Stimuli-responsive polymer gels have attracted significant attention owing to their controlled rheological properties resulted from sol-gel/gel-sol transition. Generally, the change of external conditions such as temperature and pH is usually essential to sol-gel/gel-sol transition. However, in some application scenarios, external conditions are not easy to change. Therefore, it is important to construct a gel system that can realize continuous sol-gel-sol phase transition under constant conditions. Herein, a novel polymer gel system （AGX） with the characteristic of continuous sol-gel-sol phase transition at constant temperature, was successfully constructed by using poly（hydroxyethyl acrylamide） （PHEAA） as the skeleton molecule, glyoxal （GX） as the crosslinking agent, and N, N-dimethylformamide （DMF） and water as the solvent. The effects of temperature, GX content, polymer content and water content on the gelation time, gel-breaking time and gel strength of AGX were investigated. The results showed that by changing the GX content and temperature, AGX could form a polymer gel with elastic modulus of 560 Pa within 7-2 000 min and could turn to a low-viscosity liquid （<30 mPa·s） in just 2 h. The greater the concentration of GX or PHEAA, the faster the gelation and the slower the gel-breaking. With the increase of temperature, both the gelation and gel-breaking became faster. The introduction of electrolytes had little effect on the gelation time but could greatly reduce the gel-breaking time. The sol-gel transition was mainly ascribed to the aldol condensation between GX and PHEAA, while the gel-sol transition might be resulted from the breaking of amide bonds.

The foam drainage gas recovery technique in natural gas production is widely recognized as the most cost-effective and efficient method for removing the water accumulated at the well bottom, which is an essential measure to ensure stable production for low-pressure and low-productivity gas wells. However, the bottomhole liquids are often contaminated by condensate oil, resulting in reduced effectiveness of conventional foaming agents. In this work, the foam properties of eight surfactants were investigated and the effects of oil content and temperature on their foam properties were also examined. The zwitterionic surfactant CAB, which demonstrated relatively good resistance to oil, was selected as the primary component of the foaming agent. By combining CAB with a fluorocarbon surfactant and a foam stabilizer, a new anti-condensate oil foaming agent SCU-7 was developed. The flowability, foaming performance at different oil content, and the foaming performance under simulated high-temperature and high-pressure conditions at the bottom were analyzed to explore the anti-oil mechanism of SCU-7. The results showed that, at 60 ℃ under atmospheric pressure, with an oil content of 10%, a concentration of 0.3% SCU-7 achieved the foam height of 167 mm in simulated saline water with total salinity of 4×10⁴ mg/L; the foam height was 135 mm at 3 min; after 15 min, the liquid-carrying capacity was up to 206 mL, demonstrating excellent overall performance. However, when the oil content was increased to 30%, the overall foaming performance declined to some extent. Under high pressure of 6 MPa and at temperatures of 80 ℃, 100 ℃ and 120 ℃, SCU-7 could generate dense foams in simulated saline water. Mechanism analysis indicated that CAB exhibited excellent ability of surface tension reduction in simulated saline water; mixing CAB with fluorocarbon surfactant could further decrease surface tension, while the presence of foam stabilizer could enhance the strength of foam film and thus improve foaming performance. Therefore, SCU-7 demonstrated good foaming performance with improved anti-oil properties.

Sodium cocoyl glycinate （SCG）, an environmentally friendly anionic amino acid surfactant, is widely used in daily chemical products as an upgraded alternative to traditional surfactants. In this study, crude Camellia oleifera saponin （COS） was purified using AB-8 macroporous adsorption resin, and its composition and structure were analyzed. The effects of different mole fractions of COS （α_COS） on surface tension （γ）, oil-water interfacial tension （IFT）, emulsification, and foam properties of COS-SCG binary mixed systems were investigated in mixtures of SCG with purified COS. The stability of γ and foamability under diverse environmental conditions were also discussed. The results indicated that the COS-SCG system exhibited remarkable surface-active synergism. The minimum critical micelle concentration （cmc） of the mixed system was lower than that of SCG, and adding a small mole fraction of COS （1%-2%） induced a synergistic reduction of γ. Specifically, the cmc and γ were 2.50×10^-4 mol/L and 23.1 mN/m for α_COS=1%, respectively. The system exhibited exceptional IFT reduction capacity, achieving a minimum value of 1.42 mN/mat α_COS=10%. The mixed system reached a foaming volume （at α_COS=50%） and foam stability （at α_COS=75%） were 51.0 mL and 97.37%, respectively. Microscopic analysis further confirmed these outstanding foam properties. Moreover, the COS-SCG system displayed reduced γ with enhanced foaming volume under elevated temperatures （35-75 ℃） and salinity （0-20 g/L）. However, acidic conditions and hard water compromised both γ stability and foamability.

This study utilizes a lactic acid solution, which promotes hair growth, as the aqueous phase, and compound essential oil as the oil phase, to prepare an O/W microemulsion for preventing hair loss and promoting hair growth. The formulation of the microemulsion was optimized using a pseudo-ternary phase diagram combined with the Box-Behnken response surface method, evaluating particle size and PDI as indicators to obtain the best preparation process. A seborrheic alopecia animal model was established using C57BL/6 mice to evaluate the effects of the microemulsion on hair loss prevention and hair growth. The results indicate that the optimal formulation of the microemulsion comprise 9.29% oil phase, 21.32% Tween 80, 10.66% anhydrous ethanol, and 58.71% aqueous phase, yielding an average particle size of 16.48 nm and a PDI of 0.038. The microemulsion exhibits good centrifugation and temperature stability. The formulation significantly increases hair length and weight in mice （P<0.05）, improves the number and distribution of hair follicles, upregulates the concentrations of KGF and VEGF in mouse skin, and decreases the concentration of TGF-β1 （P<0.05）. This study provides a basis for the development of new formulations containing essential oils for hair loss prevention and promotion.

The Yanchang oilfield is an ultra-low permeability reservoir with low matrix permeability, high proportion of nanoscaled pore throats, complex pore-throat structures, high salinity of formation water, and high mass concentration of Ca²⁺. The interactions among CO₂-formation water-rock and CO₂-crude oil exert more complex impacts on reservoir properties and fluid characteristics in such reservoirs. Targeted studies were conducted at three CO₂ flooding areas （Huaziping, Qiaojiawa, and Baibao） to investigate these interaction mechanisms. The results showed that long-term CO₂ injection significantly affected the reservoir properties and fluid characteristics in ultra-low permeability reservoirs. Due to the water-rock interaction, the core porosity, permeability, and contact angle were all decreased, with the magnitude of decrease initially increasing then decreasing as injection pressure was raised. Meanwhile, with the increase of pressure, the mass concentrations of HCO₃^- and Ca²⁺ increased and then reached a plateau. Under actual injection pressures, the overall core blockage rates in the three tested areas were 7.71%, 8.65%, and 13.88%, respectively, with more severe plugging observed for smaller pores （corresponding blockage rates were 21.36%, 26.66% and 32.81%）. The porosity and permeability under the influence of CO₂-crude oil interaction showed similar trends to those under water-rock interaction. Increasing injection pressure enhanced the C₃-C₁₄ and C₁₅-C₂₉ components but reduced the C₃₀₊ fractions and asphaltene content in produced oil, so the viscosity of crude oil correspondingly decreased rapidly. After the minimum miscible pressure was reached, the composition and the viscosity of crude oil became unchanged. Under actual injection pressures, the core blockage rates were 15.81%, 18.85% and 20.69%, respectively, with blockage predominantly in medium and small pores. Under miscible conditions, the core blockage rate in Baibao area in these pores was 20.84% and 11.92% higher than those in Huaziping and Qiaojiawa, respectively, reflecting stronger CO₂-oil interactions during miscible flooding.

The phase behaviors of single systems of sodium cocoyl glycinate （SCG） and potassium cocoyl glycinate （GCK）, as well as the mixed systems of SCG/GCK and SCG/GCK/cocamidopropyl hydroxysultaine （CHSB）, were investigated at pH 6.5. The results of binary phase diagram showed that the Krafft temperature of GCK was significantly lower than that of SCG, and the micellar region for GCK was considerably larger than SCG. When SCG and GCK were mixed at a mass ratio of 1:1, the phase behavior of the mixed system was similar to that of single GCK, indicating that the addition of GCK had improved the solubility of SCG. The results of ternary phase diagram showed that the addition of CHSB made the phase behavior of the mixed system more diverse. The addition of CHSB resulted in a further shrink of the undissolved region. There were regions of spherical, rod-like, worm-like and hexagonal micellar phases in the phase diagram of mixed system of SCG/GCK/CHSB. An in-depth study on the self-assembly behavior of cocoyl glycinate surfactants could provide theoretical support for the development of new amino acid-based cleansing and care products.

Ultra-low permeability reservoirs typically exhibit significant heterogeneity and complex fracture networks, making them highly susceptible to gas channeling during CO₂ flooding, thereby limiting the improvement of oil recovery efficiency. To explore the oil displacement effect of CO₂ flooding in ultra-low permeability reservoirs and develop a channeling plugging system with excellent performance, in this work, the minimum miscibility pressure experiment in Yanchang oilfield was carried out through slim tube experiments. Through core plugging and oil displacement experiments, the differences in plugging performance and oil displacement performance were compared among gel, foam and foam-gel composite channeling plugging system; the combinations of these channeling plugging systems in multiple rounds were evaluated according to oil displacement performance. The results indicated that the minimum miscibility pressure in this region was 31.1 MPa, at which injecting CO₂ could achieve complete miscibility with crude oil. The injection performance of foam was the best, and the injection performance of gel was the worst. The maximum injection pressure difference was 0.557 MPa, and the maximum plugging rate was 94.5%. The oil recovery of foam-gel composite channeling plugging system was superior to that of single foam system or gel system, and the maximum oil recovery could reach 77.5%. The oil displacement test for multi-round combined channeling plugging systems showed that, after two rounds of profile control and flooding, the oil recovery of foam-gel and then foam reached 86.8%, which was higher than the 78.2% for foam-gel and then gel. The maximum injection pressure was not more than 1 MPa, which was safe and convenient for construction.

An antioxidant dry mask dissolved in water was prepared, combining the good film-forming property of polysaccharides with the ability to combine with water to provide a good moisturizing effect for the skin. By configuring different ratios of dendrobium polysaccharide/purulan polysaccharide composite solution, dendrobium polysaccharide/purulan polysaccharide was prepared by electrostatic spinning technology, and uniform and continuous nanofibers were obtained with a fiber diameter of less than 200 nm, which can be dissolved quickly within 20 s and has good hydrophilicity and tensile strength. Infrared spectroscopy indicates the formation of intermolecular hydrogen bonds between dendrobium polysaccharides and pullulan polysaccharides. When the concentrations of 1.2% dendrobium polysaccharide and 12% purulan polysaccharide are combined, the synergistic effect of the two in scavenging the DPPH radicals and the ABTS radicals are the strongest, and the aqueous solution can scavenge 60% of the DPPH radicals and 85% of the ABTS radicals after dissolution, with good antioxidant capacity. As the whole nanofiber membrane is composed of polysaccharides, it has a certain water retention capacity and can reduce water dissipation in the environment. The toxicological safety is assessed by cytolytic hemolysis experiment, which demonstrates that the nanofibers are non-irritating, mild activity, and low immunogenicity, ensuring high compatibility with human skin, and having the potential to be applied in facial treatments.

Using aluminium sulfate and sodium hydroxide as raw materials, hydroxyl aluminium oxide （AlOOH） coated iron oxide yellow pigment was prepared by the co-precipitation method. The effects of AlOOH coating amount on the lattice structure, infrared spectrum, microscopic morphology, reflectance rate, thermal weight loss, Zeta potential and heat resistance of iron oxide yellow pigment were studied. The results show that AlOOH of the Boehmite type synthesized by the co-precipitation method is spherical particles with a size of 15-25 nm. The granular AlOOH is coated on the surface of the plate-shaped morphology of the iron oxide yellow pigment, reducing the direct heating and oxidation of the iron oxide yellow pigment at high temperatures and improving the thermal stability of the pigment. The weight loss of 15% AlOOH at 800 ℃ is 3.2%, indicating the best thermal stability. The Zeta potential of iron oxide yellow pigment continuously increases with the increase of the coating amount of AlOOH, and the Zeta potential of 20% AlOOH is the maximum value of 26.8 mV. The reflectivity of 15% AlOOH pigment in visible light reaches the maximum value of 49.3%. After heating at 240 ℃ for 30 minutes, the physical color changes and color difference value changes of iron oxide yellow pigments with different AlOOH coating amounts were tested. The color difference value ΔE of 15% AlOOH pigment is the lowest value of only 3.65, and the lowest Δa is 0.53. The degree of reddening of the pigment is the smallest and its thermal stability is the best.

Cutibacterium acnes （C. acnes） is a skin commensal bacterium that plays a crucial role in maintaining skin homeostasis. Oligosaccharides are well-known prebiotics for intestinal probiotics, and commonly used in cosmetic formulations. In this study, the effects of fructooligosaccharides （FOS）, isomaltooligosaccharide （IMO）, galactooligosaccharides （GOS）, and inulin on C. acnes CCSM0331, isolated from a healthy facial skin, were investigated with the parameters such as bacterial proliferation, the fermentation supernatant pH, short-chain fatty acids （SCFAs） production, DPPH free radicals scavenging, and inhibition of Staphylococcus epidermidis biofilm formation. Our results demonstrates that all four oligosaccharides effectively promote the growth of C. acnes CCSM0331 cells, increase the production of SCFAs, and lower the pH of the fermentation broth, with GOS demonstrating the most significant effect. Analysis of the SCFAs indicates that strain CCSM0331 predominantly employs oligosaccharides to produce propionic acid, acetic acid and isovaleric acid, differing from the SCFAs produced by gut probiotics like Lactobacillus and Bifidobacterium. Among the four oligosaccharides, the addition of 2% GOS fermentation supernatant significantly inhibits Staphylococcus epidermidis ATCC 35984 biofilm formation, and enhances antioxidant benefits. In conclusion, which indicates that GOS is a better prebiotic for strain C. acnes CCSM0331. Our findings offer a novel approach to screening prebiotics for potential skin probiotics.

In this study, water-soluble ceramide NP liposomes （CNPL） were prepared using high-pressure homogeneous microfluidization technology, and the physical and chemical properties of CNPL were thoroughly investigated. The repair mechanism and efficacy of CNPL were assessed utilizing a UVB-injured 3D epidermal skin model, alongside an examination of the repair effects on physical injury through the caudal fin excision model in zebrafish embryos. The experimental results indicate that CNPL has high transparency and stability, and the transmittance of CNPL aqueous solution within 10.00% mass fraction is close to that of the water. The average particle size is 22.25 nm （PDI=0.241）, and the pH range is 6.70-6.90. The permeability increases 3.8 times after 12 h. The improvement rates of FLG and Claudin-1 in 3.00% volume fraction CNPL are 128.21% and 73.68%, respectively. While the improvement rates of FLG and Claudin-1 in 5.00% volume fraction CNPL are 194.87% and 100.00%, respectively. The higher the concentration of CNPL, the stronger the improvement effect of FLG and Claudin-1, with 0.01 g/L and 0.03 g/L CNPL promoting the repair of zebrafish embryonic caudal fin by 3.05% and 8.60%, respectively. Overall, the findings suggest that CNPL possesses excellent water solubility, stability, transmittance, as well as superior transdermal absorption efficiency and bioavailability characteristics. It demonstrates significant reparative effects against UVB-induced light damage as well as physical injuries, thereby aiding in skin barrier restoration, delaying photoaging processes, promoting wound healing efforts, and presenting itself as an advantageous component for broader applications within cosmetic formulations.

In order to evaluate the suitability of the amplified ATP bioluminescence assay based on two cultivation systems in the rapid screening of cosmetic microorganisms, 51 commercially available cosmetic products covering 20 domestic and foreign brands, including different product types, functional claims, action sites, product dosage forms, and user groups, were widely selected for method suitability research with reference to the method suitability test requirements of sterility inspection method and microbial counting method in the Chinese Pharmacopoeia （2020 Edition）. And the suitability of the method was evaluated through sample impact test and spiking test results. The results show that 45 of the 51 products have a background fluorescence signal value less than 3-fold the signal value of blank medium, which meet the requirements of the sample impact test. While six products failed the sample impact test. Six representative strains are inoculated in 45 products that meet the requirements of the sample impact test according to the final concentration of 10-100 CFU/g, and are positively detected in 42 products after being cultured in the two cultivation systems. While some strains in three test products do not get positive detection results. In conclusion, the amplified ATP bioluminescence assay based on two cultivation systems has good suitability in the rapid screening of microbial contamination samples in cosmetics, and provides an efficient and reliable new method for microbial safety control in the whole process of cosmetics production.

Cutibacterium acnes （C. acnes） is a gram-positive facultative anaerobic bacterium and a part of the human skin symbiotic microbiome. It colonizes various parts of the body, including the face, back and chest. C. acnes is regarded as playing a significant role in the pathophysiology of acne vulgaris. In recent studies, it has been found that strains of different systemic types are associated with skin health and various disease types. This article reviews the classification of C. acnes and the current research status, summarizes the existence status of C. acnes under different skin types, emphasizes the risk of drug resistance and microbiota imbalance caused by the use of antibiotics in acne care, and discusses new acne care methods, aiming to open up new ideas for the care of acne, the development of skin care products and the evaluation of their efficacy. It proposes a new direction for the research of skin microecology.

With the increasing prosperity of the commodity market and the diversification of consumer demands, traditional single packaging forms are no longer able to meet market demand. This article aims to propose new ideas and methods for packaging design of washing and care products from the perspective of product visual expression analysis, in order to enhance the market competitiveness of products and meet consumers’ dual pursuit of aesthetic and practical functions. Firstly, based on an overview of visual expression, this article explores its significant value in the packaging design of washing and care products. Then, the visual expression design principles of washing and care product packaging are analyzed. Secondly, through the analysis of the existing problems in the packaging design of washing and care bands, it is pointed out that the visual expression design of washing and care product packaging has problems such as creative homogenization, neglect of cultural elements, stacking of visual elements, and neglect of user experience. Finally, targeted optimization strategies have been proposed for the visual expression design of the product packaging, including strengthening creative uniqueness, integrating cultural elements, emphasizing overall coordination, and enhancing interactive participation. It provides new theoretical support and practical guidance for the packaging design of washing and care products.

In this study, a high performance liquid chromatography （HPLC） method was established to simultaneously detect six major flavonoids （naringin, hesperidin, neohesperidin, naringenin, eriocitrin, and tangeretin） in grapefruit extract toothpaste. The mobile phase was methanol and 0.1% formic acid aqueous solution, and the toothpaste extraction solvent was 80% methanol. The results of the methodological investigation show that the precision RSD ranges from 0.93% to 1.42%, the stability RSD ranges from 0.94% to 1.42%, and the repeatability RSD ranges from 1.14% to 1.44%, and all RSDs are less than 2.0%. The six flavonoids show a good linear relationship in the mass concentration range of 1-100 μg/mL, with a correlation coefficient of 0.999 4-0.999 8. The average recovery rate of the six flavonoids ranges from 95.20% to 104.57%, and the RSD ranges from 0.51% to 2.06%. The detection method in this study can accurately detect the content of the six flavonoids in grapefruit extract toothpaste, which has a reference value for the quality control of grapefruit extract toothpaste.

A high performance liquid chromatography （HPLC） method was established for the simultaneous determination of 10 quaternary ammonium salt compounds （benzalkonium chloride, benzethonium chloride, dequalinium chloride, lauralkonium chloride, methamphetamine chloride, octadecyl dimethyl benzyl ammonium chloride, cetyltrimethylammonium chloride, cetylpyridinium chloride, cetrimide bromide, and cetrimide chloride） in oral care toothpaste. Acetonitrile was used as the extraction solvent, with a mobile phase of 60 mmol/L ammonium acetate buffer solution （pH=6.0） and acetonitrile for gradient elution. The column temperature was 30 ℃, the flow rate was 1.0 mL/min, and the detection wavelength was 210 nm. The results of the methodological evaluation show that the precision RSD of 10 quaternary ammonium salts is less than 6%. The 10 quaternary ammonium salts show good linear relationship in the mass concentration range of 0.1-500 mg/L, with correlation coefficients of 0.999 4-0.999 8 and detection limits of 0.03-0.09 mg/L. The average recovery of 10 quaternary ammonium salts ranges from 96.80% to 105.25%, and the RSD ranges from 0.74% to 5.45%. Using this method, benzalkonium chloride （128.09 mg/kg）, dequalinium chloride （329.13 mg/kg） and cetylpyridinium chloride （231.04 mg/kg） are detected in three toothpastes, respectively. This method has good separation effect and high precision, and can be used for the detection of quaternary ammonium salts in oral care toothpastes.