Amount Of Release Research Articles

EVOLUÇÃO DE C-CO<sub>2</sub> EM SOLOS DE DIFERENTES ECOSSISTEMAS NA REGIÃO DO ALTO ACRE, ACRE, BRASIL

Different studies, developed over the years, have shown that the increase in human activities on the soil can influence the release of gases related to the increase in the greenhouse effect. In this sense, the use of methods that evaluate the evolution of C-CO2 has been considered as important indicators to detect changes in the environment, since they can be influenced by the crop and its cultivation system as a result of impacts on microbial activity. The objective of this work was to evaluate the release of C-CO2 from soils submitted to different ecosystems. Laboratory tests were carried out where soil samples, submitted to five different ecosystems, were collected in three different periods throughout the year in the municipalities of Brasiléia and Epitaciolândia, Alto Acre region, in the state of Acre, and were subsequently incubated. Subsequently, the evolution of C-CO2 was evaluated, and the readings were carried out periodically until the 500th day of incubation of the samples. The data were analyzed in order to evaluate the effect of different plant species on the evolution of C-CO2. Regarding the collection carried out in April, there was no difference in the evolution of C-CO2 between the areas. However, in the month of June, which comprises the period of the beginning of the transition between the rainy season and the dry season, and in the month of August, the dry season, it was observed that in the area of native forest occurred the highest values of C-CO2 flux, differing statistically from other areas within these months of collection. Between the collection times, only in the area of agroforestry system no significant differences were recorded in the evolution of C-CO2. The highest accumulated values of C-CO2 were recorded in the following sequence: native forest > agroforestry system > area with cassava > cultivated pasture > area with banana. It is concluded that the areas that present a greater contribution of plant material to the soil can serve as a stimulus to the development of microorganisms that, consequently, increase the flow of CO2, especially until the beginning of the dry season and that the absence of moisture negatively influences the emission of C-CO2, causing significant differences in the amount of release of C-CO2 between the study areas at the same time of evaluation.

Understanding Geotechnical Embankment Washout Due to Overtopping: Insights From Physical Tests

Abstract Understanding the erosion process of an earth dam and flood embankment composed of noncohesive, homogeneous soils due to overflow is crucial for determining the quantity and rate of water release. This is necessary to assess the consequences of a failure, analyze the risk, and develop appropriate crisis management procedures. Despite numerous studies in this area, the process of breach evolution is not fully explored. The article presents the results of physical experiments carried out in the field laboratory of the Wrocław University of Science and Technology for a dam with a height of 0.50 m that closes a reservoir with a capacity of 14.4 m3, whose width is significantly greater than the final width of the breach. The scenario analyzed assumes that water overflows the embankment crest, as it is the most common cause of embankment failure based on dam disaster databases. At the same time, the amount of water accumulated in the reservoir is the largest possible for this scenario, suggesting that such a catastrophe may have the most severe consequences. Based on the results obtained from three experiments, four repeatable phases of erosion evolution were identified and described: (I) the initiation phase, (II) the vertical erosion phase, (III) the lateral erosion phase, divided into two cycles, and (IV) the reservoir emptying phase without further propagation of the breach. The outflow rate of the water from the reservoir was also analyzed, allowing the determination of the outflow hydrograph for each test. Hydrographs showed differences between individual experiments; however, the average erosion rate was similar for all tests. Furthermore, the final width of the breach created each time was between 2.2 and 2.5 H (where H is the height of the embankment) and the volume of eroded soil ranged from 0.52 to 0.59 m3. The article also highlights the methodology to calculate the water outflow hydrograph.

Investigation of the kinetics of imidacloprid adsorption onto bimetallic Cu-BTC MOF

Imidacloprid, which is harmful for humans as well as many other aquatic invertebrate species, is extensively present in water worldwide. Hydrophobic Cu-BTCIPA and a novel composite, Ag@Cu-BTCIPA, was synthesized for adsorption of imidacloprid from water. The synthesis of the composite and the increase in surface area and pore volume were confirmed by FTIR, XRD, SEM, and BET analysis. A comparative study of the adsorption efficiencies of the synthesized composites was performed. The maximum adsorption efficiency achieved was 83.6 % at pH 7 by the Ag@Cu-BTCIPA composite. Kinetic and isotherm analyses suggested multilayer chemisorption involving p-p conjugation and pore-filling mechanisms. Intra-particle diffusion was the rate limiting step. Release studies of imidacloprid from water showed that the percentage release amount was 90.2 % at 70 min. Kinetic analysis of the release process suggested release through chemisorption, with swelling-controlled release from the dosage form, corresponding to the super case II transport mechanism.

Preparation and evaluation of Puerarin-loaded PLGA nanoparticles for improving oral bioavailability in SD rats

BackgroundPuerarin (Pue) is an isoflavone compound with significant therapeutic effect on cardiovascular diseases, but its poor water solubility and low oral bioavailability limit clinical application. MethodsIn this study, Pue was prepared into PLGA nanoparticles (Pue-PLGA NPs) by emulsion solvent volatilization method. The morphology, particle size, Zeta potential, X-ray diffraction (XRD), and fourier transform infrared (FTIR) of the NPs were characterized. Additionally, their stability and in vitro release were evaluated. SD rats were orally administered wtih Pue and Pue-PLGA NPs, and a high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established to determine the concentration of blood samples and to investigate the pharmacokinetic behaviour of Pue and Pue-PLGA NPs in rats. ResultsThe NPs were observed by transmission electron microscopy (TEM) as regular spheroids and uniformly dispersed. The average particle size of the NPs was (167.1±5.26）nm, the Zeta potential was (-29.88±2.46)mV, the encapsulation rate was (83.12 %±4.73 %) and the drug loading capacity was (7.75 %±1.81 %). The results of in vitro release showed that the drug was released slowly and continuously from the NPs, reaching the release platform in 24 h, and the cumulative release amount was (88.55±2.86) %. The pharmacokinetic results showed that the AUC0–24, AUC0-∞, Cmax, Tmax, t1/2, MRT0–24 and MRT0-∞ of Pue-PLGA NPs were 2.196, 1.978, 1.327, 1.5, 1.385, 3.915 and 3.140 times of Pue, respectively. The relative bioavailability was (197.82±25.28) %. ConclusionThese results indicated that the prepared nanoparticles had small particle size, high encapsulation rate, drug loading capacity and good slow-release effect, and could significantly improve the oral bioavailability of Pue in rats.

Preparation of CoS2/Fe/SA hydrogel spheres with Fe2+ slow-release effect to improve Fenton reaction efficiency

Fenton reaction is a traditional advanced oxidation process that has long been used for wastewater treatment. However, the narrow pH range of 2–4, the inefficient utilization of both H2O2 and Fe2+, and the large amount of iron sludge formation limit its application. Here, we prepared sodium alginate composite hydrogel spheres with both Fe2+ and CoS2 loading (denoted as CoS2/Fe/SA hydrogel spheres) to construct a CoS2/Fe/SA + H2O2 reaction system. The degradation efficiency of carbamazepine (CBZ) in the CoS2/Fe/SA + H2O2 system was significantly enhanced with a first-order kinetic reaction constant of 0.1958 min−1, which is 8.9 times higher than that in Fe2++H2O2 system. When the initial solution pH was in the range of 2–8, the removal rate of CBZ at 90 min reaction time ranged from 96.5 % to 99.9 %. The enhanced degradation efficiency even in a slightly alkaline aqueous solution was due to the sustained slow release of Fe2+ from the CoS2/Fe/SA hydrogel spheres that enhances the utilization of Fe2+ and the promotion of Fe3+/Fe2+ cycling via CoS2. Moreover, the release amount of Fe2+ in CoS2/Fe/SA hydrogel spheres could be controlled by tuning the Fe2+ loading amount during preparation, which in turn determines its number of cycling uses.

Stem Cell in Breast Cancer Theraphy

There is a lot of research to support that cancer stem cell attract normal stem cell. The tendency of tumor cells to attract stem cells then becomes the basis for the use of stem cells in breast cancer theraphy. When neural stem cell applied as a carrier, it will make the amount, timing, and location of viral oncolytic or drug release can be precisely controlled. Finally, this situation will increase the effectiveness of breast cancer therapy and reduce side effects. This is a brief review about potency of stem cell as breast cancer treatment. This article aim to increased our knowledge about the potency of stem cell as breast cancer treatment. The tendency of tumor cells to attract stem cells then becomes the basis for the use of stem cells as enzyme/prodrug theraphy, secreted agent, viral oncolytic carrier or nanoparticle (drug) carrier which tends to be more localized around the tumor. When neural stem cell applied as a carrier, it will make the location, amount and timing of drug release or viral oncolytic can be precisely controlled.

Self-Boosting Programmable Release of Multiple Therapeutic Agents by Activatable Heterodimeric Prodrug-Enzyme Assembly for Antitumor Therapy.

Endogenous stimuli-responsive prodrugs, due to their disease lesion specificity and reduced systemic toxicity, have been widely explored for antitumor therapy. However, reactive oxygen species (ROS) as classical endogenous stimuli in the tumor microenvironment (TME) are not enough to achieve the expected drug release. Herein, a ROS-activatable heterodimeric prodrug-loaded enzyme assembly is developed for self-boosting programmable release of multiple therapeutic agents. The heterodimeric prodrug NBS-TK-PTX (namely NTP) is composed of 5-(ethylamino)-9-diethylaminobenzo[a]phenothiazinium chloride analog (NBS), paclitaxel (PTX) and ROS-responsive thioketal (TK) linker, which shows a strong binding affinity with glucose oxidase (GOx), thus obtaining NTP@GOx assembly. Notably, the enzymatic activity of GOx in NTP@GOx is inhibited by NTP. The programmable release is achieved by following steps: i) NTP@GOx is partially dissociated in acidic TME, thus releasing a small segment of NTP and GOx. Thereupon, the enzymatic activity of GOx is recovered; ii) GOx-triggered pH reduction further facilitates the dissociation of NTP@GOx, thus accelerating a large amount of NTP and GOx release; iii) The TK linker of prodrug NTP is cleaved by hydrogen peroxide generated by GOx catalysis, thus expediting the release of NBS for Type-I photodynamic therapy and PTX for chemotherapy, respectively. The NTP@GOx shows great potential for multimodal synergistic cancer therapy.

PH triggered on-demand tannic acid release via “open-close” of soybean isolate proteins spatial structure for shrimp preservation

The on-demand release intelligent packaging system ensures the quality and safety of food products by releasing antimicrobial factors in response to environmental changes. However, the complex fabrication process of traditional pH-sensitive packaging restricted their large-scale application. Herein, a novel soy protein isolate (SPI)/carboxymethyl cellulose sodium (CMC)/tannic acid (TA) composite was successfully demonstrated as on-demanded TA release active packaging film, in which TA was in situ wrapped within SPI chains via tailoring the pH. The formed volatile biogenic amines from shrimp raised the headspace pH, inducing the opening of SPI spatial structures to release antimicrobial active factors. When pH was changed from 6.5 to 7.0, the cumulative release amount of TA from SCT-5 composite film increased from 11.61 mg/cm2 to 18.69 mg/cm2. When the optimized SCT film was utilized as packing material, the shelf life of Pacific white shrimp was extended at least 8 days. Furthermore, SCT-5 composite films exhibited excellent ultraviolet resistance (200–400 nm 99.64%), gas barrier properties (OTR: 11.67 ± 0.87 (cm3·μm/(m2·d·kPa)), WVTR: 638.77 ± 13.97 g/(m2·24h)) and biodegradability. Our findings presented a facile and novel strategy for designing protein-based on-demand release active packaging, facilitating the development of food quality and safety.

Maximizing methane and hydrogen delivery capacity by carbon and boron nitride nanoscrolls

The CH4 and H2 delivery capacity of carbon and boron nitride (BN) nanoscrolls was investigated, with a focus on optimizing the interlayer and van der Waals spacings to meet the U.S. Department of Energy (DOE) targets. Through computational simulations, the effects of interlayer spacing on CH4 and H2 adsorption were evaluated, revealing that while delivery quantities increase with interlayer spacing, achieving DOE targets remains a challenge for CH4. Notably, BN nanoscrolls exhibited higher adsorption capacities compared to carbon nanoscrolls, especially under low-pressure conditions. Conversely, carbon nanoscrolls displayed greater release quantities than BN nanoscrolls. For H2, delivery quantities met DOE targets at larger interlayer spacings, with carbon nanoscrolls requiring a spacing greater than 0.9 nm and BN nanoscrolls greater than 1.1 nm. For CH4 delivery, temperature optimization showed significant peaks in delivery for carbon nanoscrolls at 248 K. In contrast, BN nanoscrolls did not exhibit a peak in delivery. In carbon nanoscrolls, the optimal weight and volumetric capacities for methane delivery are 0.275 g/g and 182 cm3/cm3, respectively. Meanwhile, for hydrogen, the maximum delivery achieved is 8.26 wt% and 0.044 kg/L, which surpasses the DOE's storage target of 5.5 wt% and 0.04 kg/L. The study also highlighted the importance of structural parameter optimization, with a significant increase in weight delivery (>500%) and in volume delivery (>120%) for both gases.

Abstract 4135700: Effects of Mitochondrial Dysfunction on Extracellular Vesicle Release and Subsequent Disruption of the Lung Vascular Endothelial Barrier

Background: Lung endothelial cell (EC) barrier disruption is a hallmark of acute lung injury (ALI), which is commonly caused by bacterial pneumonia. Alveolar epithelial cells (AEC) are the first line of defence against invading respiratory pathogens in the lungs and can mediate inflammatory signaling to the adjacent EC contributing to barrier disruption. We have previously demonstrated that pneumolysin (PLY), a major Streptococcus pneumoniae virulence factor, induces both mitochondrial dysfunction in lung AEC and release of large extracellular vesicles (EVs). These EVs, which are enriched with mitochondrial cargo, contribute to increased permeability of the lung EC barrier. Here, we investigate strategies to inhibit mitochondrial dysfunction in AEC and examine how these interventions impact EC barrier function. Methods: Human alveolar epithelial cells (A549) or immortalized AEC (Cell Biologics) were pre-treated with mitoTEMPO (mtROS scavenger), P110 (excessive fission inhibitor), or ensifentrine [dual phosphodiesterase (PDE) 3/4 inhibitor] prior to PLY treatment (100-300 ng/ml, 4 hrs). Mitochondrial function was assessed by the JC-1 assay. EVs were isolated from cell media and analyzed for their mitochondrial content (Tom20 and Tim23 expression). To assess their functional role, EVs were added to TNF-α treated human lung microvascular EC, and barrier function was then determined using the ECIS assay to measure transendothelial electrical resistance (TER). Results: PLY-induced mitochondrial dysfunction was reduced in the presence of mitoTempo or P110. EVs from PLY-treated AEC (EV PLY ; enriched mitochondrial content) exacerbated TNF-α-induced EC barrier permeability as indicated by the significant decrease in TER. EV PLY derived from MitoTEMPO or P110-pretreated AEC contained less mitochondrial cargo and resulted in less EC permeability after TNF-α. Compared to mitoTEMPO and P110, ensifentrine exhibited superior protection against mitochondrial dysfunction after PLY exposure. In addition, in the presence of ensifentrine, the quantity of EV release and their extracelllular mitochondrial content were both dramatically reduced. In contrast to control EV PLY , EV PLY from ensifentrine-pretreated AEC demonstrated no barrier disruptive properties. Conclusions: Mitochondrial dysfunction in AEC contributes to vascular endothelial injury in ALI through mechanisms involving the release of barrier-disruptive EVs, which can be effectively targeted by inhibiting PDE3/4.

An experimental study on monitoring and early warning of spontaneous coal combustion fires using CPM

At present, the conventional indicator gas has a blank temperature interval in the monitoring of coal spontaneous combustion fire area, and the monitoring accuracy is easy to be interfered by wind flow, which leads to the inaccurate grasp of the situation of the fire area. To solve this problem, the characteristics of condensable particulate matter (CPM) released into the air during spontaneous combustion and heating are analyzed in this paper through a particle collection system. The results showed that the CPM captured by the system gradually increased when the coal temperature rose above 250℃, and the diameter was above 1um. After 300℃, the release of CPM increased significantly, which was more than 10 times that below 300℃. Test analysis showed that these CPMs were mainly phenols and polycyclic aromatic hydrocarbons, which accounted for 22 % and 37 % respectively after 300℃. CPM mainly comes from the pyrolysis stage and the early stage of combustion of coal. Aliphatic macromolecules and polycyclic aromatic compounds generated by pyrolysis are the precursors of CPM. Due to the limitation of oxygen diffusion, these compounds are released into the air due to insufficient oxidation and eventually form CPM. It is worth noting that the release amount and composition of CPM have a good correspondence with coal temperature. The research results can fill the temperature gap of monitoring fire situation by conventional gas, and help to improve the accuracy of monitoring, which is of great significance for the protection of coal resources and safe production.

Effectiveness of a Local Drug Delivery System Based on Antimicrobial Peptides in Early Treatment of Peri-implantitis

ObjectiveTo analyse the effects of titanium implants coated with various antimicrobial peptide (AMP) layers on bacterial growth and early biofilm formation around the implants. MethodsA novel AMP mixture was constructed using Type I collagen, sulfonated succinimide 4- (N-Maleimidylphenyl) butyrate, and AMPs. Titanium discs treated with chitosan and hyaluronic acid solutions were reacted with the AMP mixture to obtain AMP-coated titanium discs. The drug release properties and inhibitory effects on the growth and early biofilm formation of Porphyromonasgingivalis (P. gingivalis) ATCC BAA-308 or Staphylococcus aureus (S. aureus) ATCC 25923 were analysed. ResultsThe antimicrobial activity of the 9-layer AMP-coated titanium discs against P. gingivalis ATCC BAA-308 and S.aureus ATCC 25923 was greatly higher relative to the 3-layer and 6-layer AMP-coated titanium discs (P < .05). The overall optical density and average optical density of titanium discs coated with 6 and 9 layers of AMPs were markedly inferior to those of uncoated titanium discs and discs coated with 3 layers of AMPs (P < .05). The drug release amounts from titanium discs coated with different layers of AMPs increased over time. ConclusionsThe prepared AMP-coated titanium discs effectively inhibit the growth of P. gingivalis and S. aureus, as well as early biofilm formation. The drug-laced discs demonstrate good durability and predictability in drug release, which may be beneficial for long-term therapeutic adoption.

The utilization of Rutin-loaded lipid nanoparticles as promise carriers to enhance the therapeutic efficacy in ovarian cancer: A computational and experimental study

Since natural chemicals can act as multi-targeted agents in the fight against cancer, recently, highly interested in using them to reduce the adverse effects of cancer treatment, therefore, developing novel and efficient therapeutic methods for cancer is paramount. Studies have demonstrated that Ru exhibits widespread pharmacological properties, such as antioxidant, anti-inflammatory, antiangiogenic, pro-apoptotic, and anti-proliferative activities. These qualities can potentially contribute to the prevention and treatment of cancer. This research aims to develop nano-lipid carriers (NLC) that transport the Ru to OV (SK-OV-3), forcing them to undergo apoptosis and ultimately terminate the cancer cell’s life. First, the molecular structure of water, and other materials were constructed using Material Studio software. Then, the structure of the molecules was optimized through the Forcite module in the software. In sequence, to set the temperature of the system the MD simulations were run under the NVT ensemble with velocity scale as a thermostat and total simulation time equal to 100 ps as the initialization step. We applied the hydrophobic-hydrophobic interactions and micellization process method to encapsulate Ru into NLC. The computational studies showed that in the first 30 ps of the simulation, the system was unstable, but after that, the system reached a stable condition. Moreover, we observed that the density of the system rapidly decreased to a stable mean value equal. Also, the characterizations using DLS and TEM imaging showed that the synthesized NPs have a size lower than 100 nm. The hemolysis evaluation showed that the Ru-micelles are hemocompatible and induced lower than 10 % hemolysis in all tested group. The result shows that the synthesized NLC loading efficiency was 73.63 %, and the particle size was 76 ± 3 nm. The Ru release experiment demonstrated that the loaded sample (Ru-NLC) exhibited a steady release effect, with a total release amount of 84.62 ± 1.61 % of the loaded quantity over 48 h. The findings of in vitro results indicate that Ru-NLC substantially impacts the metabolism of SK-OV-3 cells, and ultimately increases the amount of apoptosis protein levels. Because of these alterations, the cell’s capacity for growth is diminished, and it ultimately dies due to intrinsic apoptosis. The results of the Western blotting experiment indicate that Ru-NLC increases the apoptosis in cancer cells. At long last, we have demonstrated that loading Ru into NLC increased the solubility and bioavailability and could increase the therapeutic efficacy.

Folic acid conjugated sodium alginate based redox responsive smart functional microgels as a potential targeted anticancer drug carrier

In this study, we have fabricated a sodium alginate-based redox-responsive, and cancer cell-targeted specific microgel using a water in oil (w/o) mini emulsion process and characterized it accordingly. Initially, we synthesized folic acid (FA)-grafted sodium alginate (SA), a biocompatible polysaccharide, followed by the preparation of a semi-interpenetrating polymer network (semi-IPN) microgel by crosslinking polyacrylamide (PAAm) with a disulfide crosslinker. The presence of disulfide linkages in the microgel formulation accelerated the release of the anti-cancer drug Doxorubicin (DOX) in the reducing domain of cancer cells (in vitro) (cumulative drug release amount 11 ± 3 %). Folic acid was incorporated into the microgels to enhance its targeting towards cancer cells due to the presence of the folate receptor on cancer cells. MTT (3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay showed an IC50 of ∼30 μg/mL of the DOX-loaded microgels towards breast cancer cells (MDA-MB-231) and a nontoxic behaviour towards normal mouse fibroblast cells (L929). FACS (Fluorescence-Activated Cell Sorting) and cell uptake studies showed significant cell apoptosis upon application of the drug-loaded microgels. In our opinion, this type of microgel can be a potential drug delivery vector for cancer treatment.

Modulation Interference from Speech-Modulated Noise in Bimodal Cochlear Implant Users

Purpose: This study examined modulation interference in sentence recognition for bimodal cochlear implant (CI) users.Methods: Thirteen bimodal users and thirteen normal-hearing (NH) listeners (reference) participated in this study. The adaptive Korean Matrix sentence-in-noise test measured the speech reception thresholds (SRTs) required for 50% speech-in-noise intelligibility. As background noise, we presented two background noises: stationary speech-shaped noise (SSN) and single-talker speech-modulated masker (International Collegium of Rehabilitative Audiology noise, ICRA). The amount of masking release due to fluctuations in the speech-modulated noise, called speech masking release (SMR), was calculated from the difference between SRTs with SSN and SRTs with ICRA noise. The SRTs were measured twice for bimodal CI users: CI-only and bimodal listening.Results: The mean SMR for NH listeners was approximately 12 dB. The mean SMR for bimodal CI users was about -5 dB, with either CI alone or bimodal listening. This means that bimodal CI users experienced modulation interference rather than masking release from the temporal fluctuations. We observed positive bimodal benefits, yet the interference from fluctuating maskers was similar between the CI-only and bimodal listening. The low-frequency aided hearing thresholds in the non-implanted ear were unrelated to the amount of SMR for bimodal users.Conclusion: NH listeners could take advantage of temporal fluctuations in the speech-modulated noise. However, bimodal CI listeners hardly glimpsed target speech in the dips of the speech-modulated masker, regardless of listening mode. Bimodal listening did not significantly reduce modulation interference compared to CI-only listening.

Evaluation of bacterial anti-adhesion and sustained antimicrobial abilities of chlorhexidine gluconate-loaded phase-transited lysozyme nanoparticle suspension on dentine: An exvivo study.

To evaluate the effect of chlorhexidine gluconate-loaded phase-transited lysozyme (CHG@PTL) coating on inhibiting bacterial adhesion and biofilm formation in an exvivo root canal dentine model. The physicochemical and structural characteristics of CHG@PTL nanoparticle suspension and its coating formed on the dentine surface were analysed by thioflavin T fluorescence assay, transmission electron microscopy and confocal laser scanning microscopy (CLSM). The sustained chlorhexidine release profile of the CHG@PTL coating on the dentine surface was compared with that of the 2% CHG solution. By comparing with phosphate-buffered saline, 1% sodium hypochlorite and 2% CHG solutions, the sustained antibacterial ability of the CHG@PTL coating and its effects on adhesion and biofilm formation of three types of bacteria (E. faecalis, S. mutans, and A. viscous) were analysed in exvivo root canal dentine models using the serial plate transfer test (SPTT) and CLSM with live/dead bacterial staining, respectively. CHG promoted the lysozyme protein to form a higher proportion of β-sheet structure during phase transition. In the CHG@PTL nanoparticle suspension, characteristic drug-loaded nanospheres with a high concentration of CHG molecules inside and an outer PTL nanofilm were observed, and they formed a thinner and tighter coating on the dentine surface. The CHG@PTL coating on the dentine surface showed a significantly higher cumulative release amount of chlorhexidine than that of 2% CHG (p < .05). The results of SPTT showed that the CHG@PTL coating had a longer antibacterial duration than the control groups. After 12 h of incubation, a higher number of bacteria were agglutinated on the CHG@PTL coating surface compared to the control groups (p < .05). After 7 days of incubation, the number of agglutinated bacteria significantly decreased. At two time points, the percentage of dead bacteria on the CHG@PTL coating surface was the highest among all experimental groups based on CLSM observation (over 99.9% for all three bacteria, p < .001). CHG@PTL nanoparticle suspension could form an antimicrobial coating on the surface of dentine with a novel 'agglutinating bacteria and sterilizing' mode.

The Influence of Helium Addition on the Combustion Process in a Hydrogen-Fueled Turbulent Jet Ignition Engine

There are considerably fewer requirements for the quality of hydrogen combusted in an engine than its quality for fuel cells. Therefore, the analysis was carried out on the combustion of hydrogen–helium mixtures in an engine with a two-stage combustion system (TJI—Turbulent Jet Ignition). A single-cylinder research engine with a passive and active prechamber was used. A hydrogen–helium mixture was supplied to the main chamber in proportions of 100:0, 90:10, 80:20, 30:70, and 60:40 volume fractions. The prechamber was fueled only with pure hydrogen. Combustion was carried out in the lean charge range (λ = 1.5–3) and at a constant value of the Center of Combustion (CoC = 8–10 deg aTDC). It was found that the helium concentration in the mixture affected the changes in combustion pressure, heat release rate and the amount of heat release. It was observed that increasing the proportion of helium in the mixture by 10% also reduces the IMEP by approximately 10% and reduces the rate of heat release by approximately 20%. In addition, helium influences knock combustion. Limits of MAPO = 1 bar mean assumed that knock combustion occurs in the main chamber at values of λ &lt; 1.9. Increasing the excess air ratio results in a gradual reduction in the temperature of the exhaust gas, which has a very rapid effect on changes in the concentration of nitrogen oxides. Studies carried out on the helium addition in hydrogen fuel indicate that it is possible to use such blends with a partial deterioration of the thermodynamic properties of the two-stage combustion process.

A comparative analysis of the amount of fluoride release, recharge and re-release after uptake in three light-cure orthodontic bonding adhesives – An in-vitro study

Background Fluoride-releasing adhesives in orthodontics help protect enamel. The study compared the fluoride release, recharge, and re-release properties of three light-cure orthodontic bonding adhesives: Group A: TransbondTM Plus Color Change, Group B: Waldent Orthobond LC, and Group C: Koden EZ Bond. Methods The study conducted an in-vitro investigation using 24 maxillary first premolar teeth bonded with one of three fluoride-releasing adhesives after etching. Each sample was placed in artificial saliva, and fluoride release was measured over 60 days using a fluoride electrode. After initial release measurement, specimens were soaked in 1000 ppm fluoride solution for 5 minutes, rinsed, and placed in new containers with distilled water before re-release measurements. Statistical Analysis: One-way ANOVA and Repeated Measures ANOVA tests were used to determine significance, with the Bonferroni posthoc test for further analysis. Results The fluoride release rate decreased gradually over time for all three groups. The highest fluoride release occurred on Day 1 for all three bonding agents, with a significantly reduced fluoride release by Day 2. Group A exhibited consistent and highest overall fluoride release throughout the 60 days. Group B gradually declined to release fluoride until Day 7, releasing the least fluoride throughout the study. Group C had a higher fluoride release on Day 1 and Day 2 but slowly declined until Day 14. Group B and Group C sharply declined fluoride release by Day 30 and almost negligible amounts on Day 60. All three agents noted enhanced fluoride release post-recharge, with continuous release until day 14. Greater release on days 7 and 14 compared to the initial release in all three groups. Conclusion Transbond Plus Color Change: Consistent high fluoride was released initially and post-recharge. Waldent Orthobond LC: Lower release throughout the study. Koden EZ Bond: High initial release and post-recharge but continuing to decrease until Day 14.

Source apportionment of Cd in karst soil based on the delayed geochemical hazard model.

Soil Cd contamination has become increasingly prominent in karst regions. Studies have generally elucidated the natural sources of Cd in high-background areas and analyzed their migration and enrichment mechanisms. This study comprehensively analyzed the total content and speciation of Cd in high-background areas using the delayed geochemical hazard (DGH) model to identify the sources of Cd in the region. The results indicated that Cd in the research area followed a pattern of gradual geochemical disasters. In Quaternary soil, brick-red soil, and submergenic paddy soil with hydromorphic characteristics, 32%, 7.69%, and 30% of soil Cd samples exceeded the critical threshold of the releasable total amount, respectively. Based on the DGH model, it was concluded that Cd in this region was mainly influenced by human activities. Field investigations corroborated this conclusion and aligned with the findings. Compared with the traditional source apportionment receptor models (mainly PCA and PMF), the DGH model not only saved considerable time and cost, but also avoided uncertainty associated with the results and complex and varied data processing and computational analysis processes. Moreover, the DGH model was able to identify the factors having the greatest impact on the ecological risk of Cd in the research area, thus facilitating targeted prevention and management planning based on the characteristics or chemical properties of their elements.

Fabrication of bamboo nanocellulose fibril-based food packaging with dual-antimicrobial property

The development of cellulose-based packaging films with excellent antimicrobial properties and biocompatibility has garnered significant attention. In this work, nanocellulose fibrils (NCFs) derived from from bamboo parenchyma cells were utilized to fabricate nanocomposite film with antimicrobial properties. This system exhibited distinct release behaviors for two antimicrobial agents, with the slow release of Ag nanoparticle (AgNP) in the initial stage contributed to delaying food spoilage, while the subsequent pH change in the microenvironment facilitated the release of essential oil of sour orange blossoms (SEO) for secondary antimicrobial activity. Additionally, the composite film demonstrated improved thermal stability and UV blocking capacity. Moreover, AgNP has been proven to enhance the mechanical properties, with the tensile strength of the novel composite film increasing by 34.85 % compared to control group. The water vapor permeability and oxygen permeability of the novel composite film were reduced, which could potentially reduce weight loss and slow down the rate of after-ripening. Following the acidification treatment, the films containing EO@MPN (essential oil encapsulated with metal-polyphenol network) component performed different antimicrobial patterns, indicating their pH-responsive antimicrobial capabilities, and they are effective against both Gram-positive and Gram-negative bacteria. After a 24-h exposure to a food simulant, the release amount of Ag was measured at 67.6 μg/dm2, within the acceptable limit, and the release profile of Ag was characterized. Cytotoxicity and Live/Dead staining tests confirmed that the novel composite film film had no significant toxicity, thus making it safe for application in food preservation. Furthermore, in a 15-day preservation experiment with mangoes, the novel composite film demonstrated the best performance, underscoring its potential as a sustainable antimicrobial packaging material.