Search results for "Pori"
showing 10 items of 761 documents
Characterization of the trimeric, self-recognizing Geodia cydonium lectin I.
1983
A D-galactose-specific lectin I was extracted from the sponge Geodia cydonium and purified by affinity chromatography. The molecular weight of lectin I as determined by high-pressure liquid gel chromatography, was found to be 36500 +/- 1300. Disc gel electrophoresis in the presence and in the absence of sodium dodecyl sulfate showed that lectin I is a trimer composed of three different subunits (Mr: 13800, 13000 and 12200); two of the three subunits are linked by one disulfide bond. Isoelectric focusing gave a pI of 5.6 for the native molecule and a pI of 4.4 and of 7.4 for the subunits. The three subunits carry carbohydrate side chains, composed of D-galactose (94%) and of arabinose (5%). …
On-line vapor-phase generation combined with Fourier transform infrared spectrometry
2008
We present a critical review of on-line vapor-phase generation combined with Fourier transform infrared spectrometry for detection. We discuss different experimental approaches developed for generating the vapor phase based on different principles (e.g., thermal volatilization, acid-base, redox reaction and covalent hydride generation). Using examples of applications, we try to demonstrate the analytical potential of on-line vapor-phase generation in vibrational spectrometry in order to improve the selectivity and the sensitivity of the measurement step and to make environmentally-friendly procedures available for problem solving in the analytical laboratory. We pay special attention to int…
Comparison of hard vaporization and soft ionization techniques in the mass spectrometry of some palladium(II) and platinum(II) complexes with C-bonde…
1990
Abstract Electron impact, fast atom bombardment and laser induced vaporization techniques are compared in the mass spectrometric behaviour of some palladium(II) and platinum(II) complexes with C-bonded heterocyclic ligands of the type trans -[MCl(R N )(PPh 3 ) 2 ] [M = Pd, R N = 2-pyridyl, 1 ; 2-pyrazyl, 2; 2-pyrimidyl, 3; M = Pt, R N = 2-pyridyl, 4 ].
Bioinspired self-assembly of tyrosinase-modified silicatein and fluorescent core-shell silica spheres.
2014
Inspired by the intermolecular cross-linking of mussel foot proteins and their adhesive properties, tyrosinase has been used to modify recombinant silicatein. DOPA/DOPAquinone-mediated cross-linking and interfacial interactions enhanced both self-assembly of silicatein building blocks and templating of core–shell silica spheres, resulting in fluorescent biomimetic silicatein–silica hybrid mesofibers.
A pH-tunable nanofluidic diode: electrochemical rectification in a reconstituted single ion channel.
2006
We report pH-dependent electrochemical rectification in a protein ion channel (the bacterial porin OmpF) reconstituted on a planar phospholipid membrane. The measurements performed at single-channel level show that the electric current is controlled by the protein fixed charge and it can be tuned by adjusting the local pH. Under highly asymmetric pH conditions, the channel behaves like a liquid diode. Unlike other nanofluidic devices that display also asymmetric conductance, here the microscopic charge distribution of the system can be explored by using the available high-resolution (2.4 A) channel crystallographic structure. Continuum electrostatics calculations confirm the hypothesized bi…
ChemInform Abstract: Synthesis of Pyrrolidin-2-ones and of Staurosporine Aglycon (K-252c) by Intermolecular Michael Reaction.
2010
Indolo[2,3-a]pyrrolo[3,4-c]carbazoles were isolated from nature, e.g., from low plants, especially fungi, as structurally rare natural substances. Responsible for naming and also the most important representative of this type is staurosporine (1), isolated from Streptomyces staurosporeus, and its aglycon (2), also known as staurosporinone or K-252c. 3,4-Disubstituted pyrrolidin-2-ones, a group of compounds with many interesting biological properties are related to staurosporinone. The most important property is the inhibition of protein kinase C (PKC), so that this antiproliferative agent can interfere with the cell cycle. The synthetic strategy, developed by us, allows the synthesis of pyr…
Binding and activation of human and mouse complement by Cryptosporidium parvum (Apicomplexa) and susceptibility of C1q- and MBL-deficient mice to inf…
2008
Cryptosporidium parvum is a protozoan parasite (Apicomplexa) that causes gastrointestinal disease in animals and humans. Whereas immunocompetent hosts can limit the infection within 1 or 2 weeks, immunocompromised individuals develop a chronic, life-threatening disease. The importance of the adaptive cellular immune response, with CD4+ T-lymphocytes being the major players, has been clearly demonstrated. Several non-adaptive immune mechanisms have been suggested to contribute to the host defence, such as interferon-gamma (IFN-gamma) from NK cells, certain chemokines, beta-defensins and pro-inflammatory cytokines, but the influence of the complement systems has been less well studied. We ana…
Dependence on nuclear factor of activated T-cells (NFAT) levels discriminates conventional T cells from Foxp3 + regulatory T cells
2012
Several lines of evidence suggest nuclear factor of activated T-cells (NFAT) to control regulatory T cells: thymus-derived naturally occurring regulatory T cells (nTreg) depend on calcium signals, the Foxp3 gene harbors several NFAT binding sites, and the Foxp3 (Fork head box P3) protein interacts with NFAT. Therefore, we investigated the impact of NFAT on Foxp3 expression. Indeed, the generation of peripherally induced Treg (iTreg) by TGF-β was highly dependent on NFAT expression because the ability of CD4 + T cells to differentiate into iTreg diminished markedly with the number of NFAT family members missing. It can be concluded that the expression of Foxp3 in TGF-β–induced iTreg depends…
Isotope-dilution ICP-MS for trace element determination and speciation: from a reference method to a routine method?
2003
This critical review discusses the conditions under which inductively coupled plasma-isotope dilution mass spectrometry (ICP-IDMS) is suitable as a routine method for trace element and element-speciation analysis. It can, in general, be concluded that ICP-IDMS has high potential for routine analysis of trace elements if the accuracy of results is of predominant analytical importance. Hyphenated techniques with ICP-IDMS suffer both from lack of commercially available isotope-labeled spike compounds for species-specific isotope dilution and from the more complicated system set-up required for species-unspecific ICP-IDMS analysis. Coupling of gas or liquid chromatography with species-specific …
The role of cefditoren in the treatment of lower community-acquired respiratory tract infections (LRTIs): from bacterial eradication to reduced lung …
2014
Lower respiratory tract infections (LRTIs), including pneumonia and acute exacerbations of Chronic Obstructive Pulmonary Disease (COPD), are among the most common diagnoses in both outpatient and inpatient settings. Due to the burden of LRTIs healthcare providers must adopt practices focused on improving outcomes with the aim to reduce treatment failure and antibiotic resistances. Moreover, the role of acute and chronic infection in the pathogenesis of COPD has received considerable attention, since chronic infection can contribute to airways inflammation and COPD progression. This review discusses the role of cefditoren for the treatment of LRTIs, compared with the definition of "appropria…