Submitted Successfully!
To reward your contribution, here is a gift for you: A free trial for our video production service.
Thank you for your contribution! You can also upload a video entry or images related to this topic.
Version Summary Created by Modification Content Size Created at Operation
1
Xianfu Wu
 -- 2054 2024-01-27 01:41:59 |
2 Reference format revised.
Lindsay Dong
 Meta information modification 2054 2024-01-29 02:52:47 |

Video Upload Options

Do you have a full video?
Send video materials Upload full video

Confirm

Are you sure to Delete?
Yes No
Cite
If you have any further questions, please contact Encyclopedia Editorial Office.
Du, X.; He, Y.; Chen, Y.; Liu, Q.; Sun, L.; Sun, H.; Wu, X.; Lu, Y. Cosmetic Pretreatment Techniques. Encyclopedia. Available online: https://encyclopedia.pub/entry/54430 (accessed on 18 May 2024).
Du X, He Y, Chen Y, Liu Q, Sun L, Sun H, et al. Cosmetic Pretreatment Techniques. Encyclopedia. Available at: https://encyclopedia.pub/entry/54430. Accessed May 18, 2024.
Du, Xiao-Nan, Yu He, You-Wen Chen, Qian Liu, Lei Sun, Hui-Min Sun, Xian-Fu Wu, Yong Lu. "Cosmetic Pretreatment Techniques" Encyclopedia, https://encyclopedia.pub/entry/54430 (accessed May 18, 2024).
Du, X., He, Y., Chen, Y., Liu, Q., Sun, L., Sun, H., Wu, X., & Lu, Y. (2024, January 27). Cosmetic Pretreatment Techniques. In Encyclopedia. https://encyclopedia.pub/entry/54430
Du, Xiao-Nan, et al. "Cosmetic Pretreatment Techniques." Encyclopedia. Web. 27 January, 2024.
Cosmetic Pretreatment Techniques
Edit
This entry is adapted from the peer-reviewed paper 10.3390/molecules29020411

The diversity of cosmetic matrices requires appropriate pretreatment methods. For emulsified cosmetics rich in emulsifiers and thickeners, techniques such as field-assisted extraction, which utilizes oscillation or microwave-assisted heating, and supercritical fluid extraction, often with CO2, are preferred. Conversely, liquid cosmetics with simpler matrices benefit from phase separation techniques such as liquid–liquid extraction. Aqueous extraction is ideal for products rich in polar compounds, while headspace analysis is best suited for isolating volatile constituents.

pretreatment techniques cosmetics analytical technologies

1. Emulsified Cosmetics

Emulsified cosmetics, with their intricate matrices of thickeners and emulsifiers, often present challenges in traditional solvent dissolution, resulting in suboptimal analyte recovery. In 2012, Zhong et al. [1] addressed this by employing ultrasound-assisted matrix solid-phase dispersive liquid extraction (UA–MSPD), which utilizes anhydrous sodium sulfite to disperse hair dyes, facilitating the extraction of analytes into an acidic medium. Concurrently, oil-based substances and thickeners are solubilized in n-hexane, with adsorbents capturing interfering compounds. This study innovatively employs dispersants to effectively disperse viscous hair dyes, thereby significantly simplifying the operational process. The method requires only 9 min to complete the entire procedure and demonstrates a high recovery rate, ranging from 85.7% to 107%.
Solid-phase extraction (SPE), a traditional preparation technique, faces limitations when applied to emulsified cosmetics due to mass transfer resistance, which can lead to longer elution times and higher solvent consumption. In 2014, Zhan et al. [2] introduced an improved approach known as dispersive solid-phase extraction (dSPE). This method is initiated by suspending the cosmetic in acetonitrile. Subsequently, C18 silica is added as an adsorbent, and MgSO4 is employed to facilitate the dispersion of the matrix, followed by vigorous shaking and cotton filtration. The use of dispersants in conjunction with cotton filtration effectively eliminates interference from complex sample matrices in analytical results, streamlining the extraction process. This approach demonstrates excellent linearity for concentrations of up to 480 g/kg, with correlation coefficients ranging from 0.982 to 0.999.
Bimatoprost and latanoprost, as first-line pharmacological agents for glaucoma treatment, have been determined to induce hypertrichosis as a side effect. Unscrupulous cosmetic manufacturers exploit this adverse effect by incorporating these drugs into eyelash growth serums. Prolonged exposure to cosmetics containing prostaglandin drugs can potentially lead to local skin or ocular discomfort, allergic reactions, and even impact cardiovascular health. Compared with traditional extraction methods, ultrasound-assisted extraction (UAE) demonstrates superior efficiency, gentleness, and environmental friendliness. It effectively extracts active ingredients from complex matrices while preserving the stability of thermosensitive substances. In 2023, Yong et al. [3] applied UAE technology to process commercially available eyelash serums, followed by separation and purification using silica gel columns. Employing the Cosmetic Risk Substance Screening Platform, they detected suspicious components in two different fractions. These components were further purified using high-performance liquid chromatography and identified as bimatoprost and latanoprost through high-resolution mass spectrometry and nuclear magnetic resonance techniques. This extraction method exhibited an excellent linear range from 0.25–50 ng/mL (R2 > 0.9992), with notably low detection (LOD) and quantitation limits (LOQ) of 0.01 and 0.03 mg/kg, respectively.
Fullerene, a nanomaterial composed of carbon atoms, is utilized in the cosmetics industry due to its exceptional antioxidative properties. However, given its status as an emerging nanomaterial, it is imperative to conduct a comprehensive and rigorous assessment of its potential impacts and safety. Liquid–liquid extraction (LLE), a common separation technique, often struggles with emulsified cosmetics due to stable emulsions formed by emulsifiers and surfactants, which resist phase separation [4]. In 2006, Xia et al. [5] improved this method by incorporating acetic acid, which effectively dissolves these challenging components, thereby enhancing the recovery of fullerenes from facial creams and serums. This modified approach successfully overcomes the emulsification challenges that typically impede traditional liquid–liquid extraction methods.

2. Liquid Cosmetics

Liquid cosmetics, with their relatively simple matrix, are well-suited to a variety of extraction techniques, thanks to the minimal risk of emulsification and column clogging. Applicable techniques include LLE, cloud point extraction (CPE), SPE, and stir-bar sorptive extraction (SBSE) [6].
Liquid–liquid extraction is a favored method in analytical chemistry for its efficiency and simplicity [7]. Certain water-compatible organic solvents can separate into two distinct phases in the presence of inorganic salts. Cai et al. [8] efficiently isolated phthalates from cosmetic waters and perfumes using this method, which is notably straightforward, achieves rapid partition equilibrium, and integrates seamlessly with HPLC analysis. CPE, another efficient technique, employs surfactant micellization for phase separation [9][10]. In 2011, Soruraddin et al. [11] utilized this method in treating shampoo with sulfuric acid and hydrogen peroxide, subsequently warming it to 40 °C and adding 0.5% phenol to induce micelle formation, enabling the spectrophotometric determination of trace selenium (IV) within the micellar phase of Triton X-100. This study employs an economical and environmentally friendly approach, utilizing temperature elevation to the cloud point to form micelles, thereby achieving biphasic separation. This method is straightforward in operation, with a recovery rate ranging from 98% to 102%. Additionally, co-precipitation-assisted cloud point extraction enhances this technique by using co-precipitants for better analyte extraction. In 2013, Xiao et al. [12] combined aluminum hydroxide co-precipitation with sodium dodecyl sulfate-mediated cloud point extraction to effectively isolate and extract five estrogens from toners (17β-estradiol, estrone, ethinyl estradiol, diethyl stilbestrol, and dihydro stilbestrol). Similar to CPE, this study enhances the enrichment and separation of target analytes during cloud point extraction by incorporating coprecipitants to form precipitates with the analytes. Applied to the extraction of estrogens in cosmetics, this method achieves a recovery rate ranging from 77.3% to 104.1%.
SPE is extensively utilized in food safety, pharmaceutical analysis, and biomedicine, using common adsorbents like diatomaceous earth, alumina, silica, and C18 and C8 silicas [13][14]. Recently, innovative adsorbents have been developed, such as nitrated garlic skin [15], corn fibers [16], molecularly imprinted polymers [17], artificial antibodies [18], and magnetic SPE. In 2020, Zhao et al. [19] developed a technique for detecting four steroids (ethinylestradiol, norgestrel, megestrol acetate and medroxyprogesterone acetate) in shampoo, employing a deep-eutectic-solvent-based magnetic colloidal gel (DES–MCG) in magnetic SPE. They synthesized a DES–MCG adsorbent using a choline chloride–urea deep eutectic solvent with magnetic multi-walled carbon nanotubes (MMWCNTs). This novel adsorbent was used to extract analytes from concentrated shampoos, achieving recoveries ranging from 80.1% to 118.8%. This method integrates deep eutectic solvents with MMWCNTs, not only optimizing the sample processing procedure but also enhancing the recovery rate. Moreover, it exhibits superior environmental friendliness, aligning with the requirements of green analytical chemistry.
Parabens, common preservatives in cosmetics, are limited by the EU to a maximum concentration of 0.8% (w/w) in products. Traditional SPE suffers from low selectivity, often resulting in the co-extraction of various matrix components, adversely affecting the quantitative analysis of analytes. Molecularly imprinted polymers (MIP) are synthetic materials capable of selectively interacting with specific chemical functional groups. Utilizing MIPs that selectively bind parabens enhances the selectivity of SPE. In 2018, Vicario et al. [20] synthesized MIPs using propylparaben as a template. They employed MIP-based solid-phase extraction (MISPE) for pretreatment of commercially available baby wipes, followed by analysis using high-performance liquid chromatography (HPLC). This method, demonstrating an over 86.15% recovery rate, showed greater selectivity, stability, and improved retention capabilities compared to traditional SPE methods.
Acrylamide, a compound capable of forming covalent bonds with macromolecules such as proteins and DNA, is known to induce mutations and has potential carcinogenic effects. The presence of amino acids and sugars in cosmetic ingredients can lead to the formation of acrylamide during processing. Consequently, monitoring and controlling the content of acrylamide in cosmetics is of paramount importance. In 2023, Schettino et al. [21] utilized vortex-assisted reverse-phase dispersive liquid phase microextraction (LPME), employing water as the extraction solvent, to successfully extract and pre-concentrate acrylamide from liquid hand soaps and makeup removers. Subsequent analysis of the extracted acrylamide was conducted using liquid chromatography–tandem mass spectrometry (LC–MS/MS). This method, upon validation, demonstrated excellent analytical performance, including linearity, detection and quantification limits, with a recovery rate of 88–108%. Efficient, simple, and rapid, this method precisely quantifies trace levels of acrylamide, providing a robust tool for assessing the safety of cosmetics.

3. Powdered Cosmetics

Powdered cosmetics, rich in minerals that are largely insoluble in conventional solvents, present challenges in pretreatment. In 2010, Cha et al. [22] tackled this by using a mixture of nitric and hydrofluoric acids for mineral decomposition via microwave digestion, which enabled the quantitative analysis of six metals—iron, copper, zinc, lead, nickel, and cadmium—in various cosmetic products using flame atomic absorption spectroscopy (FAAS). Microwave digestion involves heating a sample with a strong acid inside a closed vessel using microwave radiation. This process significantly speeds up the digestion process, allowing for the efficient breakdown of the sample matrix. Expanding on this technique, Bocca et al. [23], in 2013, employed a similar acid digestion method followed by LC–MS for the measurement of trace metals in face powders. The acid nitration method effectively decomposes both organic and inorganic components in cosmetics, disrupting the complex matrix and insoluble inorganic constituents, thereby facilitating the detection of metal elements and other targeted analytes.
Liquid-phase microextraction (LPME) is a sample preparation technique used to isolate and concentrate analytes from liquid samples. It involves a small amount of an organic solvent, which is immiscible with the aqueous sample, to extract the analytes. In 2007, Xiao et al. [24] developed the LPME–HPLC method for the precise quantification of trace levels of estratriol, estradiol, ethinylestradiol, and estriol in toners. This methodology involved the optimization of various experimental conditions, including the selection and volume of the acceptor phase solvent, stirring speed, and extraction duration. The analysis of these four estrogens using this method yielded recovery rates ranging from 101.2% to 114.9%. Compared with traditional pretreatment methods, this novel approach employed LPME technology, resulting in a substantial reduction in organic solvent usage and a decrease in operation time, thereby offering advantages to simplicity, rapidity, sensitivity, and environmental friendliness.
Matrix solid-phase dispersion (MSPD) offers an efficient alternative to traditional solvent-based sample preparation by blending and grinding the sample directly with an adsorbent, making it particularly effective for solid and semi-solid matrices [25][26][27]. In 2019, Chen et al. [28] developed a protocol utilizing MSPD to detect colorants in solid cosmetics such as blush and eyeshadow. The method involved grinding the cosmetics with anhydrous sodium sulfate and sand, then transferring the mixture to an SPE column, eluting with methanol, and analyzing the eluates using ultra-high-performance liquid chromatography (UHPLC) coupled with quadrupole-orbitrap high-resolution mass spectrometry (Q-orbitrap HRMS). This approach successfully identified 11 prohibited colorants in cosmetics, including acid blue, acid red, acid black, acid orange, acid yellow, solvent green, solvent orange, solvent yellow, pigment red, basic violet and disperse yellow. The study demonstrated the effectiveness of combining desiccants and dispersants (anhydrous sodium sulfate and sand) in sample grinding, significantly enhancing the homogeneity of the sample and the extraction efficiency of the analytes (ranging from 64.0% to 128.4%).
Similar to MSPD, pressurized liquid extraction (PLE) [29] and accelerated solvent extraction (ASE) [30] are commonly used for extracting analytes from powdered cosmetics. The use of dispersants in these methods helps prevent sample compaction and optimizes solvent consumption. This not only enhances the efficiency of the extraction process but also minimizes the environmental footprint.

4. Wax-Based Cosmetics

The complex waxes in wax-based cosmetics hinder dissolution and separation, necessitating the use of potent yet toxic organic solvents like chloroform or dichloromethane and extensive pretreatment to isolate analytes [31][32].
To overcome the challenges associated with wax-based cosmetics, Wang et al. [33] introduced a method to isolate rhodamine B without using harsh solvents. Their technique utilized mechanical stirring along with sodium lauryl sulfate, an anionic surfactant, to disperse lipstick in water at 333 K (59.85 °C). The mixture was then subjected to SPE using a cotton-packed column to separate waxes, followed by fluorescence detection for quantification. This method effectively removed wax residues by reversing the flow of the mobile phase. This study adopts a straightforward approach, dissolving lipstick in a solvent through mechanical stirring at high temperatures, effectively circumventing complex sample pretreatment steps, thereby significantly enhancing the processing efficiency.
Ashing is a sample preparation process used in analytical chemistry to remove organic components from a sample. In this process, a sample is heated to high temperatures in the presence of air or oxygen, leading to combustion or thermal decomposition of organic substances. The result is a residue primarily composed of inorganic ash, which can then be analyzed for its elemental composition. This method is ideal for isolating heat-stable compounds in wax-based cosmetics. In 2012, Brandão et al. [34] used this technique to determine the lead content in various cosmetics, such as mascara, concealer, lipstick, and lip gloss. Their procedure involved incinerating the cosmetic samples at 600 °C, followed by digestion with nitric acid and quantification using flame atomic absorption spectroscopy for accurate lead measurements.

References

  1. Zhong, Z.; Li, G.; Wu, Y.; Luo, Z.; Zhu, B. Ultrasound-assisted matrix solid-phase dispersive liquid extraction for the determination of intermediates in hair dyes with ion chromatography. Anal. Chim. Acta 2012, 752, 53–61.
  2. Zhan, J.; Ni, M.L.; Zhao, H.Y.; Ge, X.M.; He, X.Y.; Yin, J.Y.; Yu, X.J.; Fan, Y.M.; Huang, Z.Q. Multiresidue analysis of 59 nonallowed substances and other contaminants in cosmetics. J. Sep. Sci. 2014, 37, 3684–3690.
  3. Lu, Y.; He, Y.; Wang, X.; Wang, H.; Qiu, Q.; Wu, B.; Wu, X. Screening, characterization, and determination of suspected additives bimatoprost and latanoprost in cosmetics using NMR and LC-MS methods. Anal. Bioanal. Chem. 2023, 415, 3549–3558.
  4. Flower, C.; Carter, S.; Earls, A.; Fowler, R.; Hewlins, S.; Lalljie, S.; Lefebvre, M.; Mavro, J.; Small, D.; Volpe, N. A method for the determination of N-Nitrosodiethanolamine in personal care products–collaboratively evaluated by the CTPA Nitrosamines Working Group. Int. J. Cosmet. Sci. 2006, 28, 21–33.
  5. Xia, X.R.; Monteiro-Riviere, N.A.; Riviere, J.E. Trace analysis of fullerenes in biological samples by simplified liquid-liquid extraction and high-performance liquid chromatography. J. Chromatogr. A 2006, 1129, 216–222.
  6. David, F.; Sandra, P. Stir bar sorptive extraction for trace analysis. J. Chromatogr. A 2007, 1152, 54–69.
  7. Ogunfowokan, A.O.; Torto, N.; Adenuga, A.A.; Okoh, E.K. Survey of levels of phthalate ester plasticizers in a sewage lagoon effluent and a receiving stream. Environ. Monit. Assess. 2006, 118, 457–480. Available online: https://link.springer.com/article/10.1007/s10661-006-1500-z (accessed on 10 November 2023).
  8. Cai, Y.; Cai, Y.e.; Shi, Y.; Liu, J.; Mou, S.; Lu, Y. A liquid–liquid extraction technique for phthalate esters with water-soluble organic solvents by adding inorganic salts. Microchim. Acta 2007, 157, 73–79.
  9. Pytlakowska, K.; Kozik, V.; Dabioch, M. Complex-forming organic ligands in cloud-point extraction of metal ions: A review. Talanta 2013, 110, 202–228.
  10. Prasada Rao, T.; Kala, R. On-line and off-line preconcentration of trace and ultratrace amounts of lanthanides. Talanta 2004, 63, 949–959.
  11. Soruraddin, M.H.; Heydari, R.; Puladvand, M.; Zahedi, M.M. A new spectrophotometric method for determination of selenium in cosmetic and pharmaceutical preparations after preconcentration with cloud point extraction. Int. J. Anal. Chem. 2011, 2011, 729651.
  12. Xiao, X.; Chen, X.; Xu, X.; Li, G. Co-precipitation assisted cloud point extraction coupled with high performance liquid chromatography for the determination of estrogens in water and cosmetic samples. Anal. Methods 2013, 5, 6376–6381.
  13. Azzouz, A.; Kailasa, S.K.; Lee, S.S.; Rascón, A.J.; Ballesteros, E.; Zhang, M.; Kim, K.-H. Review of nanomaterials as sorbents in solid-phase extraction for environmental samples. TrAC Trends Anal. Chem. 2018, 108, 347–369.
  14. Zhao, F.; Wang, S.; She, Y.; Zhang, C.; Zheng, L.; Jin, M.; Shao, H.; Jin, F.; Du, X.; Wang, J. Subcritical water extraction combined with molecular imprinting technology for sample preparation in the detection of triazine herbicides. J. Chromatogr. A 2017, 1515, 17–22.
  15. Zhao, Y.; Li, W.; Liu, J.; Huang, K.; Wu, C.; Shao, H.; Chen, H.; Liu, X. Modification of garlic peel by nitric acid and its application as a novel adsorbent for solid-phase extraction of quinolone antibiotics. Chem. Eng. J. 2017, 326, 745–755.
  16. Zhang, N.; Gao, Y.; Sheng, K.; Jing, W.; Xu, X.; Bao, T.; Wang, S. Effective extraction of fluoroquinolones from water using facile modified plant fibers. J. Pharm. Anal. 2022, 12, 791–800.
  17. Arabi, M.; Ostovan, A.; Bagheri, A.R.; Guo, X.; Wang, L.; Li, J.; Wang, X.; Li, B.; Chen, L. Strategies of molecular imprinting-based solid-phase extraction prior to chromatographic analysis. TrAC Trends Anal. Chem. 2020, 128, 115923.
  18. Zhao, F.; She, Y.; Zhang, C.; Wang, S.; Du, X.; Jin, F.; Jin, M.; Shao, H.; Zheng, L.; Wang, J. Selective determination of chloramphenicol in milk samples by the solid-phase extraction based on dummy molecularly imprinted polymer. Food Anal. Methods 2017, 10, 2566–2575.
  19. Zhao, Z.; Zhao, J.; Liang, N.; Zhao, L. Deep eutectic solvent-based magnetic colloidal gel assisted magnetic solid-phase extraction: A simple and rapid method for the determination of sex hormones in cosmetic skin care toners. Chemosphere 2020, 255, 127004.
  20. Vicario, A.; Aragón, L.; Wang, C.C.; Bertolino, F.; Gomez, M.R. A simple and highly selective molecular imprinting polymer-based methodology for propylparaben monitoring in personal care products and industrial waste waters. J. Pharm. Biomed. Anal. 2018, 149, 225–233.
  21. Schettino, L.; Garcia-Juan, A.; Fernandez-Lozano, L.; Benede, J.L.; Chisvert, A. Trace determination of prohibited acrylamide in cosmetic products by vortex-assisted reversed-phase dispersive liquid-liquid microextraction and liquid chromatography-tandem mass spectrometry. J. Chromatogr. A 2023, 1687, 463651.
  22. Cha, N.-R.; Lee, J.-K.; Lee, Y.-R.; Jeong, H.-J.; Kim, H.-K.; Lee, S.-Y. Determination of Iron, Copper, Zinc, Lead, Nickel and Cadmium in Cosmetic Matrices by Flame Atomic Absorption Spectroscopy. Anal. Lett. 2010, 43, 259–268.
  23. Bocca, B.; Forte, G.; Pino, A.; Alimonti, A. Heavy metals in powder-based cosmetics quantified by ICP-MS: An approach for estimating measurement uncertainty. Anal. Methods 2013, 5, 402–408.
  24. Xiao, X.; Yin, Y.; Hu, Y.; Li, G. Determination of Trace Estrogens in Cosmetic Water by Liquid-Phase Microextraction Coupled with High Performance Liquid Chromatography. Se Pu 2007, 25, 234–237. Available online: https://www.chrom-china.com/EN/Y2007/V25/I2/234 (accessed on 7 January 2024).
  25. Celeiro, M.; Garcia-Jares, C.; Llompart, M.; Lores, M. Recent advances in sample preparation for cosmetics and personal care products analysis. Molecules 2021, 26, 4900.
  26. Shi, M.-Z.; Yu, Y.-L.; Zhu, S.-C.; Yang, J.; Cao, J. Latest development of matrix solid phase dispersion extraction and microextraction for natural products from 2015–2021. Sep. Purif. Rev. 2023, 52, 262–282.
  27. Tu, X.; Chen, W. A Review on the recent progress in matrix solid phase dispersion. Molecules 2018, 23, 2767.
  28. Chen, M.; Bai, H.; Zhai, J.F.; Meng, X.S.; Guo, X.Y.; Wang, C.; Wang, P.L.; Lei, H.M.; Niu, Z.Y.; Ma, Q. Comprehensive screening of 63 coloring agents in cosmetics using matrix solid-phase dispersion and ultra-high-performance liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry. J. Chromatogr. A 2019, 1590, 27–38.
  29. Barp, L.; Višnjevec, A.M.; Moret, S. Pressurized Liquid Extraction: A powerful tool to implement extraction and purification of food contaminants. Foods 2023, 12, 2017.
  30. Sun, H.; Ge, X.; Lv, Y.; Wang, A. Application of accelerated solvent extraction in the analysis of organic contaminants, bioactive and nutritional compounds in food and feed. J. Chromatogr. A 2012, 1237, 1–23.
  31. Guerra, E.; Llompart, M.; Garcia-Jares, C. Analysis of dyes in cosmetics: Challenges and recent developments. Cosmetics 2018, 5, 47.
  32. Dimakopoulou-Papazoglou, D.; Giannakaki, F.; Katsanidis, E. Structural and physical characteristics of mixed-component oleogels: Natural wax and monoglyceride interactions in different edible oils. Gels 2023, 9, 627.
  33. Wang, C.C.; Masi, A.N.; Fernandez, L. On-line micellar-enhanced spectrofluorimetric determination of rhodamine dye in cosmetics. Talanta 2008, 75, 135–140.
  34. Brandão, J.D.O.; Okonkwo, O.J.; Sehkula, M.; Raseleka, R.M. Concentrations of lead in cosmetics commonly used in South Africa. Toxicol. Environ. Chem. 2012, 94, 70–77.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license; additional terms may apply. By using this site, you agree to the Terms and Conditions and Privacy Policy.
Upload a video for this entry
Information
Subjects: Medicine, Research & Experimental
Contributors MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to https://encyclopedia.pub/register :
Xiao-Nan Du
,
Yu He
,
You-Wen Chen
,
Qian Liu
,
Lei Sun
,
Hui-Min Sun
,
Xian-Fu Wu
,
Yong Lu
View Times: 87
Revisions: 2 times (View History)
Update Date: 29 Jan 2024
Table of Contents
    1000/1000
    Hot Most Recent
    Feedback