High-pressure Method Research Articles

Mechanochemical Synthesis of Perovskite Oxyhydrides: Insights from Shear Modulus.

Perovskite oxyhydrides have attracted recent attention due to their intriguing properties such as ionic conductivity and catalysis, but their repertoire is still restricted compared to perovskite oxynitrides and oxyfluorides. Historically, perovskite oxyhydrides have been prepared mostly by topochemical reactions and high-pressure (HP) reactions, while in this study, we employed a mechanochemical (MC) approach, which enables the synthesis of a series of ABO2H-type oxyhydrides, including those with the tolerance factor (t) much smaller than 1 (e.g., SrScO2H with t = 0.936) which cannot be obtained by HP synthesis. The octahedral tilting, often present in perovskite oxides, does not occur, suggesting that the lack of π-symmetry of the H 1s orbital and the large polarization destabilize tilted low-symmetry structures. Interestingly, SrCrO2H (t = 0.997), previously reported with the HP method, was not achieved with the MC method. A comparative analysis revealed a correlation between the feasibility of MC reactions and the (calculated) shear modulus of the starting reagents (binary oxides and hydrides). Notably, this indicator is not exclusive to oxyhydride perovskites but extends to oxide perovskites (SrMO3). This study demonstrates that MC synthesis offers unique opportunities not only to expand the compositional space in oxyhydrides in various structural types but also to provide a guide for the choice of starting materials for the synthesis of other compounds.

Development and Process Optimization of a Steamed Fish Paste Cake Prototype for Room Temperature Distribution

Surimi-based products typically demand cold storage and a cold chain distribution system, which not only affects their physical properties and flavor but also escalates production costs. In this study, we introduced a novel high-temperature and high-pressure retort processing method to enable room temperature storage and distribution of a surimi-based product, a fish paste cake. Our optimization efforts focused on refining the processing conditions for the fish paste cake. This included incorporating transglutaminase, sugar additives, natural herbal or seaweed extracts, and optimizing retort processing conditions to enhance textural properties, minimize browning and off flavor, and extend the shelf-life of the product. Our results demonstrated that the addition of 0.3% ACTIVA TG-K, 1.0% trehalose, and 0.5% sea tangle extract during the production process significantly enhanced the gel strength, minimized browning, and improved the overall flavor of the fish paste cake prototype. Importantly, the developed prototype exhibited favorable biochemical, textual, nutritional, and sensory properties, extending the shelf-life up to 160 days without compromising physical, chemical, or sensory attributes. In addition, the developed prototype exhibited improved elasticity, compared to control groups. The innovative process not only facilitates room temperature storage and distribution of surimi-based products but also holds potential for generating additional profits.

Effects of solid lipid nanocarrier containing methyl urolithin A by coating folate-bound chitosan and evaluation of its anti-cancer activity

BackgroundNanotechnology-based drug delivery systems have received much attention over the past decade. In the present study, we synthesized Methyl Urolithin A-loaded solid lipid nanoparticles decorated with the folic acid-linked chitosan layer called MuSCF-NPs and investigated their effects on cancer cells.MethodsMuSCF-NPs were prepared using a high-pressure homogenization method and characterized using FTIR, FESEM, DLS, and zeta potential methods. Drug encapsulation was assessed by spectrophotometry and its cytotoxic effect on various cancer cells (MDA-MB231, MCF-7, PANC, AGS, and HepG2) by the MTT method. Antioxidant activity was assessed by the ABTS and DPPH methods, followed by expression of genes involved in oxidative stress and apoptosis by qPCR and flow cytometry.ResultsThe results showed the formation of monodisperse and stable round nanoparticles with a size of 84.8 nm. The drug loading efficiency in MuSCF-NPs was reported to be 88.6%. MuSCF-NPs exhibited selective cytotoxicity against MDA-MB231 cells (IC50 = 40 μg/mL). Molecular analysis showed a significant increase in the expression of Caspases 3, 8, and 9, indicating that apoptosis was occurring in the treated cells. Moreover, flow cytometry results showed that the treated cells were arrested in his SubG1 phase, confirming the pro-apoptotic effect of the nanoparticles. The results indicate a high antioxidant effect of the nanoparticles with IC50 values ​​of 45 μg/mL and 1500 μg/mL against ABTS and DPPH, respectively. The reduction of catalase gene expression confirmed the pro-oxidant effect of nanoparticles in cancer cells treated at concentrations of 20 and 40 μg/mL.ConclusionsTherefore, our findings suggest that the MuSCF-NPs are suitable candidates, especially for breast cancer preclinical studies.

Properties of boron-doped HPHT diamond single crystals grown in a Fe-Ti-B-C system

Boron-doped diamond (BDD) single crystals were synthesized using a large-volume cubic high-pressure apparatus (SPD-6 × 1200) in the Fe-Ti-B-C system under conditions of 6.0 GPa and temperatures ranging from 1410 to 1435 °C. Scanning electron microscope (SEM) images revealed linear textures, cracks, and dendritic growth texture on the crystal surface. The Raman spectrum exhibited additional bands at approximately 480, and 1220 cm−1, indicating high levels of boron doping. X-ray photoelectron spectroscopy (XPS) measurements confirmed the presence of boron on the crystal surface, bonded as BC and BO. By utilizing the Hall effect, the highest recorded carrier concentration in the crystal was determined to be 1.17 × 1019 cm−3, a relatively high level for diamond single crystals synthesized via the high pressure and high temperature (HPHT) method. Moreover, thermogravimetric analysis (TG) measurements verified that boron doping enhanced the thermal stability of the diamond.

The self-designed reactor to achieve efficient degradation of polyvinyl alcohol under high-pressure and high-temperature conditions

ABSTRACT A huge amount of polyvinyl alcohol (PVA) fabric is abandoned from nuclear power plants every year, the traditional treatment process will occupy land resources and pollute the environment; therefore, a lot of research has been carried out on the chemical treatment of PVA fabric. Herein, the performance of degradation of polyvinyl alcohol under high-pressure and high-temperature conditions is investigated. The effects of the initial pH value, reaction temperature, molar ratio of H2O2/Fe2+, and H2O2 dosage on PVA degradation were evaluated. In the tested ranges in this work, the degradation of PVA fabric via high-pressure and high-temperature method was optimum at the initial pH value of 4, reaction temperature of 300℃, molar ratio of H2O2/Fe2+ as 10, and H2O2 dosage of 13 g/L. The PVA removal rate and TOC removal rate were 99.99% and 97.36%, respectively. Meanwhile, the high-pressure and high-temperature methods also had a great effect on the removal of Rhodamine-B and Reactive Red X-3B, the removal rates of Rhodamine-B and Reactive Red X-3B were 99.83% and 99.76%, respectively. The reaction mechanism of high-pressure and high-temperature methods was also discussed in this study.

The characterization of diamond single crystal growing along (100) after annealing treatment under high pressure and high temperature

Diamond has many desirable properties. In this study, temperature gradient method was used to prepare a series of type Ib diamond single crystals, which were processed again to obtain and characterize Type IaA diamonds with even more desirable properties. Before annealing, Fourier-transformed infra-red(FTIR) spectra of diamond showed peaks at 1130 cm−1 and 1344 cm−1; After annealing, the peak at 1282 cm−1 was appeared in FTIR spectra of diamonds This data indicated that the isolated nitrogen in diamond aggregated after high-pressure and high-temperature (HPHT) method annealing experiment. Moreover, photoluminescence (PL) spectra suggested that no nitrogen-related color centers existed in the diamond before annealing. In contrast, after annealing, a peak at 637 nm appeared in the PL spectra, indicating the appearance of NV−colors centers type Ib diamond post-annealing. The experimental results show that type Ib diamond crystals can be decolorized after 60 min of annealing under 7 GPa and 1850 °C, which makes part of the area transparent. Under 7 GPa and 2100 °C, type Ib diamond crystals can produce NV color center when annealed for 3 min. With increasing annealing temperature and prolonged annealing duration, the density and size of etch pits on the crystal surface escalated. Therefore, this study provides a guideline for the decolorization of diamonds by HPHT annealing. Moreover, this study also reports a method to change the crystal type and obtain NV color centers under ultra-high-temperature annealing conditions of 7 GPa pressure and 2100 °C temperature, which can be applied to develop quantum materials.

A Mini Review on Borate Photocatalysts for Water Decomposition: Synthesis, Structure, and Further Challenges.

The development of novel photocatalysts, both visible and UV-responsive, for water decomposition reactions is of great importance. Here we focused on the application of the borates as photocatalysts in water decomposition reactions, including water splitting reaction, hydrogen evolution half-reaction, and oxygen evolution half-reaction. In addition, the rates of photocatalytic hydrogen evolution and oxygen evolution by these borate photocatalysts in different water decomposition reactions were summarized. Further, the review summarized the synthetic chemistry and structural features of existing borate photocatalysts for water decomposition reactions. Synthetic chemistry mainly includes high-temperature solid-state method, sol-gel method, precipitation method, hydrothermal method, boric acid flux method, and high-pressure method. Next, we summarized the crystal structures of the borate photocatalysts, with a particular focus on the form of the B-O unit and metal-oxygen polyhedral in the borates, and used this to classify borate photocatalysts, which are rarely mentioned in the current photocatalysis literature. Finally, we analyzed the relationship between the structural features of the borate photocatalysts and photocatalytic performance to discuss the further challenges faced by the borate photocatalysts for water decomposition reactions.

High-pressure synthesis and magnetic characterization of quadruple perovskites SmA′3Co4O12 (A′ = Cu, Mn)

In this study, two novel quadruple perovskite compounds SmA′3Co4O12 (A′ = Cu, Mn) were synthesized using a high-pressure synthesis method. Structural analysis of the perovskites using synchrotron X-ray powder diffraction revealed that both SmCu3Co4O12 and SmMn3Co4O12 have cubic Im3‾ structure. In the temperature range of 2–300 K, SmCu3Co4O12 did not exhibit a magnetic phase transition, whereas SmMn3Co4O12 exhibited a paramagnetic to ferrimagnetic phase transition at ∼90 K. A comparison of structural information, X-ray absorption near edge structure, and magnetic properties revealed that the low-spin state (S = 0) characterizes the spin state of Co3+ when the A′ site is occupied by Cu3+. However, when the A′ site is occupied by Mn3+, the Co3+ spin state is in a high-spin state (S = 2), indicating that a long-range magnetic phase transition occurs owing to the magnetic interaction between the Mn and Co ions.

S-filled and Te-doped CoSb3 materials prepared by HPHT method with ultra-low thermal conductivity

In this paper, a series of S[Formula: see text]Co4Sb[Formula: see text]Te[Formula: see text] samples were prepared by high pressure and high temperature (HPHT) method under different pressures. The synthesis time was shortened from several days to 0.5 h. Te doping and S filling simultaneously optimized the thermal and electrical transport properties of the CoSb3 materials. We found a porous architecture containing rich grain boundaries, different grain sizes, nano- to micrometer-sized pores, and a large number of dislocations, which can scatter a wide spectrum of phonons. Seebeck coefficient [Formula: see text], electrical resistivity [Formula: see text], and thermal conductivity [Formula: see text] were measured between 295 K and 773 K. The minimum thermal conductivity of S[Formula: see text]Co4Sb[Formula: see text]Te[Formula: see text] synthesized at 3.0 GPa was 1.23 Wm[Formula: see text] K[Formula: see text], and its maximum zT value reached 1.07 at 773 K, especially the lattice thermal conductivity was as low as 0.49 Wm[Formula: see text] K[Formula: see text].

Preparation of High-Performance Mn-Doped SnTe Materials at High Pressure and High Temperature.

SnTe is an environmentally friendly medium-temperature thermoelectric material, but its inherent low power factor (PF) and high lattice thermal conductivity severely limit its application. In this study, based on the fact that Mn doping can induce band convergence, the high-pressure and high-temperature (HPHT) synthesis method was used to optimize the sample preparation and shorten the synthesis cycle to 30 min. The results show that the Sn0.93Mn0.10Te sample achieves the maximum PF value of 34.00 μW cm-1 K-2 at 775 K and PFave value of 21.36 μW cm-1 K-2 between 300-875 K. Microstructure analysis shows that the high-pressure synthesis method introduces abundant grain boundaries, various grain sizes, multiple defects, and pore structures into the sample. These microscopic crystal structures can effectively scatter phonons and lower the lattice thermal conductivity. The modification of these micromorphologies results in the Sn0.92Mn0.11Te sample attaining a minimum lattice thermal conductivity of 0.45 W m-1 K-1 at 625 K. The thermoelectric figure of merit (zT) of sample Sn0.92Mn0.11Te reaches a maximum value of 1.1 at 775 K, and the zTave reaches 0.63 in the range of 300-875 K. This study indicates that the synergistic effect of Mn element doping and microstructure modification can effectively optimize the thermoelectric transport performance of SnTe materials.

Improvement of thermoelectric properties of xNb:(1-x)SrTiO3 composite ceramics by high-pressure high-temperature synthesis

The high stability and low cost are considered comparative advantages of the SrTiO3 chalcogenide oxide thermoelectric material. However, the pure SrTiO3 material is characterized by low electrical conductivity and high thermal conductivity, which could eventually lead to poor overall thermoelectric performance, and limit its application in the field of high temperature thermoelectricity. The development of composite-based metal materials with SrTiO3 by using suitable methods is arising as the most promising approach to improve their electrical properties. Along these lines, in this work, xNb: (1-x) SrTiO3 composite ceramics were successfully synthesized by using the high temperature and high-pressure (HPHT) method. The Nb powder was oxidized into various niobium oxides exhibiting their own thermoelectric properties under HPHT conditions to optimize the thermoelectric properties of the Nb/SrTiO3 composites. From our analysis, it was demonstrated that with the increase of the Nb powder content, the electrical properties were significantly improved. In addition, the fabricated Nb/SrTiO3 composite ceramics possessed a special “pore” microstructure, which significantly reduced the thermal conductivity of the material. In this work, the physical phase, microscopic morphology, and thermoelectric properties of the synthesized samples were also systematically tested and analyzed, and the maximum zT value of 0.28@973 K was obtained for the final sample with x = 0.4. The implementation of the HPHT method for the preparation of chalcogenide oxide composite ceramics provides valuable insights for the improvement of their thermoelectric properties.

Preparation of mesophase-pitch-based graphite foams at atmospheric pressure

Mesophase-pitch-based graphite foams have attracted increasing attention because of their broad applications in thermal management, catalysis and so on. However, the common approach of using the high-pressure method for fabricating graphite foams is complex and risky. Herein, this research reports a simple and relatively safe technique for preparation of mesophase-pitch-based graphite foams, which is conducted under atmospheric pressure. Through foaming of mesophase pitch in the presence of epoxy resin at 700°C under atmospheric pressure and graphitization at 3000°C, graphite foam is fabricated. The obtained graphite foam is highly graphitic and has an open pore structure, the interlayer spacing of the (002) plane of which is about 0.3366 nm. Its density is 0.52 g/cm3 with a porosity of 73.5%. The properties of graphite foams can be tailored by modifying pitch particle sizes and foaming temperatures. With an increase in pitch particle size from <25 to 75–150 μm or in foaming temperature from 400 to 850°C, the pore sizes vary from 10–25 to 35–90 μm, and their bulk densities change from 0.50 to 1.11 g/cm3. Also, a foaming mechanism is proposed wherein the residue of epoxy resin can form a framework during heating, in which the pitch softens and decomposes, forming foam. This study suggests a relatively simple and safe method for production of graphite foams from mesophase pitch.

Investigating the properties of a ZnSe-based solid solution at 2.0 GPa

In this work, ZnSe-based polycrystalline ceramics were successfully synthesized from Se and Zn powders in the range of 2.0 GPa and 900 °C–1400 °C by using the high-pressure and high-temperature (HPHT) method. From the acquired experimental results, it was revealed that the fabricated samples were composed of ZnSe with a sphalerite structural type. More specifically, the samples consisted of lamellar and granular grains, and the stomata of the samples showed a trend of first increasing and then decreasing as a function of the elevated temperature. In addition, the infrared transmittance of ZnSe ceramics in the 4 to 18-μm range increased and then decreased by increasing the temperature. When the temperature exceeded the value of 1000 °C, the internal zinc surplus and selenium deficiency of zinc selenide ceramics induced a decrease in the mechanical and optical properties of the ceramics. By optimizing the conditions of the experimental process, the ZnSe synthesized at 1300 °C exhibited better performance with a transmittance of 55%.

Metal-bonded perovskite lead hydride with phonon-mediated superconductivity exceeding 46 K under ambient pressure

In the search for high-temperature superconductivity in hydrides, a plethora of multi-hydrogen superconductors have been theoretically predicted, and some have been synthesized experimentally under ultrahigh pressures of several hundred GPa. However, the impracticality of these high-pressure methods has been a persistent issue. In response, we propose a new approach to achieve high-temperature superconductivity under ambient pressure by implanting hydrogen into lead to create a stable few-hydrogen binary perovskite, Pb4H. This approach diverges from the popular design methodology of multi-hydrogen covalent high critical temperature (Tc ) superconductors under ultrahigh pressure. By solving the anisotropic Migdal–Eliashberg equations, we demonstrate that perovskite Pb4H presents a phonon-mediated superconductivity exceeding 46 K with inclusion of spin–orbit coupling, which is six times higher than that of bulk Pb (7.22 K) and comparable to that of MgB2, the highest Tc achieved experimentally at ambient pressure under the Bardeen, Cooper, and Schrieffer framework. The high Tc can be attributed to the strong electron–phonon coupling strength of 2.45, which arises from hydrogen implantation in lead that induces several high-frequency optical phonon modes with a relatively large phonon linewidth resulting from H atom vibration. The metallic-bonding in perovskite Pb4H not only improves the structural stability but also guarantees better ductility than the widely investigated multi-hydrogen, iron-based and cuprate superconductors. These results suggest that there is potential for the exploration of new high-temperature superconductors under ambient pressure and may reignite interest in their experimental synthesis in the near future.

Microstructural evolution and multi-mechanism strengthening model of nanocrystalline Al-Mg alloys

To unravel the determinants contributing to the remarkable strength observed in nanocrystalline binary alloys, we employed a high-pressure torsion method to fabricate Al-Mg alloys with varying Mg concentrations. Mechanical property analysis indicates that, with the increasing Mg content, both the hardness and yield strength exhibit an ascending trend. Notably, the nanocrystalline Al-8Mg alloy boasted an impressive hardness and yield strength of 295 HV and 889 MPa, respectively. Comprehensive characterizations of solute distribution and microstructural evolution were conducted using X-ray diffraction, electron back-scatter diffraction, transmission electron microscopy, and atom probe tomography. We clarified the distribution mechanism of Mg atoms at grain boundaries, developed a method for the precise assessment of inhomogeneous solute distribution, and proposed a multi-mechanism strengthening model, incorporating the inhomogeneous solute distribution strengthening mechanism. The calculated results aligned well with the experimental data.

ZnO/NiO Nanocomposite with Enhanced Photocatalytic H2 Production

Inorganic photocatalytic materials exhibiting a highly efficient response to ultraviolet-visible light spectrum have become a subject of widespread global interest. They offer a substantial prospect for generating green energy and mitigating water pollution. Zinc oxide (ZnO), among various semiconductors, proves advantageous for water-splitting applications due to its elevated reactivity, chemical stability, and nontoxic nature. However, its efficacy as a photocatalyst is hindered by limited light absorption capacity and swift charge carrier recombination. To improve charge separation and enhance responsiveness to ultraviolet-visible light photocatalysis, the formation of a heterojunction with another suitable semiconductor is beneficial. Thus, we employed hydrothermal route for the synthesis of the samples, which is a high-pressure method. The formations of ZnO/NiO heterostructures were revealed by scanning electron microscopy, X-ray diffraction analysis, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The nanocomposites were discovered to have a substantially higher photocatalytic activity for the generation of H2. The H2 production rates show that ZnO (i.e., 168.91 μmolg-1 h-1) exhibits good H2 production rates as compared to NiO (i.e., 135.74 μmolg-1 h-1). The best production rates were observed for ZN-30 (i.e., 247.56 μmolg-1 h-1) which is 1.46 times greater than ZnO and 1.82 times greater than NiO. This enhanced photocatalytic activity for ZN-30 is because of the good electron-hole pair separation due to the formation of depletion layer, suppression of fast charge recombination, and overcoming resistance corrosion.

Advanced Cd1-xMnxTe:Fe2+ semiconductor crystals for IR applications: The role of the composition and sin-band redshift spectra effect

Doped semiconductor crystals of solid solution Cd1-xMnxTe:Fe2+ were grown by the high-pressure Bridgman method, covering the range of their existence as a zinc blende structure (0 < x < 0.76). The concentration of the Fe2+ impurities was approximately 10−3 wt% in all the studied samples. The structural and optical properties of the crystals were investigated, including the case of high concentrations of x > 0.4. The correlations between the composition of solid solution crystals of Cd1-xMnxTe:Fe2+, the lattice constant, the band gap, and the maxima positions of the Fe2+ active ion absorption and emission spectra were found experimentally and explained physically. A theoretical model based on the principle of compositional additivity for solid solution semiconductor materials was first used for explaining the long-wavelength sin-band linear “redshift” of absorption and emission bands in the spectra of Cd1-xMnxTe:Fe2+ crystals with increasing solid solution concentration. A new effect is discovered for the differentiated redshift of the Jahn-Teller components (bands) of the total absorption spectrum. Longwavelength absorption bands have a stronger redshift than shortwavelength absorption bands. The redshifts in the maxima of the total absorption and emission spectra have shift (slope) coefficients Kab≈1.7 nm/at.% and Kem≈6.1 nm/at.%, respectively. The obtained results can be used to predict and design laser media based on Cd1-xMnxTe:Fe2+ solid solution crystals while controlling the lasing range (for all Mn concentrations).

Nanocrystal-Loaded Lipid Carriers for Improved Oral Absorption and Anticancer Efficacy of Etoposide: Formulation Development, Transport Mechanism, In Vitro and In Vivo Evaluation.

To improve the oral absorption and anticancer efficacy of the BCS-IV drug etoposide (ETO), oral nanocrystal-loaded lipid carriers (Lipo@NCs) were developed in this study by modifying the BCS-IV drug nanocrystal with the lipid bilayer. The ETO-Lipo@NCs were prepared by the thin film hydration high-pressure homogenization method, and the core of positively charged ETO nanocrystals was prepared by the sonoprecipitation-high pressure homogenization method. The optimized ETO-Lipo@NCs were spherical particles with an average particle size of 220.3 ± 14.2 nm and a zeta potential of -9.95 ± 0.81 mV, respectively. The successful coating of a lipid bilayer on the surface of nanocrystals in ETO-Lipo@NCs was confirmed by several characterization methods. Compared to nanocrystals, the release rate and degree of Lipo@NCs in SIF were significantly decreased, indicating that the lipid bilayer can effectively prevent the rapid dissolution of core nanocrystals. ETO-Lipo@NCs demonstrated a significant improvement in the intestinal permeability and absorption of ETO in a single intestinal perfusion experiment. In the cells, ETO-Lipo@NCs showed enhanced cellular uptake and transepithelial transport compared with ETO nanocrystals. Pharmacokinetic analysis indicated that ETO-Lipo@NCs had a longer plasma half-life than ETO solution, and the oral bioavailability of ETO-Lipo@NCs was 1.96- and 10.92-fold higher than that of ETO nanocrystals and ETO coarse crystals, respectively. Moreover, the ETO-Lipo@NCs orally dosed at 10 mg/kg exhibited an excellent inhibitory effect against tumors in a subcutaneous Lewis lung carcinoma (LLC) xenograft model compared with other preparations. These results indicate that the Lipo@NCs formulation has an oral absorption-promoting effect of the BCS-IV drug ETO, which could warrant further application in the oral delivery of other poorly bioavailable drugs.

Remifentanil and Propofol Co-loaded Nanoemulsion: Formulation Development and In vivo Pharmacodynamic Evaluation

Background: The present work is an effort to develop novel propofol (PPF) and remifentanil (RFT) co-loaded nanoemulsion (NME) for the treatment of anesthetic effects. Methods: The PPF/RFT NME was prepared via the high-pressure homogenization method. Its physicochemical properties were assessed to ensure good quality and suitability for i.v. administration. We also studied the in vivo pharmacokinetics and pharmacodynamics of PPF/RFT NME in dogs with an optimized formulation. Results: This study showed that the mean particle size of PPF/RFT NME was 124.2 nm and the zeta potential was −20.6 mV. In the stability test, the NME maintained a good round shape and did not demonstrate any significant changes in physicochemical characteristics. In terms of the in vitro release, the early burst release of the NME preparations containing PPF or RFT was ideal in clinical practice, where a loading dose or a rapid onset of the drug was required. Based on histopathological observations, no histological change occurred to the rat organs after the administration of PPF/RFT NME. Regarding pharmacodynamics, compared with the combination group at the same dose, PPF/RFT NME could make animals enter the anesthetic state faster and the anesthetic effects last longer. In addition, vital signs of PPF/RFT NME could be maintained in a good state while better effects were delivered. Conclusions: This study used PPF and RFT to prepare a compound NME. This could reduce the anesthesiologist's administration time and make the anesthesia process more efficient.

Nanoemulsions: Summary of a Decade of Research and Recent Advances.

Nanoemulsions consist of a combination of several components such as oil, water, emulsifiers, surfactants and cosurfactants. Various techniques for producing nanoemulsions include high-energy and low-energy approaches such as high-pressure homogenization, microfluidization, jet disperser and phase inversion methods. The properties of a formulation can be influenced by elements such as the composition, concentration, size and charge of droplets, which in turn can affect the technique of manufacture. Characterization is conducted by the assessment of several factors such as physical properties, pH analysis, viscosity measurement and refractive index determination. This article offers a thorough examination of the latest developments in nanoemulsion technology, with a focus on their wide-ranging applications and promising future possibilities. It also discusses the administration of nanoemulsions through several methods.