bluuebunny/crossref_metadata_2025 huggingface dataset:
Web 2.0 Reflective Inquiry: A Transformative Literacy Teacher Education Tool
Authors: Pitcher Sharon M.
Published: March 2015

This column features essays written by current middle school and high school teachers, media specialists, librarians, literacy coaches, curriculum specialists, administrators, preservice teachers, teacher educators, and adolescent and adult learners. They highlight diverse perspectives on teaching and/or learning with literacies to inspire reader reflection.
Curricular Reforms in Mexico
Authors: López‐Bonilla Guadalupe
Published: March 2015

In this article I present recent educational reforms implemented in Mexico and their implications for literacy instruction; in particular, I analyze changes to upper secondary education that seemingly want to promote the development of “disciplinary competences” among students enrolled in different educational tracks. The debates among the different stakeholders, the risks of poorly conceived policies, and the mediation role of participants involved in the enactment of such policies are finally discussed.
Print‐Based Texts
Authors: Blasingame James
Published: March 2015

This column provides reviews of adolescent and adult literature and provides a valuable resource for literature selection in‐ and outside the classroom.
Professional Resources
Authors: Hucks Darrell Cleveland , Fasching‐Varner Kenneth , Haddix Marcelle M.
Published: March 2015

This column provides reviews of adolescent and adult professional resources and provides a valuable resource for professional resource selection in‐ and outside the classroom.
Post‐Translational Modifications of Histones in Human Sperm
Authors: Krejčí Jana , Stixová Lenka , Pagáčová Eva , Legartová Soňa , Kozubek Stanislav , Lochmanová Gabriela , Zdráhal Zbyněk , Sehnalová Petra , Dabravolski Siarhei , Hejátko Jan , Bártová Eva
Published: March 2015

We examined the levels and distribution of post‐translationally modified histones and protamines in human sperm. Using western blot immunoassay, immunofluorescence, mass spectrometry (MS), and FLIM‐FRET approaches, we analyzed the status of histone modifications and the protamine P2. Among individual samples, we observed variability in the levels of H3K9me1, H3K9me2, H3K27me3, H3K36me3, and H3K79me1, but the level of acetylated (ac) histones H4 was relatively stable in the sperm head fractions, as demonstrated by western blot analysis. Sperm heads with lower levels of P2 exhibited lower levels of H3K9ac, H3K9me1, H3K27me3, H3K36me3, and H3K79me1. A very strong correlation was observed between the levels of P2 and H3K9me2. FLIM‐FRET analysis additionally revealed that acetylated histones H4 are not only parts of sperm chromatin but also appear in a non‐integrated form. Intriguingly, H4ac and H3K27me3 were detected in sperm tail fractions via western blot analysis. An appearance of specific histone H3 and H4 acetylation and H3 methylation in sperm tail fractions was also confirmed by both LC‐MS/MS and MALDI‐TOF MS analysis. Taken together, these data indicate that particular post‐translational modifications of histones are uniquely distributed in human sperm, and this distribution varies among individuals and among the sperm of a single individual. J. Cell. Biochem. 116: 2195–2209, 2015. © 2015 Wiley Periodicals, Inc.
Solvents effects on the mechanism of cellulose hydrolysis: A QM/MM study
Authors: Loerbroks Claudia , Heimermann Andreas , Thiel Walter
Published: March 2015

This article reports a combined quantum mechanics/molecular mechanics (QM/MM) investigation on the acid hydrolysis of cellulose in water using two different models, cellobiose and a 40‐unit cellulose chain. The explicitly treated solvent molecules strongly influence the conformations, intramolecular hydrogen bonds, and exoanomeric effects in these models. As these features are largely responsible for the barrier to cellulose hydrolysis, the present QM/MM results for the pathways and reaction intermediates in water are expected to be more realistic than those from a former density functional theory (DFT) study with implicit solvent (CPCM). However, in a qualitative sense, there is reasonable agreement between the DFT/CPCM and QM/MM predictions for the reaction mechanism. Differences arise mainly from specific solute–solvent hydrogen bonds that are only captured by QM/MM and not by DFT/CPCM. © 2015 Wiley Periodicals, Inc.
Perceived Burdensomeness and Thwarted Belongingness Predict Excessive Reassurance Seeking Among Clinical Outpatients
Authors: Hames Jennifer L. , Chiurliza Bruno , Podlogar Matthew C. , Smith April R. , Selby Edward A. , Anestis Michael D. , Joiner Thomas E.
Published: March 2015

Objective

The current study aimed to investigate whether perceived burdensomeness and thwarted belongingness (i.e., suicide risk factors) were associated with excessive reassurance seeking (a behavior linked to rejection). It was predicted that perceived burdensomeness and thwarted belongingness would predict higher levels of excessive reassurance seeking, controlling for depressive symptoms and global functioning.

Method

A cross‐sectional sample of 415 clinical outpatients (62% female; mean age = 28) was examined.

Results

Perceived burdensomeness and thwarted belongingness significantly predicted excessive reassurance seeking, controlling for depressive symptoms and global functioning.

Conclusions

Perceived burdensomeness and thwarted belongingness predicted excessive reassurance seeking, suggesting that it would be beneficial for clinicians to assess for and target excessive reassurance seeking among individuals experiencing perceived burdensomeness and thwarted belongingness so that excessive reassurance seeking does not elicit interpersonal rejection.
Cell cycle gene expression networks discovered using systems biology: Significance in carcinogenesis
Authors: Scott Robert E. , Ghule Prachi N. , Stein Janet L. , Stein Gary S.
Published: March 2015

The early stages of carcinogenesis are linked to defects in the cell cycle. A series of cell cycle checkpoints are involved in this process. The G1/S checkpoint that serves to integrate the control of cell proliferation and differentiation is linked to carcinogenesis and the mitotic spindle checkpoint is associated with the development of chromosomal instability. This paper presents the outcome of systems biology studies designed to evaluate if networks of covariate cell cycle gene transcripts exist in proliferative mammalian tissues including mice, rats, and humans. The GeneNetwork website that contains numerous gene expression datasets from different species, sexes, and tissues represents the foundational resource for these studies (www.genenetwork.org). In addition, WebGestalt, a gene ontology tool, facilitated the identification of expression networks of genes that co‐vary with key cell cycle targets, especially Cdc20 and Plk1 (www.bioinfo.vanderbilt.edu/webgestalt). Cell cycle expression networks of such covariate mRNAs exist in multiple proliferative tissues including liver, lung, pituitary, adipose, and lymphoid tissues among others but not in brain or retina that have low proliferative potential. Sixty‐three covariate cell cycle gene transcripts (mRNAs) compose the average cell cycle network with P = e−13 to e−36. Cell cycle expression networks show species, sex and tissue variability, and they are enriched in mRNA transcripts associated with mitosis, many of which are associated with chromosomal instability. J. Cell. Physiol. 230: 2533–2542, 2015. © 2015 Wiley Periodicals, Inc.
Single‐dose evaluation of safety, tolerability and pharmacokinetics of newly formulated hydromorphone immediate‐release and hydrophilic matrix extended‐release tablets in healthy Japanese subjects without co‐administration of an opioid antagonist
Authors: Toyama Kaoru , Uchida Naoki , Ishizuka Hitoshi , Sambe Takehiko , Kobayashi Shinichi
Published: March 2015

This single dose, open‐label study investigated the safety, tolerability and pharmacokinetics of single oral doses of newly formulated immediate‐release (IR) and hydrophilic matrix extended‐release (ER) hydromorphone tablets in healthy Japanese subjects without co‐administration of an opioid antagonist under fasting and fed conditions. Plasma and urinary concentrations of hydromorphone and metabolites were measured by liquid‐chromatography tandem mass‐spectroscopy. Following administration of the ER tablet, plasma concentrations of hydromorphone slowly increased with a median tmax of 5.0 h and the Cmax decreased to 37% of the IR tablet, while the AUC0‐inf was comparable with that of the IR tablet when administered at the same dose. The degree of fluctuation in the plasma concentration for the ER tablet was much lower than that of the IR tablet and certain levels of plasma concentrations were maintained after 24 h of ER dosing. The AUC0‐inf and Cmax increased with food for both IR and ER tablets. The AUC0‐inf of hydromorphone‐3‐glucoside was one‐tenth of that of hydromorphone‐3‐glucuronide. A single oral administration of the hydromorphone tablets would be well‐tolerated in healthy Japanese subjects despite a lack of co‐administration of an opioid antagonist and the newly developed ER hydromorphone tablets may have the appropriate PK characteristics for once‐daily dosing.
Mouse brain magnetic resonance microscopy: Applications in Alzheimer disease
Authors: Lin Lan , Fu Zhenrong , Xu Xiaoting , Wu Shuicai
Published: March 2015

Over the past two decades, various Alzheimer's disease (AD) trangenetic mice models harboring genes with mutation known to cause familial AD have been created. Today, high‐resolution magnetic resonance microscopy (MRM) technology is being widely used in the study of AD mouse models. It has greatly facilitated and advanced our knowledge of AD. In this review, most of the attention is paid to fundamental of MRM, the construction of standard mouse MRM brain template and atlas, the detection of amyloid plaques, following up on brain atrophy and the future applications of MRM in transgenic AD mice. It is believed that future testing of potential drugs in mouse models with MRM will greatly improve the predictability of drug effect in preclinical trials. Microsc. Res. Tech. 78:416–424, 2015. © 2015 Wiley Periodicals, Inc.
Medical management of patients on clozapine: A guide for internists
Authors: Lundblad Wynne , Azzam Pierre N. , Gopalan Priya , Ross Clinton A. , PharmD
Published: March 2015

Clozapine was approved by the US Food and Drug Administration in 1989 for the management of treatment‐resistant schizophrenia, and has since proven to reduce symptom burden and suicide risk, increase quality of life, and reduce substance use in individuals with psychotic disorders. Nevertheless, clozapine's psychiatric benefits have been matched by its adverse effect profile. Because they are likely to encounter medical complications of clozapine during admissions or consultations for other services, hospitalists are compelled to maintain an appreciation for these iatrogenic conditions. The authors outline common (eg, constipation, sialorrhea, weight gain) and serious (eg, agranulocytosis, seizures, myocarditis) medical complications of clozapine treatment, with internist‐targeted recommendations for management, including indications for clozapine discontinuation. Journal of Hospital Medicine 2015;10:537–543. © 2015 Society of Hospital Medicine
Which Factors Drive the Regional Expansion of Microfinance Institutions? Evidence from Peru
Authors: Vanroose Annabel
Published: March 2015

This paper analyses the location decisions and geographical expansion of microfinance institutions (MFIs) across Peru. To this end, econometric analyses are performed on a self‐constructed dataset that covers MFI presence and expansion in the 1832 districts of Peru, and this for 39 MFIs and 13 commercial banks over the period 2001–2008. The paper shows that Peruvian MFIs have expanded considerably during the last decade. MFIs especially increase access in districts with higher levels of development and therefore seem to follow principally a commercial logic. Districts with banks have also a higher probability of an MFI opening. Copyright © 2015 John Wiley & Sons, Ltd.
Three‐dimensional virtual histology of silurian osteostracan scales revealed by synchrotron radiation microtomography
Authors: Qu Qingming , Blom Henning , Sanchez Sophie , Ahlberg Per
Published: March 2015

We used propagation phase contrast X‐ray synchrotron microtomography to study the three‐dimensional (3D) histology of scales of two osteostracans, Tremataspis and Oeselaspis, members of a jawless vertebrate group often cited as the sister group of jawed vertebrates. 3D‐models of the canal systems and other internal structures are assembled based on the virtual thin section datasets and compared with previous models based on real thin sections. The primary homology framework of the canal systems in the two taxa is revised and new histological details are revealed based on the results of this work. There is no separation of vascular canals and lower mesh canals in the Tremataspis scale, contrary to previous results. The secondary upper mesh canals have a limited distribution to the anterior region of the Tremataspis scale. The upper and lower mesh canal systems of Tremataspis have different geometries, inferred to reflect different developmental origins: we interpret the upper system as a probable epithelial invagination, the lower system as entirely vascular. Oeselaspis has no equivalent of the upper mesh canal system. The upper mesh canal system of Tremataspis may have been sensory in function. In Oeselaspis, numerous polyp‐shaped structures opening from the canal system onto the surface of the scale resemble the innervation tracts for neuromast organs. The growth of the Oeselaspis scale proceeds by addition of small odontodes containing unmineralized lacunae, which may further mineralize and become more compact. Our results highlight that 3D‐histological investigation on scales and other dermal skeletons of osteostracans is necessary to fully appreciate the diversity of skeletal histologies in the group. Traditional 3D‐models based on thin sections alone are not reliable and should no longer be used as the basis for homology assessments or functional hypotheses. J. Morphol. 276:873–888, 2015. © 2015 Wiley Periodicals, Inc.
Off‐resonance saturation ratio obtained with ultrashort echo time‐magnetization transfer techniques is sensitive to changes in static tensile loading of tendons and degeneration
Authors: Chang Eric Y. , Du Jiang , Biswas Reni , Statum Sheronda , Pauli Chantal , Bae Won C. , Chung Christine B.
Published: March 2015

Background

To determine if off‐saturation ratio (OSR) measured with the ultrashort echo time magnetization transfer (UTE‐MT) sequence could differentiate between tendons under different states of tensile load and to compare these changes between normal versus degenerated tendons.

Methods

Fourteen tendons were imaged at 3 Tesla before and during the application of 0.5–1 kg tension. A two‐dimensional (2D) ‐UTE‐MT sequence with 1.5, 3, and 5 kHz frequency offsets was used on nine tendons and a 3D‐UTE‐MT sequence with 1.5 kHz frequency offset was used on five tendons. OSR was calculated and compared for each condition. Histologic correlation was performed using light microscopy.

Results

In general, OSR increased after the application of tension. Mean increase of 2D OSR was 0.035 (95% confidence interval [CI], 0.013–0.056) at 1.5 kHz offset (P < 0.01), 0.031 (95% CI, 0.023–0.040) at 3 kHz offset (P < 0.01), and 0.013 (95% CI, −0.013–0.027) at 5 kHz offset (P = 0.07) from pre‐ to posttension states. Mean increase of 3D OSR was 0.026 (95% CI, 0.008–0.044) at a 1.5 kHz offset (P = 0.02) from pre‐ to posttension states. Mean decrease of 2D OSR at 1.5 kHz offset was 0.074–0.087 when comparing normal versus degenerated tendons (P < 0.01).

Conclusion

OSR as measured with 2D or 3D UTE‐MT sequences can detect the changes in hydration seen when tendons are placed under two different states of tensile load, but these changes are smaller than those encountered when comparing between normal versus pathologic tendons. Lower off‐resonance saturation frequencies (3 kHz or less) are more sensitive to these changes than higher off‐resonance saturation frequencies.J. Magn. Reson. Imaging 2015. J. Magn. Reson. Imaging 2015;42:1064–1071.
Self‐Compassion as a Prospective Predictor of PTSD Symptom Severity Among Trauma‐Exposed U.S. Iraq and Afghanistan War Veterans
Authors: Hiraoka Regina , Meyer Eric C. , Kimbrel Nathan A. , DeBeer Bryann B. , Gulliver Suzy Bird , Morissette Sandra B.
Published: March 2015

U.S. combat veterans of the Iraq and Afghanistan wars have elevated rates of posttraumatic stress disorder (PTSD) compared to the general population. Self‐compassion, characterized by self‐kindness, a sense of common humanity when faced with suffering, and mindful awareness of suffering, is a potentially modifiable factor implicated in the development and maintenance of PTSD. We examined the concurrent and prospective relationship between self‐compassion and PTSD symptom severity after accounting for level of combat exposure and baseline PTSD severity in 115 Iraq and Afghanistan war veterans exposed to 1 or more traumatic events during deployment. PTSD symptoms were assessed using the Clinician Administered PTSD Scale for DSM‐IV (CAPS‐IV) at baseline and 12 months (n =101). Self‐compassion and combat exposure were assessed at baseline via self‐report. Self‐compassion was associated with baseline PTSD symptoms after accounting for combat exposure (β = −.59; p < .001; ΔR2 = .34; f2 = .67; large effect) and predicted 12‐month PTSD symptom severity after accounting for combat exposure and baseline PTSD severity (β = −.24; p = .008; ΔR2 = .03; f2 = .08; small effect). Findings suggest that interventions that increase self‐compassion may be beneficial for treating chronic PTSD symptoms among some Iraq and Afghanistan war veterans.
Critical Incident History Questionnaire Replication: Frequency and Severity of Trauma Exposure Among Officers From Small and Midsize Police Agencies
Authors: Chopko Brian A. , Palmieri Patrick A. , Adams Richard E.
Published: March 2015

Frequency and severity of trauma exposure are thought to influence posttraumatic reactions. Weiss et al.’s Critical Incident History Questionnaire (CIHQ; 2010) measures these variables among law enforcement officers; they reported findings using a sample of officers from large urban departments. We noted the need for replication studies utilizing samples from smaller and rural police agencies. The purpose of this study was to replicate the CIHQ findings from Weiss et al. using a sample (N = 193) of officers from small and midsize police departments and officers whose duties include policing rural and isolated jurisdictions. Frequency and severity findings were similar to those reported by Weiss et al. (2010). Regarding frequency, the present study found the critical incident exposure mean score was 188.5, compared to 168.5 from Weiss et al. (2010). Making a mistake that kills or injures a colleague had the highest mean nomothetic severity rating in both studies. Among the various variables examined in this study, PTSD symptoms demonstrated the strongest association with the exposure indices, based on Spearman rank correlations (r = .26–.46).
Design and manufacture of umanned aerial vehicles (UAV) wing structure using composite materials
Authors: Grodzki W. , Łukaszewicz A.
Published: March 2015

This paper presents possibilities of simulating composites materials in SolidWorks environment and selected aspects of the unmanned aerial vehicle (UAV) design and manufacturing process (real airplane model was used in Air Cargo Challenge 2013 competition). First part of article contains informations about types of composite materials, mechanical properties and their structures. UAV wing design process is presented as multistage task. Next part of manuscript includes numerical analysis which deals with two cases of composites structures: laminates and sandwich composites. Differences in values of displacement and principal stresses (P1, P3) were shown in considered structures based on equal boundary conditions. Final part of article deals with development of manufacture process.
Vascular considerations in foot and ankle free tissue transfer: Analysis of 231 free flaps
Authors: Cho Eugenia H. , Garcia Ryan M. , Pien Irene , Kuchibhatla Maragatha , Levinson Howard , Erdmann Detlev , Levin L. Scott , Hollenbeck Scott T.
Published: March 2015

Objective

Successful foot and ankle soft tissue reconstruction is dependent on a clear understanding of the vascular supply to the foot. The aim of this study was to identify risk factors for reconstructive failure following foot and ankle free tissue transfer.

Methods

The authors retrospectively reviewed their 17‐year institutional experience with 231 foot and ankle free flaps performed in 225 patients to determine predictors of postoperative foot ischemia and flap failure. Postoperative foot ischemia was defined as ischemia resulting in tissue necrosis, separate from the reconstruction site.

Results

Six (3%) patients developed postoperative foot ischemia, and 28 (12%) patients experienced flap failure. Chronic ulceration (P = 0.02) and an elevated preoperative platelet count (P = 0.04) were independent predictors of foot ischemia. The presence of diabetes was predictive of flap failure (P = 0.05). Flap failure rates were higher in the setting of an abnormal preoperative angiogram (P = 0.04), although the type and number of occluded arteries did not influence outcome. Foot ischemia was more frequent following surgical revascularization in conjunction with free tissue transfer and the use of the distal arterial bypass graft for flap anastomosis (P < 0.01). Overall, no differences were observed in foot ischemia (P = 0.17) and flap failure (P = 0.75) rates when the flap anastomosis was performed to the diseased artery noted on angiography, compared with an unobstructed native tibial artery.

Conclusions

Foot and ankle free tissue transfer may be performed with a low incidence of foot ischemia. Patients with diabetes, chronic ulceration, and an elevated preoperative platelet count are at higher risk for reconstructive failure. © 2015 Wiley Periodicals, Inc. Microsurgery 36:276–283, 2016.
Synthesis of Poly(Sodium Acrylate) Nanogels Via Semicontinuous Inverse Heterophase Polymerization
Authors: Silva Jorge Manuel , Bautista Fernando , Sánchez‐Díaz Juan Carlos , Nuño‐Donlucas Sergio Manuel , Puig J. E. , Hernández Elena
Published: March 2015

The synthesis of superabsorbent poly(sodium acrylate) by semicontinuous inverse heterophase polymerization is reported here. In this process, an aqueous solution of sodium acrylate, initiator, and a cross‐linking agent is dosed at a controlled rate over an organic solution containing surfactant. These nanogels exhibit a large swelling ratio (compared to the dry nanoparticles synthesized by inverse microemulsion polymerization), which increase to some extent with temperature, but then at ca. 30 °C, they de‐swell slightly. Possible explanations to this behavior are the release of residual stresses originated during nanoparticles purification and drying, the association–dissociation of ionic clusters, and the thermoelastic inversion point of the elastic modulus of the nanogels.
Prevalence and triage of first‐contact complaints on pelvic floor dysfunctions in female patients at a Pelvic Care Centre
Authors: Berghmans Bary , Nieman Fred , Leue C. , Weemhoff M. , Breukink S. , van Koeveringe G.
Published: March 2015

Aims

(i) To describe and analyse pelvic floor dysfunction symptoms in women referred to a Pelvic Care Centre (PCC). (ii) To describe the triage process of the same patients based on response to a first‐contact interview.

Methods

Triage started with a telephone interview using previously constructed questions, asking for seven types of PF complaints during the preceding 6 months. If present, complaint severity was registered on a 0–10 scale. Next, these first‐contact complaints were used to describe patient case mix profiles using cross‐tabular analysis. Later on, at first PCC visit, an intake questionnaire containing questions on specific PF health problem(s) was filled out. This procedure contributed to a firm baseline characterization of the individual patient profile and a clinically valid allocation to structured, predefined assessment, and treatment.

Results

From 2005 to 2013, 4473 first‐time patients (mean age 56.9 (SD 16.2) have been referred to the PCC. Most frequently mentioned complaints: voiding dysfunction (59.5%), urinary incontinence (46.6%), prolapse (41.1%), fecal incontinence (15.1%), constipation (12.6%), and sexual problems (4.6%). A first appointment to a single specialist was determined in 3.110 (69.5%) patients, in 1.192 (26.7%) consultation of >1 specialist. Data analysis revealed higher‐order interactions between PF complaints, suggesting patient profile complexity and patient population heterogeneity.

Conclusions

More than one out of four PCC patients showed multifactorial problems, needing >1 specialist. PF complaints either turned out to stand alone or cluster with others, or even to strengthen, weaken, nullify, or inverse relationships. Neurourol. Urodynam. 35:503–508, 2016. © 2015 Wiley Periodicals, Inc.
Evaluation of cartilage repair and osteoarthritis with sodium MRI
Authors: Zbýň Štefan , Mlynárik Vladimír , Juras Vladimir , Szomolanyi Pavol , Trattnig Siegfried
Published: March 2015

The growing need for early diagnosis and higher specificity than that which can be achieved with morphological MRI is a driving force in the application of methods capable of probing the biochemical composition of cartilage tissue, such as sodium imaging. Unlike morphological imaging, sodium MRI is sensitive to even small changes in cartilage glycosaminoglycan content, which plays a key role in cartilage homeostasis. Recent advances in high‐ and ultrahigh‐field MR systems, gradient technology, phase‐array radiofrequency coils, parallel imaging approaches, MRI acquisition strategies and post‐processing developments have resulted in many clinical in vivo sodium MRI studies of cartilage, even at 3 T. Sodium MRI has great promise as a non‐invasive tool for cartilage evaluation. However, further hardware and software improvements are necessary to complete the translation of sodium MRI into a clinically feasible method for 3‐T systems. This review is divided into three parts: (i) cartilage composition, pathology and treatment; (ii) sodium MRI; and (iii) clinical sodium MRI studies of cartilage with a focus on the evaluation of cartilage repair tissue and osteoarthritis. Copyright © 2015 John Wiley & Sons, Ltd.
A control‐theoretic approach towards joint admission control and resource allocation of cloud computing services
Authors: Dechouniotis Dimitrios , Leontiou Nikolaos , Athanasopoulos Nikolaos , Christakidis Athanasios , Denazis Spyros
Published: March 2015

Meeting the performance specifications of consolidated web services in a data center is challenging, as the control of the underlying cloud computing infrastructure must meet the service level agreement requirements and satisfy the system's constraints. In this article, we address the admission control and resource allocation problem jointly, by establishing a unified modeling and control framework. Convergence to a desired reference point and stability and feasibility of the control strategy are guaranteed while achieving high performance of the co‐hosted web applications. The efficacy of the proposed approach is illustrated in a real test bed. Copyright © 2015 John Wiley & Sons, Ltd.
Reactive blending of PE‐GMA/PA6 effect of composition and processing conditions
Authors: Kossentini‐Kallel Tasnim , Houichi Hikmet
Published: March 2015

Blends of ethylene‐glycidyl methacrylate copolymer (PE‐GMA) and polyamide 6 (PA6) were prepared in a corotating twin screw extruder. Two processing temperatures were used in order to disperse PA6 in two forms: at high temperature in the molten state in molted PE‐GMA Matrix (emulsion type mixture) and at lower temperature as fillers in molted PEGMA matrix (suspension type mixture). Processed blends were analyzed by scanning electron microscopy and dynamic mechanical experiments to probe the reactivity in the extruder and the compatibilization phenomena. The dependence of the morphology and the rheological properties of PE‐GMA/PA6 blends on blend composition and screw rotational speed was also investigated and is discussed in the paper. The results show that dispersion of the two polymers in the molten state leads to a higher level of interfacial reaction. They also show that whatever the screw rotational speed and the temperature of extrusion are, the rate of interfacial reaction in PE‐GMA/PA6 blends is higher for 50/50 PE‐GMA/PA blends than for 70/30 PE‐GMA/PA blends. Copyright © 2015 John Wiley & Sons, Ltd.
Preparation of poly (L‐lactic acid) with aligned structures by unidirectional freezing
Authors: Chu Yeqian , Lu Zhen , Li Junjie , Zhu Yun , Zhang Shengmiao , Chen Jianding
Published: March 2015

Honeycomb monolith structured porous poly (L‐lactic acid, PLA) was simply fabricated by employing a unidirectional freeze‐casting technique. Dimethyl sulfoxide (DMSO) was used as a solvent for PLA, and the solution was unidirectionally frozen. The DMSO was nucleated in the solution and was grown in the freezing direction. The PLA was solidified and structured with the DMSO crystal as a template. Then DMSO was leached by water, ethanol, or the mixture of them, and subsequently the porous PLA was dried by oven. It was found that the freeze‐casting protocol can significantly influence the morphological features such as the tube diameter and wall thickness of tube can be tuned by varying of PLA concentration, freezing temperature, and the nature of leaching solvent. Because DMSO has a special solubility of a number of polymers, this method may be a general way for designing and preparing aligned porous materials. Copyright © 2015 John Wiley & Sons, Ltd.
Amphiphilic poly(ethylene glycol) gels and their swelling features
Authors: Yati Ilker , Karadag Koksal , Sonmez Hayal Bulbul
Published: March 2015

This article describes the preparation of poly(ethylene glycol) (PEG) ‐based gels for removal of both organic solvents and water through a clean synthesis process without using any initiator, catalyst, activator, or liquid medium. The synthesis of the gels is based on the condensation of different molecular weights of PEG macromolecules with the nine‐functional crosslinker tris[3‐(trimethoxysilyl) propyl] isocyanurate (ICS). Solid‐state 13C and 29Si cross‐polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), and elemental analysis were used to characterize the prepared sorbents. Thermal properties of the synthesized sorbents were examined using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The swelling capacities of the sorbents were determined by swelling tests in dichloromethane (DCM), tetrahydrofuran (THF), benzene, acetone, and toluene. The water absorbency of the PEG‐based sorbents is also investigated. The effect of the reaction time and reaction temperature on swelling features of the sorbents was studied systematically. The prepared PEG gels have high swelling ratios both in polar and nonpolar solvents. Copyright © 2015 John Wiley & Sons, Ltd.
Novel polyimides obtained from a new aromatic diamine (BAPO) containing pyridine and 1,3,4‐oxadiazole moieties for removal of Co(II) and Ni(II) ions
Authors: Mansoori Yagoub , Ghanbari Mina
Published: March 2015

Novel, thermally stable polyimides (PIs) containing a 1,3,4‐oxadiazole and pyridine moieties based on a new aromatic diamine 2,5‐bis‐(aminopyridine‐2‐yl)‐1,3,4‐oxadiazole, BAPO, were synthesized. The prepared polymers were soluble in dimethysulfoxide (DMSO) and concentrated sulfuric acid at room temperature as well as in polar and aprotic solvents, such as, N‐methylpyrrolidone (NMP) and N,N‐dimethylacetamide (DMAc) at elevated temperature. Thermal behaviors of the PIs were studied by thermogravimetric analysis/dynamic thermal analysis (TGA‐DTA) and differential scanning calorimetry (DSC). The inherent viscosities of the PI solutions were in the range of 0.38–0.61 dl/g (in DMSO with a concentration of 0.125 g/dl at 25 ± 0.5°C). The removal of Co(II) and Ni(II) ions from aqueous solutions was performed using polymer 6, which was obtained from BAPO and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA). The maximum adsorption capacity was observed for Co(II) ion at pH = 7.0 (110.4 mg g−1, 1.87 mmol g−1). Copyright © 2015 John Wiley & Sons, Ltd.
SIOP‐PODC adapted risk stratification and treatment guidelines: Recommendations for neuroblastoma in low‐ and middle‐income settings
Authors: Parikh Nehal S. , Howard Scott C. , Chantada Guillermo , Israels Trijn , Khattab Mohammed , Alcasabas Patricia , Lam Catherine G. , Faulkner Lawrence , Park Julie R. , London Wendy B. , Matthay Katherine K.
Published: March 2015

Neuroblastoma is the most common extracranial solid tumor in childhood in high‐income countries (HIC), where consistent treatment approaches based on clinical and tumor biological risk stratification have steadily improved outcomes. However, in low‐ and middle‐ income countries (LMIC), suboptimal diagnosis, risk stratification, and treatment may occur due to limited resources and unavailable infrastructure. The clinical practice guidelines outlined in this manuscript are based on current published evidence and expert opinions. Standard risk stratification and treatment explicitly adapted to graduated resource settings can improve outcomes for children with neuroblastoma by reducing preventable toxic death and relapse. Pediatr Blood Cancer 2015;62:1305–1316. © 2015 The Authors. Pediatric Blood & Cancer, published by Wiley Periodicals, Inc.
Growth patterns during and after treatment in patients with pediatric ALL: A meta‐analysis
Authors: Zhang Fang Fang , Liu Shanshan , Chung Mei , Kelly Michael J.
Published: March 2015

Background

Survivors of pediatric acute lymphoblastic leukemia (ALL) have a significantly higher body mass index (BMI) than their peers. Understanding the critical time periods in which patients with pediatric ALL are vulnerable to unhealthy weight gain will lay the groundwork for developing effectively timed interventions.

Procedure

We determined the growth patterns of patients with pediatric ALL during and after treatment through the conduct of a systematic review and meta‐analysis. A search of MEDLINE, Scopus, and Web of Science was performed from its inception through May 2014. Studies met the inclusion criteria if they included at least 10 patients of pediatric ALL, and longitudinally assessed BMI at diagnosis and at least one time point after diagnosis

Results

Twenty‐one studies met the inclusion criteria for the systematic review and 16 were included in meta‐analysis. The mean increase in BMI z‐score during treatment in 1,514 patients with pediatric ALL was 0.81 (95% CI: 0.25–1.38). Specifically, patients experienced substantial weight gain in early treatment (Δ = 0.41, 95% CI: −0.34, 1.17) and again during maintenance (Δ = 0.34, 95% CI:−0.22, 0.90). The mean increase in BMI z‐score ranged between 0.52 and 0.89 beyond treatment completion. Subgroup analyses found unhealthy weight gain occurred regardless of patients' receipt of cranial radiation therapy, sex, and, weight status at diagnosis.

Conclusions

Patients with pediatric ALL experience unhealthy weight gain early in treatment, and increases in weight are maintained beyond treatment completion. Preventing early onset of obesity is a priority for improving the care and outcomes for patients with pediatric ALL. Pediatr Blood Cancer 2015;62:1452–1460. © 2015 Wiley Periodicals, Inc.
Characterization of anisotropic permeability from flow front angle measurements
Authors: Di Fratta Claudio , Koutsoukis Grigorios , Klunker Florian , Trochu François , Ermanni Paolo
Published: March 2015

Textile permeability is a generally anisotropic material property, which characterizes the ease of establishing a resin flow through the fibrous reinforcement in Liquid composite molding (LCM) processes. Unidirectional injection experiments are commonly performed to determine in‐plane permeability. Effective permeability values have to be measured along three different textile directions to calculate the full in‐plane permeability tensor. This article presents a strategy to reduce the number of the required unidirectional experiments to two or even one by considering the angle that the flow front forms with the measurement direction. The relationship between this flow front angle and the permeability tensor elements was derived theoretically and verified by both simulations and experiments with various textile reinforcements. In addition, two methods were investigated to measure the flow front angle and the effective permeability during the experiments: a standard approach based on visual observations and a new method that relies on three pressure sensors, applicable also in the case of nontransparent tooling. The results show that: (I) the two methods provide consistent measurements and are substantially equivalent; (II) the strategy devised to characterize permeability by measuring the flow front angle is effective and accurate; (III) the proposed procedure allows reducing considerably the time and the material samples required for permeability characterization by unidirectional experiments. POLYM. COMPOS., 37:2037–2052, 2016. © 2015 Society of Plastics Engineers
Recovery of carbon fibers from cured and uncured carbon fiber reinforced composites wastes and their use as feedstock for a new composite production
Authors: Giorgini Loris , Benelli Tiziana , Mazzocchetti Laura , Leonardi Chiara , Zattini Giorgio , Minak Giangiacomo , Dolcini Enrico , Cavazzoni Massimo , Montanari Ivan , Tosi Cristian
Published: March 2015

Cured and uncured scraps from manufacturing of epoxy based carbon fiber reinforced composites were treated with a pyrolytic process to provide, as solid residue, carbon fibers to be re‐used in new composites production. The industrial scraps were pyrolyzed at different temperatures in a 70 kg batch pilot plant and the pyrolysis products (gas, oil, and solid) were fully characterized. The solid residue (carbon fibers covered by a carbonaceous layer) was subjected to a further oxidative step at 500 and 600°C for different residence times to provide fibers devoid of any organic residue that did not volatilize during pyrolysis. The effects of both pyrolysis and oxidative process on the recovered fibers were evaluated by scanning electron microscopy and Raman Spectroscopy. The reinforcement behavior of pyrolyzed and pyrolyzed/oxidized chopped fibers, compared to virgin fibers, was tested in the production of new Chopped Carbon Fiber Reinforced Composites. The optimized double pyrolysis/oxidation process was found to provide fibers whose performance in the composites were comparable to the virgin ones. POLYM. COMPOS., 36:1084–1095, 2015. © 2015 Society of Plastics Engineers
Polyamide/carbonaceous particles nanocomposites fibers: Morphology and performances
Authors: Arrigo Rossella , Dintcheva Nadka Tzankova , Nasillo Giorgio , Caponetti Eugenio
Published: March 2015

In this work, the influence of carbonaceous particles with different sizes and shapes on the morphology and mechanical performances of polyamide (PA)‐based fibers was investigated. Graphene nanoplatelets (GNP) are compared with spherical and rod‐like carbon fillers such as carbon black (CB) and multiwall carbon nanotubes (CNTs). The increments of the complex viscosity as well as elastic and loss moduli, in the melt state, assessed by rheological analysis, are reduced by modifying polyamide (PA) matrix with nanofillers in a following order: CNTs > GNP > CB. All the nanocomposites, however, show viscosity and moduli higher than those of neat PA. The CB loading causes a mere increase of the viscosity without altering the relaxation spectrum of PA macromolecules, differently, both GNP and CNTs generate significant rheological alteration suggesting a good dispersion into PA and probable formation of semi‐three‐dimensional network. The increase of rigidity of the neat PA and all the three investigated nanocomposites fibers as a function of the cold draw follows the same trend observed by the rheological investigation. The morphology changes of PA achieved upon extensional flow and nanofillers adding have been investigated through transmission electron microscopy observations. Furthermore, the variation of the crystalline PA phase due to filler loading and stretching is also detected by thermal analysis and nuclear magnetic resonance analysis in the solid state. The different morphologies of the particles control and determine their dispersion and alignment in PA fibers upon elongational flow and play a key role in structure‐property relationships. POLYM. COMPOS., 36:1020–1028, 2015. © 2015 Society of Plastics Engineers
Synthesis, characterization, and use as emissive layer of white organic light emitting diodes of the highly isotactic poly(N‐pentenyl‐carbazole)
Authors: Botta Antonio , Pragliola Stefania , Venditto Vincenzo , Rubino Alfredo , Aprano Salvatore , De Girolamo Del Mauro Anna , Grazia Maglione Maria , Minarini Carla
Published: March 2015

The synthesis and the microstructural characterization of isotactic poly (N‐pentenyl‐carbazole) (i‐PPK) are reported. The achieved polymer is semicrystalline, the melting temperature is 138°C. i‐PPK Fourier transform infrared spectroscopy (FTIR) spectrum and X‐ray diffraction pattern are compared with those of polyvinylcarbazole. The observed differences are tentatively associated to higher flexibility of the i‐PPK chains due to the alkylene group connecting the carbazole group to the main chain. The presence of intrachain and interchain interactions between carbazole units, which bring these groups to stack each other, is assumed. i‐PPK optical properties are investigated and an electroluminescent behaviour of polymer is observed. Organic light emitting diodes based on i‐PPK layers are founded to emit white light. POLYM. COMPOS., 36:1110–1117, 2015. © 2015 Society of Plastics Engineers
Carbon nanotubes and carbon onions for modification of styrene–acrylate copolymer nanocomposites
Authors: Merijs‐Meri Remo , Zicans Janis , Ivanova Tatjana , Bitenieks Juris , Paddubskaya Alesya , Kuzhir Polina , Maksimenko Sergey , Macutkevic Jan , Kuznetsov Vladimir , Moseenkov Sergey
Published: March 2015

Styrene acrylate polymer (SAC) nanocomposites with various carbon nanofillers (multi‐walled carbon nanotubes, MWCNT, and onion like carbons, OLCs, annealed at two different temperatures) are manufactured by means of latex based and combined routes. Concentration of the carbon nanofillers is changed in a broad interval starting from 0.01 up to 10 wt%. Elastic, dielectric, and electromagnetic interference (EMI) shielding efficiency of SAC nanocomposites are investigated. Dynamic elastic modulus, electrical conductivity, and EMI shielding efficiency of the investigated SAC nanocomposites increase along with rising nanofiller content. The effect of the addition of anisodiametric MWCNT on the elastic properties as well as EMI shielding characteristics of the SAC nanocomposites is higher than in the case of the addition of OLCs. Modification effectiveness of the polymer matrix in respects to elastic and EMI shielding performance provided by the OLC, annealed at higher temperature, is greater in comparison with the OLC, annealed at lower temperature, generally because of more perfect structure of the first. POLYM. COMPOS., 36:1048–1054, 2015. © 2015 Society of Plastics Engineers
RATES AND TYPES OF TEACHER PRAISE: A REVIEW AND FUTURE DIRECTIONS
Authors: Jenkins Lyndsay N. , Floress Margaret T. , Reinke Wendy
Published: March 2015

The use of teacher praise in the classroom has been the subject of empirical research since the 1970s, but despite more than four decades of research on the use of teacher praise, large gaps continue to exist in the literature. Clarifying the role and benefit of teacher praise is particularly important because the use of positive, proactive strategies is promoted by large‐scale behavior initiatives (e.g., Positive Behavior Interventions and Support). The goal of this review is to summarize the existing research on teacher praise, including rates of praise, types of praise, and the association between praise and student behavior. In addition to summarizing the extant literature, future directions for research are highlighted. This review reveals that there is a need for current, large‐scale studies with consistent operational definitions that measure the rate of different types of praise across different grades and instructional activities, while simultaneously measuring student behavioral outcomes.
Poly(p‐benzamide) having isopropyl‐substituted chiral tri(ethylene glycol) side Chain: Synthesis and helical conformation
Authors: Yokoyama Akihiro , Nakano Suguru , Saiki Tomoaki , Yokozawa Tsutomu
Published: March 2015

Isopropyl‐substituted tri(ethylene glycol) is used as a chiral side chain of N‐substituted poly(p‐benzamide) in order to increase the difference of stability between the right‐ and left‐handed helical structures of the polymer. The target polymer is synthesized by the chain‐growth condensation polymerization of the corresponding monomer with an initiator using lithium 1,1,1,3,3,3‐hexamethyldisilazide as a base. A circular dichroism (CD) study of the polymer reveals that the CD signal is due to an excess of a thermodynamically controlled right‐handed helical structure of the polymer, and that the replacement of the methyl group with a bulkier isopropyl group at the side chain of poly(p‐benzamide) increases the abundance of right‐handed helical structure in chloroform. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1623–1628
In situsynthesis of ABA triblock copolymer nanoparticles by seeded RAFT polymerization: Effect of the chain length of the third a block on the triblock copolymer morphology
Authors: Kang Haijiao , Su Yang , He Xin , Zhang Shifeng , Li Jianzhang , Zhang Wangqing
Published: March 2015

Synthesis of the ABA triblock copolymer nanoparticles of poly(N,N‐dimethylacrylamide)‐block‐polystyrene‐block‐poly(N,N‐dimethylacrylamide) (PDMA‐b‐PS‐b‐PDMA) by seeded RAFT polymerization is performed, and the effect of the introduced third poly(N,N‐dimethylacrylamide) (PDMA) block on the size and morphology of the PDMA‐b‐PS‐b‐PDMA triblock copolymer nanoparticles is investigated. This seeded RAFT polymerization affords thein situsynthesis of the PDMA‐b‐PS‐b‐PDMA core‐corona nanoparticles, in which the middle solvophobic PS block forms the compacted core, and the first solvophilic PDMA block and the introduced third PDMA block form the solvated complex corona. During the seeded RAFT polymerization, the introduced third PDMA block extends, and the molecular weight of the PDMA‐b‐PS‐b‐PDMA triblock copolymer linearly increases with the monomer conversion. It is found that, the size of the PS core in the PDMA‐b‐PS‐b‐PDMA triblock copolymer core‐corona nanoparticles is almost equal to that in the precursor of the poly(N,N‐dimethylacrylamide)‐block‐polystyrene diblock copolymer core‐corona nanoparticles and it keeps constant during the seeded RAFT polymerization, and whereas the introduction of the third PDMA block leads to a crowded complex corona on the PS core. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2015,53, 1777–1784