Laser-scribing fabrication of a disposable electrochemical device for forensic detection of crime facilitating drugs in beverage samples.

A portable and disposable laser-scribed graphene (LSG) device was fabricated on polyetherimide (PEI) substrate for electrochemical detection of benzodiazepines (BZ) drugs such as diazepam (DZ) and midazolam (MZ) in commercial beverage samples. Morphological characterizations of the LSG material recorded by scanning electron microscopy (SEM) revealed the porous nature of the proposed electrochemical device, which contributed to the enhancement of the electroactive area. Besides, the structural and electrochemical characterizations performed by Raman spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) measurements revealed that the PEI-LSG material presents highly disordered graphene-like structures and high electron transfer features, respectively.

Inhomogeneous Kondo-lattice in geometrically frustrated PrIrO.

Magnetic fluctuations induced by geometric frustration of local Ir-spins disturb the formation of long-range magnetic order in the family of pyrochlore iridates. As a consequence, PrIrO lies at a tuning-free antiferromagnetic-to-paramagnetic quantum critical point and exhibits an array of complex phenomena including the Kondo effect, biquadratic band structure, and metallic spin liquid. Using spectroscopic imaging with the scanning tunneling microscope, complemented with machine learning, density functional theory and theoretical modeling, we probe the local electronic states in PrIrO and find an electronic phase separation.

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+ Y Te Using a Spin-polarized Scanning Tunneling Microscope.

The quest to understand correlated electronic systems has pushed the frontiers of experimental measurements toward the development of new experimental techniques and methodologies. Here we use a novel home-built uniaxial-strain device integrated into our variable temperature scanning tunneling microscope that enables us to controllably manipulate in-plane uniaxial strain in samples and probe their electronic response at the atomic scale. Using scanning tunneling microscopy (STM) with spin-polarization techniques, we visualize antiferromagnetic (AFM) domains and their atomic structure in Fe1+yTe samples, the parent compound of iron-based superconductors, and demonstrate how these domains respond to applied uniaxial strain.

Quasi-particle interference of heavy fermions in resonant x-ray scattering.

Resonant x-ray scattering (RXS) has recently become an increasingly important tool for the study of ordering phenomena in correlated electron systems. Yet, the interpretation of RXS experiments remains theoretically challenging because of the complexity of the RXS cross section. Central to this debate is the recent proposal that impurity-induced Friedel oscillations, akin to quasi-particle interference signals observed with a scanning tunneling microscope (STM), can lead to scattering peaks in RXS experiments.

Immune complex clearance by complement receptor type 1 in SLE.

Patients with systemic lupus erythematosus (SLE) have relative deficiencies of the C3b/C4b receptor (CR1, CD35) on erythrocytes (E). This receptor takes part in the binding, transport and endocytosis of circulating immune complex bound complement components (ICC). Besides the autoantibodies the abnormalities in IC elimination are fundamental to the pathogenesis of SLE.

Immune complex clearance by monocytes and macrophages in systemic lupus erythematosus.

During the last 30 years more than 700 patients with systemic lupus erythematosus (SLE) have been treated in our department with their data analyzed. Here we focus on circulating immune complex (CIC) and its clearance. We demonstrated, microscopically, that the uptake of IgG sensitized erythrocytes (EA), via monocytes (Mo) of SLE patients, was elevated and correlated with the high CIC content.

Determination of ligand binding capacity of soluble Fc gamma RII and Fc gamma RIII in sera of patients with SLE.

Background: Soluble, human low affinity Fcgamma receptors, such as sFcgammaRII and sFcgammaRIII, are known to play a pathologic role in different diseases. Sandwich ELISAs had previously been applied for the specific detection and determination of these soluble receptors. In these ELISAs, commercial monoclonal antibodies (Ab) were used as capture antibodies with monoclonal or polyclonal antibodies serving as detector Abs.

Possible role of factor XIII subunit A in Fcgamma and complement receptor-mediated phagocytosis.

Besides its traditional role in hemostasis, factor XIII subunit A (FXIII-A) is supposed to function as a cellular transglutaminase and to be involved in certain intracellular processes, including cytoskeletal remodeling. To investigate its intracellular role, the aim of the present study was to follow changes in FXIII-A production in combination with the receptor-mediated phagocytic activities of monocytes/macrophages and to examine the phagocytic functions of monocytes in patients with FXIII-A deficiency. Human blood monocytes were isolated from the buffy coats of healthy volunteers and cultured for 4 days.

Effect of plasmapheresis on ligand binding capacity and expression of erythrocyte complement receptor type 1 (CR1) of patients with systemic lupus erythematosus (SLE).

The functional activity and the expression of CR1 on the erythrocytes (E) of patients with SLE were, respectively, determined by measuring the binding to E of either complement-opsonized bovine serum albumin (BSA)-anti-BSA immune complexes (ICC) or specific anti-ECR1 MoAbs. We found that both the functional activity and levels of ECR1 in SLE patients homozygous for ECR1 high density allele were significantly lowered compared with healthy controls having the same allele. Soon after plasmapheresis there was a significant increase in E ICC binding activity, and this increased functional activity was stable.

Correlation of Fc gamma receptor expression of monocytes with clearance function by macrophages in systemic lupus erythematosus.

The expression of Fc gamma receptor II (Fc gammaRII) and Fc gammaRIII on monocytes in peripheral blood and the clearance of immunoglobulin (Ig)G-sensitized erythrocytes (EA) by tissue macrophages were investigated in parallel in patients with systemic lupus erythematosus (SLE). The relationship between receptor expression and the rate of clearance of EA (half-time) was analyzed. The detected decrease in mean fluorescence intensity of both FcR gammaII and Fc gammaRIII of patients' monocytes stained with specific monoclonal antibodies (IV.

Recombinant human erythropoietin modulates erythrocyte complement receptor 1 functional activity in patients with lupus nephritis.

Deposition of immune complexes (IC) is an important step in the pathogenesis of lupus nephritis. Impairment of IC-clearance contributes to the accumulation of IC. It may be partly attributed to decreased complement containing immune complex (ICC) binding by erythrocytic complement receptor 1 (ECR1).

Serum complement activation of SLE patients during plasmapheresis.

The erythrocyte complement receptor 1 (ECR1)-immune complex binding assay is a sensitive method for the determination of complement fragments which can be activated by bovine serum albumin (BSA)-anti-BSA in vitro. When the C3b/C4b containing bovine serum albumin (BSA)-anti-BSA was formed in the presence of the serum of patients with systemic lupus erythematosus (SLE) its binding to ECR1 was found to be lower than that formed in sera of normal volunteers. The plasmapheresis of SLE patients homozygous for the CR1/E high density allele displays a beneficial effect on the formation of C3b/C4b containing BSA-anti-BSA and its binding to ECR1.

Changes in superoxide anion production and phagocytosis by circulating neutrophils during tumor progression in a rat model.

The functional state of circulating neutrophils was monitored in a rat model of mesoblastic nephroma during tumor progression. Superoxide anion (O2.-) production in response to PMA and phagocytosis of yeast particles (Saccharomyces cerevisiae) were measured every second day after tumor cell implantation.

CR1 density polymorphism and expression on erythrocytes of patients with systemic lupus erythematosus.

The present study investigated the expressed number of CR1 on erythrocytes (E) in relationship of the CR1 density genotype from 46 patients with systemic lupus erythematosus (SLE) and 47 healthy volunteers. The CR1 genotype was determined by a method based on polymerase chain reaction (PCR) amplification of the genomic DNA fragment of 1.8 kb separated by HindIII endonuclease digestion and agarose gel electrophoresis.

Correlation of IgG Fc receptors on granulocytes with serum immune complex level in systemic lupus erythematosus.

The expression of Fc gamma RI, Fc gamma RII and Fc gamma RIII on granulocytes in the blood of patients with systemic lupus erythematosus was investigated. The relationship between the receptor expression and serum immune complex (IC) concentration was analysed. The decrease in mean fluorescence intensity of both Fc gamma RII and Fc gamma RIII of patients' granulocytes stained by specific monoclonal antibodies (using MoAb IV.

Correlations of monocyte phagocytic receptor expressions with serum immune complex level in systemic lupus erythematosus.

The expression of Fc gamma RI, Fc gamma RII, and Fc gamma RIII (the IgG receptors CD64, CD32, CD16) as well as CR3 (the C3bi receptor, CD11b) on monocytes in the blood of patients with systemic lupus erythematosus (SLE) was investigated. The relationship between the receptor expression and the serum immune complex (IC) concentration was analysed. The decrease in mean fluorescence intensity (FI) of the Fc gamma RII of patients' monocytes stained by specific monoclonal antibodies (MoAb IV3) was very close to statistical significance (P = 0.

Triggering of respiratory burst by phagocytosis in monocytes of patients with systemic lupus erythematosus.

The triggering of the respiratory burst by phagocytosis via different receptors in monocytes of patients with systemic lupus erythematosus (SLE) was investigated. The superoxide anion synthesis was assayed by reduction of ferricytochrome C that was inhibited by superoxide dismutase. The mononuclear cell suspensions were triggered by IgG-coated latex, C3 complement fragment-coated and uncoated yeast (Saccharomyces cerevisiae).

A sensitive simple ELISA for quantitation of sensitizing IgG from dissolved erythrocytes.

A simple enzyme-linked immunosorbent assay has been developed for quantitating the rabbit IgG present on the surface of sensitized red blood cells. A suitable cell lysis was carried out by an alkaline buffer, which dissolved the erythrocytes without forming any precipitate and without disruption of IgG, and facilitated the dissociation of the immune complexes, i.e.

Marker profile, enzyme activity, and function of a human myelomonocytic leukemia cell line.

Morphological and functional characteristics of a permanent human leukemia cell line (DD) that possesses myelomonocytic features were investigated. The cells bear a second type Fc gamma receptor and form rosettes with sheep erythrocytes sensitized with rabbit IgG (EA). However, the surface-bound EA is not internalized.

Binding and endocytosis of erythrocytes sensitized with rabbit IgG via Fc gamma receptors of human monocytes.

The properties of the monocyte Fc gamma receptors (FcR) were investigated with monoclonal antibodies (mAb) against FcRI (10.1) and FcRII (IV3). mAb against FcRI inhibited partially the binding of sheep red blood cells (SRBC) sensitized with anti-SRBC rabbit IgG (EA) at 37 degrees to monocytes pretreated with N-ethyl maleimide, which inhibits the EA ingestion.

Ligand-specific cross-inhibition of monocyte phagocytosis.

Human monocytes exposed to particles reacting with receptors of one specific type demonstrate a markedly reduced phagocytosis of particles reacting with receptors of another type. The phagocytosis of yeast particles (Saccharomyces cerevisiae) coated with C3 fragments and of uncoated ones by monocytes can inhibit the subsequent endocytosis of sheep erythrocytes sensitized with IgG antibody and vice versa. The erythrocytes were labelled with 51Cr and the yeast particles with 125I.

Inefficient binding of IgM immune complexes to erythrocyte C3b-C4b receptors (CR1) and weak incorporation of C3b-iC3b into the complexes.

The binding of soluble complement-reacted IgM immune complexes (IC) to erythrocyte (E) C3b-C4b receptors (CR1) and the incorporation of C3b-iC3b into solid phase IgM-IC was investigated. The optimal binding of liquid phase IgM-IC to E-CR1 was obtained with IC formed at moderate antibody excess, but the binding was low (2-3%) when compared to the binding of the corresponding IgG-IC (50-60%). Solid phase IC were prepared by coating microwells with heat-aggregated bovine serum albumin (BSA) followed by incubation with rabbit IgM anti-BSA antibody.

Monocytes of patients congenitally deficient in plasma factor XIII lack factor XIII subunit a antigen and transglutaminase activity.

Monocytes isolated from patients with severe deficiency in plasma Factor XIII of blood coagulation (FXIII) were tested for FXIII antigen and transglutaminase activity. By immunoperoxidase method the patients' monocytes, in contrast to normal controls, showed no reaction with a monospecific antibody against FXIII subunit a. This result was confirmed by immunoblotting technique, as well.