bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monomolecular‐Layer Ba5Ta4O15 Nanosheets: Synthesis and Investigation of Photocatalytic Properties
Authors: Xu T.‐G. , Zhang C. , Shao X. , Wu K. , Zhu Y.‐F. 
Published: July 2006

AbstractMonomolecular‐layer perovskite Ba5Ta4O15 nanosheets with hexagonal structure have been synthesized by a hydrothermal method. The thickness of the nanosheets is about 1.1 nm, which corresponds to a monolayer of Ba5Ta4O15 molecules, with the lateral size ranging from 50 to 200 nm. The optimal conditions for the formation of the nanosheets are maintaining the reactants above 270 °C for 24 h. A dissolution–recrystallization mechanism is suggested based on observations of the factors that influence nanosheet formation, such as reaction time, temperature, and basicity. Formation of Ba5Ta4O15 nanosheets takes precedence over other nanostructures under high concentrations of OH– because the hindering effect of OH– ions on the c‐axis growth is strong. Thus, the extended growth rate of polyhedrons on one monolayer is much faster than the superposition rate of the monolayer, and the crystal grows more easily along the a‐ and b‐planes. The Ba5Ta4O15 nanosheets show a high photocatalytic activity in the degradation of Rhodamine B and gaseous formaldehyde. The layered perovskite probably affects the photocatalytic activity by promoting the charge separation and delocalization of photogenerated electrons and holes.
Spectroscopic pH measurement for high temperatures, pressures and ionic strength
Authors: Raghuraman B. , Gustavson G. , Mullins O. C. , Rabbito P. 
Published: July 2006

AbstractThe optical spectroscopic technique using pH sensitive dyes has been extended to measure pH in high‐temperature, pressure, and ionic strength environments. Lack of standard calibrating buffers for these conditions necessitated a two‐step process for development of this technique. The first step involved chemical equilibrium modeling to predict pH values of simple buffer salt systems at high temperatures, pressures and ionic strengths. The second step involved using these modeled buffer solutions as calibration solutions for the dye chemistry and equilibrium dissociation constant. Optical spectra of dye in these buffer solutions were used to calibrate the dye equilibrium dissociation constant. Results are presented for 293°K to 373°K temperature range, 0.101325–65.5 MPa pressure range and 0–3 mol/kg water ionic strength range. Once the dye equilibrium dissociation constant has been characterized, pH of unknown solutions can be obtained from their dye spectra. This method has been successfully employed for high‐temperature and high‐pressure measurements of oilfield waters. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Postpartum acquired factor VIII inhibitors
Authors: Franchini Massimo 
Published: July 2006

AbstractThe development of factor VIII autoantibodies is a rare but severe complication of pregnancy. Although the natural history of postpartum acquired hemophilia A is usually benign, with a high percentage of spontaneous remissions and a low mortality, its quick recognition is important to control bleeding episodes.Based on an analysis of the literature, this review presents the current knowledge on the pathogenesis, diagnosis, epidemiology, natural history, clinical manifestations, and therapeutic management of postpartum acquired hemophilia A. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Flight‐oogenesis syndrome in a blood‐sucking bug: Biochemical aspects of lipid metabolism
Authors: Oliveira Giselle A. , Baptista Daniela L. , Guimarães‐Motta Horacio , Almeida Igor C. , Masuda Hatisaburo , Atella Georgia C. 
Published: July 2006

AbstractLipophorin (Lp), either labeled in diacylglycerol moiety with [3H]‐Palmitic acid or in phospholipid moiety with 32Pi, was injected into Rhodnius prolixus females. Insects were induced to flight for different times. In just a few minutes of flight, the transfer of radioactivity to ovaries decreased, accompanied by its increase to flight muscles. After one hour of flight, Lp density was higher (1.132 g/mL) than before flight (1.116 g/mL). Lp purified from insects after flight was analyzed by gel filtration chromatography and a polyacrylamide gel pore limit electrophoresis. Both analyses demonstrated a decrease in Lp molecular mass after flight but no changes in apoLp‐III amounts were observed. Time‐course experiments showed that only 30 min of flight are required for the detection of changes in Lp density and molecular mass. About the same time of rest is necessary for Lp density and molecular mass to return to the baseline value. The lipid content from Lp particles, determined by high‐performance thin‐layer chromatography (HPTLC), showed a decrease in total lipids after flight. At the same time, an increase of many classes of lipids was observed in flight muscles except for triacylglycerol, which was reduced. The increase of flight muscle lipids was accompanied by a decrease of the ovaries lipid content. The insects subjected to daily exhaustive flight showed a significant decrease in total number of eggs produced. But insects subjected to a single exhaustive flight showed only a small reduction in total number of eggs. Lp density variation during the flight activity of Rhodnius prolixus females is discussed in association with physiological events such as oogenesis. Arch Insect Biochem Physiol 62:164–175, 2006. © 2006 Wiley‐Liss, Inc.
Identification in human osteoarthritic chondrocytes of proteins binding to the novel regulatory site AGRE in the human matrix metalloprotease 13 proximal promoter
Authors: Fan Zhiyong , Tardif Ginette , Boileau Christelle , Bidwell Joseph P. , Geng Changshan , Hum David , Watson Alexander , Pelletier Jean‐Pierre , Lavigne Martin , Martel‐Pelletier Johanne 
Published: July 2006

AbstractObjectiveMatrix metalloprotease 13 (MMP‐13) plays a major role in osteoarthritic (OA) processes. We previously identified the AG‐rich element (AGRE) regulatory site (GAAAAGAAAAAG) in the proximal promoter of this gene. Electrophoretic mobility shift assays (EMSAs) done with nuclear extracts from OA chondrocytes showed the presence of 2 AGRE protein–binding complexes, the formation of which depended on the pathophysiologic state (high or low) of the cells; the low OA (L‐OA) chondrocytes have low MMP‐13 basal levels and high interleukin‐1β (IL‐1β) inducibility, and the high OA (H‐OA) chondrocytes have high MMP‐13 basal levels and low IL‐1β inducibility. In this study, we sought to determine the importance of individual AGRE bases in promoter activity and to identify AGRE binding proteins from L‐OA and H‐OA chondrocyte complexes.MethodsPromoter activity was determined following transient transfection into human OA chondrocytes. AGRE binding proteins were identified by mass spectroscopy.ResultsIndividual mutations of the AGRE site differentially modulated promoter activity, indicating that the intact AGRE site is required for optimal MMP‐13 expression. Damage‐specific DNA binding protein 1 (DDB‐1) was identified in the L‐OA chondrocyte–binding complex. EMSA experiments performed with the mutation of the left AGRE site (GTGCTGAAAAAG) and nuclear extracts of L‐OA chondrocytes reproduced the pattern seen in the H‐OA chondrocytes. Mass spectroscopy identified p130cas as one of the proteins in this complex. Supershift experiments showed the presence of p130cas and nuclear matrix transcription factor 4 (NMP‐4) in the wild‐type AGRE/H‐OA chondrocyte complex.ConclusionThese data suggest that the binding of p130cas and NMP‐4 to the AGRE site regulates MMP‐13 expression and may trigger the change in human chondrocytes from the L‐OA state to the H‐OA state.
RANTES and monocyte chemoattractant protein 1 as sensitive markers of disease activity in patients with juvenile rheumatoid arthritis: A six‐year longitudinal study
Authors: Yao Tsung‐Chieh , Kuo Ming‐Ling , See Lai‐Chu , Ou Liang‐Shiou , Lee Wen‐I , Chan Chin‐Kan , Huang Jing‐Long 
Published: July 2006

AbstractObjectiveTo longitudinally investigate serum and synovial fluid (SF) levels of RANTES and monocyte chemoattractant protein 1 (MCP‐1) as well as in vitro migration of mononuclear cells toward SF in patients with juvenile rheumatoid arthritis (JRA).MethodsSerum and SF levels of RANTES and MCP‐1 were determined by enzyme‐linked immunosorbent assay. Chemotaxis was performed using the modified Boyden chamber method.ResultsSerum RANTES levels were significantly increased in all onset types of JRA, with the highest levels present in systemic‐onset JRA. Serum MCP‐1 levels were significantly elevated in patients with systemic‐onset JRA and were associated with current systemic features. Although serum levels of RANTES and MCP‐1 decreased significantly after treatment, RANTES and MCP‐1 levels during disease remission were still significantly higher in JRA patients than in controls. A relationship was found between serum RANTES levels during remission and the duration of clinical remission, with low levels being associated with prolonged clinical remission and high levels with shorter clinical remission. Serum RANTES levels correlated with C‐reactive protein concentrations, hemoglobin values, white blood cell (WBC) counts, and platelet counts, whereas serum MCP‐1 levels correlated with WBC counts and serum ferritin levels. Levels of RANTES and MCP‐1 in SF were elevated as compared with levels in serum. SF chemotactic activity for mononuclear leukocytes was significantly inhibited by either anti‐RANTES or anti–MCP‐1 antibody.ConclusionRANTES is a key molecule in the pathogenesis of all onset groups of JRA, whereas MCP‐1 is particularly important in systemic‐onset JRA. Serum levels of these CC chemokines represent more highly sensitive markers of disease activity than conventional markers of inflammation.
Relationship between serum NR2a antibodies and cognitive dysfunction in systemic lupus erythematosus
Authors: Harrison Melanie J. , Ravdin Lisa D. , Lockshin Michael D. 
Published: July 2006

AbstractObjectiveTo assess the association between serum NR2a antibodies and cognitive dysfunction in systemic lupus erythematosus (SLE).MethodsThe study population consisted of English‐speaking adults who met American College of Rheumatology (ACR) criteria for SLE and had at least 1 serum sample stored in the Hospital for Special Surgery Autoimmune Registry and Repository. Demographic and clinical information was obtained, and patients completed the neuropsychological test battery recommended by the ACR, the Center for Epidemiologic Studies Depression Scale, and the Spielberger State‐Trait Anxiety Inventory. Cognitive impairment was defined as scores >1.5 SD below the mean of age‐matched published normative data on at least 2 neuropsychological tests. Sera were tested for NR2a antibodies by enzyme‐linked immunosorbent assay. Performance on neuropsychological tests was compared between NR2a‐positive and NR2a‐negative patients.ResultsOf the 93 patients, 24 (25.8%) were positive for NR2a antibodies. Of the 48 patients who were cognitively impaired based on test results, 31% were positive for NR2a antibodies, compared with 20% of those who were not cognitively impaired (P = 0.24). Among antibody‐positive patients, the mean ± SD number of neuropsychological tests with abnormal results was 2.3 ± 2.2, compared with 2.0 ± 1.8 in the antibody‐negative group (P = 0.59). Similar nonsignificant differences were found when impairment was defined using a more stringent definition (i.e., test scores >2.0 SD below the mean) and using a neuropsychologist's clinical ratings. No association was detected between NR2a antibody positivity and depressive symptoms (P = 0.73) or anxiety (P = 0.42).ConclusionNo significant association was found between NR2a antibody positivity and cognitive dysfunction, depressive symptoms, or anxiety. These results indicate that the presence of these antibodies alone does not have a direct effect on cognitive functioning or any other neuropsychiatric manifestation of SLE.
Inhibition of angiogenesis by interleukin‐4 gene therapy in rat adjuvant‐induced arthritis
Authors: Haas Christian S. , Amin M. Asif , Allen Brittany B. , Ruth Jeffrey H. , Haines G. Kenneth , Woods James M. , Koch Alisa E. 
Published: July 2006

AbstractObjectiveInterleukin‐4 (IL‐4) can modulate neovascularization. In this study, we used a gene therapy approach to investigate the role of IL‐4 in angiogenesis in rat adjuvant‐induced arthritis (AIA), a model for rheumatoid arthritis.MethodsRats received an adenovirus producing IL‐4 (AxCAIL‐4), a control virus without insert, or control vehicle (phosphate buffered saline) intraarticularly before arthritis onset. At peak onset of arthritis, rats were killed. Vascularization was determined in the synovial tissue, and correlations with inflammation were assessed. Ankle homogenates were used in angiogenesis assays in vitro and in vivo, and protein levels of cytokines and growth factors were assessed by enzyme‐linked immunosorbent assay. Synovial tissue expression of αv integrins was determined by immunohistochemistry.ResultsIL‐4 induced a reduction in synovial tissue vessel density, which was paralleled by a decrease in inflammation. AxCAIL‐4 joint homogenates significantly (P< 0.05) inhibited both endothelial cell (EC) migration and tube formation in vitro. Similarly, AxCAIL‐4 inhibited capillary sprouting in the rat aortic ring assay, and vessel growth in the in vivo Matrigel plug assay. The angiostatic effect occurred despite high levels of vascular endothelial growth factor (VEGF), and was associated with down‐regulation of the proangiogenic cytokines IL‐18, CXCL16, and CXCL5 and up‐regulation of the angiogenesis inhibitor endostatin. Of interest, AxCAIL‐4 also resulted in decreased EC expression of the αv and β3 integrin chains.ConclusionIn rat AIA, IL‐4 reduces synovial tissue vascularization via angiostatic effects, mediates inhibition of angiogenesis via an association with altered pro‐ and antiangiogenic cytokines, and may inhibit VEGF‐mediated angiogenesis and exert its angiostatic role in part via αvβ3 integrin. This knowledge of the specific angiostatic effects of IL‐4 may help optimize target‐oriented treatment of inflammatory arthritis.
Sample Size Recalculation in Internal Pilot Study Designs: A Review
Authors: Friede Tim , Kieser Meinhard 
Published: July 2006

AbstractThe adequacy of sample size is important to clinical trials. In the planning phase of a trial, however, the investigators are often quite uncertain about the sizes of parameters which are needed for sample size calculations. A solution to this problem is mid‐course recalculation of the sample size during the ongoing trial. In internal pilot study designs, nuisance parameters are estimated on the basis of interim data and the sample size is adjusted accordingly. This review attempts to give an overview on the available methods. It is written not only for biometricians who are already familar with the the topic and wish to update their knowledge but also for users new to the subject. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Construction of multi‐layered cardiomyocyte sheets using magnetite nanoparticles and magnetic force
Authors: Shimizu Kazunori , Ito Akira , Lee Jong‐Kook , Yoshida Tatsuro , Miwa Keiko , Ishiguro Hisaaki , Numaguchi Yasushi , Murohara Toyoaki , Kodama Itsuo , Honda Hiroyuki 
Published: July 2006

AbstractHeart tissue engineering requires construction of three‐dimensional (3‐D) tissues composed of cardiomyocytes (CMs) that are tightly connected to each other. The aim of this study was to construct “scaffold‐less” multi‐layered 3‐D CM sheets using magnetic force‐based tissue engineering (Mag‐TE) and to evaluate the cell‐to‐cell functional connections within the CM sheets. Original magnetite cationic liposomes (MCLs) with a positive surface charge (which facilitate adsorption to the target cell surface) were taken up by CMs that were isolated from 2‐day‐old Wistar rats. When MCLs were added to the medium of CMs at magnetite concentrations of 25, 50, and 100 pg per cell, subsequent measurements showed that 7.2, 13.2, and 27.3 pg of magnetite were taken up per cell, respectively, after 4 h incubation at 37°C. Further, no toxicity was observed after a 24 h incubation period. Using magnetically labeled CMs (magnetite concentration, 100 pg/cell), multi‐layered CM sheets were constructed. Immunofluorescent staining of connexin43 demonstrated the presence of gap junctions within the CM sheets that were constructed by Mag‐TE. Moreover, electrical connections within the CM sheets constructed by Mag‐TE were confirmed using extracellular potential mapping. These results indicate that Mag‐TE is a viable methodology for heart tissue engineering. Biotechnol. Bioeng. 2007;96:803–809. © 2006 Wiley Periodicals, Inc.
A kinetic model describing Shewanella oneidensis MR‐1 growth, substrate consumption, and product secretion
Authors: Tang Yinjie J. , Meadows Adam L. , Keasling Jay D. 
Published: July 2006

AbstractAerobic growth of Shewanella oneidensis MR‐1 in minimal lactate medium was studied in batch cultivation. Acetate production was observed in the middle of the exponential growth phase and was enhanced when the dissolved oxygen (DO) concentration was low. Once the lactate was nearly exhausted, S. oneidensis MR‐1 used the acetate produced during growth on lactate with a similar biomass yield as lactate. A two‐substrate Monod model, with competitive and uncompetitive substrate inhibition, was devised to describe the dependence of biomass growth on lactate, acetate, and oxygen and the acetate growth inhibition across a broad range of concentrations. The parameters estimated for this model indicate interesting growth kinetics: lactate is converted to acetate stoichiometrically regardless of the DO concentration; cells grow well even at low DO levels, presumably due to a very low Km for oxygen; cells metabolize acetate (maximum specific growth rate, µmax,A of 0.28 h−1) as a single carbon source slower than they metabolize lactate (µmax,L of 0.47 h−1); and growth on acetate is self‐inhibiting at a concentration greater than 10 mM. After estimating model parameters to describe growth and metabolism under six different nutrient conditions, the model was able to successfully estimate growth, oxygen and lactate consumption, and acetate production and consumption under entirely different growth conditions. Biotechnol. Bioeng. 2007;96: 125–133. © 2006 Wiley Periodicals, Inc.
Inhibitory effects of nitrogen oxides on a mixed methanogenic culture
Authors: Tugtas A. Evren , Pavlostathis Spyros G. 
Published: July 2006

AbstractThe effect of nitrate, nitrite, nitric oxide (NO), and nitrous oxide on a mixed, mesophilic (35°C) methanogenic culture was investigated. Short‐term inhibition assays were conducted at a concentration range of 10–350 mg N/L nitrate, 17–500 mg N/L nitrite, 0.02–0.8 mg N/L aqueous NO, and 19–191 mg N/L aqueous nitrous oxide. Simultaneous methane production and N‐oxide reduction was observed in 10 and 30 mg N/L nitrate and 0.02 mg N/L aqueous NO‐amended cultures. However, addition of N‐oxide resulted in immediate cessation of methanogenesis in all other cultures. Methanogenesis completely recovered subsequent to the complete reduction of N‐oxides to nitrogen gas in all N‐oxide‐amended cultures, with the exception of the 500 mg N/L nitrite‐ and 0.8 mg N/L aqueous NO‐amended cultures. Partial recovery of methanogenesis was observed in the 500 mg N/L nitrite‐amended culture in contrast to complete inhibition of methanogenesis in the 0.8 mg N/L aqueous NO‐amended culture. Accumulation of volatile fatty acids was observed in both cultures at the end of the incubation period. Among all N‐oxides, NO exerted the most and nitrate exerted the least inhibitory effect on the fermentative/methanogenic consortia. The effect of multiple additions of nitrate (300 mg N/L) on the same methanogenic culture was also investigated. Long‐term exposure of the methanogenic culture to nitrate resulted in an increase of N‐oxide reduction rates and decrease of methane production rates, which was attributed to changes in the microbial community structure due to nitrate addition. Biotechnol. Bioeng. 2007;96: 444–455. © 2006 Wiley Periodicals, Inc.
Activating an Enzyme by an Engineered Coiled Coil Switch
Authors: Yuzawa Satoshi , Mizuno Toshihisa , Tanaka Toshiki 
Published: July 2006

AbstractWe designed a de novo protein based on a circular permutant of RNaseT1, in which the enzymatic activity can be manipulated by engineered peptide binding. The circular permutant of RNaseT1 was obtained by tethering the original C‐ and N‐termini with a GPAG linker and cleaving the molecule between Glu82 and Asn83. This mutant lacked enzymatic activity, due to the destabilization of entire protein structure. We previously reported the construction of ABC‐type heterotrimeric coiled coil peptides, in which the A‐ and B‐type peptides cannot form the folded trimeric structure without the C‐type peptide. The introduction of the A‐ and B‐type coiled coil peptides to the C‐ and N‐termini of the circular permutant of RNaseT1, respectively, and the subsequent addition of the C‐type coiled coil peptide enabled the RNaseT1 domain to refold properly, thus, restoring the enzymatic activity. The formation of the trimeric coiled coil structure should bring the cleaved sites of RNaseT1 close enough to refold the RNaseT1 domain spontaneously.
Apoptolidinone A: Synthesis of the Apoptolidin A Aglycone
Authors: Schuppan Julia , Wehlan Hermut , Keiper Sonja , Koert Ulrich 
Published: July 2006

AbstractAn efficient stereocontrolled synthesis of apoptolidinone A, the aglycone of apoptolidin A is described. The synthetic strategy relies on a cross coupling between C11/C12 of a northern half (C1–C11) and a southern part (C12–C28) followed by a ring‐size selective macrolactonization. Key steps for the introduction of the southern half stereocenters are a stereoselective aldol reaction, a substrate controlled dihydroxylation and a chelation‐controlled Grignard/aldehyde addition. The conjugated triene of the northern half was built up successively by E‐selective Wittig reactions. L‐Malic acid was chosen as the chiral pool source for the C8/C9 stereocenters. The final cleavage of the silyl ethers and the conversion of the C21 methyl ketal into the hemiketal was achieved by HF⋅pyridine.
Genotoxic Potential of N‐(Benzothiazolyl)sulfonamide Copper(II) Complexes on Yeast Cells Transformed with YEGFP Expression Constructs Containing the RAD54 or RNR2 Promoter
Authors: González‐Álvarez Marta , Alzuet Gloria , del Castillo Lucas , Borrás Joaquín , Liu‐González Malva 
Published: July 2006

AbstractFour ternary complexes [Cu(L)2(phen)] where L is an N‐(benzothiazol‐2‐yl)sulfonamide derivative have been prepared and their ability to cleave DNA has been studied. The complexes were structurally characterized with the aid of single‐crystal X‐ray crystallography. Whereas the molecular structure of the [Cu(L1)2(phen)] (1) [HL1 = N‐(6‐chlorobenzothiazol‐2‐yl)benzenesulfonamide] and [Cu(L3)2(phen)] (3) [HL3 = N‐(benzothiazol‐2‐yl)benzenesulfonamide] complexes can best be described as having a distorted square‐planar geometry, that of the [Cu(L4)2(phen)] (4) [HL4 = N‐(benzothiazol‐2‐yl)toluenesulfonamide] complex shows a strictly square‐planar geometry. The [Cu(L2)2(phen)MeOH] (2) [HL2 = N‐(6‐chlorobenzothiazol‐2‐yl)toluenesulfonamide] complex displays an axially elongated square‐pyramidal coordination geometry in which the phen ligand binds at the basal plane. Viscosity and fluorescence measurements indicated that [Cu(L4)2(phen)] (4) has a propensity for binding calf thymus DNA. The four complexes were found to be efficient chemical nucleases, with ascorbate/H2O2 activation giving rise to hydroxyl and superoxide radicals as active cleaving species. The nuclease activity of 4 is not only the highest of the four complexes, but also much higher than that of the copper–phenanthroline complex. The ability of the complexes to cleave DNA within cells has been tested by monitoring the expression of the yEGFP gene containing reporter plasmid. The significant induction of fluorescence by complex 4 indicates that it is able to cleave DNA inside the cell. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)