background blood transfusion is one of the many ways, through which toxoplasma gondii (t. gondii), a protozoan parasite, can be transmitted to humans. objectives this cross sectional study aimed to evaluate the seroprevalence of toxoplasma infection and related epidemiological features among healthy blood donors. materials and methods a total of 375 blood samples from donors were tested for spe...

Fe(II)-oxidizing aerobic bacteria are poorly understood, due in part to the difficulties involved in laboratory cultivation. Specific challenges include (i) providing a steady supply of electrons as Fe(II) while (ii) managing rapid formation of insoluble Fe(III) oxide precipitates and (iii) maintaining oxygen concentrations in the micromolar range to minimize abiotic Fe(II) oxidation. Electroch...

Cobalt porphine (CoP) dissolved in the organic phase of a biphasic system is used to catalyze O(2) reduction by an electron donor, ferrocene (Fc). Using voltammetry at the interface between two immiscible electrolyte solutions (ITIES), it is possible to drive this catalytic reduction at the interface as a function of the applied potential difference, where aqueous protons and organic electron d...

In this Density Functional Theory study, it became apparent that astaxanthin (ASTA) may form metal ion complexes with metal cations such as Ca⁺², Cu⁺², Pb⁺², Zn⁺², Cd⁺² and Hg⁺². The presence of metal cations induces changes in the maximum absorption bands which are red shifted in all cases. Therefore, in the case of compounds where metal ions are interacting with ASTA, they are redder in color...

We suggest an architecture for quantum computing with spin-pair encoded qubits in silicon. Electron-nuclear spin-pairs are controlled by a dc magnetic field and electrode-switched on and off hyperfine interaction. This digital processing is insensitive to tuning errors and easy to model. Electron shuttling between donors enables multiqubit logic. These hydrogenic spin qubits are transferable to...

Electronic properties of phosphorus donors in hydrogenated silicon nanocrystals are investigated using a real-space ab initio pseudopotential method for systems with up to 500 atoms. We present calculations for the ionization energy, binding energy, and electron density associated with the doped nanocrystal. We find that the ionization energy for the nanocrystal is virtually independent of size...

1. A spectrophotometric assay is described that enables the hydroxylation of p-coumaric acid to caffeic acid, catalysed by spinach-beet phenolase, to be followed continuously. 2. Initial-velocity and inhibitor studies indicate that the order of substrate addition is oxygen, p-coumaric acid and electron donor, with an irreversible step separating the binding of each substrate. 3. Caffeic acid is...

An electron transport chain has been found and partially characterized in highly purified membranes of serotonin granules isolated from porcine platelets. In these membranes NADH, but not NADPH, is oxidized when ferricyanide or catalytic amounts of cytochrome c were present. The reduced minus oxidized spectrum of these serotonin granule membranes shows a characteristic cytochrome b spectrum wit...

Organic long-persistent luminescent systems (OLPLs) exhibiting long-lasting emission after photoexcitation consist of organic electron donors and acceptors, that are widely used in light-emitting diodes (OLEDs). Although OLPLs OLEDs include very similar excitonic processes, has never been observed OLEDs. This study confirms the presence luminescence (LPL) under electrical excitation.

Photosystem II-dependent cyclic photophosphorylation activity produced by addition of p-phenylenediamines to KCN-Hg-NH(2)OH-inhibited chloroplasts is the product of two separate reactions when a proton/electron donor is the catalyst. The activity observed with an electron donor as catalyst consists of a single reaction. One of the cyclic reactions, evoked by low (</=40 micromolar) concentration...