐related language and terminology, became more knowledgeable of LGB health issues and reported becoming more confident in providing care to LGB patients.ConclusionsRecommendations are that the training be made available across the health services in Ireland and included in postgraduate courses for trainee health and social care professionals. Copyright © 2012 John Wiley & Sons, Ltd.
An energy‐based conformer library for side chain optimization: Improved prediction and adjustable sampling
Authors: Subramaniam Sabareesh , Senes Alessandro 
Published: May 2012

AbstractSide chain optimization is a fundamental component of protein modeling applications such as docking, structural prediction, and design. In these applications side chain flexibility is often provided by rotamer or conformer libraries, which are collections of representative side chain conformations. Here we demonstrate that the sampling provided by the library can be substantially improved by adding an energetic criterion to its creation. The result of the new procedure is the Energy‐Based library, a conformer library selected according to the propensity of its elements to fit energetically into natural protein environments. The new library performs outstandingly well in side chain optimization, producing structures with significantly lower energies and resulting in improved side chain conformation prediction. In addition, because the library was created as an ordered list, its size can be adjusted to any desired level. This feature provides unprecedented versatility in tuning sampling. It allows to precisely balance the number of conformers required by each amino acid type, equalizing their chances to fit into structural environments. It also allows to scale the amount of sampling to the specific requirement of any given side optimization problem. A rotameric version of the library was also produced with the same method to support applications that require a dihedral‐only description of side chain conformation. The libraries are available at http://seneslab.org/EBL. Proteins 2012; © 2012 Wiley Periodicals, Inc.
Characterization of the impact of alternative splicing on protein dynamics: The cases of glutathione S‐transferase and ectodysplasin‐A isoforms
Authors: Barbany Montserrat , Morata Jordi , Meyer Tim , Lois Sergi , Orozco Modesto , de la Cruz Xavier 
Published: May 2012

AbstractRecent studies have shown how alternative splicing (AS), the process by which eukaryotic genes express more than one product, affects protein sequence and structure. However, little information is available on the impact of AS on protein dynamics, a property fundamental for protein function. In this work, we have addressed this issue using molecular dynamics simulations of the isoforms of two model proteins: glutathione S‐transferase and ectodysplasin‐A. We have found that AS does not have a noticeable impact on global or local structure fluctuations. We have also found that, quite interestingly, AS has a significant effect on the coupling between key structural elements such as surface cavities. Our results provide the first atom‐level view of the impact of AS on protein dynamics, as far as we know. They can contribute to refine our present view of the relationship between AS and protein disorder and, more importantly, they reveal how AS may modify structural dynamic couplings in proteins. Proteins 2012; © 2012 Wiley Periodicals, Inc.
A dynamic model of long‐range conformational adaptations triggered by nucleotide binding in GroEL‐GroES
Authors: Skjaerven Lars , Muga Arturo , Reuter Nathalie , Martinez Aurora 
Published: May 2012

AbstractThe molecular chaperone, GroEL, essential for correct protein folding in E. coli, is composed of 14 identical subunits organized in two interacting rings, each providing a folding chamber for non‐native substrate proteins. The oligomeric assembly shows positive cooperativity within each ring and negative cooperativity between the rings. Although it is well known that ATP and long‐range allosteric interactions drive the functional cycle of GroEL, an atomic resolution view of how ligand binding modulates conformational adaptations over long distances remains a major challenge. Moreover, little is known on the relation between equilibrium dynamics at physiological temperatures and the allosteric transitions in GroEL. Here we present multiple all‐atom molecular dynamics simulations of the GroEL‐GroES assemblies at different stages of the functional cycle. Combined with an extensive analysis of the complete set of experimentally available structures, principal component analysis and conformer plots, we provide an explicit evaluation of the accessible conformational space of unliganded GroEL. Our results suggest the presence of pre‐existing conformers at the equatorial domain level, and a shift of the conformational ensemble upon ATP‐binding. At the inter‐ring interface the simulations capture a remarkable offset motion of helix D triggered by ATP‐binding to the folding active ring. The reorientation of helix D, previously only observed upon GroES association, correlates with a change of the internal dynamics in the opposite ring. This work contributes to the understanding of the molecular mechanisms in GroEL and highlights the ability of all‐atom MD simulations to model long‐range structural changes and allosteric events in large systems. Proteins 2012;. © 2012 Wiley Periodicals, Inc.
Identification of the G143A mutation associated with QoI resistance in Cercospora beticola field isolates from Michigan, United States
Authors: Bolton Melvin D , Rivera Viviana , Secor Gary 
Published: May 2012

AbstractBACKGROUND: Cercospora leaf spot (CLS), caused by the fungus Cercospora beticola, is the most serious foliar disease of sugar beet (Beta vulgaris L.) worldwide. Disease control is mainly achieved by timely fungicide applications. In 2011, CLS control failures were reported in spite of application of quinone outside inhibitor (QoI) fungicide in several counties in Michigan, United States. The purpose of this study was to confirm the resistant phenotype and identify the molecular basis for QoI resistance of Michigan C. beticola isolates.RESULTS: Isolates collected in Michigan in 1998 and 1999 that had no previous exposure to the QoI fungicides trifloxystrobin or pyraclostrobin exhibited QoI EC50 values of ⩽0.006 µg mL−1. In contrast, all isolates obtained in 2011 exhibited EC50 values of > 0.92 µg mL−1 to both fungicides and harbored a mutation in cytochrome b (cytb) that led to an amino acid exchange from glycine to alanine at position 143 (G143A) compared with baseline QoI‐sensitive isolates. Microsatellite analysis of the isolates suggested that QoI resistance emerged independently in multiple genotypic backgrounds at multiple locations. A real‐time PCR assay utilizing dual‐labeled fluorogenic probes was developed to detect and differentiate QoI‐resistant isolates harboring the G143A mutation from sensitive isolates.CONCLUSION: The G143A mutation in cytb is associated with QoI resistance in C. beticola. Accurate monitoring of this mutation will be essential for fungicide resistance management in this pathosystem. Copyright © 2012 Society of Chemical Industry
Investigation of Ni/Ag contact to p‐GaN with an O2 plasma treatment and its application to GaN‐based LEDs
Authors: Lin Nan‐Ming , Shei Shih‐Chang , Chang Shoou‐Jinn 
Published: May 2012

AbstractIn this paper, the contact structure of Ni–Ag/p‐GaN with different O2 plasma treatment times for 1 and 5 min was utilized for investigation. From experimental results, the Ni–Ag contact to p‐GaN with different O2 plasma treatment for 1 and 5 min reveals Schottky behaviors. Based on the variation of the specific contact resistance with respect to temperature, the dominant transport mechanism of Ni–Ag/p‐GaN structure presented form thermionic emission to field emission as increasing time from 1 to 5 min. From the X‐ray photoelectron spectroscopy (XPS) results, the increase of the N vacancies and antisite defects (ON) would enhance the resistance of the treated p‐GaN underneath the contact, which would make the Ni–Ag/p‐GaN contact reveal Schottky behavior. With a 20 mA current injection, the operation voltage of light‐emitting diodes (LEDs) with Ni/Ag contact to p‐GaN through O2 plasma treatment 400 W–5 min was 3.13 V larger than the LEDs with Ni/Ag contact to p‐GaN through O2 plasma treatment 400 W–1 min. This is due to the larger specific contact resistance. The 3.13 V operation voltage is still good and acceptable. Furthermore, the largest output power among all devices can be achieved. Besides, the reliability is still good.
Influence of annealing atmosphere on optical properties of Al‐doped ZnO powders
Authors: Li Chundong , Lv Jinpeng , Zhou Bo , Liang Zhiqiang 
Published: May 2012

AbstractWe systematically studied the influences of annealing atmosphere on the structural and optical properties of Al‐doped ZnO (AZO) powders by performing anneals in N2, Ar2, H2 and O2 atmospheres. The results indicated that the optical properties were highly influenced by the annealing atmosphere, which were more pronounced for the AZO powders annealed in forming gas and an oxygen atmosphere. The E1 (LO) vibration mode in the Raman spectra exhibits a good correlation with the green emission and is demonstrated to be originated from VO defects. We conclude that both VO and Oi defects give rise to the green photoluminescence in ZnO, and each will play a dominant role in oxygen‐deficient and oxygen‐rich environments, respectively.magnified image
Effect of purple light on the ferroelectric and transport properties of epitaxial Mn‐doped BiFeO3 film
Authors: Peng Zengwei , Liu Baoting , Zhu Huijuan , Zhao Qingxun , Wang Yinglong 
Published: May 2012

AbstractAn epitaxial SrRuO3 (SRO)/BiFe0.95Mn0.05O3 (BFMO)/SRO heterostructure is fabricated on (001)‐SrTiO3 (STO) substrate, in which the SRO film is prepared by magnetron sputtering and the BFMO film is deposited by a sol–gel method. The effect of purple‐light irradiation on the SRO/BFMO/SRO capacitor is studied. It is found that the leakage current density of the SRO/BFMO/SRO capacitor, measured at 5 V, increases from 0.013 A/cm2 in the dark to 0.043 A/cm2 in the light. The change of the hysteresis loop of the capacitor upon irradiation can be interpreted by the trapping of photoinduced charges to incur the reorientation of domain and the increase of the leakage current density. In addition, the capacitance versus voltage (C–V) characteristic of this film is investigated and displays a typical butterfly shape. The above results indicate a potential application of BFMO film for optoelectronic devices.
InGaN quantum wells and dots on initially shaped GaN islands: Growth and luminescence studies
Authors: Xiong H. , Wang G. B. , Fang Z. L. 
Published: May 2012

AbstractDirect growth of InGaN active layers on initially shaped pyramid‐like GaN islands of low dislocation density, realized by enhanced island growth via slightly Si doping in the GaN islands, was investigated in detail. Scanning transmission electron microscopy (STEM) studies reveal the selective growth of relatively thin quantum wells (QWs) on semipolar sidewall facets, whereas In‐rich InGaN quantum dots (QDs) form on the island apex. Spatially resolved scanning electron microscopy (SEM) and cathodoluminescence (CL) studies show strong emission from the island sites, whereas very weak emission arises from the nonisland sites, suggesting the preferential growth of InGaN active layers on the GaN islands rather than on the SiNx‐treated nonisland sites. Polychromatic emissions from the InGaN QWs on island sidewall and top facets, and the In‐rich InGaN QDs on the island apex were observed. Studies on the growth mechanism and properties of InGaN/GaN QWs on nanoscale faceted islands may serve as a nanoscale investigating tool for further studies of GaN island shaping and shape variations during heteroepitaxy in the early growth stages.
Robust modular control system design using an inner‐loop reference model and μ synthesis techniques
Authors: Vermillion Chris , Sun Jing , Butts Ken 
Published: May 2012

SUMMARYFor complex dynamic systems, a modular control design process is often employed, wherein the overall design is partitioned into smaller modules. This paper considers a particular inner‐loop/outer‐loop modular control strategy in which the designer of the outer‐loop module does not know the specifics of the inner loop but instead possesses a reference model that captures the ideal inner‐loop input–output behavior. In the first part of this paper, we establish analytical properties of the modular reference‐model‐based design. In the second part, we introduce a novel mechanism, referred to as the modular control error compensation, which mitigates the performance loss that arises when the inner‐loop reference model is not matched. We propose an iterative algorithm, using μ synthesis, to design this compensator to reduce performance loss on the basis of two concrete worst‐case performance metrics. The effectiveness of the modular control strategy with the modular control error compensation is demonstrated through experimental results on an automotive system. Copyright © 2012 John Wiley & Sons, Ltd.
On the quality of VoIP with DCCP for satellite communications
Authors: Sarwar Golam , Boreli Roksana , Lochin Emmanuel 
Published: May 2012

SUMMARYWe present experimental results for the performance of selected voice codecs using Datagram Congestion Control Protocol (DCCP) with CCID4 congestion control over a satellite link. We evaluate the performance of both constant and variable data rate speech codecs for a number of simultaneous calls using the ITU E‐model. We analyse the sources of packet losses and additionally analyse the effect of jitter, which is one of the crucial parameters contributing to Voice over IP (VoIP) quality and has, to the best of our knowledge, not been considered previously in the published DCCP performance results. We propose modifications to the CCID4 algorithm and demonstrate how these improve the VoIP performance, without the need for additional link information other than what is already monitored by CCID4. We also demonstrate the fairness of the proposed modifications to other flows. Although the recently adopted changes to TCP‐Friendly Rate Control specification alleviate some of the performance issues for VoIP on satellite links, we argue that the characteristics of commercial satellite links necessitate consideration of further improvements. We identify the additional benefit of DCCP when used in VoIP admission control mechanisms and draw conclusions about the advantages and disadvantages of the proposed DCCP/CCID4 congestion control mechanism for use with VoIP applications. Copyright © 2012 John Wiley & Sons, Ltd.