bluuebunny/crossref_metadata_2025_split huggingface dataset:
Melting bulk reaction between poly(butylene terephthalate) and poly(ethylene glycol)/DL‐oligo(lactic acid)
Authors: Chen Yiwang , Zhu Xiangjun , Tan Licheng , Su Jiying 
Published: February 2008

AbstractA reactive blend of poly(ethylene glycol) (PEG) and DL‐oligo(lactic acid) (OLA) is obtained at high temperature to produce partial PEG/OLA multiblock copolymer without purification. The reactive blend of PEG and OLA easily reacts with poly(1,4‐butylene terephthalate) (PBT) in the melt leading to the formation of high‐molar mass poly(1,4‐butylene terephthalate‐co‐ethylene oxide‐co‐DL‐lactide) (PBTEOLA) copolymers. The analysis from 1H NMR and solubility test reveals that the transesterification between butylene terephthalate (BT), ethyleneoxide (EO), and lactide (LA) segments during synthesis is unavoidable. The copolyesters are segmented copolyesters with certain random properties, as confirmed by their thermal behavior. The copolyesters show only one melting temperature (Tm) on the second heating run and one crystallization temperature (Tc) on the cooling cycle from differential scanning calorimetry measurement. With increase of OLA feeding composition in PEG/OLA blend or increase of content of PEG/OLA blend, the Tm and Tc of copolyesters decrease, and solubility increases. The conventional size‐exclusion chromatography polystyrene calibration estimates weight‐averaged molecular weight of the copolyester to be as high as 66,600 g/mol. Mechanical tests indicate that the copolyesters exhibit high Young's modulus of 50–100 MPa and good elongation at break of 32–137%. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, characterization, and stimuli‐sensitive properties of triblock copolymer poly(ethylene oxide)‐b‐poly(2‐(diethylamino)ethyl methacrylate)‐b‐poly(N‐isopropylacrylamide)
Authors: Xu Xuewei , Liu Chao , Huang Junlian 
Published: February 2008

AbstractWell‐defined triblock copolymer poly(ethylene oxide)‐b‐poly(2‐(diethylamino)ethyl methacrylate)‐b‐poly(N‐isopropyl‐acrylamide) (PEO‐b‐PDMAEMA‐b‐PNIPAAm) was synthesized via sequential reversible addition‐fragmentation chain transfer polymerization (RAFT) of 2‐(dimethylamino)ethyl methacrylate (DMAEMA) and N‐isopropylacrylamide (NIPAAm) using α‐methoxy‐ω‐S‐1‐dodecyl‐S‐α‐(α,α′‐dimethyl‐α″‐acetate) poly(ethylene oxide) (mPEO‐DDAT) as macro‐RAFT agent, AIBN as initiator in dioxane at 80°C. The polymerization data indicated that the both RAFT processes were well controlled. The molecular weights of macro‐RAFT agents showed the influence on the RAFT polymerization process. The final PEO‐b‐PDMAEMA‐b‐PNIPAAm triblock copolymer can form uniform micelles in aqueous media above the lower critical solution temperature (LCST) due to containing temperature‐sensitive PNIPAAm block. The micelle size and Dh were dependent on the composition of triblock copolymer and the pH value of the solution. The PEO‐b‐PDMAEMA‐b‐PNIPAAm triblock copolymer showed dual temperature‐ and pH‐sensitive property in aqueous media. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Studies on polyethylene oxide and phenolic resin blends
Authors: Ratna Debdatta , Abraham T. N. , Karger‐Kocsis J. 
Published: February 2008

AbstractBlends of poly(ethylene oxide) (PEO) and novolac type phenolic resin were prepared by a solution cast method using acetonitrile as a solvent. In this work, we have investigated the PEO/phenolic blends having low phenolic content (0 to 30 wt %) with the objective in mind to design a crystallizable component for a shape memory polymer system having adjustable switching temperature. The blends were characterized by Fourier transform infrared (FTIR) spectroscopy, polarized optical microscopy (POM), and differential scanning calorimetry (DSC). The rate of crystallization and crystallinity (calculated from heat of crystallization value) decrease with increase in novolac content. FTIR analysis indicates the existence of H‐bonding between hydroxyl groups of novolac and ether groups of PEO. POM studies indicate that size of Maltese cross section decreases with increase in novolac content and in the blends containing higher novolac content less regular leaf like texture was obtained. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Crosslinking of unfilled carboxylated nitrile rubber with different systems: Influence on properties
Authors: Ibarra L. , Rodríguez A. , Mora‐Barrantes I. 
Published: February 2008

AbstractThe presence of two functional groups, nitrile and carboxyl, in carboxylated nitrile rubber allows it to be crosslinked with different agents. In this study, we examined the influence of different crosslinking agents on the properties of unfilled carboxylated nitrile rubber. Significant differences were found when different crosslinking agents were used, as shown in the vulcanization curves, especially in the variation of the viscous component with the reaction time. The reaction rate was highest when organic peroxide was used, and it was lowest when metallic peroxide or copper sulfate was used. When the crosslinking agents led to the formation of ionic bonds (metallic oxide and metallic peroxide), the carboxylic groups COOH had a greater participation in the crosslinking. However, when copper sulfate was used, coordination bonds were formed, and the main contribution was due to the nitrile groups. Tensile strength, tear strength, and abrasion properties were superior when the crosslinking systems used led to the formation of ionic bonds. On the contrary, the compression set was optimum when covalent bonds were formed. Copper sulfate behaved as an intermediate between the two previous situations. The mechanodynamic response of the compounds also depended on the crosslinking agent used. The correlation between crosslink density by swelling in dichloromethane, maximum damping temperature by dynamic measurements, and glass‐transition temperature by differential scanning calorimetry had to be explained in terms of the crosslink type. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Assessing the permissiveness of transcriptional activator binding sites
Authors: Rowe Steven P. , Mapp Anna K. 
Published: February 2008

AbstractBoth genetic and biochemical data suggest that transcriptional activators with little sequence homology nevertheless function through interaction with a shared group of coactivators. Here we show that a series of peptidomimetic transcriptional activation domains interact under cell‐fiee and cellular conditions with the metazoan coactivator CBP despite differences in the positioning and identity of the constituent functional groups. Taken together, these results suggest that a key activator binding site within CBP is permissive, accepting multiple arrangements of hydrophobic functional groups. Further, this permissiveness is also observed with a coactivator from S. cerevisiae. Thus, the design of small molecule mimics of transcriptional activation domains with broad function may be more straightforward than previously envisioned. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 578–581, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Cell (A549)–Particle (Jasada Bhasma) interactions using Raman spectroscopy
Authors: Pyrgiotakis G. , Bhowmick T. K. , Finton K. , Suresh A. K. , Kane S. G. , Bellare J. R. , Moudgil B. M. 
Published: February 2008

AbstractCurrent methods for the evaluation of cell interactions with particles are nonspecific, slow, and invasive to the cells. Raman spectroscopy is a noninvasive technique, and is used in the present study to investigate particle–cell interactions. The main focus of the present study is to employ Raman spectroscopy for investigating the interaction of human lung adenocarcinoma cell line (A549) with the particulate system Jasada Bhasma, a traditional Indian medicine. Jasada Bhasma is a unique preparation of zinc and is traditionally used for the treatment of various diseases like diabetes, age‐related eye diseases, and as a health promotional tonic. The Raman spectral analysis is executed by identifying the difference in intracellular DNA/RNA, and proteins and lipids concentration between particles—treated and untreated cells. Comparison between Bhasma‐treated and ‐untreated cells indicates that vibrational peaks corresponding to the DNA/RNA molecule show a significant increase in cells treated with the Jasada Bhasma. Apart from the DNA molecule, several other vibrational peaks related to the protein molecules also show a significant increase in A549 cells after treatment with Bhasma. These results indicate that Bhasma treatment of A549 possibly delays DNA degradation and enables retention of higher amount of protein molecules in the cells. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 555–564, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
A Novel Sensor Platform Based on Aptamer‐Conjugated Polypyrrole Nanotubes for Label‐Free Electrochemical Protein Detection
Authors: Yoon Hyeonseok , Kim June‐Hyung , Lee Nahum , Kim Byung‐Gee , Jang Jyongsik 
Published: February 2008

AbstractWe first present a simple yet versatile strategy for the functionalization of polymer nanotubes in a controlled fashion. Carboxylic‐acid‐functionalized polypyrrole (CPPy) nanotubes were fabricated by using cylindrical micelle templates in a water‐in‐oil emulsion system, and the functional carboxyl groups were effectively incorporated into the polymer backbone during the polymerization by using pyrrole‐3‐carboxylic acid (P3CA) as a co‐monomer without a sophisticated functionalization process. It was noteworthy that the chemical functionality of CPPy nanotubes was readily controlled in both qualitative and quantitative aspects. On the basis of the controlled functionality of CPPy nanotubes, a field‐effect transistor (FET) sensor platform was constructed to detect specific biological entities by using a buffer solution as a liquid‐ion gate. The CPPy nanotubes were covalently immobilized onto the microelectrode substrate to make a good electrical contact with the metal electrodes, and thrombin aptamers were bonded to the nanotube surface via covalent linkages as the molecular recognition element. The selective recognition ability of thrombin aptamers combined with the charge transport property of CPPy nanotubes enabled the direct and label‐free electrical detection of thrombin proteins. Upon exposure to thrombin, the CPPy nanotube FET sensors showed a decrease in current flow, which was probably attributed to the dipole–dipole or dipole–charge interaction between thrombin proteins and the aptamer‐conjugated polymer chains. Importantly, the sensor response was tuned by adjusting the chemical functionality of CPPy nanotubes. The efficacy of CPPy nanotube FET sensors was also demonstrated in human blood serum; this suggests that they may be used for practical diagnosis applications after further optimization.
Surviving recurrence: Psychological and quality‐of‐life recovery
Authors: Yang Hae‐Chung , Thornton Lisa M. , Shapiro Charles L. , Andersen Barbara L. 
Published: February 2008

AbstractBACKGROUNDTo the authors' knowledge, data characterizing patients' psychosocial experiences after a recurrence diagnosis are limited. This report provides the physical, psychological, and quality‐of‐life trajectories of patients with recurrent breast cancer. In addition, patients with a well–documented trajectory—patients with their initial diagnosis of breast cancer—were included as a referent group, providing a metric against which to gauge the impact and course of cancer recurrence.METHODSPatients with a newly diagnosed, recurrent (n = 69) or initial (n = 113) breast cancer were accrued. The groups did not differ with regard to age, race, education, family income, or partner status (all P values > .18). All patients were assessed shortly after diagnosis (baseline) and 4 months, 8 months, and 12 months later. Mixed‐effects models were used to determine health status, stress, mood, and quality‐of‐life trajectories.RESULTSIn the year after a recurrence diagnosis, patients' physical health and functioning showed no improvement, whereas quality of life and mood generally improved, and stress declined. Compared with patients who were coping with their first diagnosis, patients with recurrence had significantly lower anxiety and confusion. In contrast, physical functioning was poorer among recurrence patients, quality‐of‐life improvement was slower, and cancer‐related distress was high as that of the initially diagnosed patient. Slower quality‐of‐life recovery was most apparent among younger patients (aged <54 years).CONCLUSIONSDespite the physical burden, patients with recurrent breast cancer exhibit considerable resilience, with steady improvements in psychological adjustment and quality of life during the year after diagnosis. Management of patients' physical symptoms is particularly important, because patients cope with recurrent breast cancer as a chronic illness. Cancer 2008. © 2008 American Cancer Society.
Cellular and subcellular distribution of rat brain prolyl oligopeptidase and its association with specific neuronal neurotransmitters
Authors: Myöhänen Timo T. , Venäläinen Jarkko I. , Garcia‐Horsman J. Arturo , Piltonen Marjo , Männistö Pekka T. 
Published: February 2008

AbstractProlyl oligopeptidase (POP) is a serine endopeptidase that hydrolyzes proline‐containing peptides shorter than 30‐mer. It has been suggested that POP is associated with cognitive functions and inositol 1,4,5‐triphosphate (IP3) signaling. However, little is known about the distribution and physiological role of POP in the brain. We used immunohistochemistry to determine the cellular and subcellular distribution of POP in the rat brain. POP was specifically expressed in the glutamatergic pyramidal neurons of the cerebral cortex, particularly in the primary motor and somatosensory cortices, and also in the CA1 field of hippocampus. Purkinje cells of the cerebellum were also intensively immunostained for POP. Double immunofluorescence indicated that POP was present in the γ‐aminobutyric acid (GABA)ergic and cholinergic interneurons of the thalamus and cortex but not in the nigrostriatal dopaminergic neurons. POP did not colocalize with astrocytic markers in any part of the rat brain. We used postembedding immunoelectron microscopy to determine the distribution of POP at the subcellular level. POP was mainly present in neuronal cytosol and membranes, hardly at all in neuronal plasma membrane, but more extensively in intracellular membranes such as the rough endoplasmic reticulum and Golgi apparatus. Our findings point to a role for POP—evidently modifying neuropeptide levels—in excitatory and inhibitory neurotransmission in the central nervous system via glutamatergic, GABAergic, and cholinergic neurotransmission systems. Furthermore, according to our results, POP may be involved in thalamocortical neurotransmission, memory and learning functions of the hippocampal formation, and GABAergic regulation of voluntary movements. Subcellular distribution of POP points to a role in protein processing and secretion. J. Comp. Neurol. 507:1694–1708, 2008. © 2008 Wiley‐Liss, Inc.
Calcitonin receptor‐like receptor (CLR), receptor activity‐modifying protein 1 (RAMP1), and calcitonin gene‐related peptide (CGRP) immunoreactivity in the rat trigeminovascular system: Differences between peripheral and central CGRP receptor distribution
Authors: Lennerz Jochen K. , Rühle Victor , Ceppa Eugene P. , Neuhuber Winfried L. , Bunnett Nigel W. , Grady Eileen F. , Messlinger Karl 
Published: February 2008

AbstractCGRP meets its receptor in the rat dura mater. The CGRP receptor protein CLR (green) is expressed in smooth muscle cells (blue, SMA) in the media of meningeal arteries (left) but not in veins (right upper half). CLR is also found in trigeminal nerve bundles and mononuclear cells adjacent to the arteries. CGRP‐receptor components are however not co‐localized with axonal CGRP (red) in the dura, but expressed in Schwann cells (not visible at this magnification). J. Comp. Neurol. 507:1279–1301, 2008. © 2008 Wiley‐Liss, Inc.
Electrosynthesis of Poly(para)phenylene in an Ionic Liquid: Cyclic Voltammetry and in Situ STM/Tunnelling Spectroscopy Studies
Authors: Carstens T. , Zein El Abedin S. , Endres F. 
Published: February 2008

AbstractThe electropolymerization of benzene in the air and water‐stable ionic liquid 1‐hexyl‐3‐methylimidazolium tris(pentafluoroethyl)trifluorophosphate (HMIm)FAP is investigated. The study comprises cyclic voltammetry, IR and in situ STM/tunnelling spectroscopy measurements. The IR results indicate that poly(para)phenylene is the end product of the electropolymerization of benzene in the employed ionic liquid. The resulting conjugation lengths of the product fall between 19 and 21. A polymer reference electrode is used successfully for the electrochemical polymerization of benzene. The first in situ STM results show that the electropolymerization of benzene in the ionic liquid can be probed on the nanoscale and the band gap of the prepared polymer can be determined. The electrodeposited polymer film obtained at a constant potential of 1.0 V vs PPP (polyparaphenylene) exhibits a band gap of 2.9±0.2 eV.
Viral danger signals control CD1d de novo synthesis and NKT cell activation
Authors: Raftery Martin J. , Winau Florian , Giese Thomas , Kaufmann Stefan H. E. , Schaible Ulrich E. , Schönrich Günther 
Published: February 2008

AbstractThe nonpolymorphic CD1 molecules present lipid antigens to T cells. In myeloid DC humans express five different CD1 proteins (CD1a–e; the corresponding CD1 genes are designated CD1A–E). A role for CD1d‐restricted NKT cells in the control of virus infections has been delineated from clinical observations, mouse models and viral evasion mechanisms targeting CD1d. How NKT cells are activated by virus infections is unclear. We found that human myeloid DC differentially regulate CD1 antigen presentation in response to viral danger signals. Stimulation with type I IFN, viral TLR ligands or viruses strongly enhanced the number of CD1D transcripts in human myeloid DC but diminished the abundance of CD1A, CD1B and CD1E mRNA. These changes on the transcriptional level were mirrored by altered cellular distribution and increased surface expression of CD1d. As a consequence NKT cells were activated and showed a Th1‐like response. Moreover, NKT cell activation in PBMC exposed to viral danger signals was dependent on human plasmacytoid DC which produce large amounts of IFN‐α. In conclusion, our data indicate that viral danger signals trigger NKT cell activation by enhancing CD1d de novo synthesis through increasing the abundance of CD1D mRNA in human myeloid DC.
Phage display‐derived recombinant antibodies with TCR‐like specificity against α‐galactosylceramide and its analogues in complex with human CD1d molecules
Authors: Denkberg Galit , Stronge Victoria S. , Zahavi Efrat , Pittoni Paola , Oren Ravit , Shepherd Dawn , Salio Mariolina , McCarthy Corinna , Illarionov Petr A. , van der Merwe Anton , Besra Gurdyal S. , Dellabona Paolo , Casorati Giulia , Cerundolo Vincenzo , Reiter Yoram 
Published: February 2008

AbstractThe glycolipid α‐galactosylceramide (α‐GalCer) is a potent activator of invariant natural killer T (iNKT) cells and has been shown to be an effective agent against cancer, infections and autoimmune diseases. The effectiveness of α‐GalCer and its alkyl chain analogues depends on efficient loading and presentation by the antigen‐presenting molecule CD1d. To monitor the ability of CD1d to present the glycolipids, we have used a phage display strategy to generate recombinant antibodies with T cell receptor‐like (TCRL) specificity against the human CD1d (hCD1d)‐α‐GalCer complex. These Fab fragments were able to detect specifically hCD1d‐α‐GalCer complexes in cell‐free systems such as surface plasmon resonance and ELISA, as well as on the surface of hCD1d+ antigen‐presenting cells (APC) by flow cytometry and immunofluorescence microscopy, the latter of which could also detect intracellular complexes. We show that our TCRL antibodies can stain dendritic cells from CD11c‐hCD1d‐transgenic mice administered in vivo with α‐GalCer and its analogues. Furthermore, the antibody was also able to detect the presentation by hCD1d molecules of analogues of α‐GalCer with the same polar head structure. Using this reagent, we were able to confirm directly that the α‐GalCer analogue C20:2 preferentially loads onto cell surface CD1d rapidly without the need for internalization, while the loading of α‐GalCer is improved with longer incubation times on professional APC. This reagent will be essential for assessing the loading and presenting capabilities of hCD1d of α‐GalCer and its analogues.
Vesicle associated membrane protein (VAMP)‐7 and VAMP‐8, but not VAMP‐2 or VAMP‐3, are required for activation‐induced degranulation of mature human mast cells
Authors: Sander Leif E. , Frank Simon P. C. , Bolat Seza , Blank Ulrich , Galli Thierry , Bigalke Hans , Bischoff Stephan C. , Lorentz Axel 
Published: February 2008

AbstractMediator release from mast cells (MC) is a crucial step in allergic and non‐allergic inflammatory disorders. However, the final events in response to activation leading to membrane fusion and thereby facilitating degranulation have hitherto not been analyzed in human MC. Soluble N‐ethyl‐maleimide‐sensitive factor attachment protein receptors (SNARE) represent a highly conserved family of proteins that have been shown to mediate intracellular membrane fusion events. Here, we show that mature MC isolated from human intestinal tissue express soluble N‐ethylmaleide sensitive factor attachment protein (SNAP)‐23, Syntaxin (STX)‐1B, STX‐2, STX‐3, STX‐4, and STX‐6 but not SNAP‐25. Furthermore, we found that primary human MC express substantial amounts of vesicle associated membrane protein (VAMP)‐3, VAMP‐7 and VAMP‐8 and, in contrast to previous reports about rodent MC, only low levels of VAMP‐2. Furthermore, VAMP‐7 and VAMP‐8 were found to translocate to the plasma membrane and interact with SNAP‐23 and STX‐4 upon activation. Inhibition of SNAP‐23, STX‐4, VAMP‐7 or VAMP‐8, but not VAMP‐2 or VAMP‐3, resulted in a markedly reduced high‐affinity IgE receptor‐mediated histamine release. In summary, our data show that mature human MC express a specific pattern of SNARE and that VAMP‐7 and VAMP‐8, but not VAMP‐2, are required for rapid degranulation.
Dampening Ab responses using proteasome inhibitors following in vivo B cell activation
Authors: Cascio Paolo , Oliva Laura , Cerruti Fulvia , Mariani Elisabetta , Pasqualetto Elena , Cenci Simone , Sitia Roberto 
Published: February 2008

AbstractUpon encounter with Ag, B lymphocytes undergo terminal differentiation into plasma cells, highly specialized Ab secretors that mediate humoral immune responses. Profound changes adapt cellular morphology and proteome to the new secretory functions. Although a massive secretory activity is expected to require an efficient ubiquitin‐proteasome degradation system, recent in vitro studies have surprisingly revealed that the proteasome function sharply decreases during plasma cell development, thereby limiting the proteolytic capacity. We challenged this paradigm in mouse models of B cell activation, and observed that following polyclonal activation, proteasome activity decreases more than previously reported in vitro. This decrease is linked to enhanced apoptosis after treatment with the potent anti‐myeloma proteasome inhibitor PS‐341. Accordingly, in vivo treatment with PS‐341 decreases Ab titres in T‐dependent and ‐independent mouse immunization models. This study provides the rationale for limiting the activity of Ab‐secreting cells in vivo by impacting proteasome function.