Objective To establish a rapid on-site detection method for detecting formaldehyde in workplace air using the length detector tube method. Methods The length detector tube was applied to detect the level of formaldehyde in workplace air. Performance indicators, including accuracy, precision, stability, and interference susceptibility, of the method were validated. Results The formaldehyde length detector tube can determine formaldehyde mass concentrations ranging from 0.05 to 4.00 mg/m³ at 25 ℃, covering 0.5 to 2.0 times the occupational exposure limit for formaldehyde (0.50 mg/m³). Under conditions of 10 to 35 ℃ and relative humidity <80.00%, the average recovery was 93.33%-101.67%, and all the within-run method ranges from -21.67% to 20.00%, and all the relative standard deviations were <10.00%. The average decrease rate of formaldehyde in gas bags within 24 hours ranged from -8.33% to 8.33%. Common coexisting substances in workplaces, such as methanol, benzene, toluene, hydrogen chloride, and nitrogen dioxide, did not interfere with the measurements. However, aldehydes and ketones might cause overestimation. Conclusion The formaldehyde length detector tube method demonstrates high accuracy and specificity for detecting formaldehyde in air, making it suitable for rapid monitoring of formaldehyde in workplace air.

BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

BACKGROUND:Exosomes derived from mesenchymal stem cells play pivotal roles in cell communication and epigenetic regulation due to their low immunogenicity and targeted delivery effects,and have been clinically applied in the treatment of various diseases.OBJECTIVE:To review the isolation,purification,identification methods,and application progress of mesenchymal stem cell-derived exosomes,and to facilitate the development of large-scale preparation techniques and clinical translation of mesenchymal stem cell-derived exosomes.METHODS:The Chinese search terms"exosome,mesenchymal stem cells,isolation,purification,characterization,clinical application"and the English search terms"exosome,extracellular vesicles,mesenchymal stem cells,isolation,characterization,application"were used to search the literature published before September 2024 in CNKI,PubMed,and Web of Science databases.Articles with poor relevance to the topic,outdated,or duplicated content were excluded,and finally,109 articles were included for review.RESULTS AND CONCLUSION:(1)This paper reviews recent methods for isolating and purifying exosomes,comparing the characteristics of ultracentrifugation,ultrafiltration,size-exclusion chromatography,polymer precipitation,immunoaffinity,microfluidic methods,and other novel approaches based on their underlying principles.(2)Methods for identifying exosomes can be categorized into physical and biochemical analyses,characterizing exosomes based on their shape,size,and characteristic proteins.(3)Mesenchymal stem cell-derived exosomes have broad applications in multiple fields such as medical aesthetics,wound repair,and cancer treatment,due to their immune-regulatory properties and ability to cross biological barriers.(4)The clinical translation of exosomes faces challenges due to their complex structure,lack of universal isolation techniques,and poor stability,making it difficult to achieve in a short period of time.

Background/Aims: Transmembrane 4 L six family member 1 (TM4SF1) is highly expressed and contributes to the progression of various malignancies. However, how it modulates hepatocellular carcinoma (HCC) progression and senescence remains to be elucidated. Methods: TM4SF1 expression in HCC samples was evaluated using immunohistochemistry and flow cytometry. Cellular senescence was assessed through SA-β-gal activity assays and Western blot analysis. TM4SF1-related protein interactions were investigated using immunoprecipitation-mass spectrometry, co-immunoprecipitation, bimolecular fluorescence complementation, and immunofluorescence. Tumor-infiltrating immune cells were analyzed by flow cytometry. The HCC mouse model was established via hydrodynamic tail vein injection. Results: TM4SF1 was highly expressed in human HCC samples and murine models. Knockdown of TM4SF1 suppressed HCC proliferation both in vitro and in vivo, inducing non-secretory senescence through upregulation of p16 and p21. TM4SF1 enhanced the interaction between AKT1 and PDPK1, thereby promoting AKT phosphorylation, which subsequently downregulated p16 and p21. Meanwhile, TM4SF1-mediated AKT phosphorylation enhanced PD-L1 expression while reducing major histocompatibility complex class I level on tumor cells, leading to impaired cytotoxic function of CD8+ T cells and an increased proportion of exhausted CD8+ T cells. In clinical HCC samples, elevated TM4SF1 expression was associated with resistance to anti-PD-1 immunotherapy. Targeting TM4SF1 via adeno-associated virus induced tumor senescence, reduced tumor burden and synergistically enhanced the efficacy of anti-PD-1 therapy. Conclusions Our results revealed that TM4SF1 regulated tumor cell senescence and immune evasion through the AKT pathway, highlighting its potential as a therapeutic target in HCC, particularly in combination with first-line immunotherapy.

Background/Aims: Transmembrane 4 L six family member 1 (TM4SF1) is highly expressed and contributes to the progression of various malignancies. However, how it modulates hepatocellular carcinoma (HCC) progression and senescence remains to be elucidated. Methods: TM4SF1 expression in HCC samples was evaluated using immunohistochemistry and flow cytometry. Cellular senescence was assessed through SA-β-gal activity assays and Western blot analysis. TM4SF1-related protein interactions were investigated using immunoprecipitation-mass spectrometry, co-immunoprecipitation, bimolecular fluorescence complementation, and immunofluorescence. Tumor-infiltrating immune cells were analyzed by flow cytometry. The HCC mouse model was established via hydrodynamic tail vein injection. Results: TM4SF1 was highly expressed in human HCC samples and murine models. Knockdown of TM4SF1 suppressed HCC proliferation both in vitro and in vivo, inducing non-secretory senescence through upregulation of p16 and p21. TM4SF1 enhanced the interaction between AKT1 and PDPK1, thereby promoting AKT phosphorylation, which subsequently downregulated p16 and p21. Meanwhile, TM4SF1-mediated AKT phosphorylation enhanced PD-L1 expression while reducing major histocompatibility complex class I level on tumor cells, leading to impaired cytotoxic function of CD8+ T cells and an increased proportion of exhausted CD8+ T cells. In clinical HCC samples, elevated TM4SF1 expression was associated with resistance to anti-PD-1 immunotherapy. Targeting TM4SF1 via adeno-associated virus induced tumor senescence, reduced tumor burden and synergistically enhanced the efficacy of anti-PD-1 therapy. Conclusions Our results revealed that TM4SF1 regulated tumor cell senescence and immune evasion through the AKT pathway, highlighting its potential as a therapeutic target in HCC, particularly in combination with first-line immunotherapy.

Objective:To evaluate the effect of preoperative anxiety on the consciousness and autonomic nervous activity during propofol anesthesia.Methods:This study was a secondary analysis of data from the clinical trial in a prospective single-arm study. One hundred and thirty patients, aged 18-65 yr, with a body mass index of 18.5-27.9 kg/m 2, of American Society of Anesthesiologists Physical Status classification I or Ⅱ, scheduled to receive propofol anesthesia, were selected from the Second People′s Hospital of Lianyungang. The six-item of the state anxiety inventory (SAI) of the State-Trait Anxiety Inventory was used to assess the anxiety of patients 1 h before surgery. The patients were divided into 2 groups according to the cut-off value of 12: obvious anxiety symptom (SAI score >12) group (group A, n=49) and no obvious anxiety symptom (SAI score ≤12) group (group B, n=81). After admission to the operating room, the patient was required to hold a 50 ml syringe filled with water. Propofol was given by target-controlled infusion (TCI) with the target plasma concentration set at 5 μg/ml. When the effect-site concentration (Ce) of propofol increased to 3.5 μg/ml (all the patients lost consciousness), the closed-loop TCI was used to maintain BIS value between 45 and 55. The patients were monitored for 20 min after stopping the pump infusion (anesthesia recovery period). The disappearance time of verbal command, disappearance time of eyelash reflex, time of syringe dropping, recovery time of verbal command, recovery time of eyelash reflex, Ce at the recovery of verbal command, Ce at the recovery of eyelash reflex, Ce within the first 5 min of the closed-loop TCI, and consumption of propofol during anesthesia were recorded. The peripheral perfusion index, low frequency power and high frequency power of heart rate variability were recorded, and the ratio of low frequency power to high frequency power was calculated. Pearson correlation analysis was used to assess the correlation between preoperative SAI score and consciousness-related indicators, simulated Ce of propofol and consumption of propofol. Results:Compared with group B, the disappearance time of verbal command, disappearance time of eyelash reflex, and time of syringe dropping were significantly prolonged, the consumption of propofol, simulated Ce at recovery of verbal command and within the first 5 min of closed-loop TCI were increased, the peripheral perfusion index was decreased at each time point before administration and at 14-20 min of anesthesia recovery, and the low-frequency power was decreased during anesthesia maintenance in group A ( P<0.05). The SAI score was positively correlated with the disappearance time of verbal command ( r=0.220, P=0.012), time of syringe dropping ( r=0.206, P=0.029), consumption of propofol ( r=0.330, P<0.001), and the simulated Ce at the recovery of verbal command ( r=0.215, P=0.015) and simulated Ce at recovery of eyelash reflex ( r=0.207, P=0.022). Conclusions:Preoperative anxiety may lead to prolonged loss of consciousness and more marked inhibition of sympathetic nerve activity during propofol anesthesia.

To further standardize the management of postoperative nausea and vomiting in China, the Chinese Society of Anesthesiology initiated the development of Clinical practice guidelines on postoperative nausea and vomiting(2024 edition). The guideline development strictly adhered to internationally recognized principles. This protocol primarily described the methodology and process of guideline formulation, including essential information, background, objectives, development principles, task force and responsibilities, selection of clinical question, evidence acquisition, evidence evaluation, and expert consensus formulation.

Objective To establish a liquid chromatography method for the simultaneous determination of 13 aromatic amine compounds (AAs) in workplace air. Methods A total of 13 AAs in both vapor and aerosol phases were collected in workplace air using a new GDH-6 sampling tube. Samples were desorbed and eluted with methanol, separated using a Symmetry Shield™ RP₁₈ reversed-phase liquid chromatography column, and detected with a diode array detector. Quantification was performed using an external standard method. Results The linear range of the 13 AAs measured by this method was 0.02-373.60 μg/L with the correlation coefficients greater than 0.999 0. The minimum detection concentration was 0.09-14.37 μg/m³, and the minimum quantitative concentration was 0.31-47.90 μg/m³ (both calculated based on sampling 15.0 L of air and 3.0 mL of elution volume). The average desorption and elution efficiency ranged from 97.46% to 101.23%. The within-run relative standard deviation (RSD) was 0.10%-5.99%, and the between-run RSD was 0.17%-2.71%. Samples could be stably stored in sealed conditions at 2-8 ℃ for more than seven days. Conclusion This method is suitable for the simultaneous determination of 13 AAs in workplace air, including both vapor and aerosol phases.

Objective To establish a method for simultaneous determination of four high-molecular-weight thiol derivatives (TDs) in workplace air by gas chromatography. Methods The four kinds of vapor-phase macromolecular TDs (1-pentanethiol, 1-hexanethiol, 1-benzyl mercaptan, and n-octanethiol) in the workplace air were collected using the GDH-1 air sampling tubes, desorbed with anhydrous ethanol, separated on a DB-FFAP capillary column, and determined by flame ionization detector. Results The quantitation range of the four TDs was 0.30-207.37 mg/L, with the correlation coefficients greater than 0.999 00. The minimum detection mass concentrations and minimum quantitation mass concentrations were 0.18-0.32 and 0.60-1.05 mg/m³, respectively (both calculated based on the 1.5 L sample and 3.0 mL desorption solvent). The mean desorption efficiencies ranged from 87.07% to 103.59%. The within-run and between-run relative standard deviations were 1.92%-8.22% and 1.89%-8.45%, respectively. The samples can be stored at room temperature or 4 ℃ for three days and up to 7 days at -18 ℃. Conclusion This method is suitable for the simultaneous determination of four vapor-phase TDs in workplace air.

Objective To develop a solvent desorption-gas chromatography method for quantifying malononitrile in workplace air. Methods Malononitrile in workplace air was collected using a silica gel tube and desorbed with methanol. Separation was performed using DB-FFAP capillary column, and detection was performed by hydrogen flame ionization detector. Results The linear ranges of malononitrile were 4.00-600.00 mg/L, with the correlation coefficient of 0.999 92. The detection limit was 0.54 mg/L. The minimum detection concentration was 0.36 mg/m³ (based on a collected air volume of 1.5 L). The average desorption efficiency was 95.0%-101.0%. The within-run and between-run relative standard deviations were 0.9%-5.3% and 1.0%-6.8%, respectively. The sampling efficiency was 100.0%. The samples were stable at 4 ℃ for at least 14 days. Conclusion The solvent desorption-gas chromatography method established in this study for the determination of malononitrile in workplace air is simple to use, with high accuracy and good precision, and is suitable for the determination of malononitrile in workplace air.