bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of porous titanium dioxide sulfonated polystyrene composite microspheres with amphiphilicity
Authors: Qin Qiuju , Zhong Yanni , Cheng Jiang , Xu Shouping , Fan Xin , Pi Pihui , Wen Xiufang 
Published: March 2013

AbstractPorous particles with amphiphilicity were prepared by a nonpolymeric pore‐formation process with the sulfonation of polystyrene microspheres. Nano titanium dioxide (TiO2) particles were then grafted onto the surface via a sol–gel method to finally form the composite particles. The effects of the mass ratio of ethanol (EtOH) to water, temperature, and solubility parameter on the pore‐formation process is discussed in detail. The morphology, porous structure, and wetting properties of the particles were studied by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared (FTIR) spectroscopy, and contact angle measurement. The results show that porous sulfonated polystyrene (SP) microspheres could be fabricated at 60°C with a 1 : 1 mass ratio of EtOH–water and a solubility parameter of 29.69 MPa1/2. The TiO2 particles were determined to be grafted onto the SP microspheres by physical‐bond interaction on the basis of FTIR analysis. The contact angles for both water (aqueous‐phase) and various organic solvent (oil‐phase) droplets with different polarities on the surface of compressed tablets of TiO2–SP powder were all lower than 30°; this indicated excellent amphiphilicity in the composite particles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effects of processing steps and organoclay content in butadiene rubber/organoclay nanocomposites
Authors: Kim Min‐Su , Kim Gue‐Hyun 
Published: March 2013

AbstractEven though polybutadiene rubber (BR) is a hydrophobic polymer, BR/organoclay nanocomposites are prepared successfully without a compatibilizer by using conventional compounding method. The main objective of this article is to investigate the effect of processing steps on the dispersion of organoclays in the BR matrix. The effect of each processing step on the dispersion of organoclays is studied by using X‐ray diffraction (XRD). Also, the effect of the organoclay content on the mechanical properties is studied. According to the XRD results, mixing BR/organoclay compounds with vulcanization accelerator (MBTS) in a two‐roll mill leads to the exfoliation of organoclays in this article. However, when BR/organoclay nanocomposites were heated at 155°C for the vulcanization as a next processing step, organoclays aggregated to become intercalated structure. The tensile and tear strength of BR/organoclay (9 phr) nanocomposite are 16.6 times and 3 times larger than those of BR, respectively. Over 100% and 300% modulus of BR, 300% and 350 % improvements are observed for those of BR/organoclay (9 phr) nanocomposite, respectively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Sulfonated poly(hexamethylene terephthalate) copolyesters: Enhanced thermal and mechanical properties
Authors: Bautista Mayka , Martínez de Ilarduya Antxon , Alla Abdelilah , Muñoz‐Guerra Sebastián 
Published: March 2013

AbstractA series of poly(hexamethylene terephthalate‐co‐hexamethylene 5‐sodium sulfoisophthalate) copolyesters containing from 5 to 50 mol % of sulfonated units as well as the two parent homopolymers are prepared by melt polycondensation. The polyesters are obtained with high molecular weights, which decrease with the increased content of sulfonated units in the copolymer. Polyesters with 5 and 10 mol % of sulfonated units are semicrystalline whereas for contents equal or above 20 mol % they are unable to crystallize from the melt. Thermogravimetric analysis show that the thermal stability decreases with the content in sulfonated units. Isothermal crystallizations of semicrystalline copolyesters show that the insertion of the sulfonated units causes a reduction of crystallizability, most probably due to the occurrence of ionic aggregations. It is observed a synergistic effect on the mechanical properties for copolymers with contents of around 5 mol % where the elongation at break increases drastically. Moreover, the hydrolytic degradation of the copolymer is enhanced with the content in sulfonated units. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Extrudate swell behavior of polypropylene composites filled with microencapsulated red phosphorus
Authors: Liang Ji‐Zhao , Feng Jin‐Qing , Tsui Chi‐Pong , Tang Chak‐Yin 
Published: March 2013

AbstractThe microencapsulated red phosphorus (MRP) filled polypropylene (PP) composites were prepared using a twin‐screw extruder. The effects of load and temperature on the extrudate swell behavior of the PP/MRP composite melts were investigated by means of a melt flow indexer. The test temperatures and loads were varied from 180 to 205°C and from 2.16 to 12.5 kg, respectively. The results showed that the die‐swell ratio (B) of the composite melts increased roughly linearly with increasing load while decreased slightly with a rise of test temperature. The sensitivity of the die‐swell ratio of the composite melts to load was significant. When the test temperature or load was constant, the values of the B of the composite melts decreased slightly with increasing MRP weight fraction. The findings can provide useful information for processing of these composites. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
In situ fabrication of polyaniline‐silver nanocomposites using soft template of sodium alginate
Authors: Bhowmick Biplab , Mondal Dibyendu , Maity Dipanwita , Rahaman Mollick Md. Masud , Kanti Bain Mrinal , Kumar Bera Nirmal , Rana Dipak , Chattopadhyay Sanatan , Chattopadhyay Dipankar 
Published: March 2013

AbstractPolyaniline (PANI)‐Ag nanocomposites were synthesized by in situ chemical polymerization approach using ammonium persulfate and silver nitrate as oxidant. Characterizations of nanocomposites were done by ultraviolet–visible (UV–vis), Fourier transform infrared (FTIR), X‐ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy (TEM). UV–vis, XRD and FTIR analysis established the formation of PANI/Ag nanocomposites and face‐centered‐cubic phase of silver. PANInanofibers were of average diameter ∼ 30 nm and several micrometers in length. Morphological analysis showed that the spherical‐shaped silver nanoparticles decorate the surface of PANI nanofibers. Silver nanoparticles of average diameter ∼ 5–10 nm were observed on the TEM images for the PANI‐Ag nanocomposites. Such type of PANI‐Ag nanocomposites can be used as bistable switches as well as memory devices. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
One‐Pot Laccase‐Catalysed Synthesis of 5,6‐Dihydroxylated Benzo[b]furans and Catechol Derivatives, and Their Anticancer Activity
Authors: Wellington Kevin W. , Qwebani‐Ogunleye Tozama , Kolesnikova Natasha I. , Brady Dean , de Koning Charles B. 
Published: March 2013

AbstractA commercial laccase, Suberase® from Novozymes, was used to catalyse the synthesis of 5,6‐dihydroxylated benzo[b]furans and catechol derivatives. The yields were, in some cases, similar to or better than that obtained by other enzymatic, chemical or electrochemical syntheses. The synthesised derivatives were screened against renal (TK10), melanoma (UACC62), breast (MCF7) and cervical (HeLa) cancer cell lines. GI50, TGI and LC50 are reported for the first time. Anticancer screening showed that the cytostatic effects of the 5,6‐dihydroxylated benzo[b]furans were most effective against the melanoma (UACC62) cancer cell line with several compounds exhibiting potent growth inhibitory activities (GI50 = 0.77–9.76 µM), of which two compounds had better activity than the anticancer agent etoposide (GI50 = 0.89 µM). One compound exhibited potent activity (GI50 = 9.73 µM) against the renal (TK10) cancer cell line and two exhibited potent activity (GI50 = 8.79 and 9.30 µM) against the breast (MCF7) cancer cell line. These results encourage further studies of the 5,6‐dihydroxylated benzo[b]furans for their potential application in anticancer therapy.
Dysregulation of CD4+CD25high T Cells in the Synovial Fluid of Patients With Antibiotic‐Refractory Lyme Arthritis
Authors: Vudattu Nalini K. , Strle Klemen , Steere Allen C. , Drouin Elise E. 
Published: March 2013

ObjectiveTo examine the role of immune dysregulation in antibiotic‐refractory Lyme arthritis by comparing the phenotype, frequency, and function of CD4+ Teff cells and Treg cells in patients with antibiotic‐ responsive arthritis and patients with antibiotic‐refractory arthritis.MethodsMatched peripheral blood and synovial fluid samples from 15 patients with antibiotic‐responsive arthritis were compared with those from 16 patients with antibiotic‐refractory arthritis, using flow cytometry, suppression assays, and cytokine assays.ResultsCritical differences between the 2 patient groups were observed in the synovial fluid CD4+CD25high population, a cell subset usually composed of FoxP3‐positive Treg cells. In patients with antibiotic‐refractory arthritis, this cell population often had fewer FoxP3‐positive cells and a greater frequency of FoxP3‐negative (Teff) cells compared with patients with antibiotic‐responsive arthritis. Moreover, the expression of glucocorticoid‐induced tumor necrosis factor receptor and OX40 on CD4+CD25high cells was significantly higher in the antibiotic‐refractory group. Suppression assays showed that CD4+CD25high cells in patients with antibiotic‐refractory arthritis did not effectively suppress proliferation of CD4+CD25− cells or secretion of interferon‐γ and tumor necrosis factor α, whereas those cells in patients with antibiotic‐responsive arthritis did suppress proliferation of CD4+CD25− cells and secretion of interferon‐γ and tumor necrosis factor α. Finally, in the antibiotic‐refractory group, higher ratios of CD25high FoxP3‐negative cells to CD25high FoxP3‐positive cells correlated directly with a longer duration of arthritis after antibiotic treatment.ConclusionPatients with antibiotic‐refractory Lyme arthritis often have lower frequencies of Treg cells, higher expression of activation coreceptors, and less effective inhibition of proinflammatory cytokines. This suggests that immune responses in these patients are excessively amplified, leading to immune dysregulation and antibiotic‐refractory arthritis.
Anti–Citrullinated Protein Antibodies in Unaffected First‐Degree Relatives of Rheumatoid Arthritis Patients
Authors: Barra Lillian , Scinocca Mathias , Saunders Sheri , Bhayana Rajesh , Rohekar Sherry , Racapé Maud , Coles Robert , Cairns Ewa , Bell David A. 
Published: March 2013

ObjectiveFirst‐degree relatives (FDRs) of rheumatoid arthritis (RA) patients sharing genetic and environmental risk factors for RA may represent a pre‐RA state. Since anti–cyclic citrullinated protein/peptide antibodies (ACPAs) appear years before the onset of RA, the purpose of this study was to determine the prevalence of various ACPAs in FDRs of RA patients.MethodsWe evaluated 88 RA patients, 50 unaffected FDRs, and 20 healthy control subjects. Six different types of ACPAs were determined by enzyme‐linked immunosorbent assay. Joint and periodontal disease symptoms were self‐reported. Patients and FDRs were HLA typed for the shared epitope (SE) and the RA‐protective alleles HLA–DRB*1301/1302.ResultsFDRs had a high prevalence of ACPAs (48%) as compared to controls (10%). Prevalence of the SE and smoking in FDRs was also high (62% and 49%, respectively). Of all of the ACPAs in the FDRs, 13 of 32 (41%) were of the IgA isotype. The most commonly expressed IgG ACPA targeted citrullinated vimentin, occurring in 20% of FDRs. The FDRs had an average of 1 type of ACPA, whereas the RA patients expressed a median of 5 different ACPAs. The only FDR to later develop RA expressed 4 different ACPAs. Joint and periodontal disease symptoms in the FDRs were significantly associated with smoking (OR 5.714 [95% confidence interval (95% CI) 1.151–28.3] and OR 12.25 [95% CI 2.544–58.99], respectively), but not with ACPAs.ConclusionThe rate of ACPA positivity in unaffected FDRs of RA patients with a high prevalence of the SE and smoking was 48%, whereas ACPAs were rare in the healthy controls. ACPAs in the FDRs of RA patients was most commonly of the IgA isotype, but IgG ACPA targeting citrullinated vimentin was also frequently found.
Toll‐like Receptor 2 Is Required for Autoantibody Production and Development of Renal Disease in Pristane‐Induced Lupus
Authors: Urbonaviciute Vilma , Starke Charlotte , Pirschel Wiebke , Pohle Sandy , Frey Silke , Daniel Christoph , Amann Kerstin , Schett Georg , Herrmann Martin , Voll Reinhard E. 
Published: March 2013

ObjectiveThe mechanisms involved in breaking immunologic tolerance against nuclear autoantigens in systemic lupus erythematosus (SLE) are not fully understood. Our recent studies in nonautoimmune mice provided evidence of an important role of Toll‐like receptor 2 (TLR‐2) in antichromatin autoantibody induction by high mobility group box chromosomal protein 1–nucleosome complexes derived from apoptotic cells. The objective of this study was to investigate whether TLR‐2 signaling is required for the induction of autoantibodies and the development of SLE‐like disease in murine pristane‐induced lupus.MethodsLupus‐like disease in C57BL/6 and TLR‐2−/− mice was induced by pristane injection. The numbers of immune cells and serum cytokine concentrations were determined by flow cytometry. Renal disease was assessed by quantification of proteinuria, histologic analyses, and enzyme‐linked immunospot assay.ResultsPristane‐injected TLR‐2−/− mice generated reduced numbers of splenic CD138+/cytoplasmic κL/λL chain–positive plasma cells and displayed diminished IgG responses against double‐stranded DNA, histones, nucleosomes, some extractable nuclear autoantigens, and cardiolipin when compared with wild‐ type controls. TLR‐2 deficiency prevented the pristane‐induced systemic release of interleukin‐6 (IL‐6) and IL‐10. The absence of TLR‐2 attenuated peritoneal recruitment of CD11c+ cells and formation of lipogranulomas. Importantly, the renal disease that developed in pristane‐treated TLR‐2−/− mice was less severe than that in control mice, as reflected by milder proteinuria, reduced glomerular deposition of IgG and complement, and decreased renal infiltration of autoantibody‐secreting cells.ConclusionTLR‐2 is required for the production of prototypical lupus autoantibodies and the development of renal disease in pristane‐induced murine lupus. Interference with TLR‐2 signaling may be a promising novel strategy for the treatment of SLE.
In vitro metabolism of obovatol and its effect on cytochrome P450 enzyme activities in human liver microsomes
Authors: Joo Jeongmin , Lee Doohyun , Wu Zhexue , Shin Jung‐Hoon , Lee Hye Suk , Kwon Byoung‐Mog , Huh Tae‐Lin , Kim Yang‐Weon , Lee Su‐Jun , Kim Tae Wan , Lee Taeho , Liu Kwang‐Hyeon 
Published: March 2013

ABSTRACTObovatol, a major constituent of the leaves of Magnolia obovata Thunb, is known to inhibit nuclear factor‐κB activity and arachidonic acid‐induced platelet aggregation. This study was performed to identify the metabolites of obovatol in human liver microsomes. Human liver microsomes incubated with obovatol in the presence of NADPH and/or UDPGA resulted in the formation of six metabolites, M1–M6. M1 and M2 were identified as hydroxyobovatol, on the basis of liquid chromatography/tandem mass spectrometric (LC‐MS/MS) analysis. M1, M2 and obovatol were further metabolized to their glucuronide conjugates, obovatol‐glucuronide (M3), obovatol‐diglucuronide (M4) and hydroxyobovatol‐glucuronide (M5 and M6). The inhibitory potency of obovatol on eight major human P450s was also investigated in human liver microsomes. In these experiments, obovatol strongly inhibited CYP2C19‐mediated S‐mephenytoin hydroxylase activity with an IC50 value of 0.8 µm, which could have implications for drug–drug interactions. Copyright © 2013 John Wiley & Sons, Ltd.
The influence of misclassification bias on the reported rates of congenital anomalies on the birth certificates for West Virginia—A consequence of an open‐ended query
Authors: Li Ji , Robbins Shayhan , Lamm Steven H. 
Published: March 2013

AbstractBACKGROUNDPassive surveillance for congenital anomalies using birth certificates are generally considered to have biased reporting, though the sources of those biases are not well‐known nor controlled for. We have analyzed the congenital anomaly reporting data for 418,385 live births in West Virginia (1990–2009) from the 1989 US standard birth certificate and have newly identified a particular source of bias.METHODSCongenital anomaly prevalence rates per 100 live births have been determined for both specified birth defects and for other congenital anomalies by county, by hospital, and by year. Extreme outliers were identified by z score. Text strings for “other congenital anomaly” reports recorded for 1998–2009 were assessed for information on congenital anomalies.RESULTSWhile rates for specified birth defects reported in checked‐box format showed little variation, rates for “other congenital anomaly” collected in open‐ended format showed much variation. Nearly half of the “other congenital anomaly” reports were for neonatal conditions rather than for major structural congenital anomalies. This misclassification alone had elevated the state‐wide congenital anomaly reporting rate from 1.1 to 1.8% of live births. Geographic clustering and a temporal bulge in congenital anomaly reports disappeared after misclassified data were removed.CONCLUSIONSData collected in checked‐box format on specified birth defects showed consistent patterns over time and space, while data collected in open‐ended format on “other congenital anomalies” showed an epidemiological pattern reflecting neonatal conditions rather than birth defects. The 2003 US standard birth certificate wisely limits data collection to specified birth defects using the checked‐box format. Birth Defects Research (Part A), 2013. © 2013 Wiley Periodicals, Inc.
Systems metabolic engineering of xylose‐utilizing Corynebacterium glutamicum for production of 1,5‐diaminopentane
Authors: Buschke Nele , Becker Judith , Schäfer Rudolf , Kiefer Patrick , Biedendieck Rebekka , Wittmann Christoph 
Published: March 2013

AbstractThe sustainable production of industrial platform chemicals is one of the great challenges facing the biotechnology field. Ideally, fermentation feedstocks would rather rely on industrial waste streams than on food‐based raw materials. Corynebacterium glutamicum was metabolically engineered to produce the bio‐nylon precursor 1,5‐diaminopentane from the hemicellulose sugar xylose. Comparison of a basic diaminopentane producer strain on xylose and glucose feedstocks revealed a 30% reduction in diaminopentane yield and productivity on the pentose sugar. The integration of in vivo and in silico metabolic flux analysis by 13C and elementary modes identified bottlenecks in the pentose phosphate pathway and the tricarboxylic acid cycle that limited performance on xylose. By the integration of global transcriptome profiling, this could be specifically targeted to the tkt operon, genes that encode for fructose bisphosphatase (fbp) and isocitrate dehydrogenase (icd), and to genes involved in formation of lysine (lysE) and N‐acetyl diaminopentane (act). This was used to create the C. glutamicum strain DAP‐Xyl1 icdGTG Peftufbp Psodtkt Δact ΔlysE. The novel producer, designated DAP‐Xyl2, exhibited a 54% increase in product yield to 233 mmol mol–1 and a 100% increase in productivity to 1 mmol g–1 h–1 on the xylose substrate. In a fed‐batch process, the strain achieved 103 g L–1 of diaminopentane from xylose with a product yield of 32%. Xylose utilization is currently one of the most relevant metabolic engineering subjects. In this regard, the current work is a milestone in industrial strain engineering of C. glutamicum.See accompanying commentary by Hiroshi Shimizu DOI: 10.1002/biot.201300097
Slug increases sensitivity to tubulin‐binding agents via the downregulation of βIII and βIVa‐tubulin in lung cancer cells
Authors: Tamura Daisuke , Arao Tokuzo , Nagai Tomoyuki , Kaneda Hiroyasu , Aomatsu Keiichi , Fujita Yoshihiko , Matsumoto Kazuko , De Velasco Marco A. , Kato Hiroaki , Hayashi Hidetoshi , Yoshida Shuhei , Kimura Hideharu , Maniwa Yoshimasa , Nishio Wataru , Sakai Yasuhiro , Ohbayashi Chiho , Kotani Yoshikazu , Nishimura Yoshihiro , Nishio Kazuto 
Published: March 2013

AbstractTranscription factor Slug/SNAI2 (snail homolog 2) plays a key role in the induction of the epithelial mesenchymal transition in cancer cells; however, whether the overexpression of Slug mediates the malignant phenotype and alters drug sensitivity in lung cancer cells remains largely unclear. We investigated Slug focusing on its biological function and involvement in drug sensitivity in lung cancer cells. Stable Slug transfectants showed typical morphological changes compared with control cells. Slug overexpression did not change the cellular proliferations; however, migration activity and anchorage‐independent growth activity with an antiapoptotic effect were increased. Interestingly, stable Slug overexpression increased drug sensitivity to tubulin‐binding agents including vinorelbine, vincristine, and paclitaxel (5.8‐ to 8.9‐fold increase) in several lung cancer cell lines but did not increase sensitivity to agents other than tubulin‐binding agents. Real‐time RT‐PCR (polymerase chain reaction) and western blotting revealed that Slug overexpression downregulated the expression of βIII and βIVa‐tubulin, which is considered to be a major factor determining sensitivity to tubulin‐binding agents. A luciferase reporter assay confirmed that Slug suppressed the promoter activity of βIVa‐tubulin at a transcriptional level. Slug overexpression enhanced tumor growth, whereas Slug overexpression increased drug sensitivity to vinorelbine with the downregulation of βIII and βIV‐tubulin in vivo. Immunohistochemistry of Slug with clinical lung cancer samples showed that Slug overexpression tended to be involved in response to tubulin‐binding agents. In conclusion, our data indicate that Slug mediates an aggressive phenotype including enhanced migration activity, anoikis suppression, and tumor growth, but increases sensitivity to tubulin‐binding agents via the downregulation of βIII and βIVa‐tubulin in lung cancer cells.