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Journal of Dairy Science Mar 2021We evaluated the effects of propylene glycol (PG) on in vitro ruminal fermentation, methanogenesis, and microbial community structure. A completely randomized design was...
We evaluated the effects of propylene glycol (PG) on in vitro ruminal fermentation, methanogenesis, and microbial community structure. A completely randomized design was conducted in the in vitro incubation, and 4 culture PG dose levels (0, 7.5, 15, and 22.5 μL/g of dry matter) were used in the trial. Based on the fermentation results, the control group (0 μL/g of dry matter, CON) and the second treatment group (15.0 μL/g of dry matter, TRT) were chosen for further analysis to explore the effects of PG on the bacterial and archaeal community structure. The concentrations of propanol, propanal, and succinate increased linearly, whereas the concentration of l-lactate decreased linearly as PG doses increased. The molar proportion of propionate demonstrated a linear increase with increasing PG doses. In contrast with propionate, the molar proportion of acetate and butyrate, and acetate-to-propionate ratio decreased linearly with increasing PG doses. The addition of PG markedly decreased methane production without negative effects on nutrient degradability. In the archaeal level, the relative abundance of Methanobrevibacter tended to decrease, but that of Methanomassiliicoccus significantly increased in TRT group. At the bacterial level, the relative abundance of Bacteroidetes and Prevotella in TRT group was numerically higher than that in CON group. The analysis of the Negativicutes class showed that the relative abundance of Succiniclasticum tended to increase, whereas that of Selenomonas tended to decrease in TRT group. These results demonstrated that PG might be used as an inhibitor to mitigate methane emission. However, the small decrease in methane production will limit the application of PG as a methane inhibitor in production practices. Further research is needed to determine whether use together with other inhibitors may improve the effects of PG on the utilization of reducing equivalents ([H]) and methane production.
Topics: Animal Feed; Animals; Diet; Digestion; Female; Fermentation; Lactation; Methane; Microbiota; Rumen
PubMed: 33455765
DOI: 10.3168/jds.2020-18974 -
Acta Pharmaceutica (Zagreb, Croatia) Sep 2023Herein, thermal and non-thermal techniques were used to elucidate the putative physical and chemical interactions between poorly water-soluble methoxyflavones and...
Herein, thermal and non-thermal techniques were used to elucidate the putative physical and chemical interactions between poorly water-soluble methoxyflavones and PEG400/propylene glycol. Additionally, the biocompatibility of methoxyflavone-glycol solutions was evaluated using Caco-2 cells whereas the absorptive transport was investigated by measuring the apparent permeability coefficient ( ) of the methoxyflavones and transepithelial electrical resistance (TEER) of the Caco-2 cell monolayer. Data from differential scanning calorimetry, Fourier-transform infrared (FTIR), and proton nuclear magnetic resonance (H NMR) spectroscopic analysis revealed physico-chemical compatibility between the three methoxyflavones and PEG400/propylene glycol. Furthermore, PEG400 and propylene glycol solutions of the methoxyflavones were shown to be compatible with Caco-2 cells at pharmacologically effective concentrations. transport studies across the Caco-2 cell monolayer revealed high values of 24.07 × 10 to 19.63 × 10 cm s for PEG400 solutions of the methoxyflavones. The TEER values of the Caco-2 cell monolayers indicated that the increased drug transport was partly due to increased tight junction openings, but without compromising the epithelial barrier integrity. The good pharmaceutical and biocompatibility profiles, as well as improved transport of the methoxyflavones in PEG400 and propylene glycol solutions, are suggestive of the worthiness of this approach for further consideration pertaining to the development of these drugs into oral liquid dosage forms.
Topics: Humans; Caco-2 Cells; Polyethylene Glycols; Propylene Glycol; Permeability; Water
PubMed: 37708958
DOI: 10.2478/acph-2023-0030 -
Cytotechnology Oct 2022We evaluated a dimethyl sulfoxide (Me2SO)-free cryopreservation solution to freeze human adipose-derived mesenchymal stromal cells (hADSCs). In the first experiment, we...
Dimethyl sulfoxide-free cryopreservation solution containing trehalose, dextran 40, and propylene glycol for therapy with human adipose tissue-derived mesenchymal stromal cells.
We evaluated a dimethyl sulfoxide (Me2SO)-free cryopreservation solution to freeze human adipose-derived mesenchymal stromal cells (hADSCs). In the first experiment, we compared the combined effects of 3% trehalose (3 T) and 5% dextran (5D) in lactated Ringer's solution (LR) as a cryopreservation base solution containing 10% propylene glycol (PG). The cell viability of hADSCs immediately after thawing was significantly higher (p < 0.05) in LR supplemented with 3 T (LR-3 T) and with 3 T and 5D (LR-3 T-5D) than in LR. In the second experiment, we compared the cell characteristics of hADSCs freeze-thawed in LR-3 T-5D containing either 10% Me2SO or 10% PG. The cell viability, annexin V-positive ratio, colony-forming capacity, cell proliferation, cell surface antigen positivity, adipogenic differentiation, osteogenic differentiation, and genetic response to cytokine stimulation of hADSCs immediately after thawing were similar between the LR-3 T-5D containing 10% Me2SO and 10% PG. In the third experiment, we examined various concentrations of PG on the cell proliferative capacity of freeze-thawed hADSCs. The cell proliferative capacity of hADSCs frozen with LR-3 T-5D containing 2.5% to 5% PG was significantly higher (p < 0.05) than LR-3 T-5D containing 10% PG. Furthermore, the cell proliferative capacity of hADSCs frozen with LR-3 T-5D containing 4% PG was similar to that of fresh hADSCs. These results indicate that the combination of 3 T-5D in an LR solution as a basic solution is effective for post-thaw cell viability, and that the optimal concentration of PG to maintain the cell characteristics of hADSCs frozen with LR-3 T-5D is 2.5% to 5%, which is promising for cell therapy applications.
PubMed: 36238270
DOI: 10.1007/s10616-022-00541-3 -
ACS Omega Dec 2022To make ionic liquids (ILs) accessible and economical, ethylene glycol was mixed in 1-ethyl-3-methylimidazolium-dicyanamide ([EMIm]DCA) to obtain droplets that could...
To make ionic liquids (ILs) accessible and economical, ethylene glycol was mixed in 1-ethyl-3-methylimidazolium-dicyanamide ([EMIm]DCA) to obtain droplets that could experimentally collide white fuming nitric acid. To investigate the ignition delay (ID) time theoretically in terms of hydrodynamics, alcohol fuels and kerosene were used as combustibles, while the intermiscibility between them and nitric acid (HNO) was calculated using the ternary phase-field method alongside finite element analysis. The specific impulses of blend fuels were calculated by a thermodynamic method and compared to ILs. When the droplet was ethylene glycol/[EMIm]DCA with a 2.1 mm diameter and a 1.69 m/s colliding velocity, the ID time was the shortest. Kerosene was not an applicable additive for [EMIm]DCA owing to its lower intermiscibility with ILs and HNO than alcohol fuels; alcohol fuels, however, were appropriate. The concentration of ethylene glycol in the oxidizer pool increased faster than the concentration of propylene glycol, triggering more rapid hypergolic ignition in the first 50 ms. The protocols regarding the hypergolic ignition conditions were verified, i.e., the size of the droplet had to be minute when the colliding velocity was as fast as possible; this was carefully calculated using ethylene glycol. According to thermodynamic calculations, the addition of alcohol fuels can improve the specific impulse of fuels, with ethylene glycol performing the best. The feasibility of adding alcohol fuels to ILs was confirmed via experiments and thermodynamic computations, with the simulation results providing some guidance on selecting the experimental or engineering conditions or both.
PubMed: 36506146
DOI: 10.1021/acsomega.2c04386 -
JDS Communications Sep 2022Multiple treatments for hyperketonemia have been studied, and although propylene glycol has been the most constantly reported as successful in mitigating the effects of...
Randomized controlled trial assessing the impact of a combined treatment of insulin glargine and propylene glycol on the resolution of hyperketonemia and milk production in postpartum dairy cows.
Multiple treatments for hyperketonemia have been studied, and although propylene glycol has been the most constantly reported as successful in mitigating the effects of this condition, a recent study showed that a subpopulation of cows affected by hyperketonemia and hypoglycemia could benefit from a combined treatment of propylene glycol and insulin glargine. The objective of the present study was to assess the effect of this combination on the time-to-hyperketonemia resolution, and on milk production following the initial treatment. A randomized controlled trial was conducted on 2 commercial farms on which postpartum exams were conducted twice a week. Cows naturally affected by both hyperketonemia [β-hydroxybutyrate (BHB) ≥ 1.4 mmol/L] and hypoglycemia (glucose <2.2 mmol/L) were enrolled and randomly assigned to receive 2 mL of placebo (physiological saline) subcutaneously (PBO), or to receive 2 mL of insulin glargine (200 IU) subcutaneously (INS). Cows in both groups also received 300 g of propylene glycol orally for 3 d. Time-to-hyperketonemia resolution (return to BHB <1.4 mmol/L) and daily milk production following the initial treatment were compared between groups using Cox proportional hazard and mixed linear regression models, respectively. A total of 248 cows between 1 and 30 d in milk (median = 16) were enrolled in the trial from January 2018 to February 2022. Cows were of first (32.3%; n = 80/248), second (32.3%; n = 80/248), or third or greater (35.4%; n = 88/248) parity. The overall time-to-hyperketonemia resolution was not different between treatments, but there was a 2-way interaction between treatment group and parity. Primiparous cows had a shorter time-to-resolution in the INS group than in the PBO group; no difference was observed between treatment groups for older cows. The overall milk production of cows in the INS group was 3.4 kg higher than cows in the PBO group during the 14 d after enrollment. There was a 2-way interaction between treatment group and parity. Primiparous cows in the INS group produced 5.3 kg more milk daily than primiparous cows in the PBO group; no effect of treatment was found for older cows. These results suggest that cows affected simultaneously by hyperketonemia and hypoglycemia benefited from a combined treatment of propylene glycol and insulin glargine to improve subsequent milk production and that the effect primarily came from the positive effect in primiparous cows. Time-to-hyperketonemia resolution was also improved in primiparous cows but not in older cows.
PubMed: 36340901
DOI: 10.3168/jdsc.2022-0228 -
European Heart Journal Supplements :... Nov 2022Electronic cigarettes (e-cigarettes) are battery-powered devices containing a liquid based on propylene glycol or vegetable glycerin, compounds which, when vaporized,...
Electronic cigarettes (e-cigarettes) are battery-powered devices containing a liquid based on propylene glycol or vegetable glycerin, compounds which, when vaporized, act as a vehicle for nicotine, flavours, and other chemical components. These devices have been marketed without clear evidence of risks, long-term safety, and efficacy as a means of traditional smoking cessation. Recent clinical studies have shown how the use of the e-cigarette, combined with adequate psychological support, can be effective in reducing traditional smoking but not nicotine addiction. However, meta-analyses of observational studies have not confirmed this efficacy. Several studies have also highlighted an increase in sympathetic tone, vascular stiffness, and endothelial dysfunction, all factors associated with an increased cardiovascular risk. Clinicians, therefore, should carefully monitor the possible risks to public health deriving from the use of e-cigarettes and should discourage non-smokers and adolescents from using such devices. Finally, particular attention should be paid to smokers so that the combined use of electronic and traditional cigarettes can be limited as much as possible.
PubMed: 36380783
DOI: 10.1093/eurheartjsupp/suac105 -
Diagnostics (Basel, Switzerland) Oct 2023(1) Background: The use of electronic cigarettes has become widespread in recent years. The use of e-cigarettes leads to milder pathological conditions compared to...
(1) Background: The use of electronic cigarettes has become widespread in recent years. The use of e-cigarettes leads to milder pathological conditions compared to traditional cigarette smoking. Nevertheless, e-liquid vaping can cause morphological changes in lung tissue, which affects and impairs gas exchange. This work studied the changes in morphological and optical properties of lung tissue under the action of an e-liquid aerosol. To do this, we implemented the "passive smoking" model and created the specified concentration of aerosol of the glycerol/propylene glycol mixture in the chamber with the animal. (2) Methods: In ex vivo studies, the lungs of Wistar rats are placed in the e-liquid for 1 h. For in vivo studies, Wistar rats were exposed to the e-liquid vapor in an aerosol administration chamber. After that, lung tissue samples were examined ex vivo using optical coherence tomography (OCT) and spectrometry with an integrating sphere. Absorption and reduced scattering coefficients were estimated for the control and experimental groups. Histological sections were made according to the standard protocol, followed by hematoxylin and eosin staining. (3) Results: Exposure to e-liquid in ex vivo and aerosol in in vivo studies was found to result in the optical clearing of lung tissue. Histological examination of the lung samples showed areas of emphysematous expansion of the alveoli, thickening of the alveolar septa, and the phenomenon of plasma permeation, which is less pronounced in in vivo studies than for the exposure of e-liquid ex vivo. E-liquid aerosol application allows for an increased resolution and improved imaging of lung tissues using OCT. Spectral studies showed significant differences between the control group and the ex vivo group in the spectral range of water absorption. It can be associated with dehydration of lung tissue owing to the hyperosmotic properties of glycerol and propylene glycol, which are the main components of e-liquids. (4) Conclusions: A decrease in the volume of air in lung tissue and higher packing of its structure under e-liquid vaping causes a better contrast of OCT images compared to intact lung tissue.
PubMed: 37958237
DOI: 10.3390/diagnostics13213340 -
Journal of Advanced Pharmaceutical... 2022Previous research states that adding propolis to powdered dental materials can increase the mechanical strength of the material. To analyze the differences and...
Previous research states that adding propolis to powdered dental materials can increase the mechanical strength of the material. To analyze the differences and correlation of dentin elastic moduli and pH value after the exposure of calcium hydroxide, a mixture of propolis and calcium hydroxide, also a mixture of propylene glycol (PG), calcium hydroxide, and propolis. The dentine of bovine incisors was exposed into various compositions of a mixture of propolis, PG, and calcium hydroxide. The measurement of pH value and dentin elasstic moduli was performed after 7 days. To find difference among groups, one-way ANOVA was used, and Honestly significant difference (HSD) Tukey to compare each groups, followed by Pearson to define the correlation. A statistically meaningful difference was recorded between the groups ( < 0.05), and there was correlation between dentin elastic moduli and pH value. The more alkaline the environment, the more rigid the dentin.
PubMed: 35223444
DOI: 10.4103/japtr.japtr_261_21 -
CMAJ Open 2023Classroom-based education (CBE) is ubiquitous in postgraduate medical education (PGME), but to date no studies have synthesized the literature on the topic. We conducted... (Review)
Review
BACKGROUND
Classroom-based education (CBE) is ubiquitous in postgraduate medical education (PGME), but to date no studies have synthesized the literature on the topic. We conducted a scoping review focusing on academic half days and noon conferences.
METHODS
We searched 4 databases (MEDLINE [OVID], Embase [OVID], ERIC [EBSCO] and Web of Science) from inception to December 2021, performed reference and citation harvesting, and applied predetermined inclusion and exclusion criteria to our screening. We used 2 frameworks for the analysis: "experiences, trajectories and reifications" and "description, justification and clarification."
RESULTS
We included 90 studies, of which 55 focused on resident experiences, 29 on trajectories and 6 on reification. We classified 44 studies as "description," 38 as "justification" and 8 as "clarification." In the description studies, 12 compared academic half days with noon conferences, 23 described specific teaching topics, and 9 focused on resources needed for CBE. Justification studies examined the effects of CBE on outcomes, such as examination scores (17) and use of teaching strategies in team-based learning, principles of adult learning and e-learning (15). Of the 8 clarification studies, topics included the role of CBE in PGME, stakeholder perspectives and transfer of knowledge between classroom and workplace.
INTERPRETATION
Much of the existing literature is either a description of various aspects of CBE or justification of particular teaching strategies. Few studies exist on how and why CBE works; future studies should aim to clarify how CBE facilitates resident learning within the sociocultural framework of PGME.
Topics: Humans; Adult; Databases, Factual; Education, Medical; Propylene Glycols
PubMed: 37160324
DOI: 10.9778/cmajo.20210203 -
Toxics Dec 2023Toxicological evaluations of flavor chemicals for use in inhalation products that utilize heat for aerosol generation are complicated because of the potential effect...
Toxicological evaluations of flavor chemicals for use in inhalation products that utilize heat for aerosol generation are complicated because of the potential effect heat may have on the flavor chemical. The objective was to develop a thermal degradation technique to screen flavor chemicals as part of a toxicological testing program for their potential use in ENDS formulations. Based upon published data for acetaldehyde, acrolein, and glycidol from ENDS products (common thermal degradants of propylene glycol and glycerin), the pyrolizer temperature was adjusted until a similar ratio of acetaldehyde, acrolein, and glycidol was obtained from a 60/40 ratio (/) of glycerin/propylene glycol via GC/MS analysis. For each of 90 flavor chemicals, quantitative measurements of acetaldehyde, acrolein, and glycidol, in addition to semiquantitative non-targeted analysis tentatively identifying chemicals from thermal degradation, were obtained. Twenty flavor chemicals transferred at greater than 99% intact, another 26 transferred at greater than 95% intact, and another 15 flavor chemicals transferred at greater than 90% intact. Most flavor chemicals resulted in fewer than 10-12 tentatively identified thermal degradants. The practical approach to the thermal degradation of flavor chemicals provided useful information as part of the toxicological evaluation of flavor chemicals for potential use in ENDS formulations.
PubMed: 38250972
DOI: 10.3390/toxics12010016