Nastajanje i karakterizacija bistiourea cinkovoga formata

Formation of a new complex in the Zn(HCOO)2-CS(NH2)2-H2O system at 25 °C was established by the solubility method. Its composition was determined to be Zn(HCOO)2 * 2CS(NH2)2. The bisthiourea zinc formate (BTZF) is an incongruently soluble salt at 25 °C. It has been characterized by X-ray powder diffraction, IR spectroscopy and thermal analysis. The infrared spectra reveal that thiourea forms a zinc-sulfur bond. Thermal decomposition at a temperature of 400 °C yields ZnS.Ustanovljeno je da metodom topljivosti u sustavu Zn(HCOO)2-CS(NH2)2-H2O pri 25 °C nastaje novi kompleksnispoj. Određivanje sastava pokazalo je da se radi o Zn(HCOO)2 * 2CS(NH2)2. Pri 25 °C bistiourea cinkov format (BTZF) neprimjereno je topljiva sol. Spoj je opisan rentgenskom difrakcijom na prahu, IR spektroskopijom i termičkom analizom. U infracrvenom spektru otkrivena je vrpca koja odgovara vezi cink-sumpor. Termički raspad spoja završava kod temperature 400 °C pri čemu zaostaje cinkov sulfid

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Silk Fibroin/Calcium Phosphate Silicate Composites: In vitro Bioactivity

Abstract Co mposite materials of Silk Fib roin (SF) and Calciu m Phosphate Silicate (CPS) ceramic in the 15CaO-6SiO 2 -0.5P 2 O 5 system were prepared by method of mixing d ifferent percentage of component weight. The structure was characterized before and after in vitro test by FTIR, SEM. The concentration of Ca, Si and P after in vit ro test was analysed by ICP-A ES. FTIR of the composites before in vitro test depicts that random coil and β-sheet structures co-exist in the co mposites. CPS ceramic has a significant effect on the secondary structure of SF. SEM observed that CPS particles uniformly dispersed in SF matrix. FTIR of the composites after in vitro test revealed that carbonate containing hydroxyapatite (CO 3 HA) was formed on the surface. B-type CO 3 HA preferentially formed in the samp le with 75 wt. % CPS ceramic. SEM proved that hydroxyapatite (HA) fo rmed in a high level. ICP-A ES showed that HA precipitation were similar fo r the three composites. Based of these results, it can be concluded that the incorporation of CPS ceramic powder enhanced the in vitro bioactivity