Dispersed Systems Research Articles

Effects of soybean β-conglycinin subunits composition on its emulsifying properties and the mechanism

In the soybean β-conglycinin system, subunit composition has an important influence on its emulsification properties. To elucidate the mechanism of subunit action in the emulsification process, the separated and purified β-subunit and the mixture α- and α′-subunits (referred to αα′-subunit) were remixed in varying proportions, and then the physicochemical properties and structural properties of the subunit emulsifying system were characterized. The results demonstrated that when the ratio of αα'-subunit to β-subunit was 5:5, the subunit aqueous dispersion system exhibited a minimum particle size of 47.58 nm, a maximum solubility of 87.21%, and the emulsification stability and emulsification activity were also optimal. Scanning electron microscope (SEM) images revealed excellent cross-linking between αα′-subunit and β-subunit, forming a protein network structure that provided a structural basis for its emulsification. The emulsion with a subunit ratio of 5:5 exhibited the highest fraction of interfacial protein adsorption of 23.43% and the largest interfacial protein concentration of 11.79 mg/m2. Inter-subunit adsorption and emulsion formation were primarily driven by hydrophobic interactions, with the β-subunit exhibiting a higher affinity for adsorption than the αα′-subunit. The action mechanism of the subunits in the emulsion formation was proposed as a “three-stage” process, including establishing an initial weak protein network structure within the aqueous dispersion, followed by developing an emulsion interface layer and ultimately culminating in forming an emulsion gel network structure. Elucidating the emulsifying mechanism at the subunit level is crucial for enhancing the theoretical framework of soybean protein emulsification.

Experimental evidence of nonreciprocal propagation in space-time modulated piezoelectric phononic crystals

A nonreciprocal system composed of a one-dimensional piezoelectric phononic crystal whose periodic electrical conditions are modulated in time is presented. One-way longitudinal wave propagation is studied experimentally and compared to finite element temporal simulations. The modulation is performed by prescribing grounded or floating potential conditions on a periodic set of electrodes through external circuits. This approach makes it possible to consider a wide range of modulation speeds, and the large number of unit cells of the phononic crystal allows us to characterize experimentally the full dispersion curves of the system. This permits to observe the presence of directional bandgaps and to follow the shift in frequencies of these bandgaps as a function of the modulation speed. The experiments show the linear evolution of the central position of the bandgaps with the increase in the modulation speed, as well as their progressive closure, over a wide range of frequencies. Experiments are also used to estimate the evolution of bandgaps in a dispersive system, a problem discussed in several theoretical works but never observed experimentally. This work may constitute the foundation for experimental analysis of Floquet acoustic metamaterials, accelerated-modulation space-time metamaterials, or acoustic analog of the event horizon.

Inclusion of CoFe2O4 ultrafine nanoparticles in 7CB liquid crystal: effects on temperature-dependent magnetic properties and insights for expanding the application of LC systems in hyperthermia treatments

ABSTRACT This work presents a comprehensive analysis of the magnetic properties of pristine and citric acid-coated cobalt ferrite ( CoF e 2 O 4 ) nanoparticles (NPs) dispersed in the host nematic 4 ′ -heptyl-4-biphenylcarbonnitrile (7CB) system. Our results shed light on the promising potential of combining liquid crystals (LC) with magnetic nanoparticles for cancer treatment. This opens up exciting avenues for further exploration and possible applications in the field of oncology. The study focuses on examining the magnetic behaviour of LC dispersed systems with two concentrations of magnetic nanoparticles (0.03 and 0.04 wt%). Notably, intriguing temperature-dependent magnetisation plots reveal a distinctive cusp, which can be attributed to the freezing phenomenon of the liquid crystal. This observation offers valuable insights into the system's magnetic properties and interactions, deepening our understanding of its behavior.

A temperature-sensitive polymer with thinner effect as a rheology modifier in deepwater water-based drilling fluids

The special deepwater and deep well environment in the deepwater area of the ocean puts forward higher requirements on the temperature resistance and flat rheology performance of water-based drilling fluid. In this study, the flat rheology performance of water-based drilling fluids was improved by synthesizing a temperature-sensitive polymer with thinner effect as a rheology modifier (PVNA). PVNA was characterized by infrared spectroscopy, thermogravimetric, nuclear magnetic resonance hydrogen spectroscopy, X-ray photoelectron spectroscopy and liquid gel chromatography. The results of the evaluation experiments showed that PVNA in 4 wt% bentonite mud resisted temperature up to 180°C and had good compatibility. The slope of the viscosity-temperature curve of the 4 wt% bentonite mud after aging at 180 °C/16 h was reduced from 0.84 to 0.17 after the addition of PVNA, indicating that PVNA can substantially improve the flat rheology performance of the 4 wt% bentonite mud. Turbidity analysis, particle size analysis, thixotropy analysis and transmission electron microscopy analysized the temperature-sensitive effect of PVNA. Specifically, PVNA weakens the hydration layer on the surface of bentonite through its hydrophobic properties, reducing the low-temperature aggregation effect of bentonite, and avoiding low-temperature thickening of bentonite mud to a certain extent. At the same time, the temperature-sensitive effect of PVNA after warming brings stronger intermolecular binding, which improves the internal three-dimensional network strength of the bentonite dispersion system after warming. The two effects synergistically improved the flat rheology performance of the dispersion system. PVNA has good application prospects and can be used as a good reference for developing other rheology modifiers.

Provider- and System-Level Barriers and Facilitators to Colonoscopy and Multi-Target Stool DNA for Colorectal Cancer Screening in Rural/Remote Alaska Native Communities.

The Alaska Tribal Health System is working to increase colorectal cancer (CRC) screening among Alaska Native people, who experience the highest CRC rates in the world. This study examined CRC screening provider- and system-level barriers and facilitators from the perspective of healthcare providers serving Alaska Native people in rural/remote communities. A total of 28 provider (physicians, advanced practice, and Community Health Aides/Practitioners) interviews were held from 1 February to 30 November 2021. Colonoscopy provider-level barrier themes included time, competing priorities, and staffing, while system-level barriers included travel costs, weather, and the COVID-19 pandemic. Multi-target stool DNA (mt-sDNA) barrier themes included test viability and unfamiliarity, and previous stool tests experiences. For both tests, limited medical record reminders was a major barrier. Facilitator themes for both tests included community outreach, cultural competency and patient navigation, and clinic/system improvements. In-depth interviews with tribal health providers showed that adding mt-sDNA testing may help address system-level colonoscopy barriers such as waitlists and travel costs, but other barriers remain. Further research is needed into patient barriers and facilitators, as well as the effectiveness of integrating mt-sDNA into a geographically dispersed tribal health system to reduce cancer disparities and build equity in CRC prevention among Alaska Native people.

Novel nanocomposites based on Tetrazine liquid crystals for energy storage application

Polymethyl methacrylate (PMMA) /Tetrazine liquid crystal (LCTZ12) nanocomposites with different CNTs loadings have been prepared. The prepared nanocomposites were characterized using polarizing light microscope (POM), differential scanning calorimetry (DSC), Fourier transform Infrared Spectroscopy (FTIR) and broadband dielectric spectroscopy (BDS) in the range 10-1-106 Hz respectively. The most commonly observed texture of soft crystal phases was that of a mosaic pattern, as revealed by the POM technique. PMMA alone does not change the polarization states and appeared as isotropic material, but once LCTZ12 is added, crystal growth could be clearly noticed in the needle pattern inside the polymer matrix to compose an amazing structure of soft crystal G texture. The increase of LCTZ12 to about 20 wt% in the PMMA matrix led to more heterogeneous aggregation of liquid crystalline molecules. This ratio addition is enhancing of network connections inside the PMMA. Moreover, the dispersion of carbon nanotubes mounted on catalysts is found to accumulate in segregations in PMMA/ LCTZ12 nanocomposites. However, the location of CNTs is concentrated at bottom of polymer network due to the large difference in densities of LCs, PMMA, and CNTs. DSC is in agreement with the POM result of LCTZ12, which has multi soft crystals or highly self-assembled ordered liquid crystal phases near to room temperature. The FTIR proved that blend PMMA/ LCTZ12 (80/20) has a dramatic increase in the 1387 cm−1 peak of C = C as a response of the rise in the concentration or number of aromatic rings. Additionally, the vibrational scissoring peak located at 1477 cm−1 of methylene CH2 groups is increased significantly and C–H stretching in aliphatic regions at 2850 cm−1 and 2990 cm−1 as well. However, there is no significant change observed after CNTs addition to the PMMA/ 20 wt% LCTZ12 matrix. Regarding dielectric results, it was found that, the polymer dispersed liquid crystals PDLC system composed of (PMMA/20 wt% LCTZ12) possesses the most promising dielectric properties, that is; high dielectric permittivity with low losses compared to the other ratios. The addition of CNTs results in more localization of charge carriers along with mobile ions, causing higher ionic conductivity. The conductivity ranges altered from 3.2 × 10-10 S/cm in pure PDLC system to become 1.7 × 10-3 S/cm for PDLC doped with 10 wt% CNTs nanocomposite. The electrical energy density measurements for 3,6-bis(5-(Dodecyloxy) pyridin-2-yl)-1,2,4,5-tetrazine (LCTZ12) liquid crystals with 6 cationic centers in polymeric matrices proved to be suitable for flexible and efficient electrolytes for energy storage devices.

Research by choice of excipients ingredients of the gel for the therapy of radiation lesions of the skin based on rheological studies

The aim of this work is to conduct a research analysis of changes in the structural and mechanical properties of the gel from the addition of active substances and surfactants.
 Materials and methods. In the presented work, model samples of the gel with active substances were studied: freshly obtained stonecrop juice, sea buckthorn oil, rosehip oil, St. John's wort oil and quercetin. As substances for the manufacture of bases hydrocolloids of cellulose derivatives were used: sodium carboxymethylcellulose (NaCMC) and hydroxyethylcellulose (HEC) with a surfactant Lanette SX.
 A study of the rheological properties of the samples was performed using a rheoviscometer Rheolab QC (Anton Paar, Austria) using a system of coaxial cylinders C-CC27 / SS. The Rheolab QC rheometer is equipped with RheoPlus software, which allows you to set the necessary experimental conditions (shear rate gradient range, number of measuring points and measurement time of one point).
 Results. The rheological properties of model samples of NaCMC and HEC gels, depending on the used concentration, were studied. With increasing concentrations of both NaCMC and HEC thixotropy of dispersed systems decreases. The change of structural and mechanical parameters of hydrogels from the addition of active ingredients and surfactant is analyzed, and established that adding them into the hydrogels increases the structural and mechanical parameters of model samples.
 A study of gels with a constant concentration of sodium carboxymethylcellulose and hydroxyethylcellulose and different content of surfactant Lanette SX established that as the surfactant concentration increases, the area of the hysteresis loop and the resistance of the dispersed system to the applied mechanical fracture increase.
 Conclusions. According to the results of the obtained structural and mechanical parameters and rheograms of the studied model samples of gels, it is rational to use in further studies of sodium carboxymethyl-cellulose (1.5 %) and hydroxyethylcellulose (1.25 %) stabilized Lannete SX in concentrations of 4-5 % and 3-5 % respectively

HPAM-biomass phenol-formaldehyde resin dispersion system: evaluation of stability

HPAM-biomass phenol-formaldehyde resin dispersion system: evaluation of stability

Moving towards a comprehensive view of the spatial processes in seed dispersal networks: Embracing metacommunities.

The current biodiversity crisis requires efficient approaches to address the ongoing impoverishment of natural communities and the depletion of ecosystem services and functions. In this sense, identifying key species that promote the functioning of ecological processes can be strategic to guide actions aiming at the conservation and restoration of biodiversity. Node-level metrics in interaction networks can be helpful to identify those key species, as they measure the role each species plays in organizing the interactions. Moreover, ecological correlates of species structural roles may vary between local and global networks of interactions, reflecting distinct mechanisms acting at different spatial scales. By studying local seed dispersal networks and one global meta-network combining those local networks, Moulatlet et al. identified the most important traits explaining bird species centrality at varying spatial scales. They found that body mass was the main trait explaining centrality at the local scale, whereas range size was the main predictor of species centrality at the global scale. In this contribution, besides assessing local interaction networks, Moulatlet et al. adopt a biogeographical perspective to seed dispersal systems, extending our knowledge about the possible mechanisms that underlie the organization of interacting assemblages when changing the spatial scale of observation. Future efforts on this field could include an intermediate scale, comprising the level of metacommunities, shedding light on the interplay between local and spatial processes, both embedded in biogeographical realms, when determining the organization of interactions and the ecological correlates of species roles.

STABILIZATION OF WATER-COAL COMPO­SITE FUELS USING CARBON MICRO-NANO­MATERIALS AND AMINO ALCOHOLS

The study investigated the potential of stabilizing composite water-coal fuel (CWCF) by adding carbon micro-nanomaterials obtained through the plasma-chemical conversion of organics-containing wastewater and amino alcohols. The study focused on systems based on anthracite with a solid phase concentration of 62%. Two amino alcohols, 2-amino-­2-methyl-1-propanol (AMP) and 2-amino-­2-ethyl-1,3-propanediol (AEPD) were used at concentrations of 0.25%, 0.5%, 1%, and 2.5% by weight of CWCF.
 The low stability and heterogeneity of coal particle distribution in organic liquids cause an increase in the viscosity of dispersed systems in combined systems. To regulate the rheological properties and stabilize the CWCF, chemicals such as dispersants, plasticizers, and stabili­zers are added. The CWCF 's properties can be improved by using additives such as sodium, calcium, and magnesium lignosulfonates, and naphthalene sulfonic acids. However, these reagents may not provide the desired properties of coal slurries in organomineral environments. Therefore, substitutes for these pro­ducts need to be found.
 Amino alcohols are commonly used as dispersants and stabilizers, especially in the production of water-based paints. They are low in cost, low in toxicity, and serve as anti-corrosive agents and pH stabilizers without causing excessive foaming. To strengthen the spatial structure, reactive particles such as carbon micro- and nanomaterials (CNM) can be introduced into the CWCF. Unlike polyelectrolytes and surfactants, CNM particles can have a varying number of active centers depending on the method of formation. By varying the properties of CNMs, it is possible to increase the number of contact centers and form a spatial grid without increasing the concentration of surfactants and polyelectrolytes. This is because contact interactions are activated during grinding, forming a new surface with energy-saturated active centers. As a result, the concentration of the system can be increased, and the calorific value of the fuel can be increased as well. However, the presence of an organic component can render mechanochemical activation ineffective by shielding active sites with large organic molecules. Therefore, identifying the most effective stabilizer reagents and deve­loping technology for their introduction into the dispersed system is a crucial and intricate problem in obtaining CWCF
 The study revealed that the ξ potential of anthracite particles is 40–45 mV in the pre­sence of amino alcohols. Sedimentation stabi­lity in the presence of highly dispersed carbon additives increases from 5–6 to 10–14 days, i.e., almost twice. The introduction of highly dispersed carbon leads to an increase in the effective viscosity of the systems and can be recommended for controlling the fluidity of the CWCF. The technical and operational requirements are best met by the CWCF containing 0.25% AMR and 1% highly dispersed carbon.

Facile Synthesis of Hollow Starch Nanoparticles for the Delivery of Piroxicam, a Poorly Water‐Soluble Drug

AbstractThis paper focuses on the development of hollow starch nanoparticles (HSNPs) as promising carriers for poorly soluble drugs. A new and efficient method is presented, based on an in situ gas‐foaming/salt‐leaching process within individual starch nanoparticles prepared by a solvent displacement technique. Characterization using dynamic light scattering, transmission electron microscopy, and nitrogen adsorption/desorption analysis confirmed the successful preparation of HSNPs. Solid dispersion systems with piroxicam (PRX) as a model drug were formulated to evaluate HSNPs’ potential as poorly water‐soluble drug carriers. Solid‐state properties, dissolution behavior and stability of PRX‐HSNPs solid dispersions were investigated. In vitro dissolution studies revealed that using hydrophilic HSNPs as carriers significantly improved the release of PRX. Solid‐state characterization showed that the main reason for the improved dissolution was the adsorption of PRX on the outer and inner surfaces of the HSNPs in an amorphous state. Stability studies demonstrated that the amorphous nature of loaded PRX remained unaffected even after 12 weeks of storage at 75 % relative humidity. Accordingly, the proposed HSNPs offer a promising alternative for the delivery of poorly water‐soluble drugs. In addition, the synthesis strategy demonstrated for HSNPs is easy, efficient and could be extended to the preparation of other hollow polymeric nanoparticles.

Self emulsifying drug delivery system: norfloxacin model drug

Background Norfloxacin is a synthetic antibacterial fluoroquinolone that is poorly water soluble and active against a wide spectrum of gram-positive and gram-negative aerobic bacteria. The goal of this work was to create a self-nanoemulsion (SNE) as a colloidal dispersed drug delivery system for increasing norfloxacin dissolving rate, while also assuming intestinal lymphatic transport participation for such a nano-size system that would increase norfloxacin oral bioavailability. Methods Depending on the solubility of norfloxacin in various components, several formulations of liquid SNEDDS of the antibiotic were created using oleic acid (oil), tween20 (surfactant), and PEG200 (co-surfactant). To assess the presence of a nanoemulsion region, phase diagram was generated at various oil: surfactant: co-surfactant ratios. Results The in-vitro dissolution profile suggested an optimum norfloxacin SEDD formulation (F1) comprised of oleic acid (10%), tween 20 (45%), and PEG200 (45%), as opposed to commercially available traditional tablets. The F1 formula exhibited thermodynamic stability with a zeta potential of +60.78mV and a droplet size of 57.4nm. The F1 formula revealed an improved dissolving profile as compared to the commercial Tablet of norfloxacin. Conclusion Based on the findings, this study indicated that preparing norfloxacin as a liquid self-nanoemulsifying system improved the solubility and drug release of norfloxacin counteract the inconsistent bioavailability of the commercial tablet.

Oscillatory and regularized shock waves for a dissipative Peregrine–Boussinesq system

Abstract We consider a dissipative, dispersive system of the Boussinesq type, which describes wave phenomena in scenarios where dissipation plays a significant role. Examples include undular bores in rivers or oceans, where turbulence-induced dissipation significantly influences their behavior. In this study, we demonstrate that the proposed system admits traveling wave solutions known as diffusive-dispersive shock waves. These solutions can be categorized as oscillatory and regularized shock waves, depending on the interplay between dispersion and dissipation effects. By comparing numerically computed solutions with laboratory data, we observe that the proposed model accurately captures the behavior of undular bores over a broad range of phase speeds. Traditionally, undular bores have been approximated using the original Peregrine system, which, even though it doesn’t possess these as traveling wave solutions, tends to offer accurate approximations within suitable time scales. To shed light on this phenomenon, we demonstrate that the discrepancy between the solutions of the dissipative Peregrine system and the non-dissipative counterpart is proportional to the product of the dissipation coefficient and the observation time.

Optical properties and zeta potential of polyvinyl pyrrolidone capped gold nanoparticles dispersed nematic liquid crystal mixture E7

The effect of dispersion of polyvinyl pyrrolidone (PVP) capped gold nanoparticles in nematic mixture E7 on the optical properties (absorbance and photoluminescence, fluorescence life time and Raman imaging) and zeta potential is studied. The gold nanoparticles of 0.25, 0.5 and 1.0 wt% concentrations are dispersed into E7. It has been found that the absorbance and photoluminescence intensity of dispersed systems are increased and depend on the GNPs concentration. These increase correspond to the coupling between the radiation field (electromagnetic waves of the light source) and the GNPs low-energy phonons and constructive coupling of emissions between the E7 and GNPs, respectively. The change in the fluorescence lifetime of pristine and GNPs dispersed E7 systems has confirmed the energy transfer between E7 and GNPs molecules. The study of Raman spectrum shows the variations in the intensity of the Raman peaks with different orientations. Due to dispersion of GNPs in E7 the values of zeta potential are increased. This ensures the good stability of the dispersed systems. The conductivity of dispersed system has increased drastically. In conclusion, the dispersion of GNPs in host nematic mixture E7 has influenced significantly its properties, thereby making the dispersed material more promising for the potential applications.

Multiple mechanisms for inbreeding avoidance used simultaneously in a wild ape.

Mating with close kin can have considerable negative fitness consequences, which are expected to result in selective pressure for inbreeding avoidance mechanisms, such as dispersal, mate choice and post-copulatory biases. Captive studies have suggested that inbreeding avoidance through mate choice is far less widespread than expected and may be absent where other mechanisms already limit inbreeding. However, few studies have examined multiple mechanisms of inbreeding avoidance simultaneously, particularly in the wild. We use 13 years of detailed dispersal, copulation and paternity data from mountain gorillas to examine inbreeding avoidance. We find that partial dispersal of both sexes results in high kinship in multimale groups, but that copulations between close kin occur 40% less than expected. We find strong kin discrimination in mate choice, with significant avoidance of maternal kin but more limited avoidance of paternal kin. We find no evidence for post-copulatory inbreeding avoidance. Our analyses support familiarity-based mechanisms of kin identification and age-based avoidance that limits mating between fathers and daughters in their natal group. Our findings demonstrate that multiple complementary mechanisms for inbreeding avoidance can evolve in a single species and suggest that inbreeding avoidance through mate choice may enable more flexible dispersal systems to evolve.

High-Performance Nanogel-in-Oils as Emulsion Evolution Controller for Displacement Enhancement in Porous Media.

We designed and synthesized high-performance nanogel-in-oils with intermediate properties between solid particles and liquid droplets for multiphase flow control in porous media. The ultrasmall polymeric nanogels prepared via inverse emulsion polymerization were efficiently encapsulated in micrometer-sized oil droplets with the aid of surfactants during transfer from the oil phase to the aqueous phase. The composite colloidal system exhibited high loading capacity, unimodal size distribution, and long-term kinetic stability in suspension. The colloidal behaviors of nanogel-in-oils and the corresponding interfacial evolution during displacement in porous media were investigated via microfluidic experiments. In situ emulsification was observed with a state contrary to that of static characterizations. The spontaneous and sustainable formation of foam-like water-in-oil macroemulsions originated from aqueous phase breakup and oil film development, both enhanced by nanogel-in-oils. Sweeping efficiency enhancement by invasion events and residual oil transport in macroemulsion phases yielded exceptional displacement performances. Flow field fluctuations and emulsion state variations can be manipulated by adjusting nanogel-in-oil concentrations. The nanogel-in-oil suspension was found to exhibit optimal performance among the tested dispersed systems.

Formulation and Evaluation of Niosomal Gel for Treatment of Acne

A skin disease, like acne, is very common and normally happens to everyone at least once in their lifetime. The structure of the stratum corneum is often compared with a brick wall, with corneocytes surrounded by the mortar of the intercellular lipid lamellae. Acne vulgaris is a chronic inflammatory dermatosis which is notable for open and/or closed comedones (blackheads and whiteheads), and inflammatory lesions including papules, pustules, or nodules. It is a disorder of sebaceous follicles which are special pilosebaceous units located on the face, chest, and back. Skin is one of the most readily available organs on human body for topical management and is the major route of topical drug delivery system. Topical drug administration is a localized drug delivery system everywhere in the body during ophthalmic, vaginal, rectal and skin as topical routes. SA niosomes gel delivery system (SANG1 to SANG5) as a dispersed system, which consists of small droplets and well distributed in to immiscible vehicle. Niosome salicylic acid was prepared by Reverse phase evaporation method using cholesterol and span 80 and tween 20. Niosome were evaluated for vesicle shape, size determination, Entrapment efficiency and in-vitro drug release study. The result concluded that SANG5 was best formulation with Carbopol 940 (2g), PVP, nutmeg oil base. The drug release profile and release kinetics are two important characteristics of the dosage forms, which play an important role for describing dissolution profile of dosage form.
 Keywords: Topical drug delivery, Acne vulgaris, Niosomes, Gel, Carbopol 940, nutmeg oil

A robust way to justify the derivative NLS approximation

The derivative nonlinear Schrödinger (DNLS) equation can be derived as an amplitude equation via multiple scaling perturbation analysis for the description of the slowly varying envelope of an underlying oscillating and traveling wave packet in dispersive wave systems. It appears in the degenerated situation when the cubic coefficient of the similarly derived NLS equation vanishes. It is the purpose of this paper to prove that the DNLS approximation makes correct predictions about the dynamics of the original system under rather weak assumptions on the original dispersive wave system if we assume that the initial conditions of the DNLS equation are analytic in a strip of the complex plane. The method is presented for a Klein–Gordon model with a cubic nonlinearity.

Propagation dynamics of nonlocal dispersal competition systems in time-periodic shifting habitats

This paper is concerned with the propagation dynamics of the time periodic Lotka-Volterra competition systems with nonlocal dispersal in a shifting habitat. We first obtain three types of time-periodic forced waves connecting the extinction state to the co-existence state, itself and the semi-trivial state, which describe the conversion from the state of two aboriginal co-existent competing species, two invading alien competitors, and a saturated aboriginal competitor with another invading alien competitor to the extinction state, respectively. This provides a comprehensive explanation of the point-wise extinction dynamics of these two competing species under such a time-periodic worsening habitat. Then, we establish the spreading properties of the associated Cauchy problem depending on the range of the shifting speed. More specifically, we give a complete description on the threshold values for the extinction as well as persistence (by moving with asymptotic speed). Our results reveal the possibility that a competitively weaker species with a much faster spreading speed can drive a competitively stronger species with a slower spreading speed to extinction. The discussion in this paper applies to both cases of weak competition and strong-weak competition. In particular, we need to point out that some combined effects of nonlocal dispersal, two-variable coupling and time-periodic shifting heterogeneity in this system pose extra difficulties in mathematical treatment, which are dealt with by introducing new approaches.

Development of a Multifunctional Oral Dosage Form via Integration of Solid Dispersion Technology with a Black Seed Oil-Based Self-Nanoemulsifying Drug Delivery System.

Lansoprazole (LZP) is used to treat acid-related gastrointestinal disorders; however, its low aqueous solubility limits its oral absorption. Black seed oil (BSO) has gastroprotective effects, making it a promising addition to gastric treatment regimens. The present study aims to develop a stable multifunctional formulation integrating solid dispersion (SD) technology with a bioactive self-nanoemulsifying drug delivery system (SNEDDS) based on BSO to synergistically enhance LZP delivery and therapeutic effects. The LZP-loaded SNEDDS was prepared using BSO, Transcutol P, and Kolliphor EL. SDs were produced by microwave irradiation and lyophilization using different polymers. The formulations were characterized by particle apparent hydrodynamic radius analysis, zeta potential, SEM, DSC, PXRD, and in vitro dissolution testing. Their chemical and physical stability under accelerated conditions was also examined. Physicochemical characterization revealed that the dispersed systems were in the nanosize range (<500 nm). DSC and PXRD studies revealed that lyophilization more potently disrupted LZP crystallinity versus microwave heating. The SNEDDS effectively solubilized LZP but degraded completely within 1 day. Lyophilized SDs with Pluronic F-127 demonstrated the highest LZP dissolution efficiency (3.5-fold vs. drug) and maintained chemical stability (>97%) for 1 month. SDs combined with the SNEDDS had variable effects suggesting that the synergistic benefits were dependent on the formulation and preparation method. Lyophilized LZP-Pluronic F127 SD enabled effective and stable LZP delivery alongside the bioactive effects of the BSO-based SNEDDS. This multifunctional system is a promising candidate with the potential for optimized gastrointestinal delivery of LZP and bioactive components.