The n-pentyl peroxy radical (C5H11O2) is a crucial intermediate in the oxidation process of n-pentane,playing an important role in the chain propagation and termination of atmospheric radicals under low NOx conditions. The products from the self-reaction of C5H11O2 were detected online by a microwave discharge fast-flow reactor combined with a vacuum ultraviolet photoionization mass spectrometry in this work. The results indicated three product channels in the self-reaction of C5H11O2,corresponding to alkoxyl radicals (C5H11O),carbonyl compounds (C5H10O) and organic alcohol (C5H11OH),as well as dimeric products (C5H11OOC5H11). Further research was conducted to determine the original channels of the products through reaction kinetics experiments,revealing the self-reaction mechanism of C5H11O2 by comparing the experimental and the simulated results of the main products. The dimeric product C5H11OOC5H11,formed in the self-reaction of C5H11O2,was measured online for the first time,predicting its channel branching ratio to be approximately 10％. The molecular and ionic structures of the product were determined with the help of quantum chemical theoretical calculations.

Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannan-binding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP. Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays. Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05). Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.

Objective To investigate the performance of brands and types of high-flow nasal cnnula oxygen therapy(HFNC)devices at different altitudes.Methods Four different models of HFNC devices,including R-80S bi-level non-invasive ventilator integrated with HFNC device,HF-60A HFNC device,HFT-300 HFNC device and H-80A HFNC device,were connected with the gas flow meter,simularted head and QuickLung and then put into a low-pressure chamber.The flow rates of the HFNC devices were set to 10,15,20,25,30,35,40,45,50,55 and 60 L/min,and the simulated altitudes of the low-pressure chamber were set to 6 000,5 000,4 000,3 000,2 000,1 000 and 0 m.The actual output airway flow rates,airway pressure changes and trends of the four HFNC devices were recorded at different setting altitudes and flow rates.SPSS 25.0 software was used for statistical analysis.Results The actual output airway flow rates of the four HFNC devices showed an increasing trend as the altitude rose with the simulated altitude of 6 000 m and the setting flow rate kept constant,which increased slowly and even went to decrease when the altitude and flow rate exceeded some limits.The degree of changes in the flow rate with the increasing altitude varied,and there was no uniform pattern.With the rising of altitude,the actual output airway pressure of the four HFNC devices with the flow rate raning from 10 to 35 L/min also increased gradually,which showed a decreasing trend(turning point)after going up to some certain value when the flow rate exceeded 35 L/min,and the altitude where the turning point appeared was lowered as the flow rate increased.Conclusion The actual output airway flow rates and airway pressure during HFNC rise at a high-altitude environment,and generally considerations have to be taken on required airway pressure,patient comfort and the altitude of the patient's usual place of residence when setting the flow rates of the HFNC device.[Chinese Medical Equipment Journal,2024,45(6):49-58]

Aim To explore the protective effect of an-thocyanin B2(PCB2)on hydrogen peroxide(H2O2)induced oxidative damage and apoptosis in human oli-godendrocytes(MO3.13)and the underlying mecha-nism.Methods The optimal concentration of H2O2 and PCB2 for action was screened,and divided into normal group,PCB2 group(100 mg·L-1 PCB2 treat-ment for 24 hours),H2 O2 model group(500 μmol·L-1 H2O2 treatment for 24 hours),and H2O2+PCB2 group(500 μmol·L-1 H2O2 and 100 mg·L-1 PCB2 co-treated for 24 hours).FRAP method was used to detect the antioxidant capacity of PCB2;CCK-8 meth-od was used to detect the survival rate of cells in each group,while LDH method was used to assess cytotoxic-ity.Microenzyme-linked immunosorbent assay and ELISA were used to examine the levels of LDH,NO,H2O2,as well as the activities of CAT and SOD in each group of cells.Immunofluorescence and Western blot were used to detect the protein expression levels of NRF2,xCT,HO-1,ferritin,and GPX4 in each group of cells.FerroOrange fluorescent probe was used to de-tect the intracellular content of ferrous ions(Fe2+).Results H2O2 could induce MO3.13 oxidative dam-age and lead to cell ferroptosis,while PCB2 could alle-viate MO3.13 oxidative damage and ferroptosis.Com-pared with the H2O2 model group,PCB2 intervention could significantly increase LDH content in MO3.13,reduce NO and H2O2 content,and improve SOD and CAT activity,and up-regulate the protein expression levels of NRF2,xCT,HO-1,ferritin,and GPX4.Conclusion PCB2 can enhance cellular antioxidant capacity and alleviate H2O2 induced MO3.13 oxidative damage through the NRF2/HO-1/xCT/GPX4 axis.

The incidence of male infertility has been increasing year by year,and one of the major causes is testicular spermato-genic epithelial injury,which affects the spermatogenic function of the testis.Ferroptosis is a novel mode of cell death and plays an im-portant role in testicular cell injury.Some traditional Chinese medicines can intervene in the progression of testicular injury by regula-ting the ferroptosis pathway in testicular spermatogenic epithelia.This paper focuses on the effect of traditional Chinese drugs in regula-ting the ferroptosis pathway in testicular cells,and summarizes the advances in the studies of traditional Chinese medicines in the treat-ment of testicular spermatogenic epithelial injury,aiming to provide a theoretical basis for the selection of relevant medicines and their clinical application.

AIM To study the secondary metabolites from the endophytic fungi Candida sp.of Berberis atrocarpa Schneid.METHODS The ethyl acetate fraction and petroleum ether fraction from the secondary metabolites of Candida sp.fermentation extract were separated and purified by silica gel,Sephadex LH-20 and preparative liquid chromatography,then the structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Eighteen compounds were isolated and identified as 1-phenyl-1,2-ethanediol(1),4-hydroxyphenethyl alcohol(2),4-hydroxybenzoic acid(3),4-hydroxyphenylacetic acid(4),3-hydroxyphenylacetic acid(5),3-methylsulfinyl propionic acid(6),phenylacetic acid(7),(S)-N-nitroso-1-amino-p-hydroxy phenylethanol(8),2-phenylacetamide(9),p-hydroxybenzaldehyde(10),ethyl 2-(4-hydroxyphenyl)acetate(11),dibutyl phthalate(12),5,5'-dimethoxybiphenyl-2,2'-diol(13),3-indolealdehyde(14),N-acetyl-L-phenylalanine(15),9-hydroxy-10E,12Z-octadecadienoic acid(16),9-hydroxy-10E,12E-octadecadienoic acid(17),(6E)-5-methylene-6-tetradecenoic acid(18).CONCLUSION Compounds 1,3-8 and 10-18 are isolated from Candida sp for the first time.

AIM To investigate the effects of total Astragalus saponins on the improvement of sarcopenia in a rat model of type 2 diabetes mellitus(T2DM).METHODS The rats were divided into the normal group for a normal feeding and the model group for the feeding of high-sugar and high-fat diet combined with intraperitoneal injection of STZ to establish a T2DM model.The successful model rats were randomly divided into the model group,the metformin group(0.2 g/kg)and the total Astragalus saponins group(80 mg/kg),and given corresponding doses of drugs by gavage.After 12 weeks administration,the rats had their FBG,postprandial blood glucose(PG2h)and wet weight of skeletal muscle measured;their serum levels of INS,C-peptide(C-P),IGF-1,TNF-α and IL-1β detected by ELISA;their morphological changes of skeletal muscle observed by HE staining;their protein expressions of PI3K,p-Akt,mTOR,S6K1,FoxO1 and Murf1 in skeletal muscle detected by Western blot;and their mRNA expressions of Pi3k,Akt and mtor in skeletal muscle detected by RT-qPCR method.RESULTS Compared with the model group,the total Astragalus saponins group displayed decreased levels of FBG,PG2h,OGTT-AUC,HOMA-IR,TNF-α and IL-1β(P＜0.01);increased levels of INS,C-P,IGF-1 and wet weight of skeletal muscle(P＜0.05,P＜0.01);improved skeletal muscle atrophy and increased protein expressions of PI3K,p-Akt,mTOR and S6K1 in skeletal muscle(P＜0.05,P＜0.01);decreased protein expressions of FoxO1 and Murf1(P＜0.05,P＜0.01);and increased mRNA expressions of Pi3k,Akt and mtor(P＜0.01).CONCLUSION The improvement effects of total Astragalus saponins on sarcopenia in T2DM rats may be associated with the regulation of PI3K/Akt/mTOR and PI3K/Akt/FoxO1 pathways.

Objective:To evaluate the efficacy and safety of 532-nm picosecond laser in the treatment of early-stage facial seborrheic keratosis.Methods:A total of 95 patients with early-stage facial seborrheic keratosis were prospectively enrolled from the Department of Dermatology, General Hospital of Ningxia Medical University between December 2020 and September 2022. All the patients received a session of 532-nm picosecond laser treatment, and were followed up for 6 months. A 4-point scale was used to evaluate the overall improvement of skin lesions for assessing the clinical efficacy. A VISIA skin detector was used to quantitatively determine the characteristic counts, absolute scores, and percentiles of brown spots before and after treatment, and the paired sample t-test was used to compare the quantitative indicators of brown spots before and after treatment. The patients′ pain grades were evaluated, and adverse reactions were recorded. Results:All the 95 patients with early-stage facial seborrheic keratosis received a session of 532-nm picosecond laser treatment, and completed a 6-month follow-up. All the patients achieved over 25% regression of skin lesions in the treatment area, of whom 10 received mild improvement, 17 received favorable improvement, and 68 received marked improvement, with the response rate being 89.47% (85/95). The examination with the VISIA skin detector showed that the characteristic counts (195.19 ± 51.06) and absolute scores (28.80 ± 6.20 points) of brown spots significantly decreased, while the percentiles of brown spots (38.48% ± 10.80%) significantly increased at 6 months after treatment compared with the corresponding baseline indicators (211.48 ± 50.94, 35.16 ± 6.84 points, 30.61% ± 10.27%, t = 12.73, 16.90, -15.73, respectively, all P < 0.001). All the patients experienced varying degrees of pain during the treatment, with the pain scores being 2 - 6 (3.64 ± 1.67) points, but all of them could tolerate the pain and completed the treatment. Temporary postinflammatory hyperpigmentation and hypopigmentation occurred in 9 (9.47%) and 4 (4.21%) patients respectively, and the skin color restored to normal during the 6-month follow-up. Conclusion:The 532-nm picosecond laser was safe and effective for the treatment of early-stage facial seborrheic keratosis.

Aim To explore the inhibitory effect of Buyang Huanwu Decoction on the inflammatory response in the hippocampus of brain tissues of CIRI rats by regulating SIRT1 and the underlying mechanism. Methods The middle cerebral artery embolization (MCAO) model was prepared in rats and divided into sham operation group (Sham), model group (MCAO/R), Buyang Huanwu Decoction group (BYHWT),and BYHWT + SIRT1 inhibitor group (BYHWT + EX527). Zea Longa was used to detect the neurological function score of rats in each group; TTC staining was used to determine the volume of cerebral infarction; HE staining was used to observe the pathological damage of the hippocampus; Western blot was used to detect the expression levels of SIRT1 and IL-6; immunohistochemistry was used to detect TNF-α, IL-1β expression level. Results Compared with the sham group,the neurological function score of the MCAO/R group increased (P < 0.05); the volume of cerebral infarction increased (P < 0.05); the nerve cells in hippocampus were severely damaged, arranged disorderly, and the nucleus was broken; Western blot showed that the expression of SIRT1 decreased, IL-6 expression increased (P <0.05); immunohistochemistry showed that TNF-α,IL-1β expression increased (P < 0.05). Compared with the MCAO/R group, the neurological function score of the BYHWT group decreased (P <0.05); the volume of cerebral infarction decreased (P < 0.05); the damage of nerve cells in hippocampus was reduced; Western blot showed that the expression of SIRT1 increased and IL-6 expression decreased (P < 0.05); immunohistochemistry showed that TNF-α, IL-1β expression decreased (P < 0.05). Compared with the BYHWT group, the neurological function score of the BYHWT + EX527 group increased (P < 0.05); the volume of cerebral infarction was raised (P <0.05); the damage of nerve cells in hippocampus was aggravated; Western blot showed that the expression of SIRT1 decreased and IL-6 expression increased (P < 0.05); immunohistochemistry showed that TNF-α, IL-1β expression increased (P < 0.05). Conclusions Preliminary discussion of Buyang Huanwu Decoction can activate SIRT1 in hippocampus of rat brain tissues to reduce the inflammatory response after CIRI and play a role in brain protection.

Aim To predict the targets of Modified Danggui Shaoyao San ( MDSS) in the treatment of chronic atrophic gastritis ( CAG) based on network pharmacology and vertify the results based on experim-ention. Methods TCMSP, SWISS TARGETS, GENE CARDS and OMIM databases were used to screen the therapeutic targets of MDSS for CAG. STRING database and Cytoscape software were used to construct the protein interaction network and screen the core targets. Metascape database was used for GO analysis and KEGG enrichment pathways. And molecular docking was used for target validation. CAG rat model was pre¬pared by N-methyl-N'-nitroso-N-nitroguanidine free drink combined with sodium salicylate gastric lavage. The pathology of rat gastric mucosa was observed by hematoxylin-eosin staining,and the ultrastructure of ep¬ithelial cells was observed by transmission electron mi-croscopy. The serum IL-6 and IL-10 content was detected by enzyme-linked immunosorbent assay, and the expression of JAK2, STAT3 , p-STAT3 , c-MYC mRNA and protein in rats was detected by qPCR and Western blot. Results MDSS acted on 189 targets, mainly involved in response to oxidative stress and apoptotic signaling pathway. KEGG analysis related to pathways in cancer and JAK-STAT signaling pathway. The experimental results showed that the MDSS could improve the degree of atrophy of gastric mucosa in CAG rats and improve the status of epithelial cells, down-regulate the serum IL-6 content of CAG rats, up-regulate the IL-10 content, and reduce the expression of JAK2, STAT3 , p-STAT3 , c-MYC mRNA and protein in gastric mucosa with statistical significance. Conclusions MDSS treats CAG through multiple active ingredients, targets, and pathways, the mechanism of which may be related to the inhibition of the JAK2/STAT3 signaling pathway.