Few-cycle Yb laser source at 20 kHz using multidimensional solitary states in hollow-core fibers.

We demonstrate ultrashort pulse compression from 300 fs down to 17 fs at a repetition rate of 20 kHz and 160-µJ output pulse energy (3.2 W of average power) using multidimensional solitary states (MDSS) in a 1-meter hollow-core fiber (HCF) filled with N2O. Under static pressure, thermal limitations at this repetition rate annihilate the MDSS with suppression of spectral broadening. The results obtained in differential pressure configuration mitigate thermal effects and significantly increase the range of repetition rate over which MDSS can be used to compress sub-picosecond laser pulses.

Digital proximity tracing on empirical contact networks for pandemic control.

Digital contact tracing is a relevant tool to control infectious disease outbreaks, including the COVID-19 epidemic. Early work evaluating digital contact tracing omitted important features and heterogeneities of real-world contact patterns influencing contagion dynamics. We fill this gap with a modeling framework informed by empirical high-resolution contact data to analyze the impact of digital contact tracing in the COVID-19 pandemic. We investigate how well contact tracing apps, coupled with the quarantine of identified contacts, can mitigate the spread in real environments. We find that restrictive policies are more effective in containing the epidemic but come at the cost of unnecessary large-scale quarantines. Policy evaluation through their efficiency and cost results in optimized solutions which only consider contacts longer than 15-20 minutes and closer than 2-3 meters to be at risk. Our results show that isolation and tracing can help control re-emerging outbreaks when some conditions are met: (i) a reduction of the reproductive number through masks and physical distance; (ii) a low-delay isolation of infected individuals; (iii) a high compliance. Finally, we observe the inefficacy of a less privacy-preserving tracing involving second order contacts. Our results may inform digital contact tracing efforts currently being implemented across several countries worldwide.

An analysis of the effects of galanin on gastric acid secretion and plasma levels of gastrin in the dog.

The effects of galanin on gastric acid secretion and plasma levels of gastrin were studied in conscious dogs chronically fitted with gastric fistulas. Continuous i.v. infusion of galanin (2 micrograms.kg-1.h-1) for 2 h did not affect unstimulated total acid output or plasma levels of gastrin. In contrast, simultaneous i.v. infusion of galanin (1-2 micrograms.kg-1.h-1) inhibited the bombesin-stimulated output of acid whereas the effects of bombesin on gastrin output were not significantly modified. Galanin (2-4 micrograms.kg-1 i.v.) also depressed the secretory response to 2-deoxy-D-glucose without significantly affecting plasma gastrin levels. Galanin (2-4 micrograms.kg-1 i.v.) did not depress bethanechol-stimulated gastric acid output or inhibit histamine-stimulated gastric acid secretion. These findings indicate that glanin inhibits the bombesin- and 2-deoxy-D-glucose-stimulated secretion of gastric acid in conscious dogs by an action which is probably exerted at the level of the cholinergic nerve terminals.

Short-term effects of diethylaminoethyl-dextran on postprandial gastrointestinal hormone responses in man.

The effects of oral diethylaminoethyl-dextran (3 g total), taken 30 min before a standard mixed test meal, on plasma glucose, total cholesterol, triglycerides, total lipids, gastrin-like immunoreactivity, bombesin-like immunoreactivity, gastric-inhibitory-polypeptide-like immunoreactivity and neurotensin-like immunoreactivity were evaluated in eight healthy volunteers following a double-blind protocol. Incremental peak plasma concentrations of total lipids and triglycerides were significantly reduced by pretreatment with diethylaminoethyl-dextran pretreatment, while peaks of plasma glucose and total cholesterol were not significantly affected. Diethylaminoethyl-dextran also inhibited postprandial gastrin-like gastric-inhibitory-polypeptide-like and neurotensin-like immunoreactivity; by contrast, bombesin-like immunoreactivity was not significantly modified. The present study indicates that diethylaminoethyl-dextran is able to regulate some postprandial metabolic and hormonal parameters in man; consequently it might be useful in the treatment of hyperlipoproteinaemia and obesity.

GABA-A-mediated gastrin release induced by baclofen in the isolated vascularly perfused rat stomach.

In order to investigate the role of peripheral GABA-B receptors, the effects of the putative GABA-B agonist baclofen on immunoreactive gastrin release from an isolated vascularly perfused rat stomach preparation were examined. The vascular infusion of baclofen at graded concentrations induced a dose-dependent increase in gastrin release; this was unaffected by the GABA-B antagonist delta-aminovaleric acid, but was fully prevented by the selective GABA-A antagonist bicuculline as well as by atropine or tetrodotoxin. These results suggest that the stimulant effects of baclofen are mediated by nervous cholinergic structures associated with GABA-A receptors, and indicate that this GABA-B agonist must be regarded as a partial agonist of peripheral GABA-A receptors.

[Comparative study of 4 methods for identifying species of the genus Aeromonas]. / Estudio comparativo de 4 métodos para la identificación de especies del género aeromonas.

It is given an explanation of the results obtained with the following methods: AEROKEY II, AEROKEY II + Abbot's scheme, Api 20 NE, and the Biolog System. The study was conducted with 38 strains of Aeromonas isolated from children under 5 with acute diarrheal disease (ADD). The AEROKEY II + Abbot's scheme proved to be the best identification method.

Especies de aeromonas asociadas a diarrea: características microbiológicas y clínicas / Species of aeromonas associated a diarrhea: characteristic microbiological and clinical

Para estudiar las características microbiológicas y clínicas de Aeromonas sp. asociada a Enfermedad Diarreica Aguda (EDA) se analizaron, desde junio de 1993 1 diciembre de 1994, 397 muestras de heces de niños menores de cinco años con EDA y 121 asintomáticos. Fueron aisladas en una frecuencia de 11,8 y 5,8 por ciento en los casos de EDA y control, respectivamente. A.hydrophila y A.caviae fueron las especies más aisladas en ambos casos. Como patógenos únicos se encontraron en un 38,3 por ciento, y asociados en un 61,7 por ciento. La presentación del cuadro clínico fue 50 por ciento de tipo disentérico: 33,33 por ciento de tipo secretorio y 16.66 por ciento de tipo indeterminado. El mejor medio de cultivo fue el DNA-ampicilina. Se obtuvo un 1 por ciento con producción de H2S y un 5 por ciento fermentadoras de la lactosa. En las cepas se detectó por lo menos dos de las enzimas estudiadas; en base a esto, existe una importante circulación de este género con capacidad de producir EDA