bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of well‐defined polystyrene and poly(ε‐caprolactone) hetero eight‐shaped copolymers
Authors: Shi Gang‐Yin , Yang Li‐Ping , Pan Cai‐Yuan 
Published: August 2008

AbstractWell‐defined hetero eight‐shaped copolymers composed of polystyrene (PS) and poly(ε‐caprolactone) (PCL) with controlled molecular weight and narrow molecular weight distribution were successfully synthesized by the combination of ring‐opening polymerization, ATRP, and “click” reaction. The synthetic procedure involves three steps: (1) preparation of a tetrafunctional PS and PCL star copolymer with two PS and two PCL arms using the tetrafunctional initiator bearing two hydroxyl groups and two bromo groups; (2) synthesis of tetrafunctional star copolymer, (α‐acetylene‐PCL)2(ω‐azido‐PS)2, by the transition of terminal hydroxyl and bromo groups to acetylene and azido groups through the reaction with 4‐propargyloxybutanedioyl chloride and NaN3 respectively; (3) intramolecular cyclization reaction to produce the hetero eight‐shaped copolymers using “click” chemistry under high dilution. The 1H NMR, FTIR, and gel permeation chromatography techniques were applied to characterize the chemical structures of the resulted intermediates and the target polymers. Their thermal behavior was investigated by DSC, and their crystallization behaviors of PCL were studied by polarized optical microscopy. The decrease in chain mobility of the eight‐shaped copolymers restricts the crystallization of PCL and the crystallization rate of PCL is slower in comparison with their corresponding star precursors. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6496–6508, 2008
High performance thermosets from a curable Diels–Alder polymer possessing benzoxazine groups in the main chain
Authors: Chou Ching‐I , Liu Ying‐Ling 
Published: August 2008

AbstractA high‐molecular‐weight polymer (PBz) possessing reactive benzoxazine groups in the main chain was prepared through the Diels–Alder reaction using bis(3‐furfuryl‐3,4‐dihydro‐2H‐1,3‐benzoxazinyl)isopropane (BPA‐FBz) and bismaleimide (BMI) as monomers. The chemical structure of PBz is characterized with FTIR and 1H NMR. The polymer PBz was further thermally reacted with a high performance polymer (PBz‐R) through the ring‐opening addition reaction of benzoxazine groups and the addition reaction of maleimide groups. PBz‐R exhibit a high glass transition temperature of 242 °C, good thermal stability, high flame retardancy, high mechanical strength, and great flexibility. Another crosslinked polymer (PBz‐BR) curing from the mixture of BPA‐FBz and BMI was also prepared. The properties of PBz‐BR are also attractive but, however, not as good as what observed with PBz‐R. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6509–6517, 2008
Gold nanoparticle‐incorporated core and shell crosslinked micelles fabricated from thermoresponsive block copolymer of N‐isopropylacrylamide and a novel primary‐amine containing monomer
Authors: Zhou Yueming , Jiang Kunqiang , Chen Yaqiong , Liu Shiyong 
Published: August 2008

AbstractA novel primary amine‐containing monomer, 1‐(3′‐aminopropyl)‐4‐acrylamido‐1,2,3‐triazole hydrochloride (APAT), was prepared from N‐propargylacrylamide and 3‐azidopropylamine hydrochloride via copper‐catalyzed Huisgen 1,3‐dipolar cycloaddition (click reaction). Poly(N‐isopropylacrylamide)‐b‐poly(1‐(3′‐aminopropyl)‐4‐acrylamido‐1,2,3‐triazole hydrochloride), PNIPAM‐b‐PAPAT, was then synthesized via consecutive reversible addition‐fragmentation chain transfer polymerizations of N‐isopropylacrylamide and APAT. In aqueous solution, the obtained thermoresponsive double hydrophilic block copolymer dissolves molecularly at room temperature and self‐assembles into micelles with PNIPAM cores and PAPAT shells at elevated temperature. Because of the presence of highly reactive primary amine moieties in PAPAT block, two types of covalently stabilized nanoparticles namely core crosslinked and shell crosslinked micelles with ‘inverted’ core‐shell nanostructures were facilely prepared upon the addition of glutaric dialdehyde at 25 and 50 °C, respectively. In addition, the obtained structure‐fixed micelles were incorporated with gold nanoparticles via in situ reduction of preferentially loaded HAuCl4. High resolution transmission electron microscopy revealed that gold nanoparticles can be selectively loaded into the crosslinked cores or shells, depending on the micelle templates employed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6518–6531, 2008
Synthesis, properties, and sulfonation of novel dendritic multiblock copoly(ether‐sulfone)
Authors: Matsumura Sumiko , Hlil Antisar R. , Hay Allan S. 
Published: August 2008

AbstractMultiblock copoly(ether‐sulfone)s (PESs) bearing anchor units for the construction of dendritic blocks were synthesized by two‐step reactions: (1) synthesis of PES block with both phenoxide end‐groups; (2) chain extension and end‐capping of the block by use of excess novel hexafunctional agent, hexakis(4‐(4‐fluorophenylsulfonyl)phenyl)benzene. The optimum average block length (n) and amount (x) of the hexafunctional agent used for the synthesis of high‐molecular‐weight PES without crosslinking were n = 26 and x = 2.6 equiv, respectively. The dendritic blocks in the PES were constructed by the aromatic nucleophilic substitution reaction of the activated aromatic fluoride groups on the anchor units using 4‐tritylbenzenethiol. The clean substitution of the fluoride groups in the PES was confirmed by 1H NMR and 19F NMR. Three sulfonic acid groups were introduced on the pendant phenyl rings of the trityl groups in the PES by the reaction with chlorosulfonic acid. This is the first example of a dendritic PES bearing clusters of sulfonic acid groups only on the dendritic blocks. Cast films of presulfonated dendritic PES were strong and flexible, however, the membranes of sulfonated dendritic PES were brittle so that the conductivity measurements were not performed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6365–6375, 2008
Miscibility, morphology, and thermal properties of hyperbranched polyborates modified phenolic resins
Authors: Liu Yuhong , Jing Xinli 
Published: August 2008

AbstractA series of hyperbranched polyborates (HB) terminated with phenol hydroxyl (HBp) and boric acid hydroxyl (HBb) functional groups, respectively, were blended with phenolic resins (PR). The miscibility and specific interaction behaviors of the HB and PR were investigated by differential scanning calorimetry (DSC) and Fourier Transform infrared spectroscopy (FTIR). Cure behaviors and thermal properties of PR containing different content of HB were also studied. In addition, thermogravimetry analysis (TGA) exhibited apparent increase in thermal stability at both the initial stages and residue weight at 800 °C under nitrogen atmosphere, especially, for the HBb10/90 system that has a temperature of 458 °C at 5% mass loss and a residue weight of 75.4%. Moreover, scanning electron microscope (SEM) revealed that the initially homogeneous phase separated into two‐phase structure after the cure process, which offers a route to achieve new properties combinations that are desirable for high performance polymers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2012–2021, 2008
Polymer structure‐dependent ion interaction studied by amphiphilic nonionic poly(organophosphazenes)
Authors: Ahn Sungsook , Ahn Sung Won , Song Soo‐Chang 
Published: August 2008

AbstractThe relative effectiveness of anions and cations in altering macromolecular conformation was reported to be independent of the nature of the macromolecule. However, in terms of the degree of changes, macromolecule‐dependent ion action cannot be underestimated. The designed poly(organophosphazenes) have been selected for this study due to its versatility of the substitution with a fixed backbone. To set up the systematic explanation on the ion action related with molecular interactions, ions and polymers are arranged based on the water binding ability. As a characteristic factor specific in the thermothickening system, the temperature at which the viscosity of the polymer solution reaches the maximum (Tmax) has been compared. Anions with strong water binding ability more effectively lower the Tmax of the hydrophobic poly(organophosphazenes). Meanwhile, the Tmax of the cation‐complexed poly(organophosphazenes) are lowered by the sequence of water binding ability of the complexed cations. In both the anion and cation interactions, poly(organophosphazenes) substituted by longer PEG and more hydrophilic amino acid ester, show differentiated result due to different interaction with water when compared with other polymer systems in this study. Ion interaction with poly(organophosphazenes) mediated by water supports interfacial interactions expressed by interaction parameters, which strongly depends on the polymer structure and ion type. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2022–2034, 2008
Melting behavior of a poly(ether‐block‐amide) copolymer melt‐crystallized under quiescent, isothermal conditions
Authors: Guo Xiaoping 
Published: August 2008

AbstractSegmented poly(ether‐block‐amide) copolymers are typically known as polyamide‐based thermoplastic elastomers consisting of hard, crystallizable polyamide block and flexible, amorphous polyether block. The melting characteristics of a poly(ether‐block‐amide) copolymer melt‐crystallized under various quiescent, isothermal conditions were calorimetrically investigated using differential scanning calorimetry (DSC). For such crystallized copolymer samples, their crystalline structures under ambient condition and the structural evolutions upon heating from ambient to complete melting were characterized using ambient and variable‐temperature wide‐angle X‐ray diffractometry (WAXD), respectively. It was observed that dependent of specific crystallization conditions, the copolymer samples exhibited one, two, or three melting endotherms. The ambient WAXD results indicated that all melt‐crystallized copolymer samples only exhibited γ‐form crystals associated with the hexagonal habits of the polyamide homopolymer, whereas variable‐temperature WAXD data suggested that upon heating from ambient, a melt‐crystallized copolymer might exhibit so‐called Brill transition before complete melting. Based on various DSC and variable‐temperature WAXD experimental results obtained in this study, the applicability of different melting mechanisms that might be responsible for multiple melting characteristics of various crystallized PEBA copolymer samples were discussed. It was postulated that the low (T
m1) endotherm was primarily because of the disruption of less thermally stable, short‐range ordered structure of amorphous polyamide segments of the copolymer, which was only formed after the completion of primary crystallization via so‐called annealing effects. The intermediate (Tm2) and high (Tm3) endotherms were attributed to the melting of primary crystals within polyamide crystalline microdomains of the copolymer. The appearance of these two melting endotherms might be somehow complicated by thermally induced Brill transition. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2035–2046, 2008
Tunable morphologies of rhenium complex‐containing polystyrene‐block‐poly(2‐vinylpyridine) aggregates
Authors: Xu Peng , Ji Xin , Abetz Volker , Jiang Shimei , Shen Jiacong 
Published: August 2008

AbstractPolystyrene‐block‐poly(2‐vinylpyridine) (PS‐b‐P2VP) diblock copolymer was functionalized with luminescent chlorotricarbonyl rhenium (I) phenanthroline complex in the presence of silver perchlorate. The copolymer‐metal complex showed high sensitivity to the solvent system. Different morphologies and dimensions of the rhenium complex within nanosized micelles were controlled by changing the solvent systems. Core‐embedded rhenium complex within micelles appear by adding methanol, a poor solvent for the copolymer‐metal complex, to the solution of common solvent tetrahydrofuran (THF); the number of the core‐embedded rhenium complex and the scale of the micelles are strongly related to the addition of methanol. Moreover, a novel morphology of corona‐embedded rhenium complex micelles was prepared by dropping the original THF solution of copolymer‐metal complex into water at a low pH value. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2047–2053, 2008
Pleural effusion due to intra‐abdominal extravasation of parenteral nutrition
Authors: Been Jasper V. , Degraeuwe Pieter L.J. 
Published: August 2008

AbstractAn 8‐week‐old preterm boy experienced respiratory deterioration due to unilateral pleural effusion. Intra‐abdominal extravasation of parenteral fluid with leakage into the pleural cavity was suspected based on biochemical analysis of the effluent. Perforation of the central venous catheter in the peritoneal cavity was subsequently confirmed by contrast roentgenography. As in peritoneal dialysis and hepatic hydrothorax, pleuroperitoneal communication needs to be considered in patients exhibiting pleural effusion with a central venous line below the diaphragm. Pediatr Pulmonol. 2008; 43:1033–1035. © 2008 Wiley‐Liss, Inc.
Bringing diagnostic technologies to the clinical laboratory: Rigor, regulation, and reality
Authors: Whiteley Gordon 
Published: August 2008

AbstractWith the numerous reports of new technologies and biomarkers reported in the literature, it may be surprising that there are not an equal number of new products available to the clinical diagnostic laboratory. Powerful potential tools such as protein microarrays and MS patterns have been extensively published yet commercialization and acceptance of these technologies has yet to happen. The reasons for this are a combination of industry risk avoidance, academic focus on discovery, and a lack of appreciation for the high standards and regulation that surrounds the clinical diagnostic laboratory. The development and validation of a new technology or biomarker ensures that a test is reproducible, controllable, and has a defined accuracy and clinical predictive result but this information is only obtained through somewhat mundane but necessary experimental work. The use of design of experiment principles helps to define material parameters to ensure performance. The organization and documentation of this work through a quality system is both mandated and practical. All of this must be done before a test can reach the market with the safety and effectiveness review of regulatory agencies.
Analysis of biofluids for biomarker research
Authors: Xu Xia , Veenstra Timothy D. 
Published: August 2008

AbstractWhile many of the developments made in high‐throughput proteomics were originally applied to procaryotic and simple eucaryotic organisms, the analysis of biofluids became increasingly important as the prospect of using proteomics to discover novel biomarkers became realized. Biofluids have represented a unique challenge to proteomics as they are often present only in small amounts and, particularly in the cases of serum and plasma, can have protein concentration ranges that differ by ten orders of magnitude. While the discovery of authentic, clinically useful biomarkers in the proteomics era has been lacking, there have been a number of significant developments in the ability to more comprehensively characterize biofluid proteomes. The rapid pace of these developments suggest that the eventual discovery of clinically validate biomarkers using proteomic technologies still has a bright future.
A well‐based reverse‐phase protein array applicable to extracts from formalin‐fixed paraffin‐embedded tissue
Authors: Chung Joon‐Yong , Lee Seo‐Jin , Kris Ylaya , Braunschweig Till , Traicoff June L. , Hewitt Stephen M. 
Published: August 2008

AbstractProteomic analysis of formalin‐fixed paraffin‐embedded (FFPE) tissue offers significant diagnostic utility but is complicated due to the high level of covalently crosslinked proteins arising from formalin fixation. To address these challenges, we developed a reliable protein extraction method for FFPE tissue, based on heat‐induced antigen retrieval within a pressure cooker. The protein extraction yield from archival FFPE tissue section is approximately 90% of that recovered from frozen tissue. This method demonstrates preservation of immunoreactivity and recovery of full‐length proteins by Western blotting. Additionally, we developed a well‐based RP protein array platform utilizing an electrochemiluminescence detection system. Protein samples derived from FFPE tissue by means of laser capture dissection, with as few as 500 shots demonstrate measurable signal differences for different proteins. The lysates coated to the array plate, remain stable over 1 month at room temperature. Theses data suggest that this new protein‐profiling platform coupled with the protein extraction method can be used for molecular profiling analysis in FFPE tissue, and contribute to the validation and development of biomarkers in clinical studies.
Imaging mass spectrometry: Towards clinical diagnostics
Authors: Seeley Erin H. , Caprioli Richard M. 
Published: August 2008

AbstractImaging MS (IMS) has emerged as a powerful tool for biomarker discovery. A key advantage of this technique is its ability to probe the proteome directly from a tissue section with preservation of the spatial relationships of the sample and minimal sample preparation. This allows for direct correlation of protein expression with histology. Here, we present the latest developments in imaging MS and their relevance to clinical mass spectral analysis. IMS allows for high throughput analysis of tissue samples and is fully compatible with biostatistical analysis without prior knowledge of protein expression. Several studies are presented of applications in which direct tissue mass spectral analysis has provided insight into clinical questions not readily available by other means. Examples include the determination of lymph node status from investigation of primary breast tumors, prediction of response of breast tumors to chemotherapy, classification and prediction of progression of lung lesions, and exploration of ‘molecular’ margins in invasive disease.
High‐resolution biomarker discovery: Moving from large‐scale proteome profiling to quantitative validation of lead candidates
Authors: Hewel Johannes A. , Emili Andrew 
Published: August 2008

AbstractDiverse proteomic techniques based on protein MS have been introduced to systematically characterize protein perturbations associated with disease. Progress in clinical proteomics is essential for personalized medicine, wherein treatments will be tailored to individual needs based on patient stratification using noninvasive disease monitoring procedures to reveal the most appropriate therapeutic targets. However, breakthroughs await the successful development and application of a robust proteomic pipeline capable of identifying and rigorously assessing the relevance of multiple candidate proteins as informative diagnostic and prognostic indicators or suitable drug targets involved in a pathological process. While steady progress has been made toward more comprehensive proteome profiling, the emphasis must now shift from in depth screening of reference samples to stringent quantitative validation of selected lead candidates in a broader clinical context. Here, we present an overview of the emerging proteomic strategies for high‐throughput protein detection focused primarily on targeted MS/MS as the basis for biomarker verification in large clinical cohorts. We discuss the conceptual promise and practical pitfalls of these methods in terms of achieving higher dynamic range, higher throughput, and more reliable quantification, highlighting research avenues that merit additional inquiry.
Dose‐dependent growth inhibition in vivo of PC‐3 prostate cancer with a reduction in tumoral growth factors after therapy with GHRH antagonist MZ‐J‐7‐138
Authors: Heinrich Elmar , Schally Andrew V. , Buchholz Stefan , Rick Ferenc G. , Halmos Gabor , Mile Melinda , Groot Kate , Hohla Florian , Zarandi Marta , Varga Jozsef L. 
Published: August 2008

AbstractBackgroundAntagonists of growth hormone‐releasing hormone (GHRH) inhibit the growth of various cancers and affect tumoral growth factors.MethodsWe investigated the effect of a new GHRH antagonist MZ‐J‐7‐138 at doses of 1.25, 2.5, 5 and 10 µg/day s.c. on the growth of PC‐3 human androgen independent prostate cancers xenografted s.c. into nude mice. Binding assays were used to investigate GHRH receptors. The levels of IGF‐II and VEGF in tumors were measured by radioimmunoassays.ResultsTreatment with 2.5, 5, and 10 µg/day MZ‐J‐7‐138 caused a significant dose‐dependent growth reduction of PC‐3 tumors. The greatest inhibition of 78% was obtained with 10 µg/day. The suppression of IGF‐II protein levels in tumors was seen at all doses of MZ‐J‐7‐138, but only 10 µg dose induced a significant inhibition. MZ‐J‐7‐138 also reduced VEGF protein levels, the inhibition being significant at doses of 5 and 10 µg. Specific high affinity binding sites for GHRH were found on PC‐3 tumors using 125I‐labeled GHRH antagonist JV‐1‐42. MZ‐J‐7‐138 displaced radiolabeled JV‐1‐42 with an IC50 of 0.32 nM indicating its high affinity to GHRH receptors. Real‐time PCR analyses detected splice variant 1 (SV1) of GHRH receptor (GHRH‐R) as well as pituitary type of GHRH‐R and GHRH ligand.ConclusionOur results demonstrate the efficacy of GHRH antagonist MZ‐J‐7‐138 in suppressing growth of PC‐3 prostate cancer at doses lower than previous antagonists. The reduction of levels of growth factors such as VEGF and IGF‐II in tumors by GHRH antagonist was correlated with the suppression of tumor growth. Prostate © 2008 Wiley‐Liss, Inc.
A 3‐D QSAR Study of Catechol‐O‐Methyltransferase Inhibitors Using CoMFA and CoMSIA
Authors: Ai Chunzhi , Wang Yonghua , Li Yan , Li Yanhong , Yang Ling 
Published: August 2008

AbstractInhibitors of Catechol‐O‐Methyltransferase (COMT) play an important role in the treatment of Parkinson's Disease (PD). A new Three‐Dimensional Quantitative Structure–Activity Relationship (3‐D QSAR) analysis was performed on 36 previously reported COMT inhibitors employing Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA) methodologies to correlate the molecular fields and percent inhibition values and three predictive models were derived. The CoMFA and CoMSIA models with steric and electrostatic field yielded cross‐validatedr$\rm{ _{{\rm{cv}}}^2 }$sof 0.585 and 0.528, respectively whereas the conventionalr$\rm{ _{{\rm{ncv}}}^2 }$swere 0.979 and 0.891, respectively. The CoMSIA model with hydrophobic field exhibited ar$\rm{ _{{\rm{cv}}}^2 }$of 0.544 and ar$\rm{ _{{\rm{ncv}}}^2 }$of 0.930. The individual inspection of 3‐D contours generated from these models helps in understanding the possible region for structural modification of molecules to improve the inhibitory bioactivity. These 3‐D QSAR models are also useful for designing and predicting novel COMT inhibitors.