Type Bi Research Articles

N-Glycans and the N Terminus of Protein C Inhibitor Affect the Cofactor-enhanced Rates of Thrombin Inhibition

Protein C inhibitor (PCI) is a serine protease inhibitor, displaying broad protease specificity, found in blood and other tissues. In blood, it is capable of inhibiting both procoagulant and anticoagulant proteases. Mechanisms that provide specificity to PCI remain largely unrevealed. In this study we have for the first time provided a full explanation for the marked size heterogeneity of blood-derived PCI and identified functional differences between naturally occurring PCI variants. The heterogeneity was caused by differences in N-glycan structures, N-glycosylation occupancy, and the presence of a Delta6-N-cleaved form. Bi-, tri-, and tetra-antennary complex N-glycans were identified. Fucose residues were identified both on the core GlcNAc and as parts of sialyl-Le(a/x) epitopes. Moreover, a glycan with a composition that implied a di-sialyl antenna was observed. PCI was N-glycosylated at all three potential N-glycosylation sites, Asn-230, Asn-243, and Asn-319, but a small fraction of PCI lacked the N-glycan at Asn-243. The overall removal of N-glycans affected the maximal heparin- and thrombomodulin-enhanced rates of thrombin inhibition differently in different solution conditions. In contrast, the Delta6-N-region increased both the heparin- and the thrombomodulin-enhanced rates of thrombin inhibition at all conditions examined. These results thus demonstrate that the N-linked glycans and the N-terminal region of blood-derived PCI in different ways affect the cofactor-enhanced rates of thrombin inhibition and provide information on the mechanisms by which this may be achieved. The findings are medically important, in view of the documented association of PCI with atherosclerotic plaques and the promising effect of PCI on reducing hypercoagulability states.

Control of an Outbreak of Infection with the Hypervirulent Clostridium difficile BI Strain in a University Hospital Using a Comprehensive "Bundle" Approach

In June 2000, the hospital-acquired Clostridium difficile (CD) infection rate in our hospital (University of Pittsburgh Medical Center-Presbyterian, Pittsburgh, PA) increased to 10.4 infections per 1000 hospital discharges (HDs); the annual rate increased from 2.7 infections per 1000 HDs to 7.2 infections per 1000 HDs and was accompanied by an increase in the frequency of severe outcomes. Forty-seven (51%) of 92 HA CD isolates in 2001 were identified as the "epidemic BI strain." A comprehensive CD infection control "bundle" was implemented to control the outbreak of CD infection. The CD infection control bundle consisted of education, increased and early case finding, expanded infection-control measures, development of a CD infection management team, and antimicrobial management. Process measures, antimicrobial usage, and hospital-acquired CD infection rates were analyzed, and CD isolates were typed. The rates of compliance with hand hygiene and isolation were 75% and 68%, respectively. The CD management team evaluated a mean of 31 patients per month (11% were evaluated for moderate or severe disease). Use of antimicrobial therapy associated with increased CD infection risk decreased by 41% during the period 2003-2005 (P<.001). The aggregate rate of CD infection during the period 2001-2006 decreased to 4.8 infections per 1000 HDs (odds ratio, 2.2; 95% confidence interval, 1.4-3.1; P<.001) and by 2006, was 3.0 infections per 1000 HDs, a rate reduction of 71% (odds ratio, 3.5; 95% confidence interval, 2.3-5.4; P<.001). During the period 2000-2001, the proportion of severe CD cases peaked at 9.4% (37 of 393 CD infections were severe); the rate decreased to 3.1% in 2002 and further decreased to 1.0% in 2006--a 78% overall reduction (odds ratio, 20.3; 95% confidence interval, 2.8-148.2; P<.001). In 2005, 13% of CD isolates were type BI (20% were hospital acquired), which represented a significant reduction from 2001 (P<.001). The outbreak of CD infection with the BI strain in our hospital was controlled after implementing a CD infection control "bundle." Early identification, coupled with appropriate control measures, reduces the rate of CD infection and the frequency of adverse events.

Wild-Type ApoA-I and the Milano Variant Have Similar Abilities to Stimulate Cellular Lipid Mobilization and Efflux

The present study is a comparative investigation of cellular lipid mobilization and efflux to lipid-free human apoA-I and apoA-I(Milano), reconstituted high-density lipoprotein (rHDL) particles containing these proteins and serum isolated from mice expressing human apoA-I or apoA-I(Milano). Cholesterol and phospholipid efflux to these acceptors was measured in cell systems designed to assess the contributions of ATP-binding cassette A1 (ABCA1), scavenger receptor type BI (SRBI), and cellular lipid content to cholesterol and phospholipid efflux. Acceptors containing the Milano variant of apoA-I showed no functional increase in lipid efflux in all assays when compared with wild-type apoA-I. In fact, in some systems, acceptors containing the Milano variant of apoA-I promoted significantly less efflux than the acceptors containing wild-type apoA-I (apoA-I(wt)). Additionally, intracellular cholesteryl ester hydrolysis in macrophage foam cells was not different in the presence of either apoA-I(Milano) or apoA-I(wt). Collectively these studies suggest that if the Milano variant of apoA-I offers greater atheroprotection than wild-type apoA-I, it is not attributable to greater cellular lipid mobilization.

Circulating cardiovascular disease risk factors and signaling in endothelial cell caveolae

Caveolae are a subset of lipid rafts that are prevalent on the plasma membrane of endothelial cells. They compartmentalize signal transduction molecules which regulate multiple endothelial functions including the production of nitric oxide (NO) by the caveolae resident enzyme endothelial NO synthase (eNOS). Recent studies have demonstrated that circulating factors known to modify cardiovascular disease risk regulate signaling in endothelial cell caveolae. In particular, high density lipoprotein (HDL) maintains the lipid environment in caveolae, thereby promoting the retention and function of eNOS in the domain, and it also causes direct activation of eNOS via scavenger receptor type BI (SR-BI)-induced kinase signaling. Estrogen binding to estrogen receptors (ER) in caveolae also activates eNOS, and this occurs through G protein and kinase activation. Discrete domains within SR-BI and ER mediating signal initiation in caveolae have been identified. Counteracting the promodulatory actions of HDL and estrogen, C-reactive protein (CRP) antagonizes eNOS through FcgammaRIIB and PP2A, which dephosphorylates and inactivates the enzyme. The endothelial cell functions modified by these processes include the regulation of monocyte adhesion and endothelial cell migration. Thus, signaling events in caveolae invoked by known circulating cardiovascular disease risk factors have major impact on endothelial cell phenotypes of importance to cardiovascular health and disease.

Synthesis and properties of β type Bi(III)2−2x Dy(II)2x O3 − x x solid solution

In the present work, tetragonal β type Bi(III)2 − 2xDy(II)2xO3 − x■x (■:,empty oxygen site) solid solutions have been synthesized in the ranges 0.06 ≤ x ≤ 0.08 at 750°C and 0.05 ≤ x ≤ 0.09 at 800°C by doping small amounts of Dy2O3 into monoclinic α -Bi2O3. X-ray powder diffraction (XRD) has been used for characterisation of the doped Dy2O3 powders as well as for calculation of the unit cell parameters. The polymorphic phase transitions, crystallographic properties, particle sizes, the scanning electron microscope (SEM) microprobe analysis and Dy2O3 content dependence of the lattice parameters of the observed β-phase has been reported. The obtained solid solutions had nonstoichiometric character and nonstoichiometry increases with the increasing amount of Dy2O3 addition. The experimental results suggested that oxygen vacancies are present in the crystal structure of Dy2O3 doped β type solid solutions.

Substitution site of La ions in La-doped Bi 4Ti 3O 12–SrBi 4Ti 4O 15 intergrowth ferroelectrics

Several lanthanum-doped intergrowth ferroelectric materials of type Bi 4− x La x Ti 3O 12–SrBi 4− y La y Ti 4O 15 [BLT–SBLT( x+ y)] were prepared with the lanthanum content, ( x+ y), ranging from 0.00 to 1.50. XRD patterns imply that the lattice space of (1 1 6) for Bi 4Ti 3O 12–SrBi 4Ti 4O 15 is the average of those of (1 1 5) for Bi 4Ti 3O 12 and (1 1 7) for SrBi 4Ti 4O 15. By assuming that this relationship is not affected by doping, the La ion substitution site is calculated. The results indicate that La ions show pronounced site selectivity for the BTO blocks when the La content is lower than 1.25. As ( x+ y)=1.50, more La ions substitute the Bi ions in SBTi blocks. These calculated results are consistent with the estimation from their Curie temperature.

Rotationplasty type BI versus type BIIIa in children under the age of ten years

Type BI rotationplasty is currently indicated for children with tumours of the proximal femur whereas type BIIIa rotationplasty is reserved for those in which the entire femur has to be removed. Our aim was to compare these two types of rotationplasty and determine whether the knee should be preserved in children with tumours of the proximal femur. We compared the post-operative complications, oncological outcome, range of movement, Enneking score and radiographs of six children, who had undergone type BI rotationplasty with those of 12 who had undergone type BIIIa rotationplasty. Patients with type BI rotationplasty had a mean Enneking score of 21.6 compared with 24.4 in those with type BIIIa rotationplasty, and worse mean results in all of the parameters investigated. We conclude that type BI rotationplasty has a worse functional outcome and more complications than type BIIIa rotationplasty in children under the age of ten years.

レヴァント南部における青銅製袋穂鏃

The purpose of this paper is to reexamine the classification of bronze socketed arrowheads in the southern Levant proposed by the Israeli archaeologist E. Stern.Stern classified bronze socketed arrowheads found in Palestine into three types, namely, Types A, BI and BII. According to Stern, Type A is related to the Scythians of the 7th century B. C., and the latter two types are connected with troops of the Achaemenid dynasty.The author agrees with Stern in thinking that the arrowheads of the Seythians and the Achaemenids should be separated. However, his classification seems to be lacking in the following three points. Firstly, various types of arrowheads are treated all together as Type A. Secondly, Stern's Types BI and BII remain to be classified in detail. Thirdly, Stern did not refer to socketed arrowheads of non-Scythian/Achaemenid origin. Taking account of these three points, the author attempts to reexamine Stern's classification. The results are as follows.First, based on the chronological framework of Scythian arrowheads established by the Russian archaeologist A. I. Melyukova, the author classifies Stern's Type A into five types. Through comparison with arrowheads from Scythian graves and from other regions in Western Asia, the author concludes that each type appeared in the southern Levant at a different period or was brought in by a different caltural group.Second, to prepare for establishing the chronology of Achaemenid arrowheads, the author, adding some recently published examples, classifies Stern's Type BI into two sub-types, and BII into three, based on the shape of the blades, which range from broad to narrow. By analogy with the typology of Scythian arrowheads, the author supposes that there was a shift from broad to narrow in the blades of Achaemenid arrowheads.Last, the author examines two other types of socketed arrowheads. Through comparative analysis, the author concludes that one of these is connected with mercenaries of Saka in Central Asia, and the other is connected with the Eastern Mediterranean coast.

Predicting the position of the morphotropic phase boundary in high temperature PbTiO3-Bi(B′B″)O3 based dielectric ceramics

Two previously unreported PbTiO3-Bi(B′B″)O3 type solid solution systems possessing a high dielectric transition Curie temperature (TC) at their morphotropic phase boundary (MPB) were investigated. Both Bi(B′B″)O3 type compounds, Bi(Mg1∕2Ti1∕2)O3 and Bi(Mg1∕2Zr1∕2)O3, possess a low tolerance factor and display extensive solid solubility with PbTiO3. Dielectric and structural properties of the MPB systems were measured. Using a relationship presented in this paper, which relates the tolerance factor and the position of the MPB in PbTiO3 based systems, the approximate compositional position of the MPB in these systems was accurately predicted prior to synthesis. It is proposed that this relationship can be used as a guide in the search for PbTiO3 based MPB systems.

Scavenger receptor type BI potentiates reverse cholesterol transport system by removing cholesterol ester from HDL

Scavenger receptor type BI potentiates reverse cholesterol transport system by removing cholesterol ester from HDL

Scavenger receptor type BI potentiates reverse cholesterol transport system by removing cholesterol ester from HDL

High-density lipoprotein (HDL) plays an important role in reverse cholesterol transport by removing accumulated cholesterol from extrahepatic tissues. Subsequently, cholesterol ester (CE) on HDL in humans is transported to apolipoprotein B-containing lipoproteins by cholesteryl ester transfer protein (CETP). CETP deficiency, which is common in the Japanese population, leads to a marked increase in HDL-cholesterol levels due to impaired CE transport from HDL to LDL. It has been reported that the HDL observed in CETP deficiency is an atherogenic lipoprotein, as it contains a large amount of CE. Scavenger receptor class B type I (SR-BI) has been found to be an authentic HDL receptor that mediates the selective uptake of HDL CE and the bi-directional transfer of free cholesterol between HDL and cells. In the present study, the interaction between SR-BI and CE-rich HDL from CETP-deficient patient was studied in order to evaluate the anti-atherosclerotic role of SR-BI in relation to CE uptake and reverse cholesterol transport. When CE-rich HDL was added to the medium of SR-BI-transfected CHO (SR-BI CHO) cells, more CE accumulated in SR-BI CHO cells compared to control HDL. In contrast, the amount of cholesterol efflux from SR-BI CHO cells into HDL was almost the same between the two HDLs. Therefore, when CE-rich HDL was added to the medium of SR-BI CHO cells, the intracellular CE content increased significantly. Moreover, the particle size of HDL in CETP-deficient patient decreased significantly when the HDL was added to the medium of SR-BI CHO cells, and this HDL showed an increment of CE efflux from foam cells. These results indicate that SR-BI reduces the cholesterol content and size of the CE-rich HDL from CETP deficiency, which ultimately activate reverse cholesterol transport system.

High Density Lipoprotein-induced Signaling of the MAPK Pathway Involves Scavenger Receptor Type BI-mediated Activation of Ras

High density lipoprotein (HDL) stimulates multiple signaling pathways. HDL-induced activation of the mitogen-activated protein kinase (MAPK) pathway can be mediated by protein kinase C (PKC) and/or pertussis toxin-sensitive G-proteins. Although HDL-induced activation of MAPK involves Raf-1, Mek, and Erk1/2, the upstream contribution of p21(ras) (Ras) on the activation of Raf-1 and MAPK remains elusive. Here we examine the effect of HDL on Ras activity and demonstrate that HDL induces PKC-independent activation of Ras that is completely blocked by pertussis toxin, thus implicating heterotrimeric G-proteins. In addition, the HDL-induced activation of Ras is inhibited by a neutralizing antibody against scavenger receptor type BI. We conclude that the binding of HDL to scavenger receptor type BI activates Ras in a PKC-independent manner with subsequent induction of the MAPK signaling cascade.

Determination of Insulin in a Single Islet of Langerhans by High-Performance Liquid Chromatography with Fluorescence Detection

Rodents (rat and mouse) have two types of insulin (insulin I and II; each contains a universal chain A and a different composition of each type BI chain or type BII chain). The physiological role for each isomer is not yet clarified because of the lack of an appropriate separative determination method for these isomers. Thus, in this paper, a sensitive and selective HPLC-fluorescence determination method for the isomers was developed, which includes derivatization with a fluorogenic reagent for thiols, 7-fluoro-2,1,3-benzoxadiazole-4-sulfonate, in the presence of a reducing agent, TCEP, a nonionic surfactant, n-dodecyl beta-D-maltopyranoside, and EDTA. The resultant chain A, BI, and BII derivatives were separated on a reversed-phase column (TSK gel ODS-120T, 250 x 4.6 mm i.d.) with a mobile phase containing 5 mM phosphate buffer (pH 7.0) and were detected at 505 nm with excitation at 380 nm. The detection limits for chain A, BI, and BII derivatives were 2.2, 3.4, and 3.7 fmol on column, respectively. The method was applicable to the determination of rodent insulin in a single islet of Langerhans, and the results indicated its feasibility for the investigation of the pathophysiological roles of the isomers in diabetes in the rodent.

Nutrient absorption

Some key advances occurred last year in understanding mechanisms involved in nutrient absorption. A novel "prechylomicron transport vesicle" was identified; its movement to the Golgi is the rate-limiting step for triacylglycerol absorption. A scavenger receptor (type BI) in the brush border membrane appears to facilitate cholesterol uptake. Several studies define mechanisms for gastrointestinal peptide hormone stimulation of glucose uptake. An oligopeptide transporter, PepT1, is transcriptionally upregulated by certain dietary amino acids and dipeptides. Surprisingly, both insulin and fasting double the maximum velocity for dipeptide uptake (via PepT1), but they act by different mechanisms. Three transporters, SMVT (sodium-dependent multivitamin transporter for biotin and pantothenate), SVCT (for vitamin C), and CaT1 (for Ca uptake from the lumen) have been cloned and are active when expressed in various cells. Additional studies provide insights on Ca absorption and vitamin D action in aging, estrogen deficiency, and adaptation to a low Ca diet. Nramp2, also called DMT1 (divalent metal ion transporter), seems to be a major regulator of transferrin-independent, nonheme iron uptake. Finally, the protein HFE associates with the transferrin receptor and is part of an iron-sensing mechanism that regulates iron absorption. It is defective in hereditary hemochromatosis. HFE and Nramp2 (DMT1) genes are reciprocally regulated.

Synthesis and oxygen permeation properties of ceramic-metal dual-phase membranes

Percolative and non-percolative fluorite type Bi 1.5Y 0.3Sm 0.2O 3 (BYS) and silver dual-phase membranes were prepared by mixing BYS and Ag powders. Oxygen permeation and electric conduction through these BYS/Ag dual-phase membranes were studied in the temperature range of 650–850°C. The percolative BYS/Ag 40% and non-percolative BYS/Ag 30% membranes exhibit about 50-fold and 10-fold increase, respectively, in oxygen permeation flux compared to BYS membranes. For a 1.3 mm thick BYS/Ag 40% membrane, an oxygen permeation flux of 5.8 × 10 −7 mol/cm 2 s was measured at 850°C with oxygen partial pressures at the feed and permeate sides being 0.21 and 0.009 atm, respectively. The activation energies for oxygen permeation in the temperature range of 650–850°C are 79.30 and 87.30 kJ/mol for the BYS/Ag 30% and BYS/Ag 40% membranes, respectively. For the non-percolative BYS/Ag membrane, the presence of Ag enhances the surface reaction rate for oxygen permeation. The continuous silver phase in the percolative BYS/Ag membrane increases both the electronic conductivity and surface reaction rate which result in substantial improvement of oxygen permeance.

A bismuth cobaltite with an intrinsically modulated misfit layer structure: Bi0.87SrO22 CoO21.8

Abstract A new misfit layer cobaltite Bi 0.87 SrO 2 2 CoO 2 1.82 has been synthesized. Its structure, solved from a single crystal X-ray investigation, shows CdI 2 type CoO 2 layers similar to those encountered in misfit chalcogenides, but different rock salt (RS)-type Bi 0.87 SrO 2 layers. In contrast to the chalcogenides, these RS layers exhibit an intrinsic modulation due, as in the 2201 cobaltites, to the presence of double bismuth layers. Another fundamental difference with respect to misfit chalcogenides concerns the existence of strong Sr-O bonds between the CoO 2 layers and the Bi 0.87 SrO 2 layers, instead of weak bonds.

Establishment of a method for mapping of N-linked oligosaccharides and its use to analyze industrially produced recombinant erythropoietin.

A rapid and convenient method for N-linked oligosaccharide structure analysis was developed and applied to the quality examination of commercially manufactured recombinant human erythropoietin (rEPO). Oligosaccharides released from rEPO expressed in Chinese hamster ovary cells were labeled with 2-aminobenzamide, and analyzed by a combination of diethylaminoethyl (DEAE) column HPLC and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). This newly developed method allowed us to analyze sialylated oligosaccharides directly. The results showed that these oligosaccharides are composed of neutral-mono-di-tri-tetrasialyl oligosaccharides in a ratio of <1:2:13:34:51%, and that the core structure was a mixture of complex type bi-, tri- and tetra-antennary forms with one to three polylactosaminyl chains. Further analysis showed clearly that the N-linked oligosaccharide structure of rEPO has not changed throughout the past ten years of manufacturing by our company. The analysis was carried out using a small quantity (1 nmol) of rEPO, demonstrating the efficacy of the newly developed method. Further, the N-linked oligosaccharides of rEPO manufactured by our company almost coincided with those of the erythropoietin European Pharmacopoeia Biological Reference Preparation (Eur.Ph.BRP), a standard product.

Trace element disequilibria and magnesium isotope heterogeneity in 3655A: Evidence for a complex multi-stage evolution of a typical Allende Type B1 CAI

We used the Panurge ion microprobe to measure concentrations of the rare earth elements (REEs), Ba, Hf, and Sr in melilite, clinopyroxene, plagioclase, and perovskite and Mg isotopes in plagioclase, spinel, melilite, fassaite, hibonite, grossular, and monticellite from the Allende Type B1 calcium-, aluminum-rich inclusion (CAI), USNM 3655A. The distribution and concentration of Ba and the REE in melilite from the melilite-rich mantle of 3655A are unlike those predicted from melilite-melt REE partitioning experiments for closed system crystal fractionation. REE concentrations are lower than expected in the first crystallized gehlenitic melilite, increase rapidly to higher than expected concentrations in melilite with intermediate åkermanite contents (Ak30–Ak40), and decrease as expected only during the late stage of mantle crystallization. Barium concentrations in melilite are 10–50 times those expected, and the LREE/HREE ratio increases continuously rather than remaining constant. The unexpected distribution of trace elements in melilite reflects a progressive enrichment of trace elements in the melt during the early stages of crystallization. A partial explanation for this observation is the dissolution of precursor perovskite that contained half or more of the total REE budget of the inclusion. In addition, there are large trace element enrichments adjacent to included spinel in melilite and similar but smaller enrichments adjacent to spinet in clinopyroxene. These enrichments are consistent with the existence of trace element enriched boundary layers at the mineral/melt interfaces. The fact that kinetic processes partially control trace element abundances and distributions suggests rapid cooling during crystallization of the melilite-rich mantle. Similar trace element signatures are ubiquitous in Type B1 CAI, suggesting that each experienced a similar thermal history. The Mg isotope record of 3655A is distinguished by four salient features: (1) large 26Mg excesses correlated with the respective AI/Mg ratios in plagioclase, melilite, and hibonite, (2) F Mg, the mass-dependent fractionation of Mg, is positive, with enrichment of the heavier Mg isotopes in all primary phases, (3) a heterogeneous distribution of F Mg values, with F Mg in melilite systematically greater than in either spinel or fassaite, and (4) isotopically normal Mg in the secondary alteration phases, grossular and monticellite. The occurrence of 26Mg ∗, the decay product of 26Al, in anorthite implies early formation of 3655A, while 26Al was extant at nearly the canonical solar system value of ∼5 × 10 −5. The trace element and Mg isotope heterogeneities suggest a formation scenario for 3655A which includes (1) flash heating to partially melt a solid precursor, (2) rapid cooling to allow survival of relict phases, (3) diffusive exchange of Mg between melilite and a nebular reservoir, and (4) alteration at low temperature. Although this model explains most of the trace element and isotopic characteristics of 3655A and other Type BI CAIs, it does not provide an explanation for the rapid change of LREE/HREE ratios of melilite during crystallization.

Substitution of lead into the bismuth oxide layers of the n = 2- and n = 3-aurtvillius phases

Ceramic materials of the n = 2- and n = 3-Aurivillius phases of type Bi 2SrM 2O 9 and Bi 4Ti 3O 12 were systematically substituted by Pb 2+. The simultaneous charge compensated incorporation was performed for n = 2 with the nominal compositions Bi 2 − xPb xSr 1 − xLa xM 2O 9 and Bi 2 − xPb xSr M 2 − xW xO 9 as well as for the single lead substituted systems Bi 2 − xPb xSrM 2O 9 − δ with M = Nb, Ta (0 ≤ x ≤ 1). For n = 3 the following groups of materials were synthesized: Bi 4−xPb xTi 3 − xNb xO 12, Bi 2 − xPb xLa 2Ti 3−xNbxO 12, Bi 2 − xPb x Sr 2 − xLa xTiNb 2O 12 (0 ≤ x ≤ 1) and Bi 2Sr 2 − yPb yTiNb 2O 12 (0 ≤ y ≤ 2). The powder X-ray diffraction diagrams were single phased for all materials, thus exhibiting a solid solution behavior over the whole range of substitution but for the single lead substituted n = 2 systems. Structural investigations by X-ray powder diffractometry were carried out with different space groups and ordering schemes in order to verify the incorporation of the isoelectronic Pb 2+ for Bi 3+ in the bismuth oxide layers. A partially disordered distribution of La, Pb and Bi in Bi 2 − xPb xLa 2Ti 3 − xNb xO 12 and ordering effects of Ti/Nb in Bi 2 Sr 2 − yPb yTiNb 2O 12 were indicated.

Mixed state thermoelectric power of vanadium substituted 2223 (Bi, Pb) superconducting polycrystalline cuprates

Measurement of the mixed state thermoelectric power of pure and vanadium substituted 2223 pellets of the type (Bi 0.6 Pb 0.2-y V y ) 2 Sr 2 Ca 2 Cu 3 O x are presented for temperatures between 77 and 120 K. Mixed state Seebeck voltages for both pure and vanadium substituted samples show almost similar features. Our data for T > 0.8T c could be explained, attributing the observed dissipation to the normal quasiparticle excitations. For temperatures below 0.8T c , we argue that the dominant contribution to the mixed state Seebeck voltage may originate from the dissipation induced by the fluctuations of the order parameter across the internal weak links.