“…Sodalite consists of alternating TO 4 corner-sharing tetrahedra (where T is usually Si or Al) forming four and six ring cages, which make up the so-called β-cage or a sodalite cage. In the Cl-bearing sodalite, these cages are 6.5 Å in diameter and are accessible through 2.6 Å-wide six-membered rings that form continuous channels for diffusion of intraframework ions. − The six-membered ring is occupied by four cations tetrahedrally associated with an anion (e.g., Cl – ) at the center of the cage. With the exception of hydroxide, anions are irreversibly trapped within the cages, and once cages have formed it becomes difficult to replace anions without destroying the cage …”
Nuclear waste storage tanks at the Hanford site in southeastern Washington have released highly alkaline solutions, containing radioactive and other contaminants, into subsurface sediments. When this waste reacts with subsurface sediments, feldspathoid minerals (sodalite, cancrinite) can form, sequestering pertechnetate ( 99 TcO 4 − ) and other ions. This study investigates the potential for incorporation of perrhenate (ReO 4 − ), a chemical surrogate for 99 TcO 4 − , into mixed perrhenate/nitrate (ReO 4 − /NO 3 − ) sodalite.Mixed-anion sodalites were hydrothermally synthesized in the laboratory from zeolite A in sodium hydroxide, nitrate, and perrhenate solutions at 90°C for 24 h. The resulting solids were characterized by bulk chemical analysis, X-ray diffraction, scanning electron microscopy, and X-ray absorption near edge structure spectroscopy (XANES) to determine the products' chemical composition, structure, morphology, and Re oxidation state. The XANES data indicated that nearly all rhenium (Re) was incorporated as Re(VII)O 4 − . The nonlinear increase of the unit cell parameter with ReO 4 − /NO 3 − ratios suggests formation of two separate sodalite phases in lieu of a mixed-anion sodalite. The results reveal that the sodalite cage is highly selective toward NO 3 − over ReO 4 − . Calculated enthalpy and Gibbs free energy of formation at 298 K for NO 3 -and ReO 4 -sodalite suggest that NO 3 − incorporation into the cage is favored over the incorporation of the larger ReO 4 − , due to the smaller ionic radius of NO 3 − . Based on these results, it is expected that NO 3 − , which is present at significantly higher concentrations in alkaline waste solutions than 99 TcO 4 − , will be strongly preferred for incorporation into the sodalite cage.
■ INTRODUCTIONTechnetium-99 presents a major environmental concern due to its long half-life (211 000 years) and high mobility of pertechnetate (TcO 4 − ), the dominant ionic species in oxidized subsurface systems. 1 At the U.S. Department of Energy's Hanford site, approximately 1900 kg of 99 Tc was generated and stored underground in 177 tanks, which contain an estimated 65 million gallons of nuclear waste from the production of plutonium during the Cold War era. 2 Seventy-seven of these tanks have leaked high-level radioactive waste (HLW) into the vadose zone (the unsaturated region between the ground surface and the top of the water table), which extends 50−70 m below the storage tanks. 2 In addition 99 Tc was also released to the subsurface via cribs and trenches, which received in excess of 50 million gallons of reprocessed tank waste. Due to weak adsorption of TcO 4 − to the predominantly negatively charged, oxic sediments prevalent at the Hanford site, 99 Tc migration into the vadose zone pore water and groundwater is expected to be largely unimpeded. 3 The Hanford tank waste solutions are alkaline (free OH − is from 0.1 to 5.3 M, Na + from 2.9 to 19.6 M, and NO 3 − from 0.5 to 5.5 M), high in ionic strength (I = 2−14 M), and supersaturated with an Al(OH) 3 phase....
“…Sodalite consists of alternating TO 4 corner-sharing tetrahedra (where T is usually Si or Al) forming four and six ring cages, which make up the so-called β-cage or a sodalite cage. In the Cl-bearing sodalite, these cages are 6.5 Å in diameter and are accessible through 2.6 Å-wide six-membered rings that form continuous channels for diffusion of intraframework ions. − The six-membered ring is occupied by four cations tetrahedrally associated with an anion (e.g., Cl – ) at the center of the cage. With the exception of hydroxide, anions are irreversibly trapped within the cages, and once cages have formed it becomes difficult to replace anions without destroying the cage …”
Nuclear waste storage tanks at the Hanford site in southeastern Washington have released highly alkaline solutions, containing radioactive and other contaminants, into subsurface sediments. When this waste reacts with subsurface sediments, feldspathoid minerals (sodalite, cancrinite) can form, sequestering pertechnetate ( 99 TcO 4 − ) and other ions. This study investigates the potential for incorporation of perrhenate (ReO 4 − ), a chemical surrogate for 99 TcO 4 − , into mixed perrhenate/nitrate (ReO 4 − /NO 3 − ) sodalite.Mixed-anion sodalites were hydrothermally synthesized in the laboratory from zeolite A in sodium hydroxide, nitrate, and perrhenate solutions at 90°C for 24 h. The resulting solids were characterized by bulk chemical analysis, X-ray diffraction, scanning electron microscopy, and X-ray absorption near edge structure spectroscopy (XANES) to determine the products' chemical composition, structure, morphology, and Re oxidation state. The XANES data indicated that nearly all rhenium (Re) was incorporated as Re(VII)O 4 − . The nonlinear increase of the unit cell parameter with ReO 4 − /NO 3 − ratios suggests formation of two separate sodalite phases in lieu of a mixed-anion sodalite. The results reveal that the sodalite cage is highly selective toward NO 3 − over ReO 4 − . Calculated enthalpy and Gibbs free energy of formation at 298 K for NO 3 -and ReO 4 -sodalite suggest that NO 3 − incorporation into the cage is favored over the incorporation of the larger ReO 4 − , due to the smaller ionic radius of NO 3 − . Based on these results, it is expected that NO 3 − , which is present at significantly higher concentrations in alkaline waste solutions than 99 TcO 4 − , will be strongly preferred for incorporation into the sodalite cage.
■ INTRODUCTIONTechnetium-99 presents a major environmental concern due to its long half-life (211 000 years) and high mobility of pertechnetate (TcO 4 − ), the dominant ionic species in oxidized subsurface systems. 1 At the U.S. Department of Energy's Hanford site, approximately 1900 kg of 99 Tc was generated and stored underground in 177 tanks, which contain an estimated 65 million gallons of nuclear waste from the production of plutonium during the Cold War era. 2 Seventy-seven of these tanks have leaked high-level radioactive waste (HLW) into the vadose zone (the unsaturated region between the ground surface and the top of the water table), which extends 50−70 m below the storage tanks. 2 In addition 99 Tc was also released to the subsurface via cribs and trenches, which received in excess of 50 million gallons of reprocessed tank waste. Due to weak adsorption of TcO 4 − to the predominantly negatively charged, oxic sediments prevalent at the Hanford site, 99 Tc migration into the vadose zone pore water and groundwater is expected to be largely unimpeded. 3 The Hanford tank waste solutions are alkaline (free OH − is from 0.1 to 5.3 M, Na + from 2.9 to 19.6 M, and NO 3 − from 0.5 to 5.5 M), high in ionic strength (I = 2−14 M), and supersaturated with an Al(OH) 3 phase....
“…5 ) [ 29 ]. ROS activation triggers the process of myofibroblast formation, which affects the synthesis of collagen central to the repair of injured tissues [ 30 ]. In addition, myofibroblast ROS will also stimulate a pro-inflammatory response in tissue repair.…”
Section: Discussionmentioning
confidence: 99%
“… Fig. 5 Suggested pathway: HBOT's bactericidal role in burn injuries and its relationship with ROS [ [29] , [30] , [31] , [32] , [33] ]. …”
Section: Discussionmentioning
confidence: 99%
“…Another possible mechanism underlying HBOT's efficacy is antimicrobial by triggering the formation of ROS. ROS are reactive radicals that includes, superoxidation anions (O2--), peroxides (O2-2), hydrogen peroxide (H2O2), hydroxyl radicals (OH'), and hydroxyl ions (OH--) [ 30 ].…”
Introduction
Burn injuries are frequently encountered in emergency cases and often become the port of entry for pathogens. More than 450,000 burn injuries occur annually causing nearly 3,400 deaths in the United States. The prevalence of burn injury in Indonesia is 0.7% in 2013. More than half of these According to several studies on the use of patients were treated for bacterial infections, some of which were resistant to certain antibiotics. Using hyperbaric oxygen therapy (HBOT) to treat burns has several positive effects including managing bacterial infections, as well as accelerating the wound healing process. Therefore, this study aims to prove the effectiveness of HBOT in inhibiting bacterial growth.
Methods
This is an experimental research study in rabbits using a post-test control group design. 38 rabbits were given second-degree burns on the shoulder region with a metal iron plate that has been previously heated for 3 min. Bacterial cultures were taken on days 5 and 10 after exposure to the burns. The samples were divided into two groups, HBOT and control. Statistical analyses were performed using the Mann-Whitney U method.
Results
Gram-negative bacteria were the most frequently found pathogen in both groups
. Citrobacter freundi
was the most common Gram-negative bacteria (34%) found in the culture results of both groups.
In contrast to the control group, there was no bacterial growth found in the HBOT group's culture results, (0%) vs (58%). A significant reduction of bacterial growth was observed in the HBOT group (69%) compared with the control group (5%). Bacterial levels stagnated in 6 rabbits (31%) in the HBOT group and 7 rabbits (37%) in the control group. Overall, there was significantly less bacterial growth in the HBOT treatment group compared with the control group (p < 0.001).
Conclusion
HBOT administration can significantly reduce bacterial growth in burn injuries.
“…In an infectious event, the pro-inflammatory response of TNF-α increases rapidly that triggers other pro-inflammatory markers such as IL-6 and IL-8. 30 As the levels of IL-6 and IL-8 elevate and peak, the anti-inflammatory markers such as IL-10 begin to elevate to help the body in immuno-suppression. 31 As seen from Figure 3(a-e), the SWEATSENSER can reliably report the relative temporal levels of cytokine markers during various stages of inflammatory response, thus being suitable for dynamic profiling in the event of an infection.…”
Section: Evaluation Of Sweatsenser Analytical Performance Metricsmentioning
This work presents the viability of passive eccrine sweat as a functional biofluid toward tracking the human body's inflammatory response. Cytokines are biomarkers that orchestrate the manifestation and progression of an infection/inflammatory event. Hence, noninvasive, real-time monitoring of cytokines can be pivotal in assessing the progression of infection/inflammatory event, which may be feasible through monitoring of host immune markers in eccrine sweat. This work is the first experimental proof demonstrating the ability to detect inflammation/infection such as fever, FLU directly from passively expressed sweat in human subjects using a wearable "SWEATSENSER" device. The developed SWEATSENSER device demonstrates stable, real-time monitoring of inflammatory cytokines in passive sweat. An accuracy of >90% and specificity >95% was achieved using SWEATSENSER for a panel of cytokines (interleukin-6, interleukin-8, interleukin-10, and tumor necrosis factor-α) over an analytical range of 0.2-200 pg mL −1 . The SWEATSENSER demonstrated a correlation of Pearson's r > 0.98 for the study biomarkers in a cohort of 26 subjects when correlated with standard reference method. Comparable IL-8 levels (2-15 pg mL −1 ) between systemic circulation (serum) and eccrine sweat through clinical studies in a cohort of 15 subjects, and the ability to distinguish healthy and sick (infection) cohort using inflammatory cytokines in sweat provides pioneering evidence of the SWEATSENSER technology for noninvasive tracking of host immune response biomarkers. Such a wearable device can offer significant strides in improving prognosis and provide personalized therapeutic treatment for several inflammatory/infectious diseases.
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