bluuebunny/crossref_metadata_2025 huggingface dataset:
Human Plasmacytoid Dendritic Cells Phagocytose, Process, and Present Exogenous Particulate Antigen
Authors: Tel Jurjen , Lambeck Annechien J. A. , Cruz Luis J. , Tacken Paul J. , de Vries I. Jolanda M. , Figdor Carl G.
Published: March 2010

Plasmacytoid dendritic cells (pDCs) play a major role in shaping both innate and adaptive immune responses, mainly via their production of large amounts of type I IFNs. pDCs are considered to primarily present endogenous Ags and are thought not to participate in the uptake and presentation of Ags from the extracellular environment, in contrast to their myeloid counterparts, which efficiently endocytose extracellular particulates. In this study, we show that human pDCs are able to phagocytose and process particulate forms of Ag entrapped in poly(lactic-coglycolic acid) microparticles. Furthermore, pDCs were also able to sense TLR ligands (TLR-Ls) incorporated in these particles, resulting in rapid pDC activation and high IFN-α secretion. Combining a tetanus toxoid peptide and TLR-Ls (CpG C and R848) in these microparticles resulted in efficient pDC activation and concomitant Ag-specific T cell stimulation. Moreover, particulate Ag was phagocytosed and presented more efficiently than soluble Ag, indicating that microparticles can be exploited to facilitate efficient delivery of antigenic cargo and immunostimulatory molecules to pDCs. Together, our results show that in addition to their potency to stimulate innate immunity, pDCs can polarize adaptive immune responses against exogenous particulate Ag. These results may have important consequences for the development of new immunotherapeutic strategies exploiting Ag and TLR-Ls encapsulated in microparticles to target APC subsets.
Role of SMAD and Non-SMAD Signals in the Development of Th17 and Regulatory T Cells
Authors: Lu Ling , Wang Julie , Zhang Feng , Chai Yang , Brand David , Wang Xuehao , Horwitz David A. , Shi Wei , Zheng Song Guo
Published: March 2010

Whereas TGF-β is essential for the development of peripherally induced Foxp3+ regulatory T cells (iTreg cells) and Th17 cells, the intracellular signaling mechanism by which TGF-β regulates development of both cell subsets is less understood. In this study, we report that neither Smad2 nor Smad3 gene deficiency abrogates TGF-β–dependent iTreg induction by a deacetylase inhibitor trichostatin A in vivo, although the loss of the Smad2 or Smad3 gene partially reduces iTreg induction in vitro. Similarly, SMAD2 and SMAD3 have a redundant role in development of Th17 in vitro and in experimental autoimmune encephalomyelitis. In addition, ERK and/or JNK pathways were shown to be involved in regulating iTreg cells, whereas the p38 pathway predominately modulated Th17 and experimental autoimmune encephalomyelitis induction. Therefore, selective targeting of these intracellular TGF-β signaling pathways during iTreg and Th17 cell development might lead to the development of therapies in treating autoimmune and other chronic inflammatory diseases.
IL-4 and TGF-β1 Counterbalance One Another while Regulating Mast Cell Homeostasis
Authors: Macey Matthew R. , Sturgill Jamie L. , Morales Johanna K. , Falanga Yves T. , Morales Joshua , Norton Sarah K. , Yerram Nitin , Shim Hoon , Fernando Josephine , Gifillan Alasdair M. , Gomez Gregorio , Schwartz Lawrence , Oskeritzian Carole , Spiegel Sarah , Conrad Daniel , Ryan John J.
Published: March 2010

Mast cell responses can be altered by cytokines, including those secreted by Th2 and regulatory T cells (Treg). Given the important role of mast cells in Th2-mediated inflammation and recent demonstrations of Treg-mast cell interactions, we examined the ability of IL-4 and TGF-β1 to regulate mast cell homeostasis. Using in vitro and in vivo studies of mouse and human mast cells, we demonstrate that IL-4 suppresses TGF-β1 receptor expression and signaling, and vice versa. In vitro studies demonstrated that IL-4 and TGF-β1 had balancing effects on mast cell survival, migration, and FcεRI expression, with each cytokine cancelling the effects of the other. However, in vivo analysis of peritoneal inflammation during Nippostrongylus brasiliensis infection in mice revealed a dominant suppressive function for TGF-β1. These data support the existence of a cytokine network involving the Th2 cytokine IL-4 and the Treg cytokine TGF-β1 that can regulate mast cell homeostasis. Dysregulation of this balance may impact allergic disease and be amenable to targeted therapy.
Soluble IL-7Rα (sCD127) Inhibits IL-7 Activity and Is Increased in HIV Infection
Authors: Crawley Angela M. , Faucher Sylvie , Angel Jonathan B.
Published: March 2010

Soluble CD127 (sCD127) appears to play an important role in the immunopathogenesis of several chronic infections, multiple sclerosis, and various cancers. The function of sCD127 and whether it influences IL-7 bioavailability or activity is unknown. In this study, we demonstrated that recombinant and native sources of sCD127 significantly inhibited IL-7–mediated STAT5 and Akt phosphorylation in CD8+ T cells. IL-7–mediated proliferation and Bcl-2 expression were similarly reduced by sCD127. In each case, native sCD127 inhibited IL-7 activity to a greater degree than rsCD127. Anti–IL-7 activity was inherent to human plasma and could be reversed by depletion of CD127, revealing for the first time the biological activity of naturally occurring sCD127. Plasma sCD127 concentrations were increased in HIV+ individuals compared with HIV− controls, correlated with IL-7 levels, and remained unchanged in HIV+ individuals following 1 y of effective antiretroviral therapy. Determining the regulation and function of sCD127 may be critical for understanding both the pathogenesis of diseases in which IL-7 likely has a role (e.g., HIV infection, cancer) and its potential impact on IL-7 as a therapeutic approach.
Naive CD4+ T Lymphocytes Circulate through Lymphoid Organs To Interact with Endogenous Antigens and Upregulate Their Function
Authors: Tomura Michio , Itoh Kikuji , Kanagawa Osami
Published: March 2010

Naive T lymphocytes recirculate through the lymph-vascular system and enter and exit lymphoid organs. Using mice expressing the photoconvertible fluorescence protein Kaede, we demonstrated that naive T cells seek to interact with endogenous Ags after migrating to the lymphoid organs. The interaction with endogenous Ags transiently induces CD69 expression on T cells, which prolongs retention in the lymphoid organs. Cells that fail to express CD69 or lose CD69 expression migrate to other lymphoid organs. Functionally, CD69+-naive CD4+ T cells exhibit faster and greater cytokine production than do CD69− naive CD4+ T cells. These results indicate that CD4+ T cells continuously migrate to interact with endogenous Ags, and such an interaction plays an important role in the Ag reactivity of naive CD4+ T cells.
Postoperative Radiotherapy in Hypopharyngeal Cancer: Single-institution Outcome Analysis
Authors: Tejpal Gupta , Supriya Chopra , Prakash Agarwal Jai , Sarbani Ghosh-Laskar , Anil D'Cruz , Pankaj Chaturvedi , Ketayun Dinshaw
Published: March 2010

Purpose

To retrospectively review the outcomes of adjuvant postoperative radiotherapy (PORT) following surgery in patients with advanced hypopharyngeal cancer treated at an academic tertiary referral center.

Methods

Data of patients treated with curative intent in a single radiotherapy unit over a 15-year period (1990-2004) with upfront surgery followed by PORT was retrieved from an electronic database. Local control (LC), locoregional control (LRC) and disease-free survival (DFS) were considered as outcome measures.

Results

The study dataset constituted 159 patients with a median age of 55 years (range 30-79 years). Patients underwent either radical surgery (total laryngectomy with or without pharyngectomy) or voice-conserving surgery. All patients underwent appropriate comprehensive neck dissection. The median radiotherapy dose was 60 Gy (inter-quartile range 50-60 Gy). With a mean follow-up of 21 months (inter-quartile range 6-29 months), the 3-year LC, LRC, and DFS was 87.8%, 70.3% and 62.2% respectively. Cut margin negativity and pyriform sinus subsite predicted for improved LRC and DFS on univariate analysis. Cut margin status was the only independent predictor of outcome on multivariate analysis.

Conclusion

Hypopharyngeal cancer characterized by advanced disease at presentation. Definitive surgery (either voice-conserving or radical) followed by adjuvant radiotherapy provides good LRC and DFS and continues to remain a valid upfront treatment option for advanced hypopharyngeal cancer. Cut margin status and primary subsite are important determinants of outcome.
Areca Nut or Betel Nut Control is Mandatory if India Wants to Reduce the Burden of Cancer Especially Cancer of the Oral Cavity
Authors: Pankaj Chaturvedi
Published: March 2010

A lesser known reason of epidemic proportion of oral cancer in India is the rampant use of Areca nut chewing. Just like tobacco, areca nut or betel nut is a psychostimulant, an addictive substance and a carcinogen. The cancer causing properties of areca nut have been well-reported in animal, human and epidemiologic studies. The World Health Organization and International Agency for Research on cancer classified areca nut as a Group 1 human carcinogens with sufficient evidence of increased risk of submucus fibrosis (precancerous oral lesion) and cancers of the oral cavity, pharynx, and esophagus. This was based upon several studies from India, Bangladesh, Pakistan and Taiwan. Cancers caused by betel nut chewing also shows a strong dose–response relationship for frequency and duration of chewing. It is postulated that areca nut-specific N-nitroso compounds converted from alkaloids are responsible for oral and pharyngeal cancer. There are several other reports that have linked areca nut chewing (with or without tobacco) with hepatocellular carcinoma, cholangiocarcinoma, cancers of the larynx, stomach, lung and cervix in humans.
Intracapsular Carcinoma ex Pleomorphic Adenoma in the Buccal Space: Management Dilemma
Authors: Anil D'Cruz , Mitali Dandekar , Devendra Chaukar , Shubhada Kane , Shashikant Juvekar
Published: March 2010

Objective

Rare case of intracapsular carcinoma ex pleomorphic adenoma in the buccal space with focus on its appropriate management.

Method

Case report with review of current literature on buccal space lesions and intracapsular carcinoma ex pleomorphic adenoma.

Result

Although salivary gland tumors are common, intracapsular carcinoma ex pleomorphic adenoma is a rare entity especially within the buccal space with no similar case report in the current literature.

Conclusion

Our case is unusual due to its unusual presentation in the buccal space and pathological features. This case report also highlights issues regarding its appropriate management.
Colossal Malignant Nonteratoid Medulloepithelioma of the Eye with Unusual Metastases: The Natural History
Authors: Sajid Qureshi
Published: March 2010

Background

Medulloepithelioma is rare intraocular tumor seen predominantly in children, and arising mainly from undifferentiated nonpigmented epithelium of the ciliary body.

Methods

We present a typical neglected case of malignant nonteratoid medulloepithelioma of the eye with extensive metastases to the facial soft tissue parotid and cervical lymph nodes.

Results

An aggressive surgical approach with orbital exenteration and comprehensive disease clearance with total parotidectomy and neck dissection augmented by postoperative radiotherapy was utilized after initial unsuccessful chemotherapy.

Conclusions

The present case highlights the natural history of untreated medulloepithelioma of the eye. Colossal growth at the primary site with extensive regional lymph node metastases develops without distant metastases. Complete surgical excision supplemented with postoperative radiotherapy should be considered even in the setting of advanced locoregional disease.
Carcinoma Larynx in Children
Authors: Pankaj Chaturvedi , Devendra Chaukar , Prathamesh Pai , Manish Julaha , Anil Pantvaidya Gauri D'Cruz
Published: March 2010

Carcinoma of the larynx is uncommon in children 15 years of age or younger. Because of low index of suspicion, the diagnosis of childhood laryngeal carcinoma is often delayed. Other factors contributing to its delayed diagnosis are the similarity of its early symptoms to those of other benign, common childhood conditions and the relative difficulty encountered during pediatric laryngeal examination. Treatment of pediatric laryngeal cancers is challenging, because no guidelines are available.

We believe that every single case of childhood laryngeal cancer should be reported, because of paucity of literature on this childhood entity, it is limited only to case reports and reviews. This makes treatment options and outcomes difficult to interpret.
The nature of white privilege in the teaching and training of adults
Authors: Lund Carole L.
Published: March 2010

This chapter describes white privilege and how it impacts the learning environment. Included are actual examples of white privilege from practice and how enforcing white privilege results in racism.
Modifying interpretation and imagination in clinical depression: A single case series using cognitive bias modification
Authors: Blackwell Simon E. , Holmes Emily A.
Published: March 2010

The current cognitive bias modification (CBM) paradigm targets interpretation bias (CBM‐I) in depression via promoting positive imagery. We investigated the impact of repeated sessions of this CBM‐I on interpretation bias, mood and mental health in participants currently experiencing a major depressive episode. Seven participants completed daily sessions of CBM‐I at home for one week in a single case series. Outcome measures were completed pre and post a one‐week baseline period, and after the week of daily CBM‐I. Depressive symptoms were also assessed at a 2‐week follow‐up. Four of seven participants demonstrated improvements in mood, bias and/or mental health after one week of CBM‐I, with improvements in depressive symptoms maintained at follow‐up. Discussion of the remaining three highlights difficulties involved in translating CBM‐I interventions from the laboratory to the clinic. To bridge this gap, we suggest that it is critical to examine the failures as well as the successes. Copyright © 2010 John Wiley & Sons, Ltd.
Training the forgetting of negative words: The role of direct suppression and the relation to stress reactivity
Authors: LeMoult Joelle , Hertel Paula T. , Joormann Jutta
Published: March 2010

Recent research has demonstrated that people can be trained to forget negative material. This experiment assessed the possible benefit of direct suppression in addition to the benefit of thought substitutes (indirect suppression) on subsequent attempts to recall words. We also investigated the association between recall following suppression training and subsequent responses to an acute laboratory stressor. After learning cue‐target word pairs, participants completed a training phase in which they practiced suppressing targets and recalling substitutes or simply recalling substitutes with no instruction to suppress. Our results show similar effects of suppression condition on forgetting. Importantly, however, the absence of direct suppression predicted mood change in response to a subsequently presented laboratory stressor. These results suggest that direct suppression is not necessary for forgetting to occur, but it seems to protect against negative emotional consequences of interference‐induced forgetting. Copyright © 2010 John Wiley & Sons, Ltd.
Defect‐Related Emissions and Magnetization Properties of ZnO Nanorods
Authors: Panigrahy Bharati , Aslam Mohammed , Misra Devi Shanker , Ghosh Manoranjan , Bahadur Dhirendra
Published: March 2010

A clear correlation between defect‐related emissions and the magnetization of ZnO nanorods synthesized by a one‐step aqueous chemical method is demonstrated. The relative contribution of the emission bands arising from various types of defects is determined and found to be linked with the size of the nanorods and annealing conditions. When the size of the nanorods and the annealing temperature are increased, the magnetization of pure ZnO nanorods decreases with the reduction of a defect‐related band originating from singly charged oxygen vacancies ($V_{\rm o}^ +$). With a sufficient increase of annealing temperature (at 900 °C), the nanorods show diamagnetic behavior. Combining with the electron paramagnetic resonance results, a direct link between the magnetization and the relative occupancy of the singly charged oxygen vacancies present on the surface of ZnO nanorods is established.
Solar Energy Collectors with Tunable Transmission
Authors: Debije Michael G.
Published: March 2010

A new type of “smart” window is proposed that makes use of fluorescent dye guests in a liquid‐crystal host sandwiched between glass panels. The dye absorbs a variable amount of light depending on its orientation, and re‐emits this light, of which a significant fraction is trapped by total internal reflection at the glass–air interface, and becomes concentrated along the edges. Such a device could both generate electricity via an attached photovoltaic as well as allow user control of the amount of transmitted light. By applying a voltage across the cell, absorption could be varied 31%, while the usable light output only varied 11% due to the increased efficiency of light collection at homeotropic dye orientation.
Glyconanomaterials: Synthesis, Characterization, and Ligand Presentation
Authors: Wang Xin , Ramström Olof , Yan Mingdi
Published: March 2010

Glyconanomaterials, nanomaterials carrying surface‐tethered carbohydrate ligands, have emerged and demonstrated increasing potential in biomedical imaging, therapeutics, and diagnostics. These materials combine the unique properties of nanometer‐scale objects with the ability to present multiple copies of carbohydrate ligands, greatly enhancing the weak affinity of individual ligands to their binding partners. Critical to the performance of glyconanomaterials is the proper display of carbohydrate ligands, taking into consideration of the coupling chemistry, the type and length of the spacer linkage, and the ligand density. This article provides an overview of the coupling chemistry for attaching carbohydrate ligands to nanomaterials, and discusses the need for thorough characterization of glyconanomaterials, especially quantitative analyses of the ligand density and binding affinities. Using glyconanoparticles synthesized by a versatile photocoupling chemistry, methods for determining the ligand density by colorimetry and the binding affinity with lectins by a fluorescence competition assay are determined. The results show that the multivalent presentation of carbohydrate ligands significantly enhances the binding affinity by several orders of magnitude in comparison to the free ligands in solution. The effect is sizeable even at low surface ligand density. The type and length of the spacer linkage also affect the binding affinity, with the longer linkage promoting the association of bound ligands with the corresponding lectins.
Multiproduct batch plants design using linear process performance models
Authors: Moreno Marta S. , Montagna Jorge M.
Published: March 2010

In this contribution, a novel linear generalized disjunctive programming (LGDP) model is developed for the design of multiproduct batch plants optimizing both process variables and the structure of the plant through the use of process performance models. These models describe unit operations using explicit expressions for the size and time factors as functions of the process variables with the highest impact. To attain a linear formulation, values of the process variables as well as unit sizes are selected from a set of meaningful discrete values provided by the designer. Regarding structural alternatives, both kinds of unit duplications in series and in parallel are considered in this approach. The inclusion of the duplication in series requires different detailed models that depend on the structure selected. Thus, in a new approach for the multiproduct batch plant design, a set of potential structural alternatives for the plant is defined. © 2010 American Institute of Chemical Engineers AIChE J, 2011
CFD simulations and particle image velocimetry measurements in an industrial scale rotating disc contactor
Authors: Drumm Christian , Hlawitschka Mark W. , Bart Hans‐Jörg
Published: March 2010

Fluid dynamics of the single‐phase and two‐phase flow in a segment of a rotating disc contactor (RDC) liquid–liquid extraction column with 450 mm inner diameter were studied by performing computational fluid dynamics (CFD) simulations and particle image velocimetry (PIV) measurements. The fluid dynamics were investigated to test the predictivity of CFD at industrial scale. Different turbulence models in conjunction with the Eulerian approach were applied in the single‐phase and two‐phase simulations. The turbulent flow characteristics were analyzed by PIV measurements to validate the CFD simulations. An iso‐optical system composed of CaCl2/water–butylacetate allows for the two‐phase PIV measurements. Local turbulent energy dissipation was derived from velocity gradients in PIV data. In this connection, the influence of the PIV spatial resolution on the measured energy dissipation was also analyzed, and different fit functions were tested to scale the measured energy dissipation. Simulated velocity fields as well as the energy dissipation were compared with the experimental PIV data. The results from the simulations and experiments are in good agreement. The work shows that CFD can predict hydrodynamic characteristics even at bigger scales but is still subject to some minor restrictions. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Surface radiative transfer in gas‐to‐gas cocurrent microheat exchanger
Authors: Mahulikar Shripad P. , Herwig Heinz , Zhou Jing‐Wei , Sodhani Yash M.
Published: March 2010

The influence of surface radiative transfer in parallel flow microheat exchanger is numerically studied for its importance at high temperatures and for small flow dimensions. For these heat exchangers, the role of radiation is beneficial when the convective heat transfer to the annulus flow exceeds the convective heat transfer from the core flow. For this case, radiation improves the heat exchanger performance by decreasing the logarithmic mean temperature difference and by increasing the capacity, effectiveness, and volumetric heat transfer coefficient. Additional surface area is made available for convection to the annulus flow, thereby increasing the specific heat transfer surface for fixed geometry. Therefore, a high emissivity layer over the surfaces of microheat exchanger can improve the heat exchange performance. The active heat transfer area weighted by the convective heat flow rates is introduced as the true measure of heat exchanger compactness. © 2010 American Institute of Chemical Engineers AIChE J, 2011
A low‐energy emulsification batch mixer for concentrated oil‐in‐water emulsions
Authors: Caubet Sylvain , Le Guer Yves , Grassl Bruno , El Omari Kamal , Normandin Eric
Published: March 2010

This work shows the formation of a high internal phase ratio oil‐in‐water (O/W) emulsion using a new type of a two‐rod batch mixer. The mixture components have sharply different viscosities [1/3400 for water‐in‐oil (W/O)], similar densities (1/0.974 for W/O), and an O/W ratio of 91% (wt/wt). The simple design of this mixer leads to a low‐energy process (106 < energy density [J m−3] < 107), characterized by low rotational speed and laminar flow. The droplet size distribution during the emulsification was investigated according to different physical and formulation parameters such as stirring time (few minutes < t < 1 h), rotational speed (60 < Ω < 120 rpm), surfactant type (Triton X‐405 and X‐100), concentration (from 1 to 15.9 wt % in water), and salt addition (30 g/L). We show that all studied parameters allow a precise control of the droplet size distribution and the rheology. The resulting emulsions are unimodal and the mean droplet diameter is between 30 μm and 8 μm. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Hazardous task recognition among U.S. adolescents working in the retail or service industry
Authors: Vladutiu Catherine J. , Rauscher Kimberly J. , Runyan Carol W. , Schulman Michael , Villaveces Andrés
Published: March 2010

Background

Although the hazardous tasks adolescent workers perform in service and retail industries are well documented, little is known about the extent to which young workers recognize these tasks as hazardous or dangerous.

Methods

Using data from a nationally representative cross‐sectional telephone survey conducted in 2003, we examined hazardous task recognition among 858 adolescents working in the retail or service industry.

Results

Approximately 13% (n = 123) of respondents reported that they consider at least one of their job tasks to be hazardous or dangerous. Among the respondents who performed tasks known to be hazardous, very few actually recognized these tasks as being hazardous or dangerous.

Conclusion

Working adolescents appear to underestimate the dangers associated with work, thus increasing the potential likelihood of injury. Emphasis should be placed on eliminating or reducing hazards in the workplace while simultaneously improving young workers' recognition of the hazardous nature of many of the tasks they perform. Am. J. Ind. Med. 53:686–692, 2010. © 2010 Wiley‐Liss, Inc.
The P‐value illusion: How to improve (psychiatric) genetic studies
Authors: Niculescu Alexander B. , Le‐Niculescu Helen
Published: March 2010

There is an emerging appreciation that genome‐wide association studies (GWAS) have failed to live up to expectations and deliver major advances to date. A “surge” strategy, of pooling resources and increasing number of subjects tested, is underway. We argue that, while useful, it will not be enough by itself. Complementary approaches are needed to mine these large datasets. We describe a series of problems, opportunities, and offer a potential comprehensive solution. © 2010 Wiley‐Liss, Inc.
Synthesis and properties of partially conjugated hyperbranched light‐emitting polymers
Authors: Lu Chunliang , Wang Haiqiao , Wang Xiaochen , Li Yongfang , Oiu Teng , He Lifan , Li Xiaoyu
Published: March 2010

Via A2 + B4 and A2 + B3 [where A2 is 1,4‐distyrylol‐2,5‐butoxybenzene, B3 is 1,1,1‐tris‐(p‐tosyloxymethyl)‐propane, and B4 is pentaerythritol tetra(methyl benzene sulfonate)] approaches, we synthesized two kinds of partially conjugated hyperbranched polymers, hyperbranched polymer with 3 arms (HP1) and hyperbranched polymer with 4 arms (HP2), which had rigid conjugated segments [oligo‐poly(phenylene vinylene)] and flexible, nonconjugated spacers arranged alternately through ether bonds in the skeleton. The conjugated segments were modified by pendant butoxy groups, which imparted the resulting polymers with excellent solubility in common organic solvents and excellent film‐forming abilities. Fourier transform infrared and nuclear magnetic resonance spectroscopy were used to identify the structure of the monomers and polymers. Thermal property investigations showed that two polymers both had good thermal stability with their decomposition temperatures in the range 396–405°C and high glass‐transition temperatures, which are of benefit to the fabrication of high‐performance light‐emitting devices. The photophysical properties were studied, and the relative photoluminescence quantum efficiencies of HP1 and HP2 in dilute chloroform solution amounted to 56.8 and 49.3%, respectively. A brief light‐emitting diode device with a configuration of indium tin oxide/HP1/Ca/Al was fabricated, and its electroluminescence performance was studied. The brightness of the device reached an optimistic maximum of 190 cd/m2 at 8.2 V. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Surface initiated ATRP of acrylic acid on dopamine‐functionalized AAO membranes
Authors: Wang Wen‐Cai , Wang Jin , Liao Yuan , Zhang Liqun , Cao Bing , Song Guojun , She Xilin
Published: March 2010

A facile method for surface‐initiated atom transfer radical polymerization (ATRP) on the anodic aluminum oxide (AAO) membranes has been developed. The AAO membrane was firstly functionalized by poly(dopamine), the bromoalkyl initiator was then immobilized on the poly(dopamine) functionalized AAO membrane surface in a two‐step solid‐phase reaction, followed by ATRP of acrylic acid in a aqueous solution. The poly(acrylic acid) (PAAc)‐grafted AAO membranes were characterized by X‐ray photoelectron spectroscopy, fourier transform infrared spectroscopy and scanning electron microscopy. The XPS and FTIR results indicated that PAAc was successfully grafted on the AAO membrane surface. The degree of grafting increases linearly with the increase of monomer concentration, and it reaches a plateau when the reaction time up to 4 h. The results indicate that the thickness of the grafted polymer inside the isocylindrical pores of AAO membranes could be well controlled by changing the reaction time and monomer concentration. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Molecular imprinting micropolymerbeads having cooperative effect of both surfactant and inosine template
Authors: Kusunoki Takayuki , Kobayashi Takaomi
Published: March 2010

Molecular imprinted polymer (MIP) microbeads were prepared by emulsion copolymerization of divinylbenzene (DVB) and methacrylic acid (MAA) in the presence of inosine (INO) template and laurylbenzenesulfonic acid (LBSA) as surfactant. The polymerization was carried out at 55°C under ultrasound exposure. The resulting copolymer microbeads, having 0.1–0.4 μm diameter, were observed to have a binding behavior of INO and surfactant to the polymer which was strongly dependent of the bulk pH; for example, at pH 3, 6, and 10 values of binding for INO to the imprinted copolymer were 3.7 μmol/g, 2.1 μmol/g, and 0 μmol/g, respectively. It was found that LBSA surfactant bound to the MIP microbeads similarly depending on pHs. At pH 3, 6, and 10, the LBSA values of binding were 23 μmol/g, 1.3 μmol/g, and 4.8 μmol/g. It was also noted that the surfactant binding was enhanced in the presence of the INO template. This demonstrated that a cooperative binding with the surfactant was cooperatively occurred in the presence of INO. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Epoxy and hyperbranched polymer blends: Morphology and free volume
Authors: Ratna Debdatta , Simon George P.
Published: March 2010

In this work, the phase separation of an epoxy‐functionalized hyperbranched polymer (HBP) in a blend with a conventional epoxy resin is examined. Morphology development with the advancement of curing reaction was investigated by hot‐stage polarized optical microscope, where it was found that HBP is miscible in epoxy resin solvent at 120°C and undergoes phase separation during the curing reaction, leading to a two‐phase microstructure which maintains a dispersed morphology up to 20 wt % HBP. The degree of phase separation and morphology were also investigated using differential scanning calorimetry, and the resultant microstructure was confirmed by atomic force microscopy. The epoxy/HBP blends were characterized by positron annihilation lifetime spectroscopy for their free volume characteristics where behavior typical of miscible blends was seen, likely due to chemical bonding between the two phases. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Cellulose acetate membrane synthesis from biomass of ramie
Authors: Fan Xiu‐Shan , Liu Zhao‐Tie , Liu Zhong‐Wen , Lu Jian
Published: March 2010

A new route was developed for preparation of cellulose acetate (CA) membrane from ramie fiber, a sustainable biomass. Sulfuric acid catalyzed acetylation of ramie fiber was carried out in acetic anhydride. The optimum reaction conditions were determined as ramie fiber to acetic anhydride ratio 1 : 6 (w/w), temperature 353 K, and reaction time 0.5 h. To prepare CA membranes with improved properties, CA was modified with polyethylene glycol (PEG 600, MW = 600 g/mol−1) and tributyl citrate (TBC). The effects of CA content and additive concentrations given by a mixture design of experiments on CA membrane compaction, morphology, water flux, water content, and mechanical properties were studied. The thermal stability and hydrophobicity/hydrophilicity of membranes prepared with PEG 600 or TBC additives were also investigated. Addition of PEG 600 increased and addition of TBC decreased the thermal stability of CA membrane. The CA membranes prepared were used to separate dyes from their solutions. An inverse trend of the separation of solutions of Disperse Red S‐R (DR) and Acid Scarlet 2G (AC) was observed for CA membranes modified with PEG 600 or TBC. The contact angle of CA membranes modified with PEG 600 or TBC decreased with increase in PEG 600 content, and increased with increase in TBC content. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Use of expanded‐EPDM as protecting layer for moderation of photo‐degradation in wood/NR composite for roofing applications
Authors: Yamsaengsung W. , Sombatsompop N.
Published: March 2010

Changes in tensile properties, sample size, interfacial strength, and thermal conductivity of melt‐laminating layers of wood/ebonite natural rubber (NR) and expanded ethyelene–propylene diene rubber (EPDM) for polymeric roofing applications were monitored under a period of UV aging times for 60 days, the results being compared with single rubber layers of wood/NR and expanded‐EPDM. The experimental results suggested that the tensile modulus of the wood/NR‐EPDM melt‐laminating layer increased with increasing aging time. The tensile strength of the wood/NR layer decreased after prolonged UV aging, and positioned between that of the wood/NR and expanded‐EPDM layers. The sample size reduction of wood/NR layer with expanded‐EPDM top coating layer was lower than that for wood/NR single layer. The peel strength of the wood/NR‐EPDM melt‐laminating layer was found to decrease with increasing UV aging time as a result of delamination of the rubber layers. The thermal conductivity of the wood/NR‐EPDM melt‐laminating layer decreased from 0.085 to 0.070 W/m K with increasing aging times upto 40 days, but tended to increase to 0.080 W/m K at the aging time of 60 days. The experimental results in this work clearly suggested that expanded‐EPDM could be used as protecting layer, not only for moderation of photo‐oxidative degradations of wood/NR layer for roofing application, but also for minimization of dimension changes of the wood/NR‐EPDM melt‐laminating layer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and characterization of thermoplastic polyurethane/organoclay nanocomposites by melt intercalation technique: Effect of nanoclay on morphology, mechanical, thermal, and rheological properties
Authors: Barick A. K. , Tripathy D. K.
Published: March 2010

Nanocomposites based on thermoplastic polyurethane (TPU) and organically modified montmorillonite (OMMT) were prepared by melt blending. Organically modified nanoclay was added to the TPU matrix in order to study the influence of the organoclay on nanophase morphology and materials properties. The interaction between TPU matrix and nanofiller was studied by infrared spectroscopy. Morphological characterization of the nanocomposites was carried out using X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy techniques. The results showed that melt mixing is an effective process for dispersing OMMT throughout the TPU matrix. Nanocomposites exhibit higher mechanical and thermal properties than pristine TPU. All these properties showed an increasing trend with the increase in OMMT content. Thermogravimetric analysis revealed that incorporation of organoclay enhances the thermal stability of nanocomposites significantly. Differential scanning calorimetry was used to measure the melting point and the glass transition temperature (Tg) of soft segments, which was found to shift toward higher temperature with the inclusion of organoclays. From dynamic mechanical thermal analysis, it is seen that addition of OMMT strongly influenced the storage and loss modulus of the TPU matrix. Dynamic viscoelastic properties of the nanocomposites were explored using rubber process analyzer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Catalytic activity of Schiff base cobalt(III) complexes immobilized on terpolymers of glycidyl methacrylate in the addition of carboxylic acids to terminal epoxides
Authors: Bukowska Agnieszka , Bukowski Wiktor , Noworól Jarosław
Published: March 2010

Immobilization of Schiff base cobalt(III) complexes on a gel‐type terpolymer obtained from glycidyl methacrylate (GMA, 20 mol %), styrene (S, 77 mol %) and diethyleneglycol dimethacrylate (DMDMG, 3 mol %) was carried out using a multi‐step procedure. GMA resin was reacted first with an excess of diamine (ethylenediamine, trans‐1,2‐diaminocyclohexane or 1,3‐diaminopropane) and then with salicylaldehyde (non‐substituted or its 3,5‐dichloro‐ and 3,5‐di‐t‐butyl‐substituted derivatives). Series of salicylaldimine ligands immobilized on the polymer matrix obtained in this way were then applied to complex cobalt ions from solution of cobalt(II) acetate in the mixture of MeOH and CH2Cl2 (1/3 V/V). Obtained polymer bound cobalt salicylaldimine complexes were tested as catalysts of the addition of aliphatic carboxylic acids to terminal epoxides. It was found that the catalysts with 1,2‐diamine moieties are clearly more active than the complexes with 1,3‐diaminopropane one. Furthermore, the studies showed the highest activity of the complex with 3,5‐di‐t‐butylsalicylaldehyde moiety and the least with 3,5‐dinitrosalicylaldehyde one. The negative effect of methacrylic acid on the rate of the addition was also found. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermally expandable microspheres with excellent expansion characteristics at high temperature
Authors: Jonsson Magnus , Nordin Ove , Kron Anna Larsson , Malmström Eva
Published: March 2010

Thermally expandable core/shell particles with a poly(acrylonitrile‐co‐methacrylonitrile) shell and a hydrocarbon core (blowing agent) have been prepared by suspension polymerization. The objective of this study was to gain a deeper understanding of the parameters determining the expansion properties of these microspheres. It was found that the amount, the boiling point, and the structure of the blowing agent are important parameters for the expansion properties. For example, a higher maximum expansion was reached when using bulkier blowing agents and thus a lower diffusion rate through the polymer shell. Further, the amount and structure of the crosslinker were also found to be essential for the expansion properties. For this particular system, it was found that a dimethacrylate‐functional crosslinker gave significantly better expansion when compared with diacrylate‐ or divinylether‐based crosslinkers. Beside these parameters, it was also observed that the particle‐size distribution influence the expansion properties of the microspheres. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effects of nutrition and origin on the amino acid, grease, and suint composition and color of cashmere and guard hairs
Authors: McGregor B. A. , Tucker D.J.
Published: March 2010

Nutritional and environmental effects on the amino acid, wax, and suint contents and color of raw cashmere were investigated. Cashmere was obtained from goats fed with or without dietary protected protein, goats fed different levels of dietary energy and feeds, and goats from Australia, China, and Iran. The determined attributes included the production, diameter, length, fiber curvature, crimp, wax and suint contents, amino acid composition, lightness, and yellowness of cashmere. The content of suint, but not that of wax, was affected by nutrition management. The amino acid composition of cashmere was affected by the energy and protein nutrition, feed type, and country of origin. The amino acid composition of cashmere was different from that of guard hair. The lightness and yellowness of cashmere was affected by the nutrition treatment, grazing, cashmere production, and sum of the wax and suint contents of the raw cashmere. The variation in the amino acid composition of cashmere likely affected both its physical and chemical reactivity. Nutrition manipulation of cashmere goats and the origin of goats have implications with respect to the properties of cashmere as changes in fiber cell biosynthesis can alter the amino acid composition of the fiber. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermal curing of glass‐epoxy prepregs by luminescence spectroscopy
Authors: Sales R. C. M. , Diniz M. F. , Dutra R. C. L. , Thim G. P. , Dibbern‐Brunelli D.
Published: March 2010

In this study, we investigated the application of the luminescence spectroscopy technique in steady‐state conditions to study glass fiber‐epoxy F161 prepregs. We conducted this study by comparing the results obtained from the intrinsic fluorescence with Fourier transform near infrared spectroscopy. The extrinsic fluorescence of 9‐anthroic acid (9‐AA) was also used. Fourier transform infrared spectroscopy was also used to characterize the epoxide resin. The prepregs containing 9‐AA and those that did not were heat‐treated at 177°C (F161) for 1100 min at a 2°C/min heating rate. The results obtained by both methods indicated that the crosslinking reaction could be monitored by analysis of the spectral changes of the emission bands of the prepreg and 9‐AA. The intrinsic emission at 320 nm was attributed to the fluorophore group containing the epoxy ring and was used to calculate the conversion degree. The photophysical behavior of the 9‐AA probe indicated a reduction of free volume of the polymeric matrix with curing process. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Crystallization behavior of poly(L‐lactic acid)/montmorillonite nanocomposites
Authors: Huang Su‐Mei , Hwang Jiunn‐Jer , Liu Hsin‐Jiant , Lin Li‐Huei
Published: March 2010

In this study, we modified montmorillonite (MMT) with dilauryl dimethyl ammonium bromide (DDAB) and then exfoliated the structures in a poly(L‐lactic acid) (PLLA) matrix. We used polar optical microscopy and X‐ray diffraction (XRD) to examine the morphologies of the resulting composites, differential scanning calorimetry to study the melting and crystallization behavior, and Fourier transform infrared (FTIR) and Raman spectroscopy to measure the influence of the intermolecular interactions between PLLA and MMT on the isothermal crystallization temperature. We found that the DDAB‐modified MMT was distributed uniformly in the PLLA matrix. At temperatures ranging from 130 to 140°C, the crystalline morphology resembled smaller Maltese cross‐patterned crystallites; at temperatures from 150 to 170°C, however, the number of crystallites decreased, their sizes increased, and they possessed ringed spherulite structures. In the XRD spectra, the intensity of the diffraction peaks of the 200/110 and 203 facets of the PLLA/MMT nanocomposites decreased as the crystallization temperature increased. In the FTIR spectra, the absorption peak of the CO groups split into two signals at 1748 and 1755 cm−1 when the isothermal crystallization temperature was higher than 140°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and Antineoplastic Activity of O‐Alkylated Derivatives of 7‐Hydroximinoandrost‐5‐ene Steroids
Authors: Bansal Ranju , Guleria Sheetal , Ries Christina , Hartmann Rolf W.
Published: March 2010

Varied positioning of the hydroximino group on the parental steroid skeleton results in remarkable changes in the antineoplastic activity profile of the compounds. Here, the compound 7‐oximino‐5‐androstene and its O‐alkylated derivatives have been prepared and screened for cytotoxic and aromatase inhibitory activity. The steroidal 7‐oximino ether derivatives exhibited insignificant cytotoxic effects when screened against three cancer cell lines, MCF‐7 (breast), NCl‐H460 (lung), and SF‐268 (CNS) at 100 μM. However, the imidazolyl‐substituted steroidal oxime ethers displayed moderate inhibition of cytochrome P450 aromatase.
Rheumatoid arthritis risk allele PTPRC is also associated with response to anti–tumor necrosis factor α therapy
Authors: Cui Jing , Saevarsdottir Saedis , Thomson Brian , Padyukov Leonid , van der Helm‐Van Mil Annette H. M. , Nititham Joanne , Hughes Laura B. , de Vries Niek , Raychaudhuri Soumya , Alfredsson Lars , Askling Johan , Wedrén Sara , Ding Bo , Guiducci Candace , Wolbink Gert Jan , Crusius J. Bart A. , van der Horst‐Bruinsma Irene E. , Herenius Marieke , Weinblatt Michael E. , Shadick Nancy A. , Worthington Jane , Batliwalla Franak , Kern Marlena , Morgan Ann W. , Wilson Anthony G. , Isaacs John D. , Hyrich Kimme , Seldin Michael F. , Moreland Larry W. , Behrens Timothy W. , Allaart Cornelia F. , Criswell Lindsey A. , Huizinga Tom W. J. , Tak Paul P. , Bridges S. Louis , Toes Rene E. M. , Barton Anne , Klareskog Lars , Gregersen Peter K. , Karlson Elizabeth W. , Plenge Robert M.
Published: March 2010

Objective

Anti–tumor necrosis factor α (anti‐TNF) therapy is a mainstay of treatment in rheumatoid arthritis (RA). The aim of the present study was to test established RA genetic risk factors to determine whether the same alleles also influence the response to anti‐TNF therapy.

Methods

A total of 1,283 RA patients receiving etanercept, infliximab, or adalimumab therapy were studied from among an international collaborative consortium of 9 different RA cohorts. The primary end point compared RA patients with a good treatment response according to the European League Against Rheumatism (EULAR) response criteria (n = 505) with RA patients considered to be nonresponders (n = 316). The secondary end point was the change from baseline in the level of disease activity according to the Disease Activity Score in 28 joints (▵DAS28). Clinical factors such as age, sex, and concomitant medications were tested as possible correlates of treatment response. Thirty‐one single‐nucleotide polymorphisms (SNPs) associated with the risk of RA were genotyped and tested for any association with treatment response, using univariate and multivariate logistic regression models.

Results

Of the 31 RA‐associated risk alleles, a SNP at the PTPRC (also known as CD45) gene locus (rs10919563) was associated with the primary end point, a EULAR good response versus no response (odds ratio [OR] 0.55, P = 0.0001 in the multivariate model). Similar results were obtained using the secondary end point, the ▵DAS28 (P = 0.0002). There was suggestive evidence of a stronger association in autoantibody‐positive patients with RA (OR 0.55, 95% confidence interval [95% CI] 0.39–0.76) as compared with autoantibody‐negative patients (OR 0.90, 95% CI 0.41–1.99).

Conclusion

Statistically significant associations were observed between the response to anti‐TNF therapy and an RA risk allele at the PTPRC gene locus. Additional studies will be required to replicate this finding in additional patient collections.