bluuebunny/crossref_metadata_2025 huggingface dataset:
La réglementation française des agences de location de personnel : l’intégration des travailleurs temporaires dans les communautés d’origine et d’accueil
Authors: Fontaine Laurence Léa
Published: August 2013

Le néolibéralisme a non seulement conduit à la création de nouvelles catégories d’emploi, concrétisant la précarisation des relations de travail, mais aussi à l’externalisation de plus en plus fréquente de la main-d’oeuvre. Au coeur de ce marché du travail renouvelé et défavorable aux travailleurs, les entreprises de travail temporaire occupent une place de premier ordre. Celles-ci fournissent à des entreprises une main-d’oeuvre qualifiée, sur demande, sans être contraintes par la totalité des lois du travail. Le législateur français a très tôt choisi de réguler ce type de relations de travail tripartites ; tel n’est pas le cas au Québec. Aucune loi spécifique n’ayant été élaborée, de très nombreux travailleurs temporaires y sont livrés à eux-mêmes, mais aussi aux pratiques peu orthodoxes des « agences de location de personnel », telles qu’elles sont nommées au Québec. Ces agences gèrent les travailleurs temporaires comme n’importe quelle autre fourniture, disparaissent du jour au lendemain ou encore se dédoublent pour échapper aux réclamations salariales. Le législateur québécois gagnerait à s’inspirer du modèle français : celui-ci, bien qu’il soit imparfait, propose plusieurs mesures très intéressantes. L’angle d’approche choisi par l’auteure pour présenter les dispositions françaises est celui des communautés d’origine et d’accueil des travailleurs temporaires. À son avis, il importe que le législateur québécois régule les activités des agences de location de personnel et s’attaque sérieusement et rapidement au cas de cette catégorie de travailleurs qui, plus que n’importe quelle autre, souffre de la crise économique.
Fibromyalgia: A Clinical Update
Authors: Hawkins Robert A.
Published: August 2013

Fibromyalgia is a common chronic syndrome defined by core symptoms of widespread pain, fatigue, and sleep disturbance. Other common symptoms include cognitive difficulty, headache, paresthesia, and morning stiffness. Fibromyalgia is increasingly understood as 1 of several disorders that are referred to as central sensitivity syndromes; these disorders share underlying causes and clinical features. Tender points are often detected in patients with fibromyalgia and were formerly required for diagnosis. Newly proposed criteria, however, rely on patients' reports of widespread pain and other somatic symptoms to establish the diagnosis of fibromyalgia. The management of fibromyalgia requires a multidimensional approach including patient education, cognitive behavioral therapy, exercise, and pharmacologic therapy. The present review provides an update on these various aspects of treating a patient with fibromyalgia.
Frequency of Counterstrain Tender Points in Osteopathic Medical Students
Authors: Snider Karen T. , Glover John C. , Rennie Paul R. , Ferrill Heather P. , Morris William F. , Johnson Jane C.
Published: August 2013

Context:Counterstrain is 1 osteopathic manipulative treatment technique taught to osteopathic medical students, but teaching all 300 counterstrain tender points is not feasible at most colleges of osteopathic medicine (COMs) because of time limitations.

Objective:To identify high-yield tender points in osteopathic medical students for teaching and to assess for correlations between tender points and demographic information, weight, and history of pain or trauma.

Methods:First- and second-year osteopathic medical students at 5 COMs were surveyed regarding the presence and absence of tender points found on themselves by fellow students. Demographic information, weight, and history of pain and trauma data were collected. The McNemar test was used to compare the frequency of positive tender points between the right and left sides. Multiple logistic regression models were fit to the data to determine if participant characteristics were related to having 1 or more positive tender points in a tender point group. Wilcoxon signed rank tests were used to compare the percentage of positive anterior vs posterior tender points. Multiple logistic regression models were used to test for differences between COMs after accounting for differences in participant characteristics.

Results:Frequency of 78 tender point groups was obtained. Forty tender point groups (51%) were positive for the presence of 1 or more tender points by 50% or more of the participants. Positive tender points were more common on the right side for 23 groups (allP<.001). Female participants were more likely to have tender points for 22 groups (allP<.001). The 20- to 25-year-olds had more tender points for 6 groups (allP≤.03). Tender points were more common in participants with a history of pain for 29 groups (allP<.001) and with a history of trauma for 4 groups (allP≤.05). Anterior tender points were more common for cervical, thoracic, rib, and lumbar body regions (P<.001). Differences were found between COMs for all tender point groups (P≤.02).

Conclusion:Nearly half of the tender point groups surveyed were reported positive by 50% or more of participants, and high-yield tender points were found in each body region. Ultimately, these results may guide counterstrain curricula for COMs.
Use of Multiple Methods to Estimate Walrus (Odobenus rosmarus rosmarus) Abundance in the Penny Strait-Lancaster Sound and West Jones Sound Stocks, Canada
Authors: Stewart Robert EA , Born Erik W , Dunn J Blair , Koski William R , Ryan Anna K
Published: August 2013

Surveys to estimate walrus abundance at terrestrial haulout sites in the Penny Strait-Lancaster Sound (PS-LS) and West Jones Sound (WJS) stocks were conducted in 1977 and 1998-2009. The Minimum Counted Population (MCP) was similar in 1977 (565) to recent years (557) for the PS-LS stock. The MCP for the WJS stock was higher in recent surveys (404) than in 1977 (290). Regression analysis of MCP and density (number of walrus divided by number of haulouts surveyed) showed no significant trends over time. We also calculated bounded count estimates for comparison. Finally, we used broad-scale behavioural data to estimate the proportion of the total stock that could be considered countable, to produce two adjusted estimates. We selected recent surveys with good coverage and ignored adjusted estimates that were lower than MCP. For the PS-LS stock, the adjusted MCP (with 95% CL) was 672 (575-768) and 727 (623-831) walrus in 2007 and 2009, respectively. For WJS, the best estimates were the adjusted MCP of 503 (473-534) in 2008 and the adjusted bounded count of 470 (297-1732) in 2009. While both stocks appear to have remained stable over three decades, differences in survey coverage and possible differences in walrus distribution make precise population estimation difficult.
Comparative Study Evaluating the Role of Color Doppler Sonography and Computed Tomography in Predicting Chest Wall Invasion by Lung Tumors
Authors: Sripathi Smiti , Mahajan Abhishek
Published: August 2013

Objectives

To analyze qualitative and quantitative parameters of lung tumors by color Doppler sonography, determine the role of color Doppler sonography in predicting chest wall invasion by lung tumors using spectral waveform analysis, and compare color Doppler sonography and computed tomography (CT) for predicting chest wall invasion by lung tumors.

Methods

Between March and September 2007, 55 patients with pleuropulmonary lesions on chest radiography were assessed by grayscale and color Doppler sonography for chest wall invasion. Four patients were excluded from the study because of poor acoustic windows. Quantitative and qualitative sonographic examinations of the lesions were performed using grayscale and color Doppler imaging. The correlation between the color Doppler and CT findings was determined, and the final outcomes were correlated with the histopathologic findings.

Results

Of a total of 51 lesions, 32 were malignant. Vascularity was present on color Doppler sonography in 28 lesions, and chest wall invasion was documented in 22 cases. Computed tomography was performed in 24 of 28 evaluable malignant lesions, and the findings were correlated with the color Doppler findings for chest wall invasion. Of the 24 patients who underwent CT, 19 showed chest wall invasion. The correlation between the color Doppler and CT findings revealed that color Doppler sonography had sensitivity of 95.6% and specificity of 100% for assessing chest wall invasion, whereas CT had sensitivity of 85.7% and specificity of 66.7%.

Conclusions

Combined qualitative and quantitative color Doppler sonography can predict chest wall invasion by lung tumors with better sensitivity and specificity than CT. Although surgery is the reference standard, color Doppler sonography is a readily available, affordable, and noninvasive in vivo diagnostic imaging modality that is complementary to CT and magnetic resonance imaging for lung cancer staging.
Potential Role of Strain Elastography for Detection of the Extent of Large‐Scar Endometriosis
Authors: Xie Meng , Zhang Xuyin , Zhan Jia , Ren Yunyun , Wang Wenping
Published: August 2013

Objectives

The purpose of this study was to evaluate the clinical value of strain elastography for detection of the lesion extent of large‐scar endometriosis and compare it to conventional sonography and magnetic resonance imaging (MRI).

Methods

Eight patients suspected of having large‐scar endometriosis underwent transabdominal sonography, strain elastography, and MRI. The mass was located and assessed for its size, imaging appearance, and, especially, widest boundary and vertical extent. After wide surgical excision and pathologic diagnosis, lesions in the central area shown on conventional sonography and the extended area shown on strain elastography underwent immunohistochemical examination.

Results

Nodules were always deep in the subcutaneous plane, in contact with the fascia or muscle. Horizontally, the mean lesion size shown on conventional sonography was mainly consistent with the size on MRI in all cases, but it was obviously smaller on sonography than on strain elastography in 7 cases. Vertically, the lesion depth was mainly consistent with the depth on MRI in 7 cases, but it was more infiltrative on strain elastography in 6 cases. The vertical and horizontal infiltration scales of the postoperative specimens were consistent with strain elastography in all cases. All 8 patients showed strong collagen type I expression in the central area of the lesions; 6 patients showed strong collagen type I expression and the other 2 showed moderate expression in the extended area.

Conclusions

Strain elastography can elevate the diagnostic accuracy of large‐scar endometriosis, the extent of which may be evaluated insufficiently by transabdominal sonography and MRI.
Evaluating Lesion Segmentation on Breast Sonography as Related to Lesion Type
Authors: Pons Gerard , Martí Joan , Martí Robert , Ganau Sergi , Vilanova Joan Carles , Noble J. Alison
Published: August 2013

Breast sonography currently provides a complementary diagnosis when other modalities are not conclusive. However, lesion segmentation on sonography is still a challenging problem due to the presence of artifacts. To solve these problems, Markov random fields and maximum a posteriori–based methods are used to estimate a distortion field while identifying regions of similar intensity inhomogeneity. In this study, different initialization approaches were exhaustively evaluated using a database of 212 B‐mode breast sonograms and considering the lesion types. Finally, conclusions about the relationship between the segmentation results and lesions types are described.
Self‐Assembled Vehicle Construction via Boronic Acid Coupling and Host–Guest Interaction for Serum‐Tolerant DNA Transport and pH‐Responsive Drug Delivery
Authors: Yang Bin , Jia Huizhen , Wang Xuli , Chen Si , Zhang Xianzheng , Zhuo Renxi , Feng Jun
Published: August 2013

By exploiting boronic acid coupling and host–guest chemistry, a pH‐responsive drug/gene co‐delivery nanoplatform is designed for cancer treatments with the excellently serum‐tolerant transfection activity and the capability to load and release hydrophobic drugs in an acidity‐accelerated manner. Via boronate linkage, γ‐CD is allowed to spontaneously attach onto phenylboronic‐acid‐modified oligoethylenimine (PEI1.8K‐PB2.9) at neutral condition. The formed vehicle/DNA nanoformulation is thus surrounded densely by γ‐CD moieties to biomimic the carbohydrate‐rich cell surface, providing a novel approach to overcome serum‐susceptible drawbacks frequently associated with synthetic gene carriers. PEI1.8K‐PB2.9‐γ‐CD conjugates demonstrate significantly improved cell‐biocompatibility and transfection activity over PEI1.8K‐PB2.9. Noticeably, serum‐associated inhibition effect is negligible for PEI1.8K‐PB2.9‐γ‐CD‐mediated transfection whereas marked transfection reduction occurs for PEI25K and PEI1.8K‐PB2.9 upon serum exposure. Consequently, PEI1.8K‐PB2.9‐γ‐CDs afford much higher transfection efficiency, that is, 25‐fold higher luciferase expression over PEI25K in presence of 30% serum. An anticancer drug of doxorubicin (DOX) is shown to be readily accommodated into the nanoformulation via host–guest chemistry and intracellularly co‐delivered together with plasmid DNA. Due to the acidity‐labile feature of boronate linkage, DOX/γ‐CD inclusion complexes would be mostly detached from the nanoformulation triggered by acidity, leading to faster drug release. Furthermore, drug inclusion does not alter the serum‐compatible transfection efficiency of PEI1.8K‐PB2.9‐γ‐CD.
Nanostructured Hollow Tubes Based on Chitosan and Alginate Multilayers
Authors: Silva Joana M. , Duarte Ana Rita C. , Custódio Catarina A. , Sher Praveen , Neto Ana I. , Pinho António C. M. , Fonseca Jaime , Reis Rui L. , Mano João F.
Published: August 2013

The design and production of structures with nanometer‐sized polymer films based on layer‐by‐layer (LbL) are of particular interest for tissue engineering since they allow the precise control of physical and biochemical cues of implantable devices. In this work, a method is developed for the preparation of nanostructured hollow multilayers tubes combining LbL and template leaching. The aim is to produce hollow tubes based on polyelectrolyte multilayer films with tuned physical‐chemical properties and study their effects on cell behavior. The final tubular structures are characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), microscopy, swelling, and mechanical tests, including dynamic mechanical analysis (DMA) in physiological simulated conditions. It is found that more robust films could be produced upon chemical cross‐linking with genipin. In particular, the mechanical properties confirms the viscoelastic properties and a storage and young modulus about two times higher. The water uptake decreases from about 390% to 110% after the cross‐linking. The biological performance is assessed in terms of cell adhesion, viability, and proliferation. The results obtained with the cross‐linked tubes demonstrate that these are more suitable structures for cell adhesion and spreading. The results suggest the potential of these structures to boost the development of innovative tubular structures for tissue engineering approaches.
Outcomes of elderly de novo acute myeloid leukemia treated by a risk‐adapted approach based on age, comorbidity, and performance status
Authors: Yoon Jae‐Ho , Cho Byung‐Sik , Kim Hee‐Je , Kim Jung‐Ho , Shin Seung‐Hwan , Yahng Seung‐Ah , Lee Sung‐Eun , Eom Ki‐Seong , Kim Yoo‐Jin , Lee Seok , Min Chang‐Ki , Cho Seok‐Goo , Kim Dong‐Wook , Lee Jong‐Wook , Min Woo‐Sung , Park Chong‐Won
Published: August 2013

Several criteria to define fitness for induction chemotherapy in elderly acute myeloid leukemia (AML) have been proposed; however, no studies have reported outcomes according to the application of a risk‐adapted approach. We treated 256 consecutive patients with elderly AML (≥60 years) with a risk‐adapted approach based on age, comorbidity score (CS), and performance status (ECOG). Eighty‐five low‐risk patients (age ≤ 65 years and ECOG 0–1 with CS < 2), 86 intermediate‐risk patients (age > 65 years or ECOG = 2 with CS < 2), and 85 high‐risk patients (ECOG > 2 or CS ≥ 2) were treated with induction chemotherapies, including standard intensive regimens, abbreviated‐scheduled regimens, and modified low‐dose cytarabine with oral etoposide (mLDAC), respectively. Overall response rates (ORR; complete response and complete response with incomplete recovery) for these three groups were 71.8%, 60.5%, and 41.2%, respectively, without a significant difference in early death rate (17.6%, 25.6%, 23.5%, P = 0.415). Among three abbreviated‐scheduled regimens, a gemtuzumab ozogamicin (GO)‐containing regimen (n = 43) showed a similar ORR rate (72.1%) to the intensive regimen. After achieving remission, 142 patients went on postremission treatments, including reduced‐intensity allogeneic transplantation (RIC, n = 41), standard consolidation (n = 71), and repeated mLDAC (n = 30) according to donor availability, age, ECOG, and CS. Multivariate analyses revealed that not only RIC, but also repeated mLDAC, resulted in significantly superior survival outcomes to standard consolidation independent of age, ECOG, and CS. Clinical benefits of mLDAC for high‐risk patients and abbreviated induction with GO for intermediate‐risk patients should be confirmed with further studies. Our results also suggest that RIC should be actively considered in elderly AML as a postremission treatment. Am. J. Hematol. 88:1074–1081, 2013. © 2013 Wiley Periodicals, Inc.
Rituximab versus splenectomy in persistent or chronic adult primary immune thrombocytopenia: an adjusted comparison of mortality and morbidity
Authors: Moulis Guillaume , Sailler Laurent , Sommet Agnès , Lapeyre‐Mestre Maryse , Derumeaux Hélène , Adoue Daniel
Published: August 2013

Splenectomy and rituximab are both recommended as second‐line treatment in immune thrombocytopenia (ITP), but they have never been directly compared. We compared their efficacy and serious adverse outcomes in a retrospective cohort of 105 adult primary ITP patients exposed to one or other of these treatments. Primary outcome was composite: death from hemorrhage or from infection and hospitalization for bleeding or for infection. Secondary outcomes were overall mortality, hospitalization for bleeding, hospitalization for infection, as well as response and complete response (international definitions). Analyses were adjusted on a propensity score. Patients treated with rituximab (n = 43) were older and had more comorbidities than the splenectomized patients (n = 62). Mean follow‐up was, respectively, 3 and 8.4 years. After adjustment on the propensity score, there was no difference between the two groups regarding the primary and other clinical outcomes. In the multivariate analysis, only a history of mucosal bleeding (HR 3.2 95% CI [1.2–8.5]) and a Charlson score ≥1 (HR 4.2 95% CI [1.8–9.6]) were associated with the primary outcome. These two factors were also associated with hospitalization for bleeding. As expected, response, complete response and maintenance rates were higher in the splenectomy group. Splenectomy compared with rituximab was independently associated with a response at 12 months (OR 4.4, 95% CI [1.7–11.8]). Then, adjusted analyses in this real‐life cohort confirmed the better results of splenectomy compared with rituximab. Am. J. Hematol. 89:41–46, 2014. © 2013 Wiley Periodicals, Inc.
Image‐guidance in endoscopic sinus surgery: is it associated with decreased medicolegal liability?
Authors: Eloy Jean Anderson , Svider Peter F. , D'Aguillo Christine M. , Baredes Soly , Setzen Michael , Folbe Adam J.
Published: August 2013

Background

The use of image‐guidance (IG) in endoscopic sinus surgery (ESS) has escalated over the last decade despite a lack of consensus that its use improves outcomes or decreases complications. One theoretical reason for using IG in ESS is its potential to minimize legal liability should an adverse outcome occur. In this study, we aimed to characterize the role of IG in ESS litigation, and further detail other factors in pertinent cases. A secondary objective was to characterize recent malpractice litigation for other relevant factors.

Methods

Relevant cases from Westlaw were examined to determine whether the use of IG played a role in initiating litigation in ESS malpractice suits. Factors such as patient demographics and alleged cause(s) of malpractice litigation were examined.

Results

Out of 30 malpractice cases from 2004 to April 2013, 4 (13.3%) mentioned the use of IG during ESS, although this did not appear to be a factor affecting the plaintiff's decision to initiate litigation, nor the case outcomes. In the 26 cases (86.7%) in which IG was not used, its non‐use was not specified as an alleged cause of negligence. Eleven (36.7%) cases were resolved in the defendant's favor. Frequently‐cited factors included iatrogenic injury (83.3%), permanent deficits (66.7%), needing additional surgery (63.3%), orbital and intracranial injury, and perceived deficits in informed consent (40.0%).

Conclusion

The use of IG was not found to be a factor in ESS litigation. This suggests that not using IG does not necessarily make one more vulnerable to malpractice litigation.
Protective efficacy of sunglasses on the conjunctival symptoms of seasonal rhinitis
Authors: Ozturk Ayse Bilge , Celebioglu Ebru , Karakaya Gul , Kalyoncu A. Fuat
Published: August 2013

Background

Although allergen avoidance can lead to significant improvements in symptoms of allergic rhinitis, there are very few studies in this area. Sunglasses could be effective for protection of eyes from pollen as a cheap, comfortable, and simple avoidance option for allergens. The aim of this study is to determine if wearing sunglasses can decrease ocular symptoms.

Methods

Ocular symptomatic patients (39 total) who had a confirmed history of seasonal rhinitis by skin prick tests and negative skin prick tests for perennial allergens were included in the study. The duration of the study was 4 weeks with 3 required visits. At the onset of the 1‐week run‐in period, patients were randomized and divided into 2 groups. Group I (n = 18) received topical aqueous nasal budesonide regularly and loratadine once daily as a rescue medication. Group II (n = 21) wore sunglasses during daytime as an addition to this medication. Subjective data included a daily diary recording nasal and ocular symptom scores and antihistamine need during the study period.

Results

Sunglasses significantly reduced ocular symptoms (p = 0.002) and use of antihistamines (p = 0.009).

Conclusion

Sunglasses are an inexpensive and simple treatment for patients with allergic conjunctivitis.
Chronic rhinosinusitis and sleep: a contemporary review
Authors: Alt Jeremiah A. , Smith Timothy L.
Published: August 2013

Background

Patients with chronic rhinosinusitis (CRS) exhibit centrally mediated behavioral changes commonly referred to as “sickness behavior.” Sleep alteration is a component of sickness behavior which is estimated to affect up to 70 million patients annually. Patients with CRS have poor sleep quality, and little is known about the underlying etiology and pathophysiology. This narrative review aims to further organize and present the current knowledge associating sleep and CRS.

Methods

A literature search was conducted of the OVID MEDLINE database using key search words including: “chronic rhinosinusitis,” “sleep,” “sleep disorders,” and “sleep dysfunction.” Additional keywords “nasal obstruction,” “nasal polyp,” and “fatigue” were identified and used to further delineate relevant articles.

Results

The articles that specifically addressed sleep and CRS were dissected and presented as follows: (1) chronic rhinosinusitis and sleep; (2) chronic rhinosinusitis and fatigue; (3) chronic rhinosinusitis, nasal obstruction, and sleep; and (4) pathophysiology of sleep in chronic rhinosinusitis (cytokines in both sleep and chronic rhinosinusitis and their association to the neuroimmune biology of chronic rhinosinusitis).

Conclusion

Patients with CRS have sleep dysfunction that is associated with their disease severity and overall quality of life. The etiology of sleep dysfunction in CRS is most likely multifactorial. Increasing evidence suggests sleep dysfunction in patients with CRS is partly due to the inflammatory disease process, and sleep physiology in patients with CRS may be actively regulated by the inflammatory component of the disease.
Assembling DNA through Affinity Binding to Achieve Ultrasensitive Protein Detection
Authors: Zhang Hongquan , Li Feng , Dever Brittany , Wang Chuan , Li Xing‐Fang , Le X. Chris
Published: August 2013

Recent advances in DNA assembly and affinity binding have enabled exciting developments of nanosensors and ultrasensitive assays for specific proteins.1–6 These sensors and assays share three main attractive features:1, 4, 7 1) the detection of proteins can be accomplished by the detection of amplifiable DNA, thereby dramatically enhancing the sensitivity; 2) assembly of DNA is triggered by affinity binding of two or more probes to a single target molecule, thereby resulting in increased specificity; and 3) the assay is conducted in solution with no need for separation, thus making the assay attractive for potential point‐of‐care applications. We illustrate here the principle of assembling DNA through affinity binding, and we highlight novel applications to the detection of proteins.
Synthesis and characterization of s‐histidine‐derived poly (ionic liquid)/silica nanocomposites and their application in the enantioselective hydrolysis of a chiral ester
Authors: Kowsari E. , Hosseini S. M. , Bakhshandeh M. B. , Ghrehkhani E.
Published: August 2013

In this study, a new optically active monomer containing two chemically preformed imide rings was synthesized. The monomer was then used to synthesize optically active poly(amide imide)s (OAPAIs) and an optically active polyionic liquid (OAPIL), which were finally reacted with various amounts of silica nanoparticles in an in situ polymerization reaction to produce OAPAI/SiO2 and OAPIL/SiO2 hybrid materials containing sulfonic acid groups. The prepared monomers and the OAPAI and OAPIL nanocomposites were characterized by 1H‐NMR spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, X‐ray diffraction, scanning electron microscopy, X‐ray photoelectron spectroscopy, and differential scanning calorimetry. OAPIL/SiO2 served as an excellent catalyst in water as a solvent for the hydrolysis of d,l‐phenylglycine methyl ester with the advantage of a markedly enhanced enantioselectivity and activity. Also, the enantioselectivity was strongly dependent on the SiO2 content in the OAPIL/SiO2 systems; a favorable SiO2 content was 20% (w/w). The enantioselectivity was 95.2% (substrate conversion = 62.3%). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39595.
Development of ultrasmall chitosan/succinyl β‐cyclodextrin nanoparticles as a sustained protein‐delivery system
Authors: Taranejoo Shahrouz , Monemian Seyedali , Moghri Mehdi , Derakhshankhah Hossein
Published: August 2013

In this article, we introduce a new method for preparing ultrasmall chitosan (CS)/succinyl β‐cyclodextrin (SCD) nanoparticles (NPs) intended for loading bovine serum albumin (BSA) as a model protein. The proposed method is based on the complex coacervation technique followed by ionotropic gelation with tripolyphosphate. SCD, an anionic derivative of cyclodextrin, was synthesized and used in CS‐based NPs to enhance the entrapment efficiency of BSA. The results show that with this approach, ultrasmall, compact, and neutralized NPs with a mean particle size near 30 nm were obtained. A high degree of protein entrapment in the NPs led to a significant improvement in the BSA release profile with a low initial burst release (ca. 3% w/v of the initially loaded BSA) and a sustained release over time. This enabled a suitable nanocarrier for long‐term protein delivery (30% release over 120 h). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39648.
Calculating hansen solubility parameters of polymers with genetic algorithms
Authors: Vebber Guilherme Cañete , Pranke Patricia , Pereira Cláudio Nunes
Published: August 2013

In materials engineering, it is often essential to know what are the best solvents to process any polymer, and employing methods based on Hansen solubility parameters are an effective way to find them. In this work the Hansen solubility parameters of polyether sulfone, lignin, and bitumen have been calculated by an alternative optimization procedure. It has been shown that, by applying an evolutionary strategy to Hansen's correlation method, it is possible to improve the fitting of solubility spheres. Compared with previous calculations, most quality‐of‐fit parameters are optimized. As a result, the sphere radii are reduced and, except for lignin, at least one of the solubility parameters is considerably changed (by 0.9–1.5 MPa1/2). Shortcomings of the correlation method are also pointed out, such as lack of data quality evaluation on set of solvents and uncertain character for partially solving solvents. At least the former could be handled by a proposed parameter called fill factor. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39696.
Thermal stability and ablation properties study of aluminum silicate ceramic fiber and acicular wollastonite filled silicone rubber composite
Authors: Yu Lin , Zhou Shengtai , Zou Huawei , Liang Mei
Published: August 2013

The thermal stability and ablation properties of silicone rubber filled with silica (SiO2), aluminum silicate ceramic fiber (ASF), and acicular wollastonite (AW) were studied in this article. The morphology, composition, and ablation properties of the composite were analyzed after oxyacetylene torch tests. There were three different ceramic layers found in the ablated composite. In the porous ceramic layer, the rubber was decomposed, producing trimers, tetramers, and SiO2. ASF and part of AW still remained and formed a dense layer. The SiO2/SiC filaments in the ceramic layer reduced the permeability of oxygen, improving the ablation properties of the composites. The resultant ceramic layer was the densest, which acted as effective oxygen and heat barriers, and the achieved line ablation rate of the silicone composite were optimum at the proportion of 20 phr/40 phr (ASF/AW). Thermogravimetric analysis (TGA) confirmed that thermal stability of the composites was enhanced by the incorporation of ASF and AW. The formation of the ceramic layer was considered to be responsible for the enhancement of thermal stability and ablation properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39700.
Pulverized polyurethane foam particles reinforced rigid polyurethane foam and phenolic foam
Authors: Yang Chao , Zhuang Zhe‐Hui , Yang Zhen‐Guo
Published: August 2013

Polyurethane consumption has been increasing in recent years, raising concerns about how to deal with the polymer waste. Post‐consumer rigid polyurethane foams or polyurethane foam scraps (PPU) ground into particles were utilized to strengthen mechanical properties of rigid polyurethane foam (PUF) and phenolic foam (PF). Viscosity of prepolymer with PUF was measured and PPU was well dispersed in prepolymer, as observed by optical microscope. Microstructures and morphologies of the reinforced foam were examined with scanning electron microscope (SEM) while cell diameter and density were measured by Scion Image software. Universal testing machine was employed to optimize compressive properties at various weight ratios of PPU. Both PUF and PF with 5 wt % PPU, respectively, exhibited considerable improvement in mechanical properties especially compressive property. The compressive modulus of PUF with 5 wt % PPU was 12.07 MPa, almost 20% higher than pure PUF while compressive strength of PF with 5 wt % PPU reached 0.48 MPa. The thermal stability of the reinforced foam was tested by thermal gravity analysis (TGA) and the result shows no obvious impact with PPU. The decomposition temperatures of PUF with PPU and PF with PPU were 280°C, because PPU has relatively weak thermal stability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39734.
Electrosynthesis and characterization of an electrochromic material from poly(1,6‐bis(2‐thienyl)pyrene) and its application in electrochromic device
Authors: Cheng Xinfeng , Fu Yunzhi , Zhao Jinsheng , Zhang Yucang
Published: August 2013

Electrochemical polymerization of 1,6‐bis(2‐thienyl)pyrene (BTP) could be achieved in acetonitrile/dichloromethane (ACN/DCM) (1:1, by volume) solution containing sodium perchlorate (NaClO4) as a supporting electrolyte. The resulting polymer poly(1,6‐bis(2‐thienyl)pyrene) (PBTP) were characterized by cyclic voltammetry, UV–vis spectroscopy, and scanning electron microscopy. The resulting polymeric film has distinct electrochromic properties and exhibits three different colors under various potentials. Moreover, the PBTP film showed reasonable optical contrast (DT %) at 700 nm is found to be 29% and satisfactory response time is measured as 1.3 s. An electrochromic device (ECD) based on PBTP and poly(3,4‐ethylenedioxythiophene) was also constructed and characterized. This ECD has these qualities: quick switching time, reasonable contrast, and good optical memories and redox stability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39770.
Mechanical and damping properties of epoxy/liquid rubber intercalating organic montmorillonite integration nanocomposites
Authors: Mao Duming , Zou Huawei , Liang Mei , Zhou Shengtai , Chen Yang
Published: August 2013

Two different kinds of micro‐nanoconstrained damping structure units (M‐NCDSUs) were prepared by carboxyl‐terminated butadiene acrylonitrile copolymer and epoxy‐terminated butadiene acrylonitrile copolymer liquid rubbers intercalating organic montmorillonite, respectively. The prepared M‐NCDSUs were then blended with epoxy resin to obtain damping structure integration nanocomposites. The X‐ray diffraction and transmission electron microscope measurements applied for the obtained samples confirmed the good formation of M‐NCDSUs in the epoxy network. The tensile strength decreased slightly with the addition of M‐NCDSUs, whereas the damping properties measured by dynamic mechanical analysis showed a remarkable increase. Besides, the cured epoxy resin exhibited a two‐phase morphology where the spherical rubber phase dispersed uniformly in the epoxy matrix. The nanocomposites containing M‐NCDSUs showed superior comprehensive properties compared with that without the functional units. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39797.
Acetophenone‐assisted main‐chain photocrosslinking of poly(ethylene terephthalate)
Authors: Yun Deuk‐Won , Jang Jinho
Published: August 2013

Maximum gel fraction of 99.1% was obtained under continuous UV irradiation of a UV energy of 200 J cm−2 on poly(ethylene terephthalate) (PET) containing only in presence of 2.9%(w/w) acetophenone (AP). The fragmented AP radicals abstract the hydrogen atoms of methylene units in PET, producing secondary methine radicals which couples to main‐chain crosslinks. The crystal structure of the crosslinked PET became disordered remarkably. The glass transition temperature disappeared and the peak thermal decomposition temperature was significantly retarded as much as 85°C. The crosslinking density and molecular weight between crosslinks reaches up to 0.129 mol g−1 and 7.7 g mol−1, respectively. Also tensile modulus and strength increased by 200 and 72% compared with those of the pristine PET respectively, resulting in more toughened PET. The solid‐state photocrosslinking may extend high‐temperature applications of PET with enhanced thermal and mechanical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39802.
Influence of the coupling agent on the mechanical properties of SiCf/poly(phenylene benzobisoxazole) composites
Authors: Wang Li , Luo Fa , Zhou Wancheng , Zhu Dongmei
Published: August 2013

Poly(phenylene benzobisoxazole) (PBO) was first used as matrix to fabricate the two‐dimensional SiCf/PBO composites by a lamination method. Different amounts of coupling agent were introduced to improve the bonding between silicon carbide (SiC) fibers and the PBO matrix during the fabrication of the SiCf/PBO composites. The surface structure and composition of the as‐received PBO and PBO treated with the coupling agent were analyzed, and the morphology and flexural strength of the composites were characterized. The Fourier transform infrared analysis indicated that the hydroxyl groups from the coupling agent were successfully introduced to PBO. The flexural strength of the composites increased at first with increasing content of the coupling agent but decreased with excessive addition of the coupling agent. The flexural strength of the composites was improved from 15 to 89 MPa. The test results suggested that the interaction between the SiC fiber and the treated PBO with the coupling agent was intensified. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39805.
Cyclic and monotonic testing of free and constrained recovery properties of a chemically crosslinked acrylate
Authors: Arrieta J. Sebastian , Diani Julie , Gilormini Pierre
Published: August 2013

A chemically crosslinked acrylate network was submitted to various thermomechanical strain and stress recoveries whilechanging the experimental parameters in order to better define the benefits and the limits of using chemically crosslinked polymers for multicycle applications or applications under external constraints. The results showed that the free recoveries and the constrained recoveries remained the same at the first cycle and during the next ones. It was also shown that the low stress usually generated by a crosslinked network when submitted to a constrained recovery can be significantly increased by choosing suitable experimental conditions. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39813.
Flame retardancy and thermal properties of carboxyl‐containing polysiloxane derivatives in polycarbonate
Authors: Song Rongjun , Chang Liyan , Li Bin
Published: August 2013

Carboxyl‐containing polysiloxane (LCCP) has been successfully applied in the flame retardancy of polycarbonate (PC). The LCCP was synthesized by hydrosilylation and condensation reaction. The presence of carboxyl groups has been demonstrated to be crucial to provide high flame retardant effectiveness. The flame retardancy of LCCP–PC composites is investigated by limiting oxygen index (LOI), vertical burning tests (UL‐94). At the mole ratio of diethoxymethyl (1‐propionyloxy) silane/diethoxydimethylsilane = 8/100 in LCCP(3), the best flame retardant performance of LCCP‐PC composites was obtained. The LOI value of the composites is 38.5 and the UL‐94 rating reaches V‐0 when the content of LCCP(3) is as low as 0.5 wt %. Evolution of the thermal behaviors of the composites tested by thermogravimetric analysis shows that addition of LCCP(3) in PC can reduce the degradation speed of PC and induce a reduction of the initiated decomposition temperature of PC. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39814.
Thermoplastic elastomers derived from bio‐based monomers
Authors: Ghassemi Hossein , Schiraldi David A.
Published: August 2013

Series of copolyesters based on poly(propylene succinate) (PPS) and poly(butylene succinate) (PBS), which can be produced from biological feedstock, and postconsumer poly(ethylene terephthalate) (PET) were synthesized with the aim of developing sustainable materials, which combine the mechanical properties of high performance elastomers with those of flexible plastics. The aliphatic polyesters were synthesized by the catalyzed two‐step transesterification reaction of dimethyl succinate, 1,3‐propanediol, and 1,4‐butanediol followed by melt reaction with PET in bulk. The content of PET segments in the polymer chains was varied from about 10 to 100 wt % per 100 wt % PPS or PBS. The effect of the introduction of the PET segments on the structure, thermal, physical, and mechanical properties was investigated. The composition and structure of these aliphatic/aromatic copolyesters were determined by NMR spectroscopy. The thermal properties were investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The level of crystallinity was studied by means of DSC and wide‐angle X‐ray scattering. A depression of melting temperature and a reduction of crystallinity of copolyesters with increasing content of PET segments were observed. Consequently, the tensile modulus and strength of copolyesters decreased, and the elongation at break increased with PET content in the range of 10−50 wt %. Thus, depending on PET content, the properties of copolyesters can be tuned ranging from semicrystalline polymers possessing good tensile modulus (380 MPa) and strength (24 MPa) to nearly amorphous polymer of high elongation (∼800%), and therefore they may find applications in thermoplastics as well as elastomers or impact modifiers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39815.
Chemical modification of bisphenol a polycarbonate by reactive blending with ethylene carbonate
Authors: Colonna Martino , Berti Corrado , Fiorini Maurizio
Published: August 2013

A new method for the insertion of aliphatic moieties into bisphenol A (BPA) polycarbonate (PC) by reactive blending with ethylene carbonate (ETC) has been developed. By this route, new polymeric materials with modified thermal and rheological properties have been synthesized; the structure of the poly(ether‐co‐carbonate)s prepared can be controlled using different ETC/PC molar ratios. Using model compounds and selective degradation reactions, the different chemical structures of the aliphatic units inserted into PC backbone were identified. ETC/PC molar ratios below 1 afforded both aliphatic–aromatic carbonate and ether groups, while higher ETC/PC molar ratios afforded aliphatic–aromatic ether and aliphatic–aliphatic carbonate groups. The co‐polymers prepared by the new process were clear without discoloration or opacity. The thermal analyses of the co‐polymers showed that, by the insertion of aliphatic moieties, it is possible to modulate the glass transition temperature (Tg) in a 30°C range. A decreased melt viscosity of the co‐polymers was also observed and therefore an improved processability should be expected with respect to standard PC. The reaction with aliphatic carbonates can be also considered as a promising chemical recycling process for PC scraps, through the synthesis of monomers such as bis(hydroxyethyl)ether of BPA. This monomer has already been used for the preparation of co‐polyesters of terephthalic acid with high Tg and thermal stability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39820.
Viscoelastic properties and structure of poly(acrylonitrile‐co‐methacrylic acid) polymer solutions for gel spinning at long aging times
Authors: Brown Tracy R. , Choudhury Rudra P. , Meree Caitlin E. , Beckham Haskell W. , Kumar Satish , Shofner Meisha L.
Published: August 2013

The objective of the research is to obtain a more complete understanding of how aging affects the viscoelastic properties of polymer solutions to be used as starting materials for gel spinning of polymer fibers. Specifically, poly(acrylonitrile‐co‐methacrylic acid) solutions were prepared and characterized using rheological measurements and nuclear magnetic resonance spectroscopy. The results indicate that elastic character increased with increasing polymer concentration and that gelation of these solutions continued up to aging times of several weeks. Additionally, comparing the results from the two characterization methods show that while gelation continues to occur, the viscoelastic properties decrease after a critical time point suggesting that a chemical change occurs in the solutions at long times. However, these changes impact the solution dynamics minimally as the effective network properties were similar at the aging times studied here, but considerations for long‐term storage of polymer solutions for gel spinning are warranted. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39821.
Frontal polymerization of superabsorbent nanocomposites based on montmorillonite and polyacrylic acid with enhanced soil properties
Authors: Zhang Ruobing , Qiu Zhaoxia , Qiu Haixia , Zhang Xionghui
Published: August 2013

Polyacrylic acid/montmorillonite(MMT)/carboxymethylcellulose (CMC) superabsorbent nanocomposites were prepared by frontal polymerization (FP), an economic method characterized by low‐energy consumption and short‐reaction time. They were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy. The effects of reaction parameters on the front propagation and the water absorbency of the nanocomposites were investigated. Furthermore, the effects of the obtained products on soil water holding capacity and soil water stable macro‐aggregates were studied. Compared with the control soil, soil mixed with the nanocomposites showed a significant increase (by 52.4%) in field water holding capacity. The incorporation small amounts of MMT effectively promoted the formation of soil water stable macro‐aggregates, which increased by 76% as the addition of the MMT increased to 4 wt %. The samples obtained by FP showed much better performance in the formation of soil water stable macro‐aggregates, salt resistance, and thermal stability than those obtained by conventional batch polymerization. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39825.
Effect of K0.5Na0.5NbO3 filling particles on the charge carrier trap distribution of polyimide films
Authors: Lin Jiaqi , Xie Zhibin , Yang Wenlong , Zhang Panpan , Liu Ying , Lin Hui , Li Xiaokang
Published: August 2013

Polyimide (PI) films filled with K0.5Na0.5NbO3 (KNN50) particles at different weight 0, 5, 10, and 15 wt % had been prepared by in‐situ dispersion polymerization process. The thermally stimulated current (TSDC) method was used to investigate the charge carrier trap levels and their distribution of the composite films. The TSDC spectra show that pure film has
‐peaks and
‐peak, but the composite films only have
‐peaks and an extraordinary peak at high temperature region. The trap parameters were calculated by an approximate model, and the results indicate that charge released of the shallow traps show a nonlinear behavior. The trap energies decrease from 0.879–0.968 eV to 0.549–0.839 eV with the increase of the KNN50 content. The surface and interface between KNN50 and PI matrix was considered to the variation of the trap levels. The extraordinary peak of the composite films was correlated with the phase transition of the KNN50 particles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39828.
Improvement in impact strength of modified cardanol‐bonded cellulose thermoplastic resin by using olefin resins
Authors: Kiuchi Yukihiro , Soyama Makoto , Iji Masatoshi , Tanaka Shukichi , Toyama Kiyohiko
Published: August 2013

Impact strength of a modified cardanol‐bonded cellulose thermoplastic resin was greatly improved by using a small amount of olefin resins. As we showed, this thermoplastic resin (3‐pentadecylphenoxy acetic acid (PAA)‐bonded cellulose diacetate (CDA): PAA‐bonded CDA) exhibited high practical properties such as bending strength, heat resistance, and water resistance. However, its impact strength was insufficient for use in durable products. We improved the impact strength of PAA‐bonded CDA by adding hydrophobic olefin resins, such as polyethylene or polypropylene, while maintaining good bending strength and breaking strain. Furthermore, the application of olefin resins also increased water resistance and fluidity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39829.