Multiple Approaches to Determine Toxicity of Micro and Nano-sized Titanium Dioxide Materials When Exposed to Human Red Blood Cells

Introduction: The utility of engineered nanomaterials’ is growing, particularly the titanium dioxide (TiO2) polymorphs. TiO2 is very useful for brightening paints, and coloring foods. Nano-sized TiO2 is also useful for sunscreens, cosmetics, and can be utilized as a photocatalyst. However, the nanometer size and the large specific surface area of the TiO2 materials are physicochemical characteristics which may contribute to human red blood cell (RBC) damage. Using RBCs as a cellular model, we have evaluated the effects of TiO2 nanoparticle exposure to RBCs by quantifying oxidized glutathione, oxidized membrane vitamin E, hemolysis, hemoglobin adsorption, and cellular aggregation. Results: Red blood cells are rich in the antioxidant glutathione (GSH). HPLC testing revealed that some TiO2 materials have the ability to cause oxidation of GSH to the oxidized form, glutathione disulfide (GSSG). Due to surface area characteristics, some TiO2 materials have the ability to adsorb protein (visualized as hemoglobin) to their surface. Additionally, some TiO2 materials microscopically form red blood cell aggregates, significantly changing the red cell morphology. The aggregation data was quantified using a hemacytometer. Red blood cell membrane vitamin E was also measured by HPLC, and after exposure to these TiO2 polymorphs, some materials caused vitamin E membrane oxidation. Some TiO2 materials have the ability, through multiple different mechanisms, to cause hemolysis of the red blood cell. Conclusions: Our results indicated that some of the TiO2 polymorphs assayed contributed to red blood cell hemolysis via different mechanisms, whereas some polymorphs did not cause cellular damage. These data indicated that red blood cells can ultimately be hemolyzed by biological oxidative damage (BOD), intracellular oxidation of GSH to GSSG, oxidation of vitamin E in the RBC membrane, material adsorption to the RBC membrane, physical contact, or by a combination of these mechanisms

Promoters, enhancers, and transcription target RAG1 binding during V(D)J recombination

RAG1 binding to TCR gene elements is dictated by transcriptional control elements and by transcription itself; these findings provide direct confirmation of the long-held accessibility model

Global, regional, and national age-sex-specific mortality for 282 causes of death in 195 countries and territories, 1980-2017: a systematic analysis for the Global Burden of Disease Study 2017.

BACKGROUND: Global development goals increasingly rely on country-specific estimates for benchmarking a nation's progress. To meet this need, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 estimated global, regional, national, and, for selected locations, subnational cause-specific mortality beginning in the year 1980. Here we report an update to that study, making use of newly available data and improved methods. GBD 2017 provides a comprehensive assessment of cause-specific mortality for 282 causes in 195 countries and territories from 1980 to 2017. METHODS: The causes of death database is composed of vital registration (VR), verbal autopsy (VA), registry, survey, police, and surveillance data. GBD 2017 added ten VA studies, 127 country-years of VR data, 502 cancer-registry country-years, and an additional surveillance country-year. Expansions of the GBD cause of death hierarchy resulted in 18 additional causes estimated for GBD 2017. Newly available data led to subnational estimates for five additional countries-Ethiopia, Iran, New Zealand, Norway, and Russia. Deaths assigned International Classification of Diseases (ICD) codes for non-specific, implausible, or intermediate causes of death were reassigned to underlying causes by redistribution algorithms that were incorporated into uncertainty estimation. We used statistical modelling tools developed for GBD, including the Cause of Death Ensemble model (CODEm), to generate cause fractions and cause-specific death rates for each location, year, age, and sex. Instead of using UN estimates as in previous versions, GBD 2017 independently estimated population size and fertility rate for all locations. Years of life lost (YLLs) were then calculated as the sum of each death multiplied by the standard life expectancy at each age. All rates reported here are age-standardised

THE TEMPERATURE AND PRESSURE DEPENDENCE OF THE NEAR INFRARED ABSORPTION BANDS OF LIQUID WATER

Near infrared absorption spectra have been obtained as a function of temperature and pressure for the 1.0, 1.2, 1.4, and 1.9 micron bands of water and the OH overtone region (1.4 micron region) for dilute solutions of HDO in D(,2)O. Also, near infrared spectra have been obtained for the 1.4 and 1.9 micron bands of highly supercooled water and the OH overtone region of supercooled HDO in D(,2)O solutions. The results suggest that application of pressures up to 2000 bars does not alter the water structure enough to result in the breaking of hydrogen bonds but does cause a bending of the bonds. This assumption is supported from estimates of the hydrogen bond energy, (DELTA)H, which decreases from 2.50 kcal/mol H-bonds at 1 atmosphere to 2.02 kcal/mol of H-bonds at 2 kbars. These results are in agreement with the findings from Ramon studies and, when coupled with the observed thermodynamic and transport properties of water, lend support to a two-state random network model for the structure of liquid water

Complementary Nutrients in Decoupled Aquaponics Enhance Basil Performance

Aquaponics combines raising fish and growing plants by recycling water and nutrients to reduce water consumption and reliance on chemical fertilizers. Coupled aquaponics systems recirculate water between fish and plant crops, whereas decoupled systems send mineralized fish effluent and wastewater unidirectionally to an independent hydroponic loop. Decoupling enables changes to the water, such as pH adjustments and complementary nutrient additions, to promote plant performance. In this study, basil, Ocimum basilicum (L.), was transplanted into 4 L containers filled with decoupled aquaponic (DAP), nutrient-complemented decoupled aquaponic (DAP+), or chemical-based conventional hydroponic (CON) nutrient solutions and grown for 21 days at pH 5.8. Plants grown in DAP+ and CON had greater biomass, height, and Soil Plant Analysis Development (SPAD) chlorophyll index and lower root:shoot biomass ratios than those in DAP. Shoot fresh and dry biomass was 11% greater for CON than DAP+, while height, SPAD chlorophyll index, and root:shoot ratio did not differ. We concluded that added nutrients in DAP+ enhanced performance compared to DAP, and the biologically derived nutrition in DAP+ enhanced performance to be similar, but not equal, to CON. We cannot recommend specific adjustments to the targeted blend of complementary nutrients tested, but findings suggest that complementary nutrients are effective in decoupled aquaponics