Reaction of Amino-Terminated PAMAM Dendrimers with Carbon Dioxide in Aqueous and Methanol Solutions

Polyamines have been used as active materials to capture carbon dioxide gas based on its well-known reaction with amines to form carbamates. This work investigates the reactions between three amino-terminated poly(amidoamine) (PAMAM) dendrimers (G1, G3 and G5) and CO2(g) in aqueous (D2O) and methanolic (CD3OD) solutions. The reactions were monitored using 1H NMR spectroscopy, and yielded dendrimers with a combination of terminal carbamate and terminal ammonium groups. In aqueous media the reaction was complicated by the generation of soluble carbonate and bicarbonate ions. The reaction was cleaner in CD3OD, where the larger G5 dendrimer solution formed a gel upon exposure to CO2(g). All reactions were reversible, and the trapped CO2 could be released by treatment with N2(g) and mild heating. These results highlight the importance of the polyamine dendrimer size in terms of driving changes to the solution’s physical properties (viscosity, gel formation) generated by exposure to CO2(g).

Ti2O3/TiO2-Assisted Solar Photocatalytic Degradation of 4-tert-Butylphenol in Water

Colored Ti2O3 and Ti2O3/TiO2 (mTiO) catalysts were prepared by the thermal treatment method. The effects of treatment temperature on the structure, surface area, morphology and optical properties of the as-prepared samples were investigated by XRD, BET, SEM, TEM, Raman and UV–VIS spectroscopies. Phase transformation from Ti2O3 to TiO2 rutile and TiO2 anatase to TiO2 rutile increased with increasing treatment temperatures. The photocatalytic activities of thermally treated Ti2O3 and mTiO were evaluated in the photodegradation of 4-tert-butylphenol (4-t-BP) under solar light irradiation. mTiO heated at 650 °C exhibited the highest photocatalytic activity for the degradation and mineralization of 4-t-BP, being approximately 89.8% and 52.4%, respectively, after 150 min of irradiation. The effects of various water constituents, including anions (CO32−, NO3, Cl and HCO3−) and humic acid (HA), on the photocatalytic activity of mTiO-650 were evaluated. The results showed that the presence of carbonate and nitrate ions inhibited 4-t-BP photodegradation, while chloride and bicarbonate ions enhanced the photodegradation of 4-t-BP. As for HA, its effect on the degradation of 4-t-BP was dependent on the concentration. A low concentration of HA (1 mg/L) promoted the degradation of 4-t-BP from 89.8% to 92.4% by mTiO-650, but higher concentrations of HA (5 mg/L and 10 mg/L) had a negative effect.

The effects of bathing in neutral bicarbonate ion water

Percutaneously absorbed carbon dioxide enhances blood flow. The mechanism by which it does so is unclear, but we hypothesized that it involves bicarbonate ions. BALB/c mice were bathed in neutral bicarbonate ionized water (NBIW) and showed increased blood bicarbonate levels and blood flow via phosphorylation of peripheral vascular endothelial nitric oxide synthase (eNOS) and production of nitric oxide (NO). Phosphorylation of eNOS and NO production were also increased in human umbilical vein endothelial cells cultured in medium containing NBIW, and NBIW showed reactive oxygen species scavenging activity. In a double-blind, randomized study in men and women aged 30 to 59 years with subjective cold intolerance, bathing in NBIW elevated body temperature faster than bathing in a control solution and improved chills and sleep quality. Taken together, our results show that percutaneously absorbed carbon dioxide changes to bicarbonate ions, which act directly on endothelial cells to increase NO production by phosphorylation of eNOS and thus improve blood flow.

Green technologies for air pollution treatment by microalgae in tubular photobioreactor

Air pollution in general and motorcycle exhaust, in particular, is a big problem attracting a lot of attention from people and researchers worldwide because of the significant impacts it has on humans and the environment. The issue of air pollution is growing, and the impact is more evident than ever. Carbon dioxide represents a series of problems that we face daily but have not yet been effectively solved. Currently, microalgae are known to photosynthesize and use free CO2, bicarbonate ions as a source of nutrients to grow. Microalgae are developed under appropriate environmental conditions, which will bring admirable CO2 treatment efficiency and obtain biomass for other applications. The study approach was an inexpensive and natural air purification solution by microalgae, which is designed as a tubular photobioreactor. The study was conducted by evaluating the ability of Chlorella Vulgaris to grow and absorb CO2 emissions in the newly established system with exhaust gas supplied from a mini motorcycle engine. The results showed that microalgae grew stably in the tubular photobioreactor system with a biomass concentration of 6×106 cells/ml after 42 days of the experiment. Simultaneously with the stable growth of microalgae, the CO2 emission concentration was reduced with 26.59% absorption efficiency after 11 days of the experiment. Finally, establishing the tubular photobioreactor technology system has yielded impressive initial results in cultivating stable growing microalgae combined with CO2 emission treatment.

Prevalence and risk factors of human Balantidium coli infection and its association with haematological and biochemical parameters in Ga West Municipality, Ghana

Background In Ghana, Balantidium coli (B. coli) has been identified in vegetables and in pigs, although there is a paucity of data regarding human balantidiosis. This study sought to assess human B. coli infection in Ghana, factors associated with the infection as well as its association with haematological and biochemical parameters. Methods Two pig rearing communities in the Ga West Municipality, Ghana, were involved in this study. Stool and blood samples were collected from pig farmers and their exposed household members as well as relevant information on potential associated factors. Eosin-saline wet preparation was done on the same day of stool samples were collected while formol ether concentration technique was performed later. Haematological, biochemical parameters and serum electrolytes were determined using Celltac MEK-6500 K, PKL-125 biochemical analyser, and FT-320 electrolyte analyser, respectively. Results The overall prevalence of balantidiosis was 10.4 %, significantly higher among farmers (21.7 %) than in exposed household members (5.8 %) (x2 = 17.8, p = 0.000025). Of the 43 infected individuals, 20.9 % were co-infected with either Entamoeba histolytica, Giardia lamblia, or Schistosoma mansoni. In B. coli infection, mild to moderate anaemia together with a reduction in levels of platelet, albumin and, sodium, chloride, and bicarbonate ions were observed. However, white blood cells were significantly elevated in infected states. Poor farming practices such as free-range systems, improper disposal of pig faeces, lack of use of protective farming clothing, and unavailability of dedicated farming clothing were found to be associated with B. coli infection status. Finally, frequent diarrhea (OR = 12.30, p = 0.006) with occult blood (OR = 25.94, p < 0.0001) were found to be predictors of B. coli infection. Conclusions Human balantidiosis is endemic in Ga West Municipality, Ghana. Individuals living closed to pig rearing communities presenting with frequent diarrhea with occult blood in stool should be screened and treated for balantidiosis to mitigate the clinical consequences of the infection.

Global Carbon Dioxide Removal Potential of Waste Materials From Metal and Diamond Mining

There is growing urgency for CO2 removal strategies to slow the increase of, and potentially lower, atmospheric CO2 concentrations. Enhanced weathering, whereby the natural reactions between CO2 and silicate minerals that produce dissolved bicarbonate ions are accelerated, has the potential to remove substantial CO2 on decadal to centennial timescales. The global mining industry produces huge volumes of fine wastes that could be utilised as feedstock for enhanced weathering. We have compiled a global database of the enhanced weathering potential of mined metal and diamond commodity tailings from silicate-hosted deposits. Our data indicate that all deposit types, notably mafic and ultramafic rock-hosted operations and high tonnage Cu-hosting deposits, have the potential to capture ~1.1–4.5 Gt CO2 annually, between 31 and 125% of the industry's primary emissions. However, current knowledge suggests that dissolution rates of many minerals are relatively slow, such that only a fraction (~3–21%) of this potential may be realised on timescales of &lt;50 years. Field trials in mine settings are urgently needed and, if this prediction is confirmed, then methodologies for accelerating weathering reactions will need to be developed.

Groundwater chemistry: a case study of the Mesta River Basin

The present study describes the hydrochemistry of ground waters found in the Mesta River Basin, located in the south-western part of Bulgaria. The groundwater’s composition can be expressed as follows: Ca2+ > Na+ > Mg2+ > K+; Ca2+ > Mg2+ > Na+ > K+ in equivalent units for the cations, and HCO3– > SO42– > Cl– in equivalent units for the anions. The chemical composition of the studied groundwater can be described as calcium-bicarbonate. The calcium ions make up from 17.90% to 38.62% (30.18% on average), and the bicarbonate ions make up from 35.30% to 48.98% (43.70% on average) of all ions. Taken together, the calcium and bicarbonate ions make up from 61.44% to 87.60% (73.88% on average) of all ions. The groundwater itself is of slightly alkaline nature, having pH of 7.3 to 8.6, and TDS of 67 mg/l to 611 mg/l. One groundwater sample from the Mesta River catchment area was found to be of the low-mineralized type (TDS = 193 mg/l) alkaline water (pH = 9.8) in the Mesta Lowlands – the Banichan groundwater mineral source. The water can be described as sodium-bicarbonate, with sodium ions making up to 93.5% of the cations, and bicarbonate ions – 69.6% of the anions. Out of all ions, the sodium ions were found to be 48%, and the bicarbonate ions – 33.86%. The sequence of ions is in the following order: Na+ > Ca2+ > Mg2+ > K+, and HCO3– > Cl– > SO42– > CO32–.

New insights into the allosteric effects of CO2 and bicarbonate on crocodilian hemoglobin

Crocodilians are unique among vertebrates in that their hemoglobin (Hb) O2 binding is allosterically regulated by bicarbonate, which forms in the red blood cell upon hydration of CO2. Although known for decades, this remarkable mode of allosteric control has not yet been experimentally verified with direct evidence of bicarbonate binding to crocodilian Hb, probably because of confounding CO2-mediated effects. Here we provide the first quantitative analysis of the separate allosteric effects of CO2 and bicarbonate on purified Hb of the spectacled caiman (Caiman crocodilus). Using thin-layer gas diffusion chamber and Tucker chamber techniques, we demonstrate that both CO2 and bicarbonate bind to Hb with high affinity and strongly decrease Hb-O2 saturation. We propose that both effectors bind to an unidentified positively charged site containing a reactive amino group in the low-O2 affinity T conformation of the Hb. These results provide the first experimental evidence that bicarbonate binds directly to crocodilian Hb and promotes O2 delivery independently of CO2. Using the gas-diffusion chamber, we observed similar effects in Hbs of a phylogenetically diverse set of other caiman, alligator, and crocodile species, suggesting that the unique mode of allosteric regulation by CO2 and bicarbonate evolved &gt;80-100 million years ago in the common ancestor of crocodilians.Our results show a tight and unusual linkage between O2 and CO2 transport in the blood of crocodilians, where build-up of erytrocytic CO2 and bicarbonate ions during breath-hold diving or digestion facilitates O2 delivery, while Hb desaturation facilitates CO2 transport as protein-bound CO2 and bicarbonate.

Cystic Fibrosis Human Organs-on-a-Chip

Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane regulator (CFTR) gene: the gene product responsible for transporting chloride and bicarbonate ions through the apical membrane of most epithelial cells. Major clinical features of CF include respiratory failure, pancreatic exocrine insufficiency, and intestinal disease. Many CF animal models have been generated, but some models fail to fully capture the phenotypic manifestations of human CF disease. Other models that better capture the key characteristics of the human CF phenotype are cost prohibitive or require special care to maintain. Important differences have been reported between the pathophysiology seen in human CF patients and in animal models. These limitations present significant limitations to translational research. This review outlines the study of CF using patient-derived organs-on-a-chip to overcome some of these limitations. Recently developed microfluidic-based organs-on-a-chip provide a human experimental model that allows researchers to manipulate environmental factors and mimic in vivo conditions. These chips may be scaled to support pharmaceutical studies and may also be used to study organ systems and human disease. The use of these chips in CF discovery science enables researchers to avoid the barriers inherent in animal models and promote the advancement of personalized medicine.