5,196 research outputs found
Gender differences in COVID-19 infection. The estrogen effect on upper and lower airways. Can it help to figure out a treatment?
Epidemiologic evidence from the first large-scale studies suggests that males are more se- verely affected than females by Severe Acute Respiratory Syndrome-CoronaVirus-2 (SARS-CoV-2). They present worse outcomes, require longer hospitalization time and have a higher mortality rate when compared with women. Scientists have speculated that female hormones, especially estrogen, could explain the better outcomes and the higher resistance to the virus observed in women. This higher resistance is due to the systemic and local effect of female hormones on the different cells. In particular, estrogens stimulate the immune system by modulating the function of B cells and improving T-helper 2 cell activity. Based on this evidence, we hypothesize the potential utility of a local nasal spray with low- dose isoflavones from soya (natural estrogen) suspended in a solution with sodium could stimu- late nasal receptor by stopping or reducing the aggressiveness of COVID-19 as already suggested by a previous animal study
Electrochemical properties and electrochemical impedance spectroscopy of polypyrrole-coated platinum electrodes
Polypyrrole (PPy) films of different thickness were characterized by electrochemical impedance spectroscopy (EIS) measurements in acetonitrile and aqueous solutions, containing 0.1 M NaClO4 or sodium dodecylsulfate as the dopant. The PPy films were electrochemically deposited on Pt, and their electrochemical properties studied by cyclic voltammetry. Impedance spectra were obtained at potentials ranging from 0 to 0.8 V/SCE. The EIS data were fitted using two different equivalent electrical circuits (depending on the nature of the dopant). They involve a diffusive capacitance, which increased with the passing charge during electrosynthesis (i.e. film thickness) for ClO4--doped PPy, but was practically unaffected by the film thickness in the case of SDS-doped PPy. Also, a double-layer capacitance was found only in the circuit of ClO4--doped PPy. It increased with the film thickness, and showed a minimum near the open-circuit potential. Finally the charge-transfer resistance (Rct) obtained with SDS is nearly 200-fold higher than that obtained with ClO4- in the same solvent (H2O). With the same dopant (ClO4-), Rct is about five times higher in acetonitrile relative to water. All these EIS results of the different types of PPy suggest a relation with the wettability of the polymer.KEY WORDS: Conducting polymers, Polypyrrole, Electrochemical impedance spectroscopy, Equivalent-electrical circuit, Micellar mediaBull. Chem. Soc. Ethiop. 2006, 20(2), 279-293
Spiral ganglions and speech perception in the elderly. Which turn of the cochlea is the more relevant? a preliminary study on human temporal bones
OBJECTIVES: To identify the cochlear segment in which spiral ganglion neuron (SGN) loss may more severely impact discrimination thresholds. MATERIALS and METHODS: Thirteen temporal bones from 13 subjects between 55 and 77 years of age were analyzed. The organ of corti was analyzed to identify the loss of hair cells, and the number of SGNs in each cochlear segment were counted. The results of the speech perception test (SPT) and pure tone audiometry (PTA) tests were collected. PTA averages for low and high frequencies were calculated. One-way analysis of variance (ANOVA), Pearson, Spearman, and multilinear regression tests were performed. RESULTS: No statistically significant correlation was identified between the patient’s age and number of SGNs. Statistically significant differences were observed between the number of SGNs in the different cochlear segments (one-way ANOVA: p<0.0001) and between poor PTA average and SPT scores (negative correlation) (p=0.03). A statistically significant correlation was identified between the overall number of cochlear SGNs and SPT scores (p=0.02) and between the number of SGNs in cochlear segments I (p=0.04) and II and the SPT score (p=0.03). CONCLUSIONS: We identified that residual SGNs in the basal and middle turns of the cochlea might be determinants of speech perception
Gold oxide films grown in the confined aqueous layer between gold and organic solvents
The properties of anodic passive films potentiostatically formed on polycrystalline gold in aqueous phosphate solutions were studied using voltammetry, electrochemical impedance spectroscopy, and contact angle measurements. The nature of the gold oxide layer was analyzed as a function of a potential holding in the aqueous double layer charge region at the interface between gold and the aqueous layer confined by insoluble organic solvents (hexane, chloroform, anisole, butyl acetate, xylene, and isopropyl ether). Different growth conditions change the homogeneity of the oxide layer leading to different passive properties. A synergetic effect on the gold oxidation of hydrogen dissolved in both the bulk metal and the confined aqueous layer is discussed.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasInstituto de Física de Líquidos y Sistemas Biológico
Rare occult macular dystrophy with a pathogenic variant in the RP1L1 gene in a patient of Swiss descent
Purpose: We report a first case of bilateral occult macular dystrophy (OMD) with a c.133C>T (p.Arg45Trp) pathogenic variant in the retinitis pigmentosa 1-like 1 (RP1L1) gene in a patient of Caucasian Swiss decent. Observations: A 34-year-old man presented with decreased visual acuity known since childhood. Fundus examination of both eyes revealed no pathology other than mildly increased granularity of the foveal retinal pigment epithelium. The full-field electroretinogram (ffERG) presented with normal findings while the multifocal electroretinogram (mfERG) showed severely reduced amplitudes of the foveal response. Optical coherence tomography (OCT) showed foveal outer retinal atrophy. Fundus autofluorescence (FAF) imaging demonstrated near-normal findings with minimal mottling at the posterior pole. The genetic analysis revealed a heterozygous pathogenic variant (c.133C>T, p.Arg45Trp) in the RP1L1 gene. Conclusion and importance: Our present case suggests that OMD shows a wide range of clinical presentations with a variety of ophthalmological findings, age of disease onset, visual acuity, and genetic diversity
Reply Brief for the Petitioner, \u3cem\u3eTVA v. Hill\u3c/em\u3e, No. 76-1701
Reply brief for the petitioner in the case of Tennessee Valley Authority v. Hiram G. Hill Jr., et al., heard by the United States Supreme Court in the October Term of 1977
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