Changes in air quality in Mexico City, London and Delhi in response to various stages and levels of lockdowns and easing of restrictions during COVID-19 pandemic.

The impacts of COVID-19 lockdown restrictions have provided a valuable global experiment into the extent of improvements in air quality possible with reductions in vehicle movements. Mexico City, London and Delhi all share the problem of air quality failing WHO guideline limits, each with unique situations and influencing factors. We determine, discuss and compare the air quality changes across these cities during the COVID-19, to understand how the findings may support future improvements in their air quality and associated health of citizens. We analysed ground-level PM10, PM2.5, NO2, O3 and CO changes in each city for the period 1st January to August 31, 2020 under different phases of lockdown, with respect to daily average concentrations over the same period for 2017 to 2019. We found major reductions in PM10, PM2.5, NO2 and CO across the three cities for the lockdown phases and increases in O3 in London and Mexico City but not Delhi. The differences were due to the O3 production criteria across the cities, for Delhi production depends on the VOC-limited photochemical regime. Levels of reductions were commensurate with the degree of lockdown. In Mexico City, the greatest reduction in measured concentration was in CO in the initial lockdown phase (40%), in London the greatest decrease was for NO2 in the later part of the lockdown (49%), and in Delhi the greatest decrease was in PM10, and PM2.5 in the initial lockdown phase (61% and 50%, respectively). Reduction in pollutant concentrations agreed with reductions in vehicle movements. In the initial lockdown phase vehicle movements reduced by up to 59% in Mexico City and 63% in London. The cities demonstrated a range of air quality changes in their differing geographical areas and land use types. Local meteorology and pollution events, such as forest fires, also impacted the results.

Photoprotective activity of Buddleja scordioides.

The purpose of this study was to determine the photoprotective properties of the methanolic extract of Buddleja scordioides, as well as verbascoside and linarin which were isolated from this extract, and linarin acetate prepared in the laboratory. The photoprotective effect of substances against UV-B induced cellular death was evaluated by challenge experiments using Escherichia coli. Verbascoside and linarin acetate showed the highest protection. The sun protection factor (SPF) of the methanolic extract, linarin, linarin acetate, and verbascoside was evaluated by guinea pig bioassays. Verbascoside showed the largest SPF measurement.

Spanish validation of the Syndrom Kurztest (SKT).

There is an urgent need in multinational studies for efficient and sensitive tests for the evaluation of dementias. These tests are used to investigate the regional characteristics of dementias, providing possible insight into the different etiologies of the disorders. These tests are also utilized to assess the outcome of treatment interventions at multinational levels. We validated and standardized the Syndrom Kurztest, a brief European neuropsychological test, in a population of elderly Chileans, possessing high levels of illiteracy. In our sample, the SKT was found to be an effective instrument for the diagnosis of dementias, and for differentiating mild-moderate from severe degrees of the disease. There was a good correlation between the scores on the SKT and the age of the participants, but the gender and the years of schooling had no effect. The test is a useful contribution to the study of dementias, found in the aging developing world, particularly because it can be used in illiterate populations.

[Breast cancer in Mexico. Is it a young women disease?]. / Cáncer de mama en México. Enfermedad de mujeres jóvenes?

Breast cancer in México has the second place in frequency in general population (10.6%) as well as in females (16.4%). There has been found an increase in mortality from 3.6, in 1985, to 6 x 100,000 inhabitants, in 1994. Breast cancer diagnosis is made in advanced stages (III, IV, N.C.) in two out of three of our patients and a great proportion of them are younger than 50 years old. In order to know if age at diagnosis of breast cancer women in Mexico is similar of that of women of other countries, and in consequence, if breast screening has to be done as they have determined, we analyzed the age at diagnosis of 29,075 mexican women with breast cancer from 1993 to 1996. We found that median age of our patients was 51 years, one decade younger than that of European or white American women (60-64 years), and 45.5% of Mexican women are less than 50 years old at diagnosis of breast cancer, therefore, breast cancer screening indications adopted in Mexico, do not cover, not even theoretically, almost 50% of our women. It is mandatory to determine indications of breast screening according to our reality.

Nonradiative and radiative deactivation of singlet molecular oxygen (O2(a1deltag)) in micellar media and microemulsions.

The effects of microheterogeneous media (micelles and microemulsions) on the lifetime and, to our knowledge for the first time, on the emission of singlet molecular oxygen (O2 (a1Ag), denoted as 1O2) were investigated. Micellar media and various types of microemulsions based on anionic (sodiumdodecyl sulfate), cationic (cetyltrimethylammonium chloride) or nonionic (Triton X-100) surfactants were formulated for this purpose. The nonradiative and radiative deactivation rate constants (k(d) and k(e), respectively) were determined in selected microheterogeneous media and in the pure solvents used for their formulation, by combining steady-state and time-resolved 1O2, luminescence detection techniques. We have shown that a simple additive model, as used in homogeneous mixtures of solvents, was inadequate for predicting values of k(d) and k(e) in organized media. In contrast, both 1O2 lifetimes (taudelta = 1/k(d)) and k(e) in the microheterogeneous systems investigated could be predicted with good precision from the composition of the media and the taudelta and k(e) values in the pure solvents, using a two-pseudophase kinetic model for the 1O2 distribution. Such a model takes into account the average times spent by 1O2 in the aqueous and lipophilic pseudo-phases of the organized media, the corresponding equilibrium constant (Keq) depending on the nature of the system.

Pulse-Gradient Spin-Echo (1)H, (7)Li, and (19)F NMR Diffusion and Ionic Conductivity Measurements of 14 Organic Electrolytes Containing LiN(SO2CF3)2.

The self-diffusion coefficients of the lithium ion, the anion, and the solvent in lithium bis(trifluromethanesulfonyl)imide (LiTFSI, LiN(SO2CF3)2) solvent systems were measured using the pulse-gradient spin-echo (PGSE) NMR method. Fourteen different organic solvents that are commonly used as organic solution electrolytes in lithium batteries were studied. The self-diffusion coefficients of the corresponding pure solvents were also measured. Since a good correlation between the self-diffusion coefficients of the pure solvents and the inverse of the viscosity was obtained, the results are discussed in terms of the Stokes-Einstein equation. Comparisons of the self-diffusion coefficients of the solvent, the lithium ion, and the anion (TFSI ion) illustrate the solvation behavior for each solvent. The relationship between the ionic conductivity and the sum of the diffusion coefficients of the lithium ion and the anion gives the degree of ion-pair formation and permits the roles of the solvents in the electrolytes to be clearly explained.

The entry of reovirus into L cells is dependent on vacuolar proton-ATPase activity.

Inhibitors of vacuolar proton-ATPase activity (5 microM bafilomycin A1 or 50 nM concanamycin A) prevented infection by reovirus particles but not by infectious subviral particles (ISVPs). Neither compound affected virus attachment or internalization. However, both compounds potently blocked cleavage of the viral protein mu 1C. Finally, both reovirus particles and ISVPs efficiently translocated the toxin alpha-sarcin to the cytosol during virus entry. Bafilomycin A1 blocked translocation of alpha-sarcin by reovirus particles but not by ISVPs.