Superioniclike Diffusion in an Elemental Crystal: bcc Titanium.

Recent theoretical investigations [A. B. Belonoshko et al. Nat. Geosci. 10, 312 (2017)1752-089410.1038/ngeo2892] revealed the occurrence of the concerted migration of several atoms in bcc Fe at inner-core temperatures and pressures. Here, we combine first-principles and semiempirical atomistic simulations to show that a diffusion mechanism analogous to the one predicted for bcc iron at extreme conditions is also operative and of relevance for the high-temperature bcc phase of pure Ti at ambient pressure. The mechanism entails a rapid collective movement of numerous (from two to dozens) neighbors along tangled closed-loop paths in defect-free crystal regions. We argue that this phenomenon closely resembles the diffusion behavior of superionics and liquid metals. Furthermore, we suggest that concerted migration is the atomistic manifestation of vanishingly small ω-mode phonon frequencies previously detected via neutron scattering and the mechanism underlying anomalously large and markedly non-Arrhenius self-diffusivities characteristic of bcc Ti.

A serosurvey for spotted fever group Rickettsia and Coxiella burnetii antibodies in rural dogs and foxes, Chile.

Antibodies against Spotted Fever Group (SFG) Rickettsia and Coxiella burnetii, investigated through indirect antibody immunofluorescence tests, were detected in serum samples from 3.1% and 0% of 358 rural dogs, respectively, and in none of 32 wild foxes tested. SFG Rickettsia seropositive dogs were only detected in the Mountain Desert (8%) and the Steppe-Mediterranean (9%) regions. Exposure in the Mountain Desert, where no ticks and fleas were found on any dog, could correspond to a new SFG Rickettsia sp. recently described in soft ticks or to a related agent. Our survey confirms low endemicity in the country of C. burnetii, as observed in recent serosurveys in humans.

Insight into the bioreductive mode of action of antitrypanosomal 5-nitrofuryl containing thiosemicarbazones.

In order to get insight into the trypanocidal mechanism of action of a series of 5-nitrofuryl containing thiosemicarbazones some studies related to their bioreduction were performed. Electron spin resonance spectra of radicals generated in T. cruzi by compounds' bioreduction were analyzed. Three different patterns of ESR signals were observed for the different assayed compounds. These results were in agreement with the changes in the T. cruzi-oxygen uptake promoted by these compounds. On the other hand, free-radical scavenger properties, measured as oxygen radical absorbance capacity (ORAC), did not seem to correlate with the trypanocidal activity.

Age-related changes in the neuromuscular junctions in the human posterior cricoarytenoid muscles: a quantitative study.

The posterior cricoarytenoid muscle is unique histochemically, ultrastructurally, and functionally. It has been suggested that the posterior cricoarytenoid muscle undergoes early aging. Aging in peripheral nerves has been reported to resemble a "dying back" neuropathy in that the most severe and earliest age-related changes occur at the most distal levels of the nerve fibers. The lengths and terminal axonal branching of neuromuscular junctions in 17 human posterior cricoarytenoid muscles aged 4 days to 95 years were determined. Both neuromuscular junction lengths and the numbers of axonal terminal branches in the very young group differed significantly from values in two older groups. In contrast to results reported for some other muscles, there was no significant age-related change in these parameters in the posterior cricoarytenoid muscle during adult life. This difference may be related to the repetitive contraction of the posterior cricoarytenoid muscle.

Three-dimensional computer reconstruction of the neuromuscular junction distribution in the human posterior cricoarytenoid muscle.

Recent studies have indicated that in a denervated muscle highly specific interactions occur between regenerating axons and the basal lamina of the myofiber precisely at the original synaptic sites. Since these findings suggest that synapse regeneration is facilitated at the original synaptic sites, a knowledge of the distribution of neuromuscular junctions in the human posterior cricoarytenoid (PCA) muscle may guide reinnervation procedures in this muscle. We, therefore, have used histochemical and computer graphics techniques to reconstruct the three-dimensional distribution of neuromuscular junctions in the human PCA taken fresh at autopsy. The results indicated a more localized pattern of neuromuscular junctions as compared to the human thyroarytenoid muscle. The results will be discussed with respect to their implications for procedures for reinnervation of the posterior cricoarytenoid muscle.

A standard aminophylline intravenous solution with flow rate label adapted to a manufacturer's standard solution.

The development of a standard aminophylline intravenous solution system utilizing a flow rate label is described. The original system was developed using 500 mg aminophylline in 250 ml of 5% dextrose injection in a polyvinyl chloride bag (PVC). An ancillary label was developed to be affixed to the bag to assist in maintaining flow rates. Later, this system was adapted to a premixed solution prepared by Travenol Laboratories. The difference, though, was the fact that a solution of 400 mg theophylline (equivalent to 500 mg of aminophylline) in 250 ml of 5% dextrose solution (PVC) was used. Hence, a new auxiliary label indicating flow rates between aminophylline and theophylline was developed. The success of both systems gave us more advantages than disadvantages. This was especially true with the premixed system. We feel that the auxiliary flow rate label helped maintain rates whether the physicians orders were written in theophylline or aminophylline. With proper nursing inservice, this standard aminophylline program could be successful using this auxiliary flow rate label.

Potential therapeutic applications of metal compounds directed towards hypoxic tissues.

Medicinal Inorganic Chemistry offers the high diversity of metal coordination chemistry for the development of bioactive compounds for therapeutic or diagnostic medicinal purposes. The design of novel metal-based antitumor agents occupies a privileged position in this discovery process. On the other hand, the research on metal-based radiopharmaceuticals for therapy and imaging is a subarea of high priority and development. This review describes therapeutic applications of metal compounds directed towards hypoxic tissues. Strategies in the search for new bioreductive metal-based prodrugs will be discussed. In addition, approaches for the imaging of hypoxic tissues by using metal radionuclides will be exemplified.

Spectroscopic behavior and biological activity of K3[VO(O2)2CO3]∙H2O.

The potassium salt of the carbonato oxodiperoxovanadate(V) complex, obtained by a known synthetic procedure, was thoroughly characterized by infrared, Raman, and electronic spectroscopy. The bioactivity of the complex on the cell proliferation was tested on osteoblast-like cells (MC3T3E1 osteoblastic mouse calvaria-derived cells and UMR106 rat osteosarcoma-derived cells) in culture. At low doses, the complex is more toxic for the nontransformed osteoblasts than for the tumoral ones, whereas at higher doses the deleterious effects are similar for both cell lines. This peroxo complex seems to be the most toxic compound that has so far been tested on osteoblast-like cells in culture.