Rate Enhancement Research Articles

Micelle-modulated ribonuclease-like activities of oxo-bridged binuclear copper(ii) complexes with novel imidazole derivatives

Three bis-tridentate imidazole derivatives as ligands and their alkoxo-bridged binuclear copper(II) complexes (1, 2 and 3) were synthesized and characterized. Single crystals show that furan or thiophene moiety of 2 or 3 is free without a coordination with the central copper. Five-coordinated structure of 1 is constructed via two Cu-N and three Cu-O coordination bonds involving the participation of phenolic oxygen, alkoxo-bridged oxygen and the one carboxylate oxygen. Furthermore, catalytic reactivity of the as-synthesized binuclear complexes was evaluated for the transesterification of classic RNA model HPNP (2-hydroxypropyl-4-nitrophenyl phosphate). Overall, three complexes displayed the almost similar activity in both non-micellar and micellar solutions. HPNP transesterification achieved more obvious acceleration in micellar solutions of three kinds of cationic surfactants. All of three complexes obtained relatively good reactivity in CTAB micellar solution, respectively achieving approximately 804-fold (for 1), 762-fold (for 2) and 785-fold (for 3) rate enhancement compared to background rate of HPNP spontaneous cleavage. The as-synthesized binuclear complexes displayed approximately two times dominative activity in CTAB micellar solution over that in the non-micellar system. However, to some extent the introduction of amphoteric n-lauroylsarcosine sodium (LSS) and non-ionic polyoxyethylene lauryl ether (Brij35) inhibited the catalytic transesterification of HPNP. This study is beneficial to the design and application of novel mimic esterolases.

How Droplets Can Accelerate Reactions─Coacervate Protocells as Catalytic Microcompartments.

ConspectusCoacervates are droplets formed by liquid-liquid phase separation (LLPS) and are often used as model protocells-primitive cell-like compartments that could have aided the emergence of life. Their continued presence as membraneless organelles in modern cells gives further credit to their relevance. The local physicochemical environment inside coacervates is distinctly different from the surrounding dilute solution and offers an interesting microenvironment for prebiotic reactions. Coacervates can selectively take up reactants and enhance their effective concentration, stabilize products, destabilize reactants and lower transition states, and can therefore play a similar role as micellar catalysts in providing rate enhancement and selectivity in reaction outcome. Rate enhancement and selectivity must have been essential for the origins of life by enabling chemical reactions to occur at appreciable rates and overcoming competition from hydrolysis.In this Accounts, we dissect the mechanisms by which coacervate protocells can accelerate reactions and provide selectivity. These mechanisms can similarly be exploited by membraneless organelles to control cellular processes. First, coacervates can affect the local concentration of reactants and accelerate reactions by copartitioning of reactants or exclusion of a product or inhibitor. Second, the local environment inside the coacervate can change the energy landscape for reactions taking place inside the droplets. The coacervate is more apolar than the surrounding solution and often rich in charged moieties, which can affect the stability of reactants, transition states and products. The crowded nature of the droplets can favor complexation of large molecules such as ribozymes. Their locally different proton and water activity can facilitate reactions involving a (de)protonation step, condensation reactions and reactions that are sensitive to hydrolysis. Not only the coacervate core, but also the surface can accelerate reactions and provides an interesting site for chemical reactions with gradients in pH, water activity and charge. The coacervate is often rich in catalytic amino acids and can localize catalysts like divalent metal ions, leading to further rate enhancement inside the droplets. Lastly, these coacervate properties can favor certain reaction pathways, and thereby give selectivity over the reaction outcome.These mechanisms are further illustrated with a case study on ribozyme reactions inside coacervates, for which there is a fine balance between concentration and reactivity that can be tuned by the coacervate composition. Furthermore, coacervates can both catalyze ribozyme reactions and provide product selectivity, demonstrating that coacervates could have functioned as enzyme-like catalytic microcompartments at the origins of life.

Size-Dependent Photocatalytic Reactivity of Conjugated Microporous Polymer Nanoparticles.

Particle size is a critical factor for improving photocatalytic reactivity of conjugated microporous polymers (CMPs) as mass transfer in the porous materials is often the rate-limiting step. However, due to the synthetic challenge of controlling the size of CMPs, the impact of particle size is yet to be investigated. To address this problem, a simple and versatile dispersion polymerization route that can synthesize dispersible CMP nanoparticles with controlled size from 15 to 180nm is proposed. Leveraging the precise control of the size, it is demonstrated that smaller CMP nanoparticles have dramatically higher photocatalytic reactivity in various organic transformations, achieving more than 1000% enhancement in the reaction rates by decreasing the size from 180 to 15nm. The size-dependent photocatalytic reactivity is further scrutinized using a kinetic model and transient absorption spectroscopy, revealing that only the initial 5nm-thick surface layer of CMP nanoparticles is involved in the photocatalytic reactions because of internal mass transfer limitations. This finding substantiates the potential of small CMP nanoparticles to efficiently use photo-generated excitons and improve energy-efficiency of numerous photocatalytic reactions.

Silver nanoparticles incorporated with superior silica nanoparticles-based rice straw to maximize biogas production from anaerobic digestion of landfill leachate

Treating hazardous landfill leachate poses significant environmental challenges due to its complex nature. In this study, we propose a novel approach for enhancing the anaerobic digestion of landfill leachate using silver nanoparticles (Ag NPs) conjugated with eco-friendly green silica nanoparticles (Si NPs). The synthesized Si NPs and Ag@Si NPs were characterized using various analytical techniques, including transmission electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The anaerobic digestion performance of Si NPs and Ag@Si NPs was tested by treating landfill leachate samples with 50 mg/L of each NP. The results demonstrated an enhancement in the biogas production rate compared to the control phase without the nanocomposite, as the biogas production increased by 14% and 37% using Si NPs and Ag@Si NPs. Ag@Si NPs effectively promoted the degradation of organic pollutants in the leachate, regarding chemical oxygen demand (COD) and volatile solids (VS) by 58% and 65%. Furthermore, microbial analysis revealed that Ag@Si NPs enhanced the activity of microbial species responsible for the methanogenic process. Overall, incorporating AgNPs conjugated with eco-friendly green Si NPs represents a sustainable and efficient approach for enhancing the anaerobic digestion of landfill leachate.

O-019 Outcomes and correlations between traditional Intracytoplasmic Sperm Injection (ICSI) method and a new AI-enhanced system

Abstract Study question In the context of ICSI, how does the Sperm Tracer Deep Neural Network analysis compare to the embryologist’s sperm selection technique? Summary answer Sperm Tracer AI system significantly improves fertilization rates, offering a standardized, objective approach to sperm selection, but nuanced correlations highlight complexities in sperm parameters. What is known already Traditional sperm selection during ICSI relies on subjective, manual methods, introducing variability and affecting pregnancy success. In response, AI applications, aim to enhance objectivity, potentially improving pregnancy rates. Study design, size, duration Between September and December 2023, the study examined 26 fresh ICSI cycles in a total of 268 sibling oocytes. Men aged 18 years and above with 34.4 mean women’s age. The Sperm Tracer group underwent single embryo culture, while the Embryologists' group underwent group embryo culture. The study analyzes statistical differences in fertilization rates, day 3 and day 5 embryo development. The study duration aligns with the analyzed cycles. Participants/materials, setting, methods The study compared real-time AI-assisted sperm evaluation with the Sperm Tracer system to the traditional ICSI method by embryologists. Correlation analysis was performed for the following kinematic parameters: Amplitude of Lateral Head displacement (ALH), Dance (DNC), Linearity (LIN), Straightness (STR), Wobble (WOB), Curvilinear Velocity (VCL), Linear Velocity (VSL) and Average Path Velocity (VAP). Statistical analysis involved Odds Ratios (OR) with 95% confidence intervals, Mann-Whitney U tests and correlation analyses by Pearson’s coefficient. Main results and the role of chance The Sperm Tracer system exhibited a noteworthy enhancement in fertilization rates (OR: 0.46, 95% Confidence Intervals (CI) [0.23, 0.89], p = 0.0224) but no significant differences in cleavage stages, blastocyst formation, or the production of good-quality embryos compared to conventional methods. For correlation analysis used two groups of sperm population. Group A comprises spermatozoa subjected to ICSI with the Sperm Tracer system, resulting in unsuccessful oocyte fertilization and Group B consists of spermatozoa that achieved successful fertilization. In Group A, correlation analysis identified significant negative associations between DNC and linear parameters (LIN, STR, WOB) (p < 0.001), highlighting the clinical relevance in sperm motility. Group B displayed a distinct negative correlation between DNC and LIN (p = 0.03941), indicating potential effects on sperm linear velocity. LIN in Group A exhibited strong negative correlations with WOB (p = 0.0001), moderate negative correlations with STR (p = 0.0028), and VCL (p = 0.0773). Moreover, ALH analysis in Group A unveiled robust negative correlations with LIN, STR, and WOB, suggesting clinical significance in sperm motility. These intricate findings underscore the Sperm Tracer system's primary advantage in optimizing fertilization rates, offering valuable insights for refining sperm selection strategies in assisted reproduction. Limitations, reasons for caution The study faces limitations due to a small sample, impacting generalizability. Divergence in culture embryo strategies introduces bias, necessitating validation in larger studies. The system includes morphology analysis, but no data analysis has been conducted. Exploring the correlation between morphology, considering embryo culture variations, and motility could provide valuable insights. Wider implications of the findings This study highlights AI applications like Sperm Tracer, showcasing their potential to improve assisted reproduction outcomes. Recognizing AI's impact on IVF success is vital for adoption. Integrating AI into clinic protocols may boost IVF efficiency, requiring training for embryologists to ensure effective utilization. Trial registration number Not applicable

Effects of ball milling on hydrochar for integrated adsorption and photocatalysis performance

In this study, hydrochar (HC) was firstly treated by ball milling for methylene blue (MB) removal through combined adsorption-photodegradation. The ball-milled bamboo hydrochar (BM-HC) exhibited a maximum adsorption capacity of 49.522 mg/g and a synergistic adsorption-photodegradation removal rate of 95.22% within 30 min, which was superior to those of pristine HC (20.530 mg/g, 79.47%). Compared with HC, BM-HC had smaller particle size, increased quantities of polyfuran rings, enhanced adsorption of visible light, which were favorable for the enhancement of adsorption capacity and photodegradation rate. The effect of the catalyst dosage, MB concentration, water matrix, pH, coexisting ions on MB photodegradation were examined. The possible synergistic adsorption and photodegradation mechanism of MB was illustrated. The foremost active specie in the synergistic removal of MB was h+. In addition, the possible degradation pathways of MB were proposed depending on the intermediates detected by Liquid chromatography-mass spectrometry (LC-MS), and the biotoxicity of MB and its intermediates was evaluated by Ecological Structure-Activity Relationship (ECOSAR) program. This work confirms that ball-milled hydrochar could be used as a potential catalyst for pollutants removal in water via synergistic adsorption and photocatalysis.

Mie Resonant Metal Oxide Nanospheres for Broadband Photocatalytic Enhancements.

Metal oxides are widely used in heterogeneous catalysis as supports to disperse catalytically active nanoparticles, isolated atomic sites, or even as catalysts themselves. Herein, we present a method to produce optically active metal oxide supports that exhibit size-dependent Mie resonances based on TiO2 nanospheres with tunable size, crystalline phase composition, and optical properties. Mie resonant TiO2 nanospheres were used as supports to disperse Au, Pt, and Pd nanoparticles. We have found up to a 50-fold enhancement of the electric field at the metal oxide/metal interface corresponding to wavelength-dependent multipolar resonances in the TiO2 structure. Using Au/TiO2 as a prototypical photocatalyst, we demonstrate broadband rate enhancements between 400 and 800 nm during CO oxidation, with a noticeable increase below 500 nm. This increased reactivity at higher photon energies is due to improved photon utilization and interband absorption in the gold that results in greater secondary electron generation through electron-electron scattering processes, thus leading to higher rates in conjunction with the Mie scattering TiO2 support. This study not only highlights the potential of Mie resonant TiO2 in broadband photocatalytic enhancements but also for developing various Mie resonant metal oxide supports, such as ZnO or Cu2O, which can improve photocatalytic performance for a number of critical reactions. As the chemical and energy industries move toward conversion technologies driven by renewable energy sources, the strategy of designing optical resonances into oxide supports that are already widely used could enable a straightforward adaptation of photochemical processing based on traditional heterogeneous catalysts.

Efficient In Situ Doping of Strained Germanium Tin Epilayers at Unusually Low Temperature

AbstractEfficient p‐ and n‐type in situ doping of compressively strained germanium tin (Ge1‐xSnx) semiconductor epilayers, grown by chemical vapor deposition on a standard Si(001) substrate, is demonstrated. Materials characterization results reveal unusual impact of dopants manifesting via a pronounced reduction of Sn content in the epilayer, accompanied by an enhancement of the growth rate, due to increasing p‐type doping concentration. Furthermore, the opposite behavior for n‐type doping is observed, resulting in a less pronounced increase of Sn concentration and no effect on growth rate. Nevertheless, a very high density of electrically active holes up to ≈4 × 1020 cm−3 is obtained in p‐type doped Ge1‐xSnx epilayer resulting in the lowest resistivity of 0.15 mΩ cm among all in situ doped epitaxial and strained group‐IV semiconductors. Also, the metal‐to‐insulator transition in Ge1‐xSnx is experimentally demonstrated for doping levels above 1 × 1017 cm−3, which is substantially lower than in any group‐IV semiconductor, and theoretically predict it to be as low as ≈1 × 1017 cm−3. The findings enabled by the doping regime explored in this work can open novel prospects to engineer low resistivity contacts and charge current injection in applications covering next‐generation transistors, qubits, diodes, electrically driven light sources, sensors and hybrid quantum devices.

Preparation and Characterization of Dutasteride Nanoparticles as Oral Fast-Dissolving Film

Background: Dutasteride, is a drug whose mechanism of action is inhibition of the enzyme 5-alpha reductase. It has been approved for use in the treatment of benign prostatic hyperplasia. Dutasteride has low solubility and high permeability, which classifies it as Biopharmaceutics classification system class II, according to the Biopharmaceutics Classification System. It has a water solubility of only 0.038 ng/mL and a slow dissolving rate, resulting in its exclusive availability in the market as a formulation contained within soft gelatin capsules. Objective: The aim of this study involves two parts. First, is the enhancement of dutasteride dissolution rate, by the creation of dutasteride nanosuspension, and second is the enhancement of patient compliance by the transformation of this nanosuspension to oral fast-dissolving film, which is characterized by its fast disintegration, stability, and ease of administration. Methods: The solvent anti/solvent precipitation method was used to formulate dutasteride nanosuspension. In addition, dutasteride nanoparticles oral fast dissolving films were prepared by using the solvent casting method. To compare the in vitro release patterns of pure dutasteride film and selected dutasteride nanoparticles film, the statistical analysis for the dissolution investigation was conducted using the model-independent technique (employing similarity factor f2) utilizing a DD solver. The selected dutasteride nanoparticle film was supposed to be the test material, while the pure dutasteride film was supposed to serve as the reference. Results: dutasteride nanosuspension demonstrated a high enhancement of the dissolution rate. In addition, the prepared dutasteride nanoparticles oral fast-dissolving film exhibited a further increase in the rate of dissolution and fast disintegration, and the administration is easy, all of these properties making it a promising dosage form. Conclusion: Nanosuspension is an excellent approach for enhancing the solubility, dissolution rate, and effectiveness of drugs with limited aqueous solubility such as dutasteride. In addition, the oral fast-dissolving film can be considered a promising dosage form that will increase patient compliance due to its high dissolution rate, fast disintegration, and easy administration.

Room temperature optical coupling of neodymium ions to photonic crystal L3 cavity in gallium nitride semiconductor

We demonstrate the optical coupling of implanted neodymium (Nd) ions in a photonic crystal (PhC)-L3 cavity on GaN at RT. The structure of the PhC-L3 cavity is designed by the electromagnetic field simulation to enhance the 4 F 3/2–4 I 9/2 and 4 F 3/2–4 I 11/2 transitions (916 and 1107 nm) in Nd3+. The highest enhancement ratio of 20-fold is achieved under our measurement conditions by the enhancement of spontaneous emission rate due to the Purcell effect in addition to the improvement of light collection efficiency. These results pave the way for the development of Ln-doped GaN based quantum light–matter interface and nanophotonics.

Improving pressurized liquid extraction of passion fruit (P. edulis) bagasse: Exploring the effects of high-temperature, particle size, and extraction bed dimensions

Extraction techniques to obtain bioactive molecules from passion fruit bagasse have emerged recently. The driving force behind this effort lies in the array of biological properties related to its compounds, including anti-carcinogenic, antioxidant, anti-inflammatory, and vasorelaxant properties. Given this background, this work proposes improvements to the extraction process from defatted passion fruit bagasse (DPFB). The effect of pressurized liquid extraction (PLE) temperature was examined at 70, 90, and 110 °C, revealing an increase in global yield and total reducing content (TRC) with rising temperature. However, the yield of piceatannol was statistically equal between 70 and 90 °C and decreased at 110 °C, suggesting thermal degradation. These findings were corroborated by thermal stability analysis and oxygen radical absorbance capacity assessment. The impact of raw material particle size was investigated and showed that granulometric classification led to an increase in the TRC and piceatannol yields by 35% and 84%, respectively, and allowed identifying the piceatannol's location within the outer layer of the passion fruit seed (FR1). Mathematical modelling was applied to the kinetic extraction of DPFB-FR1 to assess the effect of bed height to diameter ratio (H/D). The two-site desorption model has properly fitted experimental data and indicated an enhancement in piceatannol mass transfer rate when increasing H/D. In summary, the present work presents findings and conclusions not previously documented in the literature, contributing to the improvement of PLE and pre-treatment methods for passion fruit bagasse.

Optimized mass transfer of PHI-type zeolite for nitrogen/methane sieve separation

The separation of nitrogen and methane via molecular sieving is often accompanied by mass transfer limitations. Here, we report a NaK-PHI zeolite that not only achieves the precise sieving of nitrogen and methane, but also significantly enhances the diffusion rate of nitrogen. By adjusting the framework composition of the zeolite, the metal cation in the NaK-PHI channel allows smaller nitrogen molecules to enter the channel but blocks methane entry, achieving precise N2/CH4 sieving. A growth inhibitor (GI) was introduced to reduce the crystal size of the NaK-PHI@GI zeolite, and the adsorption kinetics were optimized, resulting in a diffusion rate enhancement of approximately three times; NaK-PHI@GI also exhibited an enhanced nitrogen adsorption capacity (10.5 cm3 g−1) as well as a higher nitrogen/methane uptake ratio (20.9). After multiple cycle-breakthrough tests and regeneration processes involving evacuation and depressurization, NaK-PHI@GI maintained a stable separation capacity, confirming its good recyclability.

Role of the in situ formed LiAl(NH)2 and LiNH2 in significantly improving the hydrogen storage properties of the Mg(NH2)2-2LiH systems with Li3AlH6 addition

The Mg(NH2)2-2LiH system has attracted considerable interest due to its high hydrogen capacity and low theoretical dehydrogenation enthalpy. However, its practical application is limited by sluggish kinetics due to the slow mass transfer rate and the stable N-H bond. In response to these problems, this study introduced Li3AlH6 into the Mg(NH2)2-2LiH system, leveraging the mutual destabilization effects between lithium alanates and metal amides to attenuate the stability of the N-H bond in Mg(NH2)2. The results show that the Mg(NH2)2-2LiH-0.1Li3AlH6 composite can reversibly desorb/absorb hydrogen up to 4.33 wt% at 140 °C with an initial dehydrogenation temperature of 90 °C. This represents a significant improvement over the pristine sample's capacity of 1.23 wt% under the same conditions. Phase structure analyses reveal that the in situ formed LiAl(NH)2 and LiNH2 particles during ball milling play a crucial role in decreasing the energy required for cleaving the N-H bond, transferring mass, and initiating nucleation. Dehydrogenation curves suggest that the dehydrogenation process follows the Avrami-Erofe'ev equation, signifying that the process is controlled by both nucleation and diffusion processes. A pronounced correlation exists between dehydrogenation kinetic energy barriers and nucleation energy barriers of the dehydrogenation products. This finding implies that future reductions in operating temperature and enhancements of the dehydrogenation rate in the Mg(NH2)2-2LiH system can be achieved by decreasing the nucleation energy barriers of the dehydrogenation products.

Research on the Welding Process and Weld Formation in Multiple Solid-Flux Cored Wires Arc Hybrid Welding Process for Q960E Ultrahigh-Strength Steel.

This paper proposes a novel welding process for ultrahigh-strength steel. The effects of welding parameters on the welding process and weld formation were studied to obtain the optimal parameter window. It was found that the metal transfer modes of solid wires were primarily determined by electrical parameters, while flux-cored wires consistently exhibited multiple droplets per pulse. The one droplet per pulse possessed better welding stability and weld formation, whereas the short-circuiting transfer or one droplet multiple pulses easily caused abnormal arc ignition that decreased welding stability, which could easily lead to a "sawtooth-shaped" weld formation or weld offset towards one side with more spatters. Thus, the electrical parameters corresponding to one droplet per pulse were identified as the optimal parameter window. Furthermore, the weld zone (WZ) was predominantly composed of AF, and the heat-affected zone (HAZ) primarily consisted of TM and LM. Consequently, the welded joint still exhibited excellent mechanical properties, particularly toughness, despite higher welding heat input. The average tensile strength reached 928 MPa, and the impact absorbed energy at -40 °C for the WZ and HAZ were 54 J and 126 J, respectively. In addition, the application of triple-wire welding for ultrahigh-strength steel (UHSS) demonstrated a significant enhancement in post-weld deposition rate, with increases of 106% and 38% compared to single-wire and twin-wire welding techniques, respectively. This process not only utilized flux-cored wire to enhance the mechanical properties of joints but also achieved high deposition rate welding.

Kinetic isotope effects on hydrogen/deuterium disordering and ordering in ice crystals: A Raman and dielectric study of ice VI, XV, and XIX.

Ice XIX and ice XV are both partly hydrogen-ordered counterparts to disordered ice VI. The ice XIX → XV transition represents the only order-to-order transition in ice physics. Using Raman and dielectric spectroscopies, we investigate the ambient-pressure kinetics of the two individual steps in this transition in real time (of hours), that is, ice XIX → transient ice VI (the latter called VI‡) and ice VI‡ → ice XV. Hydrogen-disordered ice VI‡ appears intermittent between 101 and 120K, as inferred from the appearance and subsequent disappearance of the ice VI Raman marker bands. A comparison of the rate constants for the H2O ices reported here with those from D2O samples [Thoeny et al., J. Chem. Phys. 156, 154507 (2022)] reveals a large kinetic isotope effect for the ice XIX decay, but a much smaller one for the ice XV buildup. An enhancement of the classical overbarrier rate through quantum tunneling for the former can provide a possible explanation for this finding. The activation barriers for both transitions are in the 18-24kJ/mol range, which corresponds to the energy required to break a single hydrogen bond. These barriers do not show an H/D isotope effect and are the same, no matter whether they are derived from Raman scattering or from dielectric spectroscopy. These findings favor the notion that a dipolar reorientation, involving the breakage of a hydrogen bond, is the rate determining step at the order-to-order transition.

Phase transfer catalysts shift the pathway to transmetalation in biphasic Suzuki-Miyaura cross-couplings

The Suzuki-Miyaura coupling is a widely used C-C bond forming reaction. Numerous mechanistic studies have enabled the use of low catalyst loadings and broad functional group tolerance. However, the dominant mode of transmetalation remains controversial and likely depends on the conditions employed. Herein we detail a mechanistic study of the palladium-catalyzed Suzuki-Miyaura coupling under biphasic conditions. The use of phase transfer catalysts results in a remarkable 12-fold rate enhancement in the targeted system. A shift from an oxo-palladium based transmetalation to a boronate-based pathway lies at the root of this activity. Furthermore, a study of the impact of different water loadings reveals reducing the proportion of the aqueous phase increases the reaction rate, contrary to reaction conditions typically employed in the literature. The importance of these findings is highlighted by achieving an exceptionally broad substrate scope with benzylic electrophiles using a 10-fold reduction in catalyst loading relative to literature precedent.

An adaptive MLP-based joint optimization of resource allocation and relay selection in device-to-device communication using hybrid meta-heuristic algorithm

Enhancement in both energy efficiency and spectral efficiency in cellular networks is made possible by means of an advanced technique called device-to device (D2D) communication. The enhancement of these efficiencies is done by utilizing the cellular user (CU) resources once again to make communication with nearby cellular devices in an effective manner by spectral means. As the D2D communication technology is capable of providing a direct communication link with nearby devices effectively with enhanced spectral efficacy, this approach is considered as an ideal solution for the futuristic cellular communication network. A flexible and reliable relay-assisted communication by means of D2D technology is required that acts as an intermediate relay when the attenuation between the channels across the D2D devices becomes high. The throughput of the system is increased by utilizing D2D communication technology as it uses direct data transmission within cellular devices. When the cellular user is far apart from one another, the data loss in the D2D communication system is minimized with the utilization of the relay. When the channels are good, then the relay nodes (RNs) serve the cellular user. However, it is noted that the D2D systems are affected by issues such as higher consumption of energy and spectral sharing. Also, the sum rate gets degraded as a result of mutual interference between resource-sharing cellular devices in the relay-assisted D2D communication system. The transmission of the data in a traditional relay-assisted D2D communication system is carried out between the D2D receiver (DR) and D2D transmitter (DT) only with the utilization of its own energy by the RN. The issues in relay selection and resource allocation in the conventional joint resource allocation schemes are tackled by executing a scheme for performing the task of optimal relay selection and joint resource allocation. The enhancement of the overall sum rate in the D2D communication is the main motive behind the implemented scheme. This goal is attained along with the minimization of the link rates in the cellular and D2D networks. The ideal selection of the relay and the execution of the joint resource allocation are done with the utilization of a new optimization scheme called the hybrid flow direction with the chameleon swarm algorithm (HFDCSA), in which the flow direction algorithm (FDA) is fused along with chameleon swarm algorithm. This optimal selection of the relays is assisted by considering constraints like the network’s sum rate and energy efficiency in the network to achieve high performance. The data obtained from distinct sources are given to the adaptive multi-layer perceptron (AMLP) in which optimal resource allocation and the relay selection are performed with the help of the suggested HFDCSA. The parameters in the MLP are tuned by the same HFDCSA. Finally, the performance validation is conducted in the stage to verify the working of the suggested approach.

Solubility and Dissolution Rate Enhancement of Aceclofenac by Solid Dispersion Employing Kneading and Solvent Evaporation Techniques

Background: Aceclofenac (ACF) is a non-steroidal anti-inflammatory drug with potent anti-inflammatory and analgesic properties. ACF is belongs to BCS class II which has poor solubility in water (practically insoluble) and high permeability that leads to a low dissolution rate and reduced bioavailability. Objective: to enhance the solubility and dissolution rate of ACF using the solid dispersion method (SD) by two common techniques which were solvent evaporation (SE) and kneading (Kn) by using different carriers Mannitol, PVP k30, Soluplus®, and Urea in both techniques at 1:1 and 1:5 wight ratio. Methods: The effects of type of carrier and preparation method on solubility and dissolution rate of SD were studied. Solid dispersions were characterized for their, percentage yield, drug content, drug solubility and in-vitro dissolution rate in comparison with pure drug. Results: The best formula is obtained by the Kn formula (F16) which was formulated by the use of ACF: Soluplus®: with a weight ratio of 1:5 which gave a high percentage yield (99.5%), high drug content (99.8± 0.003%) and the best solubility enhancement which was 361 folds compared to pure ACF and faster dissolution rate which was 80% in 10 minutes compared to 20% for pure drug. Conclusion: the solubility and in-vitro dissolution rate of ACF was efficiently improved when prepared by SD techniques, utilizing both solvent evaporation and kneading methods. Furthermore, the kneading method was superior to solvent evaporation method due to the greater enhancement of solubility and dissolution rate obtained by all carriers and ratios with higher improvement by 1:5 ratio, and can be considered a successful and efficient strategy for solubility and in-vitro dissolution rate improvement of hydrophobic drugs.

Sodium chloride solution transport through a carbon nanotube with an embedded carbon nanotube via molecular dynamics simulations

Carbon nanotubes hold significant potential for developing highly efficient desalination membranes. However, achieving both enhanced water transfer rate and salt rejection efficiency simultaneously has been challenging due to the pore size limitation. In this study, we discovered that embedding a carbon nanotube within a large-diameter carbon nanotube enables the simultaneous enhancement of both water transfer rate and salt rejection efficiency. This outcome is attributed to the accelerated water velocity and the blockage of ions entering the narrowed cross-section of the carbon nanotube. These findings have valuable implications for the design of fast water transport membranes with high salt rejection efficiency.

Effects of Yacon (Smallanthus sonchifolius) Juice Byproduct Administered Using Different Feeding Methods on the Growth Performance, Digestive Enzyme Activity, Antioxidant Status, and Disease Resistance against Streptococcus iniae of Juvenile Black Rockfish (Sebastes schlegelii)

This study was designed to evaluate the effects of yacon (Smallanthus sonchifolius) juice byproduct (YJB) on the growth performance, digestive and antioxidant enzyme activities, and disease resistance against Streptococcus iniae of juvenile black rockfish (Sebastes schlegelii) based on different feeding schedules. Four different YJB feeding strategies were evaluated: feeding the fish a basal diet continuously (control, T0), feeding them YJB (2.5 g/kg) continuously (T1), feeding them YJB for 1 day and the basal diet the next day (T2), and feeding them YJB for 1 day and the basal diet for the following 2 days (T3). No difference in survival among the treatments was found after the 8-week feeding trial (p > 0.05). However, the T1 and T2 groups exhibited significant enhancements in final body weight, weight gain, and specific growth rate compared with the T0 and T3 groups. Furthermore, the T1 and T2 groups showed a significant improvement in feed consumption, feed efficiency, and protein efficiency ratio compared with the T0 and T3 groups. No significant differences in the condition factor or viscerosomatic and hepatosomatic indices were observed among all the groups. Intestinal amylase, trypsin, and lipase activity was significantly (p < 0.05) higher in the T1 and T2 groups than in the T0 and T3 groups. Lysozyme, superoxide dismutase, and catalase activity along with glutathione peroxidase content were significantly (p < 0.05) higher under all YJB feeding regimens than those under the control treatment. The survival rates in all the YJB treatment groups after the S. iniae challenge were significantly (p < 0.05) enhanced. In conclusion, we recommend offering YJB at day-to-day intervals to improve growth performance, digestive enzyme activity, antioxidant status, and disease resistance against S. iniae.