Apexification with Calcium Hydroxide vs. Revascularization.
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ABSTRACT:
SUBMITTER: Boufdil H
PROVIDER: S-EPMC7275243 | biostudies-literature | 2020
REPOSITORIES: biostudies-literature
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Project description:The development of inexpensive and environmentally friendly graphene-like carbon is critical for its integration into industrial products. This work highlights the production of graphene-like carbon structures from calcium hydroxide. The chemical vapor deposition conditions to grow graphitic carbon on a calcium hydroxide catalyst are reported. Acetylene, steam, and calcium hydroxide are used to grow a crumpled carbon morphology. The crumpled carbon resulted in a high surface area of 1276 m2/g and high electrical conductivity (>105 S/m). Additionally, the significance and origin of the C 1s X-ray photoelectron spectroscopy (XPS) π-π* plasmon loss peak as it is related to high electrical conductivity is reported. A unique mechanism for the catalytic process involving calcium acetylide is proposed. Several deposition times, steam concentration, and catalyst morphology were tested to synthesize a variety of carbon morphologies from calcium-based materials. Crumpled carbon, hollow nanospheres, bamboo-like carbon nanotubes, multi-walled carbon nanotubes, and graphene fiber morphologies were all formed using calcium-based catalysts. Multiple reaction conditions, a scaled reaction (300 g), and catalyst recyclability were investigated. Calcium-based materials were then used as catalysts for the growth of other graphene-like carbons.
| S-EPMC8613825 | biostudies-literature
Project description:ImportanceThe optimal conduits for coronary artery bypass grafting (CABG) remain controversial in multivessel coronary artery disease.ObjectiveTo compare the long-term clinical outcomes of total arterial revascularization (TAR) vs non-TAR (CABG with at least 1 arterial and 1 saphenous vein graft) in a multicenter population-based study.Design, setting, and participantsThis multicenter population-based cohort study using propensity score matching took place from October 2008 to March 2017 in Ontario, Canada, with a mean and maximum follow-up of 4.6 and 9.0 years, respectively. Individuals with primary isolated CABG were identified, with at least 1 arterial graft. Exclusion criteria were individuals from out of province and younger than 18 years. Patients undergoing a cardiac reoperation or those in cardiogenic shock were also excluded because these conditions would potentially bias the surgeon toward not performing TAR. Analysis began April 2019.ExposuresTotal arterial revascularization.Main outcomes and measuresPrimary outcome was time to first event of a composite of death, myocardial infarction, stroke, or repeated revascularization (major adverse cardiac and cerebrovascular events). Secondary outcomes included the individual components of the primary outcome.ResultsOf 49 404 individuals with primary isolated CABG, 2433 (4.9%) received TAR, with the total number of bypasses being 2, 3, and 4 or more vessels in 1521 (62.5%), 865 (35.6%), and 47 individuals (1.9%), respectively. The mean (SD) age was 61.2 (10.4) years and 1983 (81.5%) were men. After propensity score matching, 2132 patient pairs were formed, with equal total number of bypasses (mean [SD], 2.4 [0.5]) but with more arterial grafts in the TAR group (mean [SD], 2.4 [0.5] vs 1.2 [0.4]; P < .01). In-hospital death (15 [0.7%] vs 21 [1.0%]; P = .32) did not differ between TAR vs non-TAR groups after propensity score matching. Throughout 8 years, TAR was associated with improved freedom from major adverse cardiac and cerebrovascular events (hazard ratio, 0.78; 95% CI, 0.68-0.89), death (hazard ratio, 0.80; 95% CI, 0.66-0.97), and myocardial infarction (hazard ratio, 0.69; 95% CI, 0.51-0.92). There was no difference in stroke and repeated revascularization.Conclusions and relevanceTotal arterial revascularization was associated with improved long-term freedom from major adverse cardiac and cerebrovascular events, death, and myocardial infarction and may be the procedure of choice for patients with reasonable life expectancy requiring CABG.
| S-EPMC7042852 | biostudies-literature
Project description:Slaked lime (calcium hydroxide) is a commonly used disinfectant for fecal sludge. Although viruses are inactivated by lime treatment, whether RNA viruses adapt to lime treatment has not yet been determined. Here, we show that murine norovirus developed higher tolerance during serial passages with lime treatment. We compared synonymous and non-synonymous nucleotide diversities of the three open reading frames of viral genome and revealed that virus populations were subjected to enhanced purifying selection over the course of serial passages with lime treatment. Virus adaptation to lime treatment was coincident with amino acid substitution of lysine to arginine at position 345 (K345R) on the major capsid protein VP1, which accounted for more than 90% of the population. The infectious clones with the K345R produced using a plasmid-based reverse genetics system exhibited greater tolerance in a lime solution, which indicated that the specific amino acid substitution was solely involved in the viral tolerance in lime treatment.
| S-EPMC9009222 | biostudies-literature
Project description:The keynote COURAGE and BARI-2D trials changed the way the interventional community selects patients for revascularization. What we now consider appropriate, especially for percutaneous coronary intervention, has narrowed significantly in scope compared to previous practice a decade ago. Medical therapy has been shown to be both safe and effective as a primary treatment modality for patients with stable ischemic heart disease on the whole. However, it appears that patients with a heavy ischemic burden may benefit from revascularization, although investigation of this is ongoing. Evidence preliminarily supports this practice with coronary artery bypass grafting, and possibly in specific populations undergoing multivessel intervention with functional assessment of lesion severity during PCI.
| S-EPMC5774643 | biostudies-literature
Project description:Importance:The Carotid Revascularization Endarterectomy vs Stenting Trial (CREST) showed greater safety of carotid artery stenting (CAS) in patients younger than 70 years and carotid endarterectomy (CEA) in those older than 70 years. It is unknown how the result of CREST has influenced carotid revascularization choices in the United States. Objective:To evaluate national patterns in CAS performance in patients older than 70 years in the post-CREST (2011-2014) compared with the pre-CREST (2007-2010) era. Design, Setting, and Participants:All adults older than 70 years undergoing carotid revascularization in the United States from 2007 to 2014 were retrospectively identified from the 2007-2014 National Inpatient Sample using International Classification of Disease, Ninth Revision procedural codes. From 61 324 882 unweighted hospitalizations contained in the 2007-2014 National Inpatient Sample, 494 733 weighted carotid revascularization admissions in adults older than 70 years were identified using International Classification of Disease, Ninth Revision procedural codes. Main Outcomes and Measures:The proportion of CAS performed in all age groups over time was estimated and multivariable-adjusted models were used to compare the odds of receiving CAS in the pre-CREST with those in the post-CREST era in adults older than 70 years. Results:A total of 41.8% of all patients were women, and mean (SE) age at presentation was 78.1 (0.03) years. A total of 16.3% of CAS and 10.1% of CEA procedures were performed in patients with symptomatic stenosis. The proportion of patients older than 70 years receiving CAS increased from 11.9% in the pre-CREST to 13.8% in the post-CREST era (P = .005). In multivariable models, the odds of receiving CAS increased by 13% in all patients older than 70 years in the post-CREST compared with the pre-CREST period (odds ratio [OR], 1.13, 95% CI, 1.00-1.28, P = .04), including symptomatic women (OR, 1.31, 1.05-1.65, P = .02). Symptomatic stenosis (OR 1.39; 95% CI, 1.27-1.52; P < .001), congestive heart failure (OR, 1.48; 95% CI, 1.35-1.63; P < .001), and peripheral vascular disease (OR, 1.35; 95% CI, 1.27-1.43; P < .001) were associated with higher odds of CAS; comorbid hypertension (OR, 0.70; 95% CI, 0.66-0.74; P < .001), smoking (OR, 0.84; 95% CI, 0.78-0.91; P < .001), and weekend admission (OR, 0.77; 95% CI, 0.68-0.88; P < .001) were negatively associated with the odds of CAS. Conclusions and Relevance:Despite concerns for higher periprocedural complications with CAS in elderly patients, the odds of CAS increased in the post-CREST compared with pre-CREST era in patients older than 70 years, including symptomatic women.
| S-EPMC5833495 | biostudies-literature
Project description:The use of calcium hydroxide (CH) as an intracanal medicament for apexification is widespread. However, because of a short residence time in the root canal, the CH must be refreshed frequently, increasing the number of appointments required and leading to patient non-compliance. We hypothesized that a core-/shell-structured CH microsphere system would lead to sustained slow release of calcium and hydroxide ions of CH for long periods of time, eliminating the need for multiple visits for apexification. In this study, calcium hydroxide microspheres (CHMSs) with a core/shell structure were prepared by an emulsion method. The CHMS shell was composed of alginate, which was crosslinked by the Ca(2+) released from the CH in the CHMSs. Therefore, this system provides a unique feedback loop that controls the release of ions from the CHMSs. The in vitro experiments from the root canals of extracted human teeth showed that the CHMSs had a sustained, slow release of Ca(2+), at a constant rate of approximately 2 to 3% per month from day one to the six-month endpoint of the experiment. After 6 months, 72.1 ± 5.8% of the total CH from the CHMSs remained in the root canals of the teeth, while only 46.9 ± 10.9% and 36.8 ± 7.5% remained from a commercial product (UltraCal(®)XS) and CH powder alone, respectively (p < 0.01). The pH of all of the formulations (CHMS, UltraCal(®) XS, and CH powder) in the extracted teeth never rose above 9 during the release period, indicating a buffering effect of the teeth. The core-/shell-structured CHMSs are, therefore, a promising delivery vehicle for the sustained slow release of Ca(2+) and OH(-) in the root canal.
| S-EPMC3525129 | biostudies-literature
Project description:Calcium hydroxide (Ca(OH)2), a commodity chemical, finds use in diverse industries ranging from food, to environmental remediation and construction. However, the current thermal process of Ca(OH)2 production via limestone calcination is energy- and CO2-intensive. Herein, we demonstrate a novel aqueous-phase calcination-free process to precipitate Ca(OH)2 from saturated solutions at sub-boiling temperatures in three steps. First, calcium was extracted from an archetypal alkaline industrial waste, a steel slag, to produce an alkaline leachate. Second, the leachate was concentrated using reverse osmosis (RO) processing. This elevated the Ca-abundance in the leachate to a level approaching Ca(OH)2 saturation at ambient temperature. Thereafter, Ca(OH)2 was precipitated from the concentrated leachate by forcing a temperature excursion in excess of 65 °C while exploiting the retrograde solubility of Ca(OH)2. This nature of temperature swing can be forced using low-grade waste heat (≤100 °C) as is often available at power generation, and industrial facilities, or using solar thermal heat. Based on a detailed accounting of the mass and energy balances, this new process offers at least ≈65% lower CO2 emissions than incumbent methods of Ca(OH)2, and potentially, cement production.
| S-EPMC8693611 | biostudies-literature
Project description:Food additive grade calcium hydroxide (FdCa(OH)2) in the solution of 0.17% was evaluated for its bactericidal efficacies toward Legionella pneumophila with or without sodium hypochlorite (NaOCl) at a concentration of 200 ppm total residual chlorine, at room temperature (RT) (25°C ± 2°C) and 42°C, either with or without 5% fetal bovine serum (FBS). Besides, FdCa(OH)2 in different concentration solutions were prepared in field water samples (hot spring and bath tab water) and evaluated for their bactericidal efficacies at 42°C. FdCa(OH)2 (0.17%) inactivated the L. pneumophila to the undetectable level (<2.6 log CFU/ml) within 5 min and 3 min, respectively, at RT and 42°C, with 5% FBS. At RT and 42°C, NaOCl inactivated L. pneumophila to the undetectable level within 5 min, without 5% FBS, but with 5% FBS, it could only inactivate this bacterium effectively (?3 log reductions). Conversely, at RT and 42°C, the mixture of 0.17% FdCa(OH)2 and 200 ppm NaOCl could inactivate L. pneumophila to the undetectable level, respectively, within 3 min and 1 min, even with 5% FBS, and it was elucidated that FdCa(OH)2 has a synergistic bactericidal effect together with NaOCl. FdCa(OH)2 0.05% solution prepared in hot spring water could inactivate L. pneumophila to the undetectable within 3 min at 42°C. So, FdCa(OH)2 alone could show nice bactericidal efficacy at 42°C, even with 5% FBS, as well as in field water samples.
| S-EPMC6785613 | biostudies-literature
Project description:Livestock farming is affected by the occurrence of infectious diseases, but outbreaks can be prevented by proper sanitary control measures. Calcium hydroxide (Ca(OH)2), commonly called slaked lime, powder is traditionally used as a disinfectant to prevent infectious diseases in livestock. Since Ca(OH)2 can inactivate a wide variety of pathogens, has a small environmental impact, does not require a disinfection tank (i.e., can be spread directly on the ground) and is produced inexpensively worldwide, it is used for the prevention of epidemics on farms worldwide. Water is essential for the strong alkalinity that underlies its disinfecting effect, but it is unknown how much water is required under field conditions. In addition, Ca(OH)2 reacts with carbon dioxide in the environment, reducing its pH, but it is unclear how long its degradation takes under actual field use. Thus, we measured the water adsorption ability of Ca(OH)2-based disinfectants and its relation to disinfectant activity, as assessed by colony counts and live/dead staining and observation. We found that 15-20% (w/w) water in Ca(OH)2 was necessary for disinfection to occur in practice. Moreover, we found that the pH of Ca(OH)2 decreased within about two weeks to one month under actual use in practical conditions and lost its ability to disinfect. We further showed that granules prepared from Ca(OH)2 and zeolite maintained high alkalinity more than twice as long as calcium powder. These findings will help to establish a suitable method of applying Ca(OH)2 to protect farms from infectious diseases.
| S-EPMC8041792 | biostudies-literature
Project description:Our objective was to evaluate the inclusion of calcium-magnesium carbonate [CaMg(CO3)2] and calcium-magnesium hydroxide [CaMg(OH)4] in corn silage-based diets and their impact on ruminal microbiome. Our previous work showed a lower pH and molar proportion of butyrate from diets supplemented with [CaMg(CO3)2] compared to [CaMg(OH)4]; therefore, we hypothesized that ruminal microbiome would be affected by Mg source. Four continuous culture fermenters were arranged in a 4 × 4 Latin square with the following treatments defined by the supplemental source of Mg: 1) Control (100% MgO, plus sodium sesquicarbonate as a buffer); 2) CO 3 [100% CaMg(CO3)2]; 3) OH [100% CaMg(OH)4]; and 4) CO 3 /OH [50% Mg from CaMg(CO3)2, 50% Mg from CaMg(OH)4]. Diet nutrient concentration was held constant across treatments (16% CP, 30% NDF, 1.66 MCal NEl/kg, 0.67% Ca, and 0.25% Mg). We conducted four fermentation periods of 10 d, with the last 3 d for collection of samples of solid and liquid digesta effluents for DNA extraction. Overall, 16 solid and 16 liquid samples were analyzed by amplification of the V4 variable region of bacterial 16S rRNA. Data were analyzed with R and SAS to determine treatment effects on taxa relative abundance of liquid and solid fractions. Correlation of butyrate molar proportion with taxa relative abundance was also analyzed. Treatments did not affect alpha and beta diversities or relative abundance of phylum, class and order in either liquid or solid fractions. At the family level, relative abundance of Lachnospiraceae in solid fraction was lower for CO3 and CO3/OH compared to OH and Control (P < 0.01). For genera, abundance of Butyrivibrio (P = 0.01) and Lachnospiraceae ND3007 (P < 0.01) (both from Lachnospiraceae family) was lower and unclassified Ruminococcaceae (P = 0.03) was greater in CO3 than Control and OH in solid fraction; while abundance of Pseudobutyrivibrio (P = 0.10) and Lachnospiraceae FD2005 (P = 0.09) (both from Lachnospiraceae family) and Ruminobacter (P = 0.09) tended to decrease in CO3 compared to Control in liquid fraction. Butyrate molar proportion was negatively correlated to Ruminococcaceae (r = -0.55) in solid fraction and positively correlated to Pseudobutyrivibrio (r = 0.61) and Lachnospiraceae FD2005 (r = 0.61) in liquid. Our results indicate that source of Mg has an impact on bacterial taxa associated with ruminal butyrate synthesis, which is important for epithelial health and fatty acid synthesis.
| S-EPMC9335223 | biostudies-literature