Release Characteristics Research Articles

Investigation of the energy release characteristics and damage of thermobaric explosive under unconstrained conditions

To investigate the energetic release attributes and damage potential of a specific thermobaric explosive at atmospheric pressure, we had employed a pressure testing system, high-speed camera system, and thermal imager to elucidate the impact of explosive mass on the energetic release characteristics. Our findings underscored that thermobaric explosive can significantly enhance the after-burning effect. We noted a discernible positive relationship among the magnitude of the explosive force, post-detonation combustion effects, and the inherent quality of the given explosive. In addition, the resultant overpressure from the shockwave, positive pressure-area impulse, and the duration of the positive pressure, all markedly exceeded those produced by TNT, exhibiting increases of 38.9 %, 51.48 %, and 7 %, respectively. To quantify their explosive potency, empirical formulae were derived to account for the shock wave parameters of thermobaric explosive. Under equivalent mass conditions, the peak thermal radiation flux per unit area from thermobaric explosive substantially exceeded that of TNT. When the PROBIT (probability unit) model and the overpressure-impulse criteria were utilized to ascertain the damage potential of the respective explosives on human targets and structures, it emerged that TBX imparted superior destructive effects. This analysis underpinned the foundational assessment concerning the blast hazard presented by TBX.

Heating manifestations at the onset of the 29 June 2012 flare

Analysis of GOES data for the SOL2012-06-29T04:09 flare, class C4.6, shows a thermal character of the energy release for several minutes before the impulsive stage. Plasma heating to temperatures above 10 MK leads to the appearance of plasma jets along open field lines and in large loops. This work examines the relationship between the heated plasma and the flare structure and its dynamics, using observations in the X-ray, extreme ultraviolet (EUV), and radio-wave ranges. Particular attention is drawn to the detection of narrow-band fine temporal structures of radio emission before and after the impulsive stage of the flare in dynamic spectra. In the initial stage, broadband pulses in the decimeter range are observed which can be associated with the formation of thermal fronts in the jets. A series of super-bright drifting bursts in the centimeter range occurs after the end of the impulsive energy release in the flare kernel. Using data from the Siberian Solar Radio Telescope (5.7 GHz), we managed to localize the position of the source of the fine structure of drifting bursts at the remote footpoint of the large-scale flare loop.

Проявления нагрева в начале вспышки 29 июня 2012 г.

Analysis of GOES data for the SOL2012-06-29T04:09 flare, class C4.6, shows a thermal character of the energy release for several minutes before the impulsive stage. Plasma heating to temperatures above 10 MK leads to the appearance of plasma jets along open field lines and in large loops. This work examines the relationship between the heated plasma and the flare structure and its dynamics, using observations in the X-ray, extreme ultraviolet (EUV), and radio-wave ranges. Particular attention is drawn to the detection of narrow-band fine temporal structures of radio emission before and after the impulsive stage of the flare in dynamic spectra. In the initial stage, broadband pulses in the decimeter range are observed which can be associated with the formation of thermal fronts in the jets. A series of super-bright drifting bursts in the centimeter range occurs after the end of the impulsive energy release in the flare kernel. Using data from the Siberian Solar Radio Telescope (5.7 GHz), we managed to localize the position of the source of the fine structure of drifting bursts at the remote footpoint of the large-scale flare loop.

Microstructure and energy release properties of W-Zr-Al energetic structural material fabricated by explosive consolidation

Multi-element intermetallic energetic structural materials (ESMs) as a new typical ESMs characterized by their high heat release properties and strength, which could be applied as reactive fragment, reactive shell and reactive shaped charge. Al-based ESMs had been extensively studied due to their excellent mechanical properties and high energy release characteristics. But, the low density of Al-based ESMs hindered its application. However, the need for higher density and energy release persists. In this work, the nearly fully dense W-Zr-Al ESMs with a molar ratio of 1.9:1:1 was fabricated successfully by explosive consolidation. The density reached 10.12 g/cm3 (97.5 % of the theoretical maximum density). Microstructure of the specimen was characterized by X-ray diffractometer (XRD), optical microscopy (OM), scanning electron microscope (SEM), energy dispersive spectrometry (EDS) and transmission electron microscope (TEM). The heat treatment was used to further improve the performance of the specimen and the mechanical properties of quasi-static compression was investigated before and after heat treatment. The reaction activity and process of W-Zr-Al ESMs was discussed by differential scanning calorimetry (DSC). Besides, the impact-induced energy release tests were carried out to evaluate the reactive characteristics of the W-Zr-Al ESMs. The results indicated that high-density, good-strength and high energy release unreacted W-Zr-Al energetic materials were fabricated successfully by explosive consolidation.

Development and Optimization of Gellan Gum-Based Gastro-Retentive Microbeads for Enhanced Controlled Release of Acyclovir.

Modified release systems offer enhanced spatial and temporal control over drug delivery, leading to better blood plasma profiles, targeted therapy, reduced side effects, and improved patient compliance. Recent advancements focus on using biocompatible polymers to achieve sustained or controlled drug release, particularly for gastroretentive systems that enhance oral bioavailability and minimize dose-dependent toxicity. This study explores the formulation of floating microbeads of acyclovir (ACV) using various hydrophilic polymers. The prototype oral formulations demonstrated superior micrometric properties, including bulk density, tapped density, Carr’s index, Hausner’s ratio, angle of repose, average particle size, yield, and drug content. In-vitro dissolution studies revealed controlled release characteristics, with optimal floating time and entrapment efficiency achieved using specific concentrations of olive oil and polymers. Drug release trailed the Korsmeyer-Peppas model, indicating a diffusioncontrolled mechanism. The formulations exhibited good storage stability, in-vivo floating ability, and higher bioavailability in rabbits compared to ACV solutions. The results suggest that hydrophilic polymers are effective for formulating floating microbeads with controlled release and reproducible profiles.

Effects of three types of additives on mechanical properties and impact energy release characteristics of Al/PTFE reactive structural material

Effects of three types of additives on mechanical properties and impact energy release characteristics of Al/PTFE reactive structural material

Research Progress on the Mechanisms and Control Methods of Rockbursts under Water–Rock Interactions

Rock bursts are among the most severe and unpredictable hazards encountered in deep rock engineering, posing substantial threats to both construction safety and project progress. This study provides a comprehensive investigation into how moisture infiltration influences the propensity for rock bursts, aiming to establish new theoretical foundations and practical methods for their prevention. Through the analysis of meticulous laboratory mechanical experiments and sophisticated numerical simulations, we analyzed the variations in the physical and mechanical properties of rocks under different moisture conditions, with a particular focus on strength, brittleness, and energy release characteristics. The findings reveal that moisture infiltration significantly diminishes rock strength and reduces the likelihood of brittle fractures, thereby effectively mitigating the risk of rock bursts. Additionally, further research indicates that in high-moisture environments, the marked reduction in rock burst tendency is attributed to increased rock toughness and the suppression of crack propagation. This study advocates for the implementation of moisture control measures as a pre-treatment strategy for deep rock masses. This innovative approach presents a viable and effective solution to enhance engineering safety and improve construction efficiency, offering a practical method for managing rock burst risks in challenging environments.

Development of Sinomenine Hydrochloride Sustained-release Pellet With Multiple Release Characteristics.

Due to the gastrointestinal side effects, the clinical application of sinomenine hydrochloride (SH) in rheumatoid arthritis is limited. The elderly population constitutes the primary group affected by this disease, and within this demographic, there are significant variations in gastric emptying time. To reduce the influence of individual differences on drug efficacy and concurrently alleviate gastrointestinal side effects, the SH sustained-release pellets with multiple release characteristics were developed, which comprised both regular sustained-release pellets and enteric-coated sustained-release pellets. The drug-loaded layer formulation was optimized by full factorial design. With the optimal formulation, the drug-loaded pellets achieved a yield of 96.05%, an encapsulation efficiency of 83.36% for SH, a relative standard deviation of 3.26% in SH content distribution, an average roundness of 0.971 for the pellets, and the particle size span of 0.808. The pellets with a 4h SH release profile in an acidic environment and pellets displaying 4h acid resistance followed by an 8h SH release behavior in the intestinal environment were individually prepared through in vitro dissolution tests. The results demonstrated stable and compliant dissolution behavior of the formulation, along with excellent stability and physical appearance. This research offers novel insights and references for the innovative formulation of SH.

Tofacitinib Citrate-Loaded Topical Gel for the Treatment of Rheumatoid Arthritis: Formulation and In-vitro-In-vivo Characterization.

This study aims to create and assess the anti-arthritic activity of tofacitinib citrate (TC) as a topical gel formulation. Using the gelling agent Carbopol 980 P, seven gel formulations were formed. The gel formulations were assessed for pH, drug content, spreadability, homogeneity, and in-vitro diffusion profile. Out of all the formulations, G7 exhibited superior release characteristics (99.1%) in comparison to the other formulations. The DSC research revealed a strong endothermal peak at 214.17°C and demonstrated an interaction with the excipients taken into consideration in this investigation. While carrying out the in-vivo study, formulation G7 successfully reduced inflammation induced by CFA. Ultimately, the optimal formulation for the “G7” can be determined & successfully treats inflammation associated with arthritis. As per stability studies, it was specified that there are no such major changes in the long-term and accelerated stability testing study.

QBD approach for green synthesis of Rutin silver nanoparticles- screening for antioxidant, anticancer and anticlastogenic potential

Rutin is a flavonoid glycoside abundant in many plants exhibiting pharmacological activities like antioxidant, anticancer, anti-inflammatory and antimicrobial activities. Plant biomarkers suffer low bioavailability and solubility that lack clinical effectiveness. The smart nanoparticles conversion addresses this limitation with optimal particle size and targeted drug delivery. The present study involves QbD approach for formulation of Rutin silver nanoparticles and evaluation of antioxidant, anticancer and anticlastogenic potential. QbD experimentation involved particle size and drug release as dependent variables over the silver nitrate concentration, methanol and sonication time as independent variables devising 15 formulations (F1 –F15). F12 formulation was found to be optimized with 126.3 nm average size, stable and dispersible characterized by UV, FTIR, SEM and DLS studies. The calibration curve of Rutin was plotted at 352 nm with linearity (LOD = 0.061 μg/ml and LOQ = 0.187 μg/ml). The invitro drug release studies by USP dissolution apparatus I (Basket type) proved the sustained release characteristics with 97.3 % drug release when compared to the Rutin. The pharmacological screening for potential antioxidant and anticancer activity on G361 and MCF 7 cell line of F12 formulation have shown promising results and also enhanced solubility in water compared to Rutin. Anticalstogenic potential as a function of induced micronuclei frequency was evaluated as a characteristic feature in bone marrow cells obtained from mice. Results indicate pre-treatment with the F12 reduced frequency of micronuclei in mouse bone marrow cells caused by Cyclophosphamide (CP) significantly. The protective effect of F12 in suppression was demonstrated at both dosages of 100 and 200 mg/kg. Thus the findings suggest the novel Rutin silver nanoparticles as lead drug serving as antioxidant, anticancer and anticlastogenic agent.

TRPV1-targeted ion-responsive hydrogel against pyroptosis of dry eye disease

Dry eye disease (DED) is a complex ocular surface abnormality characterized by tear film hyperosmolarity, inflammation, and damage. Left untreated, DED can lead to a self-perpetuating vicious cycle of worsening symptoms. Existing treatments for DED face challenges related to limited drug delivery to the ocular surface and potential side effects from nonspecific drug targeting. In an effort to address these issues, we developed a novel ion-responsive in situ gelling system targeting the transient receptor potential vanilloid 1 (TRPV1), based on co-assembly of the hydrogelator KFQ12 with the functional peptide V1-Cal. The KFQ12/V1-Cal (KVC) aqueous solution, when dripped and mixed with the ionic tear film on the ocular surface, rapidly transformed into a honeycomb-like hydrogel. This hydrogel exhibited prolonged retention on the ocular surface, serving as a stable scaffold for corneal epithelium regeneration and providing protection against external pathogens while maintaining gas exchange. In a murine model of DED, the KVC hydrogel demonstrated superior therapeutic efficacy due to its sustained release characteristics and specific inhibition of the TRPV1 channel activated by hyperosmotic or desiccating stress. By performing transcriptome sequencing and experimental validation both in vivo and in vitro, we confirmed the mechanism of the TRPV1-Ca2+-Pyroptosis axis in the pathogenesis of DED. Our research provides novel perspectives on the understanding and treatment of DED, and introduces a potential ocular surface drug delivery system characterized by superior biosafety, prolonged retention, and improved therapeutic outcomes.

Commercial Silver-Based Dressings: In Vitro and Clinical Studies in Treatment of Chronic and Burn Wounds.

Chronic wounds are a major health problem because of delayed healing, causing hardships for the patient. The infection present in these wounds plays a role in delayed wound healing. Silver wound dressings have been used for decades, beginning in the 1960s with silver sulfadiazine for infection prevention for burn wounds. Since that time, there has been a large number of commercial silver dressings that have obtained FDA clearance. In this review, we examine the literature involving in vitro and in vivo (both animal and human clinical) studies with commercial silver dressings and attempt to glean the important characteristics of these dressings in treating infected wounds. The primary presentation of the literature is in the form of detailed tables. The narrative part of the review focuses on the different types of silver dressings, including the supporting matrix, the release characteristics of the silver into the surroundings, and their toxicity. Though there are many clinical studies of chronic and burn wounds using silver dressings that we discuss, it is difficult to compare the performances of the dressings directly because of the differences in the study protocols. We conclude that silver dressings can assist in wound healing, although it is difficult to provide general treatment guidelines. From a wound dressing point of view, future studies will need to focus on new delivery systems for silver, as well as the type of matrix in which the silver is deposited. Clearly, adding other actives to enhance the antimicrobial activity, including the disruption of mature biofilms is of interest. From a clinical point of view, the focus needs to be on the wound healing characteristics, and thus randomized control trials will provide more confidence in the results. The application of different wound dressings for specific wounds needs to be clarified, along with the application protocols. It is most likely that no single silver-based dressing can be used for all wounds.

Effect of tannic acid modification on antioxidant activity, antibacterial activity, environmental stability and release characteristics of quercetin loaded zein-carboxymethyl chitosan nanoparticles

The stability of quercetin remains a challenge for their application in industrial food production. In order to solve this shortcoming, zein-tannic acid covalent complex was prepared. Fourier transform infrared spectroscopy demonstrated the formation of CN bond between zein and tannic acid. Quercetin loaded nanoparticles (QZTC) were prepared by zein-tannic acid complex and carboxymethyl chitosan by anti-solvent co-precipitation and pH migration method. The structure of the nanoparticles was characterized and the effects of tannic acid modification and carboxymethyl chitosan addition on the encapsulation efficiency, oxidation resistance, antibacterial property, environmental stability and microstructure of the nanoparticles were studied. The results showed that compared with zein nanoparticles, QZTC had higher encapsulation rate, smaller and more uniform spherical microstructure. Compared with free quercetin and the other two nanoparticles, QZTC showed higher light, heat, storage stability, antioxidant and antibacterial abilities (p < 0.05). It was also found that the improvement of stability mainly depended on the formation of CN covalent bond, hydrogen bond, electrostatic interaction and hydrophobic interaction between components. This study provides new ideas for improving the environmental stability, antioxidant and antibacterial properties of quercetin and for developing nanoparticles that can be used in food processing.

Carbon, nitrogen, and phosphorus release characteristics and underlying mechanisms in fish manure from recirculating aquaculture systems under alternating aerobic-anaerobic conditions

To mitigate the adverse environmental impacts of aquaculture operations, recirculating aquaculture systems (RASs) have emerged as promising alternatives to traditional aquaculture methods. Fish manure is the primary pollutant in RASs, and oxygen fluctuations significantly influencing the release of pollutants. However, the release characteristics and underlying mechanisms of carbon (C), nitrogen (N), and phosphorus (P) during alternating aerobic-anaerobic conditions in RASs remain poorly understood. This study conducted batch incubation experiments to examine the release dynamics of C, N, and P from fish manure under simulated alternating aerobic-anaerobic conditions. Results showed that the overlying water exhibited anaerobic and reductive conditions, with both COD and TOC concentrations decreasing over time. NH4+-N levels significantly decreased from days 1–9, while NO3--N concentrations peaked on day 16. Furthermore, the alternating aerobic-anaerobic conditions significantly increased TP concentration in the overlying water. Soluble microbial byproduct-like substances in the overlying water transformed into humic acid-like substances over time. The relative abundance of Proteobacteria and Firmicutes decreased by 13.6 % and 6 %, respectively, while the relative abundance of Actinobacteria, Bacteroidota, and Chloroflexi increased by 7 %, 12.8 %, and 1.4 %, respectively. Overall, both abiotic and biotic factors influenced the release of C, N, and P from fish manure. The coupled effects of abiotic factors, specific bacterial communities, and functional genes played a critical role in the release and transformation of these elements. These findings provide new insights into the release behaviours and mechanisms of pollutants in RASs, contributing to improved environmental risk management in RASs.

Chitosan/Sodium Alginate Hydrogel for the Release of Berberine as an Algae Suppressant: RSM Optimization and Analysis of Sustained Release Characteristics.

In this study, we used chitosan/sodium alginate hydrogel as a carrier to prepare berberine sustained-release capsule materials that can inhibit algae for a long time and safely. The preparation conditions of the material were optimized by the response surface method, and the optimized capsule material was characterized and the sustained release characteristics were analyzed to study the change of the algae inhibition effect of the material within 30 days. The results showed that the optimum preparation parameters of the material were 0.54% chitosan content, 2.46% sodium alginate content and 1.09% anhydrous calcium chloride content by response surface optimization design, which was consistent with the parameters set by each factor at the central point. The algae inhibition rate of the material under this preparation condition was 93.75 ± 1.01%, which was similar to the predicted value. The release characteristics analysis showed that the material continuously released up to 90% of berberine within 24 days, and its release characteristics were sustained release after burst release, with good sustained release effect. The results of material characterization showed that chitosan/sodium alginate hydrogel could effectively load berberine and was beneficial to the loading and release of berberine. The results of algae inhibition experiments showed that low concentration materials could control the outbreak of cyanobacterial blooms in a short time, while under high concentration conditions, the materials could inhibit Microcystis aeruginosa efficiently and for a long time.

Lipid-based nanodelivery systems of curcumin: Recent advances, approaches, and applications

Despite its many beneficial effects, pharmaceutical applications of curcumin (CUR) are limited due to its chemical instability, low solubility/absorption and weak bioavailability. Recent advances in nanotechnology have enabled the development of CUR-loaded nanodelivery systems to tackle those issues. Within many different nanocarriers developed for CUR up to date, lipid-based nanocarriers (LBNs) are among the most extensively studied systems. LBNs such as nanoemulsions, solid lipid carriers, nanostructured phospholipid/surfactant carriers are shown to be potential delivery systems capable of improving the solubility, bioavailability, and chemical stability of CUR. The particle characteristics, stability, bioavailability, and release properties of CUR-loaded LBNs can be tailored via optimizing the formulation and processing parameters. This paper reviews the most recent studies on the development of various CUR-loaded LBNs. Approaches to the improvement of CUR bioavailability and release characteristics of LBNs are discussed. Furthermore, challenges in the development of CUR-loaded LBNs and their potential applications are presented.

Preparation of Aloysia citriodora (Lemon verbena) extract loaded lipid-nano capsules for topical antibacterial treatment

Nanocapsules have become a promising drug delivery approach for fighting bacterial infections. Extract from Aloysia citriodora (Lemon verbena), known for its biological activities and culinary applications, was investigated as a potential source for topical antibacterial treatment. The aim was to prepare and optimize lipid nanocapsules loaded with Aloysia citriodora extract, using both water and ethanol as solvents. The production, optimization, and characterization of these nanocapsules were conducted employing a Box-Behnken design to examine the impact of various factors on the polydispersity index, particle size, and entrapment efficiency. Assessments were made on solubility, stability, pH, and homogeneity, along with evaluations of in-vitro drug release, dermatokinetic properties, antioxidant activity, and antibacterial effects. The physical stability and quality of the nanocapsules were demonstrated with an average size of 104.6 nm and a polydispersity index (PDI) of 0.246. The encapsulation effectiveness was determined to be 87.08 %. In-vitro drug release studies revealed sustained release characteristics by the Korsmeyer Peppas model. Additionally, the formulation displayed significant antioxidant activity and promising antibacterial effects against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Stability tests over ninety days showed that the formulation maintained structural integrity, consistent pH values and drug content, and good spreadability. The nanoformulation combined the benefits of Aloysia citriodora extract with the advantages of nanocapsule technology, offering a novel approach to addressing various pharmaceutical and antimicrobial challenges.

The Use of Systemically Absorbed Drugs to Explore An In Vitro Bioequivalence Approach For Comparing Non-Systemically Absorbed Active Pharmaceutical Ingredients in Drug Products For Use in Dogs.

Currently, for veterinary oral formulations containing one or more active pharmaceutical ingredient (API) that are not systemically absorbed and act locally within the gastrointestinal (GI) tract, the use of terminal clinical endpoint bioequivalence (BE) studies is the only option for evaluating product BE. This investigation explored the use of a totality of evidence approach as an alternative to these terminal studies. Three formulations of tablets containing ivermectin plus praziquantel were manufactured to exhibit distinctly different in vitro release characteristics. Because these APIs are highly permeable, plasma drug concentrations served as a biomarker of in vivo dissolution. Tablets were administered to 27 healthy Beagle dogs (3-way crossover) and the rate and extent of exposure of each API for each formulation was compared in a pairwise manner. These results were compared to product relative in vitro dissolution profiles in 3 media. In vivo and in vitro BE predictions were compared. In vivo/in vitro inconsistencies in product relative performance were observed with both compounds when considering product performance across the 3 dissolution media. Formulation comparisons flagged major differences that could explain this outcome. The finding of an inconsistent in vivo/in vitro relationship confirmed that in vitro dissolution alone cannot assure product BE for veterinary locally acting GI products. However, when combined with a comparison of product composition and manufacturing method, this totality of evidence approach can successfully alert scientists to potential therapeutic inequivalence, thereby supporting FDA's efforts to Replace, Reduce, and/or Refine terminal animal studies.

Eco-friendly, pH-sensitive curcumin-loaded sodium alginate/hydroxyapatite/quaternary ammonium chitosan microspheres with enhanced antibacterial and antioxidant activities for fruit preservation

The development of intelligent responsive reactive packaging materials with natural polymers shows excellent potential in food preservation. In this study, eco-friendly, pH-sensitive sodium alginate (SA)/hydroxyapatite (HA)/quaternary ammonium chitosan (HACC) composite microspheres loading curcumin (CUR) with excellent antibacterial and antioxidant activities were successfully synthesized. Scanning electron microscopy (SEM) and nitrogen adsorption/desorption tests indicated that the doping of HA substantially increased the specific surface area and pore volume of the microspheres. The loading experiments showed that the efficiency of the microspheres was significantly increased by 49.47 % and 55.10 %, respectively, when HA and HACC were incorporated into the SA network. The release test results suggested that the release rate of SA/HA/HACC microspheres loading CUR (SA/HA/HACC@CUR) increased as the pH decreased, demonstrating notable pH-responsive release characteristics. DPPH free radical scavenging experiments demonstrated that the SA/HA/HACC@CUR had excellent and long-lasting antioxidant capacity. The antibacterial experiments revealed that the SA/HA/HACC@CUR had excellent antibacterial properties, with inhibition rates of 88.73 % and 92.52 % against E. coli and S. aureus, respectively. Making coatings out of microspheres could effectively slow down the rotting and deterioration of cherry tomatoes during storage, suggesting that microspheres with intelligent responses have a broad application prospect in fruit preservation.

Studies on Propranolol hydrochloride floating tablets formulated with different concentrations of Aegle marmelos gum

This research employs Aegle marmelos gum in various ratios as a natural polymer to formulate and assess Propranolol hydrochloride floating tablets. Because of its high solubility and permeability, propranolol hydrochloride, a non-selective beta-adrenergic receptor blocker, has a restricted bioavailability. Floating tablets are intended to improve the absorption and bioavailability of drugs by staying afloat in the stomach. Aegle marmelos gum (AMG) was used as a polymer in varied ratios to create distinct formulations. The tablets were then tested for a number of characteristics, including hardness, friability, drug content, in vitro buoyancy, and drug release profiles. The findings showed that the Aegle marmelos gum content had a major impact on the tablets' floating qualities and drug release characteristics.