Search results for "Complex."

Orbital Decomposition of the Carbon Chemical Shielding Tensor in Gold(I) N-Heterocyclic Carbene Complexes.

2020

The good performance of N‐heterocyclic carbenes (NHCs), in terms of versatility and selectivity, has called the attention of experimentalists and theoreticians attempting to understand their electronic properties. Analyses of the Au(I)–C bond in [(NHC)AuL]+/0 (L stands for a neutral or negatively charged ligand), through the Dewar–Chatt–Duncanson model and the charge displacement function, have revealed that NHC is not purely a σ‐donor but may have a significant π‐acceptor character. It turns out, however, that only the σ‐donation bonding component strongly correlates with one specific component of the chemical shielding tensor. Here, in extension to earlier works, a current density analysi…

Index-based triangulation method for efficient generation of large three-dimensional ultrasonic C-scans

2018

The demand for high-speed ultrasonic scanning of large and complex components is driven by a desire to reduce production bottlenecks during the non-destructive evaluation (NDE) of critical parts. Emerging systems (including robotic inspection) allow for the collection of large volumes of data in short time spans, compared to existing inspection systems. To maximise throughput, it is crucial that the reconstructed inspection datasets are generated and evaluated rapidly without loss of detail. This requires new data visualisation and analysis tools capable of mapping complex geometries while guaranteeing full coverage. This paper presents an entirely new approach for the visualisation of thre…

Genotype‐phenotype correlations in Brazilian patients with hereditary angioedema due to C1 inhibitor deficiency. [Carta]

2019

Plasma calprotectin levels in patients suffering from acute pancreatitis

2006

Calprotectin (Cal) concentration is elevated in acute inflammatory reactions and its increase in the plasma suggests a diagnostic potential for Cal assay. This study aimed (a) to evaluate the Cal plasma levels in patients suffering from acute pancreatitis (AP) and (b) to assess whether early assay of Cal plasma levels can be helpful in assessment of the severity of AP. Forty-six consecutive patients, median age 45 years, suffering from a first attack of AP were recruited at two medical centers. Data collected on admission included age, sex, delay between pain onset and admission, and Glasgow score. A severe outcome was defined according to the Atlanta criteria. AP was defined as edematous o…

Long-term Additions of Organic Amendments in a Loire Valley Vineyard. I. Effects on Properties of a Calcareous Sandy Soil

2008

International audience; A long-term experiment (28 years) was conducted to Study the effects of various organic amendments oil physical, chemical, and biological properties of a sandy vineyard soil. Annual applications of either crushed pruned vine-wood (2 t/ha fresh wt), cattle manure (10 and 20 t/ha fresh wt.), or spent mushroom compost (8 and 16 t/ha fresh wt) were compared to all unamended treatment, In plots unamended for 28 years, total organic C (TOC) showed a slow and limited decrease (19%). For the highest rates of exogenous organic amendments, the increase in TOC reached a saturation Value after 20 years and carbon (C) sequestered after 28 years reached 30 Mg/ha. Final predicted T…

Supramolecular Construction of Cyanide-Bridged Re I Diimine Multichromophores

2019

The reactions of labile [Re(diimine)(CO)3(H2O)]+ precursors (diimine = 2,2′-bipyridine, bpy; 1,10-phenanthroline, phen) with dicyanoargentate anion produce the dirhenium cyanide-bridged compounds [{Re(diimine)(CO)3}2CN)]+ (1 and 2). Substitution of the axial carbonyl ligands in 2 for triphenylphosphine gives the derivative [{Re(phen)(CO)2(PPh3)}2CN]+ (3), while the employment of a neutral metalloligand [Au(PPh3)(CN)] affords heterobimetallic complex [{Re(phen)(CO)3}NCAu(PPh3)]+ (4). Furthermore, the utilization of [Au(CN)2]−, [Pt(CN)4]2–, and [Fe(CN)6]4–/3– cyanometallates leads to the higher nuclearity aggregates [{Re(diimine)(CO)3NC}xM]m+ (M = Au, x = 2, 5 and 6; Pt, x = 4, 7 and 8; Fe, x…

Reduced T-cell receptor CD3ζ-chain protein and sustained CD3ε expression at the site of mycobacterial infection

2001

Control of mycobacterial infection by the cellular immune system relies both on antigen-presenting cells and on T lymphocytes. The quality of an effective cellular immune response is dependent on functional signal transduction residing in the cytoplasmic tails of the T-cell receptor CD3 components. In order to investigate potential effects of mycobacteria on T-cell receptor signalling, we examined the protein expression of T-cell signal transduction molecules (CD3zeta, ZAP-70, p59fyn, p56lck). In Western blots of peripheral blood mononuclear cells of Mycobacterium tuberculosis infected patients, only the CD3zeta-chain showed a marked reduction in protein expression. To investigate the situa…

Defective expression of CD95 (FAS/APO-1) molecule suggests apoptosis impairment of T and B cells in HLA-B8, DR3-positive individuals.

1997

Activation-induced apoptosis is one of the primary control mechanisms for the negative selection of an immune response, leading to maintenance of immune homeostasis and selective T cell deletion. The interaction between the surface molecule Fas and its ligand (FasL) has been proposed as a primary mechanism initiating T cell apoptosis. The T cell receptor modulates the expression and function of these molecules. Defects in the Fas/FasL apoptosis pathway have been shown to result in autoimmune disease in humans and in murine models. Because subjects carrying the HLA-B8, DR3 haplotype show a number of immune dysfunctions, including membrano-proliferative glomerulonephritis, systemic lupus eryt…

Antigen-independent in vitro expansion of T cells does not affect the T cell receptor V beta repertoire.

1997

Analysis of the variable chains (V alpha/V beta) of the specific T cell receptor (TCR) of organ-infiltrating T cells may provide further insights into the pathogenesis of many infectious diseases, malignancies, and autoimmune disorders. To determine the TCR V beta repertoire of these small T cell populations antigen-independent in vitro expansion is necessary but may select for certain T cell subpopulations. In this study various antigen independent T cell activation protocols were used to stimulate peripheral blood mononuclear cells (PBMC) of six healthy blood donors, and TCR V beta molecules were analyzed by flow cytometry and semiquantitative reverse-transcriptase polymerase chain reacti…

Anti-GD3 antibodies are potent activators of human gamma/delta and alpha/beta positive T cells.

1995

The ganglioside GD3 has a variety of biological functions. These include stimulatory effects on proliferation, natural killer activity and cytokine production by freshly isolated peripheral T cells. In this study we have characterized anti-GD3 antibody (MoAb Z21) mediated effects on T cell clones. Our data indicate that alpha/beta TCR CD4+ and CD8+ as well as gamma/delta TCR positive T cells can be stimulated resulting in proliferation and cytokine production. This effect could be blocked by cyclosporin A and did not involve the LFA-3 or CD4 molecule. Apart from IFN-gamma and IL-2 production by T helper 1 and T helper 0 cells we have observed production of IL-4 and IL-10 by T helper 2 cells…