AIM To establish a UPLC-ESI-MS/MS method for analyzing the toxic material basis of 95％ethanol cold soaked ultrasonic extract(EC),95％ethanol heated reflux extract(EH)and water decoction extract(WD)from Dryopteris crassirhizoma Nakai.METHODS The analysis was performed on a 25 ℃ thermostatic agilent ZORBAX RRHD StableBond C18 column(2.1 mm×150 mm,1.8 μm),with the mobile phase comprising of methanol-0.2％formic acid flowing at 0.30 mL/min,and heated electrospray ion source was adopted in positive and negative ion scanning.Compounds were identified by Compound Discover 3.3 software combined with the database and related literature,and the main differential components were screened by Heatmap cluster analysis and partial least squares discriminant analysis.RESULTS 72 compounds were identified(22 phloroglucinols,19 flavonoids,8 phenylpropanoids,6 terpenoids and 17 other components).The main toxic differential components were phloroglucinols such as flavaspidic acid AB,didemethylpseudoaspidin AA and filixic acid PBP,flavonoids such as(-)-epicatechin,(-)-epigallocatechin,cianidanol,and other compounds such as indole-3-carboxaldehyde.CONCLUSION This method can rapidly,effectively and comprehensively characterize the main chemical composition of D.crassirhizoma,and provide a reference for the study of its pharmacological mechanism.

Objective To design a high altitude adaptive oxygen generator for the crews to alleviate their high altitude reaction in high altitude environment and meet their requirements for oxygen supply.Methods A high altitude adaptive oxygen generator based on the mature pressure swing adsorption oxygen production method was designed with the key technologies of discharge capacity compensation of air compression pump and airway fusion of molecular sieve tower,which had the components of molecular sieve tower,air compression pump,controller,cooling fan,cooler,solenoid valve,regulator,flow meter and etc.Trials were carried out at the simulated altitude and field plateau environment so as to verify the high altitude adaptive performance of the oxygen generator developed.Results The trial results showed the oxygen generator met the desired objectives and the requirements for oxygen volume fraction in GJB 2799-1996 General specification for medical oxygen generator using molecular sieve method.Conclusion The oxygen generartor provides oxygen supply effectively for vehicle operators in plateau environments or the ones rushing into the plateau.[Chinese Medical Equipment Journal,2025,46(4):29-34]

Aim To study the mechanism of adipose mesenchymal stem cell exosomes(ASC-exo)inhibition of fluorescein isothiocyanate(FITC)-induced atopic dermatitis(AD).Methods The mouse age,extrac-tion method,and the concentration of a solution of typeⅠ collagen enzyme and other conditions were compared to study the effects on the morphology and quantity of adipose mesenchymal stem cells(ASCs)after extrac-ted.FITC-induced mouse model in vivo was estab-lished and different doses of ASC-exo were given to measure ear thickness,ear weight and ear scratching times of mice.HE staining was used to observe the pathological changes of ear tissue of mice.The non-toxicity of ASC-exo was detected.IgE,IL-5,IL-13 and other cytokines were detected by ELISA.The gene ex-pressions of TSLP,IL-33,occludin,Claudin-1(CLDN-1)and E-cadherin were detected by RT-qPCR.The protein expression was detected by immunohistochemis-try.Results An efficient method for extracting ASCs was established.Compared with the blank group,mice in the model group showed obvious AD symptoms.Compared with the model group,ASC-exo administra-tion group significantly reduced the number of ear scratches,epidermal thickening,inflammatory cell infil-tration and the secretion of Th2 cytokines IL-5 and IL-13.Meanwhile,ASC-exo administration group signifi-cantly increased the expression of structural proteins CLDN-1 and occludin in epithelial cells and decreased the expression of TSLP and IL-33.Conclusions ASC-exo can significantly improve Th2 skin inflamma-tion in AD mice,and its mechanism may be through in-creasing the expression of tight junction proteins and adhesion link protein in epithelial cells,repairing the skin barrier,and inhibiting the key promoters of allergy TSLP and IL-33.

Paclitaxel(PTX)is a first-line chemotherapy drug for breast cancer,but its resistance issues significantly impact clinical treatment efficacy.Fucosylation,especially core fucosylation,is closely related to tumor chemoresistance,resulting in poor chemotherapy responses and poor prognosis in patients.In this study,we investigated the effect and mechanism of the fucosylation inhibitor 2-fluorofucose(2-F-Fuc)on the chemosensitivity of paclitaxel-resistant breast cancer MCF-7/PTX cells.The drug resistanceindex(RI)of MCF-7/PTX cells was 8.49 by MTT assays.Western blotting,real-time PCR,enzyme-linked immu-nosorbent assay(ELISA)and Lens Culinaris Agglutinin(LCA)lectin imprinting showed that compared with MCF-7 cells,the expression of FUT8,MDR1and core fucosylation in MCF-7/PTX cells was high.Western blotting showed that 2-F-Fuc had a significant inhibitory effect on the growth of MCF-7/PTX cells,and the expression levels of FUT8 and MDR1 were significantly down-regulated after 2-F-Fuc treatment,and the down-regulation was more pronounced in the PTX and 2-F-Fuc combination group(P＜0.05).Compared to the control,expression of PCNA in MCF-7/PTX cells in the PTX and the 2-F-Fuc group were down-regulated,and the apoptosis-related proteins,such as cleaved caspase-3 and Bax/Bcl-2 were in-creased.The level of p-PI3K and p-AKT were down-regulated,and the changes in the combination of 2-F-Fuc and PTX were more robust(P＜0.05).The above results showed that the core fucosylation level of MCF-7/PTX cells was significantly increased,and 2-F-Fuc could reduce the core fucosylation level of MCF-7/PTX cells by inhibiting the expression of FUT8,and enhance the sensitivity of drug-resistant cells to PTX,which may correlate with the downregulation of PI3K/AKT signaling pathway proteins.

Paclitaxel(PTX)is a first-line chemotherapy drug for breast cancer,but its resistance issues significantly impact clinical treatment efficacy.Fucosylation,especially core fucosylation,is closely related to tumor chemoresistance,resulting in poor chemotherapy responses and poor prognosis in patients.In this study,we investigated the effect and mechanism of the fucosylation inhibitor 2-fluorofucose(2-F-Fuc)on the chemosensitivity of paclitaxel-resistant breast cancer MCF-7/PTX cells.The drug resistanceindex(RI)of MCF-7/PTX cells was 8.49 by MTT assays.Western blotting,real-time PCR,enzyme-linked immu-nosorbent assay(ELISA)and Lens Culinaris Agglutinin(LCA)lectin imprinting showed that compared with MCF-7 cells,the expression of FUT8,MDR1and core fucosylation in MCF-7/PTX cells was high.Western blotting showed that 2-F-Fuc had a significant inhibitory effect on the growth of MCF-7/PTX cells,and the expression levels of FUT8 and MDR1 were significantly down-regulated after 2-F-Fuc treatment,and the down-regulation was more pronounced in the PTX and 2-F-Fuc combination group(P＜0.05).Compared to the control,expression of PCNA in MCF-7/PTX cells in the PTX and the 2-F-Fuc group were down-regulated,and the apoptosis-related proteins,such as cleaved caspase-3 and Bax/Bcl-2 were in-creased.The level of p-PI3K and p-AKT were down-regulated,and the changes in the combination of 2-F-Fuc and PTX were more robust(P＜0.05).The above results showed that the core fucosylation level of MCF-7/PTX cells was significantly increased,and 2-F-Fuc could reduce the core fucosylation level of MCF-7/PTX cells by inhibiting the expression of FUT8,and enhance the sensitivity of drug-resistant cells to PTX,which may correlate with the downregulation of PI3K/AKT signaling pathway proteins.

AIM To establish a UPLC-ESI-MS/MS method for analyzing the toxic material basis of 95％ethanol cold soaked ultrasonic extract(EC),95％ethanol heated reflux extract(EH)and water decoction extract(WD)from Dryopteris crassirhizoma Nakai.METHODS The analysis was performed on a 25 ℃ thermostatic agilent ZORBAX RRHD StableBond C18 column(2.1 mm×150 mm,1.8 μm),with the mobile phase comprising of methanol-0.2％formic acid flowing at 0.30 mL/min,and heated electrospray ion source was adopted in positive and negative ion scanning.Compounds were identified by Compound Discover 3.3 software combined with the database and related literature,and the main differential components were screened by Heatmap cluster analysis and partial least squares discriminant analysis.RESULTS 72 compounds were identified(22 phloroglucinols,19 flavonoids,8 phenylpropanoids,6 terpenoids and 17 other components).The main toxic differential components were phloroglucinols such as flavaspidic acid AB,didemethylpseudoaspidin AA and filixic acid PBP,flavonoids such as(-)-epicatechin,(-)-epigallocatechin,cianidanol,and other compounds such as indole-3-carboxaldehyde.CONCLUSION This method can rapidly,effectively and comprehensively characterize the main chemical composition of D.crassirhizoma,and provide a reference for the study of its pharmacological mechanism.

Objective To investigate the effects and mechanisms of ubiquitin-associated domain-containing protein 2(UBAC2)mediated by m6A methylation modification on the invasion and migration abilities of colorectal cancer cells.Methods The GEPIA2.0 database was utilized to analyze the expression differences of UBAC2 mRNA between colorectal cancer tissues and adjacent normal tissues,as well as its expression in colorectal cancer tissues at different stages.The correlation between Wilms tumor 1-associated protein(WTAP)and UBAC2 expression was analyzed.The Kaplan-Meier plotter online tool was applied to analyze the correlation between UBAC2 and the overall survival rate of colorectal cancer patients.The RMVar and SRAMP databases were employed to predict potential m6A methylation modification sites in the UBAC2 gene.Quantitative real-time PCR(qRT-PCR)and Western blotting were performed to detect the expression levels of UBAC2 mRNA and protein in colorectal cancer cell lines.For UBAC2 knockdown experiments,SW480 cells were divided into control group(no treatment),sh-NC group(transfected with sh-NC negative control plasmid),and sh-UBAC2 group(transfected with sh-UBAC2 plasmid).For WTAP knockdown experiments,groups included control group(no treatment),si-NC group(transfected with negative control siRNA),and si-WTAP group(transfected with WTAP-targeting siRNA).For UBAC2 overexpression experiments,groups were control group(no treatment),si-WTAP group(transfected with pcDNA3.1 empty plasmid),and si-WTAP+OE-UBAC2 group(transfected with UBAC2 overexpression plasmid pcDNA3.1-UBAC2).Western blotting was used to detect the protein expression levels of UBAC2,WTAP,E-cadherin,N-cadherin,and Vimentin;qRT-PCR was applied to detect the expression level of UBAC2 mRNA;Transwell assays were conducted to assess cell invasion and migration abilities.MeRIP-qPCR was employed to detect the m6A methylation modification of UBAC2 mRNA;RIP-qPCR experiments were conducted to verify the binding of WTAP to UBAC2 mRNA.In nude mouse colorectal cancer lung metastasis experiments,groups included LV-sh-NC group(tail vein injection of SW480 cells stably infected with LV-sh-NC)and LV-sh-UBAC2 group(tail vein injection of SW480 cells stably infected with LV-sh-UBAC2).After 42 d of tumor-implantation in nude mice,lung tissues were harvested:the number of lung nodules observed by hematoxylin/eosin(HE)staining,and the expression level of Luc2 mRNA detected by qRT-PCR.Results GEPIA2.0 database analysis revealed that the expression level of UBAC2 mRNA in colorectal cancer tissues was significantly higher than that in adjacent normal tissues,and it gradually increased with the progression of tumor stage(P<0.05).The expression levels of UBAC2 mRNA and protein in multiple colorectal cancer cell lines were significantly higher than those in normal colonic epithelial cells(P<0.05).Compared with sh-NC group,sh-UBAC2 group showed significantly increased E-cadherin protein expression,significantly decreased N-cadherin and Vimentin protein expression,and significantly reduced number of invaded and migrated SW480 cells(P<0.05).GEPIA2.0 database analysis results indicated a positive correlation between WTAP and UBAC2 expression(r=0.24,P<0.001).Compared with si-NC group,si-WTAP group showed significantly decreased expression levels of WTAP and UBAC2 mRNA and protein in SW480 cells(P<0.05).MeRIP-qPCR results demonstrated that the m6A modification level of UBAC2 mRNA in si-WTAP group was significantly lower than that in si-NC group(P<0.05).RIP-qPCR further confirmed that WTAP could bind to UBAC2 mRNA.Compared with control group,si-WTAP group showed significantly increased E-cadherin protein expression and significantly decreased N-cadherin and Vimentin protein expression in SW480 cells(P<0.05);compared with si-WTAP group,si-WTAP+OE-UBAC2 group showed significantly decreased E-cadherin protein expression and significantly increased N-cadherin and Vimentin protein expression in SW480 cells(P<0.05).The number of lung nodules in LV-sh-UBAC2 group was significantly fewer than that in LV-sh-NC group,and the expression level of Luc2 mRNA in lung tissues was significantly lower than that in LV-sh-NC group(P<0.05).Conclusion UBAC2 mediated by m6A methylation modification can regulate the epithelial-mesenchymal transition(EMT)process in colorectal cancer cells,thereby affecting the invasion and migration abilities of colorectal cancer cells.

Aim To study the mechanism of adipose mesenchymal stem cell exosomes(ASC-exo)inhibition of fluorescein isothiocyanate(FITC)-induced atopic dermatitis(AD).Methods The mouse age,extrac-tion method,and the concentration of a solution of typeⅠ collagen enzyme and other conditions were compared to study the effects on the morphology and quantity of adipose mesenchymal stem cells(ASCs)after extrac-ted.FITC-induced mouse model in vivo was estab-lished and different doses of ASC-exo were given to measure ear thickness,ear weight and ear scratching times of mice.HE staining was used to observe the pathological changes of ear tissue of mice.The non-toxicity of ASC-exo was detected.IgE,IL-5,IL-13 and other cytokines were detected by ELISA.The gene ex-pressions of TSLP,IL-33,occludin,Claudin-1(CLDN-1)and E-cadherin were detected by RT-qPCR.The protein expression was detected by immunohistochemis-try.Results An efficient method for extracting ASCs was established.Compared with the blank group,mice in the model group showed obvious AD symptoms.Compared with the model group,ASC-exo administra-tion group significantly reduced the number of ear scratches,epidermal thickening,inflammatory cell infil-tration and the secretion of Th2 cytokines IL-5 and IL-13.Meanwhile,ASC-exo administration group signifi-cantly increased the expression of structural proteins CLDN-1 and occludin in epithelial cells and decreased the expression of TSLP and IL-33.Conclusions ASC-exo can significantly improve Th2 skin inflamma-tion in AD mice,and its mechanism may be through in-creasing the expression of tight junction proteins and adhesion link protein in epithelial cells,repairing the skin barrier,and inhibiting the key promoters of allergy TSLP and IL-33.

Objective To design a high altitude adaptive oxygen generator for the crews to alleviate their high altitude reaction in high altitude environment and meet their requirements for oxygen supply.Methods A high altitude adaptive oxygen generator based on the mature pressure swing adsorption oxygen production method was designed with the key technologies of discharge capacity compensation of air compression pump and airway fusion of molecular sieve tower,which had the components of molecular sieve tower,air compression pump,controller,cooling fan,cooler,solenoid valve,regulator,flow meter and etc.Trials were carried out at the simulated altitude and field plateau environment so as to verify the high altitude adaptive performance of the oxygen generator developed.Results The trial results showed the oxygen generator met the desired objectives and the requirements for oxygen volume fraction in GJB 2799-1996 General specification for medical oxygen generator using molecular sieve method.Conclusion The oxygen generartor provides oxygen supply effectively for vehicle operators in plateau environments or the ones rushing into the plateau.[Chinese Medical Equipment Journal,2025,46(4):29-34]

Against the backdrop of the comprehensive advancement of the Healthy China Strategy and the Rural Revitalization Strategy,the stability and healthy development of the rural medical workforce have become increasingly significant.China's rural doctors are facing the dilemma of"disembedding"and the construction of the merged county medical alliance ( MCMA ) offers an opportunity to address this issue.Based on the theory of embeddedness,this paper deconstructs the structural disembedding,relational disembedding,and cognitive disembedding faced by rural doctors,and provides a theoretical analysis of the mechanisms through which MCMA can solve the disembedding dilemma of rural doctors.Furthermore,the case of Tang County Hospital Group is used to illustrate this.The conclusion can be drawn that MCMA can achieve the structural re-embedding,relational re-embedding,and cognitive re-embedding of rural doctors through organizational integration mechanisms,interest coordination mechanisms,and multifaceted activation mechanisms.The combination of administrative and economic means under organizational integration is the foundation for promoting the re-embedding of rural doctors.The re-embedding of rural doctors requires the synergy of internal and external changes within the MCMA.Multifaceted activation mechanisms are the endogenous driving force for the re-embedding of rural doctors.There is a progressive and coupled relationship between the structural,relational,and cognitive re-embedding of rural doctors.