ObjectivePhotoacoustic pump-probe imaging can effectively eliminate the interference of blood background signal in traditional photoacoustic imaging, and realize the imaging of weak phosphorescence molecules and their triplet lifetimes in deep tissues. However, background differential noise in photoacoustic pump-probe imaging often leads to large fitting results of phosphorescent molecule concentration and triplet lifetime. Therefore, this paper proposes a novel triplet lifetime fitting method for photoacoustic pump-probe imaging. By extracting the phase of the triplet differential signal and the background noise, the fitting bias caused by the background noise can be effectively corrected. MethodsThe advantages and feasibility of the proposed algorithm are verified by numerical simulation, phantom and in vivo experiments, respectively. ResultsIn the numerical simulation, under the condition of noise intensity being 10% of the signal amplitude, the new method can optimize the fitting deviation from 48.5% to about 5%, and has a higher exclusion coefficient (0.88>0.79), which greatly improves the fitting accuracy. The high specificity imaging ability of photoacoustic pump imaging for phosphorescent molecules has been demonstrated by phantom experiments. In vivo experiments have verified the feasibility of the new fitting method proposed in this paper for fitting phosphoometric lifetime to monitor oxygen partial pressure content during photodynamic therapy of tumors in nude mice. ConclusionThis work will play an important role in promoting the application of photoacoustic pump-probe imaging in biomedicine.

Objective:To investigate the effects of melatonin(MT)on spinal cord ischemia reperfusion injury(SCIRI)and its possible mechanisms in rats.Methods:Forty-two 6-week-old male Sprague Dawley rats were selected for the study and randomly divided into three groups:① Sham group(Sham group,n=14);② model group(model/SCIRI group,n=14);and ③ treatment group(MT group,n=14).Neurological function analysis was used to assess the motor conditions of rats in each group.Nissl staining and hematoxylin eosin(HE)staining were used to observe the number and morphology of neurons in each group,and TUNEL staining was used to evaluate the occurrence of apoptosis of neurons in each group.The expression levels of NOD-like receptor thermal protein domain-associated protein 3(NLRP3),apoptosis-associated speck-like protein(ASC),gasdermin D(GSDMD),the N-terminal fragment of gasdermin D(GSDMD-N),and cysteine proteinase 1(caspase-1)were evaluated using immunofluorescence,immunohistochemistry staining,and Western blot analysis.Results:Compared with the sham operation group,the neurological function score of the model group was significantly decreased,while the neurological function score of the treatment group was higher than that of the model group(P＜0.05).The model group had fewer Nissl corpuscles compared with that in the sham operation group and abnormal neuronal morphology(P＜0.05).Compared with the model group,the treatment group had a rise in the number of Nissl corpuscles and restored neuronal morphology(P＜0.05).Compared with the Sham group,the number of apoptotic neurons increased in the model group,and the protein expression levels of NLRP3,ASC,GSDMD,and caspase-1 increased(P＜0.05).Compared with the model group,The number of apoptotic neurons and the protein expressions of NLRP3,ASC,GSDMD and caspase-1 in the treatment group were significantly decreased(P＜0.05).Conclusions:MT may alleviate spinal cord ischemia-reperfusion injury by inhibiting pyroptosis in neurons.

This study aimed to characterize and identify the non-volatile components in aqueous and ethanolic extracts of the stems and leaves of Rhododendron tomentosum by using sensitive and efficient ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry(UHPLC-Q-TOF-MS) combined with a self-built information database. By comparing with reference compounds, analyzing fragment ion information, searching relevant literature, and using a self-built information database, 118 compounds were identified from the aqueous and ethanolic extracts of R. tomentosum, including 35 flavonoid glycosides, 15 phenolic glycosides, 12 flavonoids, 7 phenolic acids, 7 phenylethanol glycosides, 6 tannins, 6 phospholipids, 5 coumarins, 5 monoterpene glycosides, 6 triterpenes, 3 fatty acids, and 11 other types of compounds. Among them, 102 compounds were reported in R. tomentosum for the first time, and 36 compounds were identified by comparing them with reference compounds. The chemical components in the ethanolic and aqueous extracts of R. tomentosum leaves and stems showed slight differences, with 84 common chemical components accounting for 71.2% of the total 118 compounds. This study systematically characterized and identified the non-volatile chemical components in the ethanolic and aqueous extracts of R. tomentosum for the first time. The findings provide a reference for active ingredient research, quality control, and product development of R. tomentosum.
Rhododendron/chemistry* ; Chromatography, High Pressure Liquid/methods* ; Drugs, Chinese Herbal/chemistry* ; Mass Spectrometry/methods* ; Plant Leaves/chemistry*

The present study employed UPLC-MS/MS to analyze and identify compounds in the raw powder of Tongluo Shenggu capsules. An HPLC method for the determination of vitexin content was established. The analysis of this drug was performed on a 30 ℃ thermostatic Acquity UPLC® BEH C18 (2.1 mm×100 mm,1.7 μm) column, with the mobile phase comprising 0.2% formic acid-methanol flowing at 0.3 mL /min in a gradient elution manner. Mass spectrometry was detected by ESI sources in both positive and negative ion modes for qualitative identification of chemical constituents. 12 flavonoid and 3 stilbenes compounds in the raw powder of Tongluo Shenggu capsules were successfully identified. Additionally, an HPLC method for the determination of vitexin content was established using a XBridge C18 column (4.6 mm × 250 mm, 5 µm) with a mobile phase of 0.05% glacial acetic acid in methanol for gradient elution, at a column temperature of 30 °C, a flow rate of 1.0 mL/min, and an injection volume of 20 μL. The method demonstrated good linearity in the concentration range of 10 µg/mL to 40 µg/mL (R=1.000) with an average recovery rate of 96.7%. The establishment of these methods provides a scientific basis for the quality control and development of the raw powder of Tongluo Shenggu capsules.

ObjectiveTraditional Chinese medicine (TCM) constitutes a valuable cultural heritage and an important source of antitumor compounds. Poria (Poria cocos (Schw.) Wolf), the dried sclerotium of a polyporaceae fungus, was first documented in Shennong’s Classic of Materia Medica and has been used therapeutically and dietarily in China for millennia. Traditionally recognized for its diuretic, spleen-tonifying, and sedative properties, modern pharmacological studies confirm that Poria exhibits antioxidant, anti-inflammatory, antibacterial, and antitumor activities. Pachymic acid (PA; a triterpenoid with the chemical structure 3β-acetyloxy-16α-hydroxy-lanosta-8,24(31)-dien-21-oic acid), isolated from Poria, is a principal bioactive constituent. Emerging evidence indicates PA exerts antitumor effects through multiple mechanisms, though these remain incompletely characterized. Neuroblastoma (NB), a highly malignant pediatric extracranial solid tumor accounting for 15% of childhood cancer deaths, urgently requires safer therapeutics due to the limitations of current treatments. Although PA shows multi-mechanistic antitumor potential, its efficacy against NB remains uncharacterized. This study systematically investigated the potential molecular targets and mechanisms underlying the anti-NB effects of PA by integrating network pharmacology-based target prediction with experimental validation of multi-target interactions through molecular docking, dynamic simulations, and in vitro assays, aimed to establish a novel perspective on PA’s antitumor activity and explore its potential clinical implications for NB treatment by integrating computational predictions with biological assays. MethodsThis study employed network pharmacology to identify potential targets of PA in NB, followed by validation using molecular docking, molecular dynamics (MD) simulations, MM/PBSA free energy analysis, RT-qPCR and Western blot experiments. Network pharmacology analysis included target screening via TCMSP, GeneCards, DisGeNET, SwissTargetPrediction, SuperPred, and PharmMapper. Subsequently, potential targets were predicted by intersecting the results from these databases via Venn analysis. Following target prediction, topological analysis was performed to identify key targets using Cytoscape software. Molecular docking was conducted using AutoDock Vina, with the binding pocket defined based on crystal structures. MD simulations were performed for 100 ns using GROMACS, and RMSD, RMSF, SASA, and hydrogen bonding dynamics were analyzed. MM/PBSA calculations were carried out to estimate the binding free energy of each protein-ligand complex. In vitro validation included RT-qPCR and Western blot, with GAPDH used as an internal control. ResultsThe CCK-8 assay demonstrated a concentration-dependent inhibitory effect of PA on NB cell viability. GO analysis suggested that the anti-NB activity of PA might involve cellular response to chemical stress, vesicle lumen, and protein tyrosine kinase activity. KEGG pathway enrichment analysis suggested that the anti-NB activity of PA might involve the PI3K/AKT, MAPK, and Ras signaling pathways. Molecular docking and MD simulations revealed stable binding interactions between PA and the core target proteins AKT1, EGFR, SRC, and HSP90AA1. RT-qPCR and Western blot analyses further confirmed that PA treatment significantly decreased the mRNA and protein expression of AKT1, EGFR, and SRC while increasing the HSP90AA1 mRNA and protein levels. ConclusionIt was suggested that PA may exert its anti-NB effects by inhibiting AKT1, EGFR, and SRC expression, potentially modulating the PI3K/AKT signaling pathway. These findings provide crucial evidence supporting PA’s development as a therapeutic candidate for NB.

Although teniposide(VM26)is widely used in the treatment of lymphoma,its poor water sol-ubility,low bioavailability and systemic toxicities still limit its clinical application.Nano-delivery systems are effective in increasing the bioavailability and reducing the toxicity of VM26,but there is an urgent need to overcome the problem of its non-specific targeting.Therefore,in this paper,we designed and constructed a hyaluronic acid-modified teniposide-targeted nano-delivery system(VM26-TNDS),and characterised its drug encapsulation rate,particle size and zeta potential.We also investigated the effects of VM26-TNDS on B-cell lymphoma cells with different expression of CD44 receptor,in terms of cellular targeting,inhibitory effect of proliferation,and induction of apoptosis and necrosis.The results showed that the drug encapsulation efficiency of VM26-TNDS exceeded 85％,and its liquid formulation could be stably stored at 4 ℃ for more than 6 months without precipitation.Based on CD44 receptor expression,Granta-519(high expression),Raji(medium-low expression)and SU-DHL-4(almost no expression)were screened for cellular experiments.Compared with VM26-NDS,the targeted modification could effec-tively reduce the uptake of VM26-TNDS by RAW264.7 and increase the uptake of VM26-TNDS by CD44 receptor-expressing lymphoma cells.The inhibitory proliferative effect and apoptotic necrosis-inducing a-bility of VM26-TNDS were stronger than those of VM26-NDS for Granta-519 and Raji cells,whereas there was no significant difference in the inhibitory effect on proliferation and ability to induce apoptosis and necrosis between VM26-NDS and VM26-TNDS in SU-DHL-4 cells,reflecting the targeting advantage for VM26-TNDS,as expected.However,its toxic effect on B-cell lymphoma cells only reflected the targeting advantage at some concentrations(0.25 μmol/L and 0.5 μmol/L),which met the expectation.The a-bove results indicate that a teniposide-targeted nano-delivery system,VM26-TNDS,has been successfully prepared in this study.VM26-TNDS improves the delivery efficiency of VM26 by targeting human B-cell lymphoma cells expressing the CD44 receptor,thus killing human B-cell lymphoma cells more effectively and overcoming the problem of non-specific targeting in drug delivery to improve the therapeutic effect.Its biological therapeutic effects and mechanisms still need to be proved by more in vitro and in vivo ex-perimental evidence.

Objective To detect diatoms in tissues and water samples from drowning cases by gene array,and explore the application value of DNA microarray.Methods Diatoms in the lung,liver,kidney samples,and on-site water samples from 19 drowned corpses that appeared in the rivers of Zhongshan City between July 2021 and April 2022,were detected by gene arrays.Moreover,diatom detection was also performed on 28 samples from 7 corpses by microscope.Then the testing results were compared and analyzed.Results For those 28 samples,diatom types in both tissue and water samples by gene detection were more than those detected by microscopy,the detection was statistically significant(P<0.05).However,there was no statistically significant difference(P>0.05)in the detection of diatom types between tissue samples and water samples both using gene arrays.In terms of tissue samples,diatoms were easier to be detected in lung than liver or kidney,and there were also more types of diatoms detected in lung.Diatom detection by gene arrays showed that the diatom types showed a decreasing trend as the tissue was further away from the entrance of body,and the difference of diatom types increased among tissues.Conclusion The gene array can effectively detect the diatom types and distribution characteristics in drowned corpses,and has great potential in the research of the traceability analysis of corpses found in water and the causes of death.

Toxin-antitoxin(TA)systems serve as central hubs of bacterial adaptive regulation and play critical roles in the pathogenesis of Mycobacterium tuberculosis(M.tb)and Bordetella pertussis(B.per-tussis).This review summarizes the functional evolution and therapeutic potential of TA systems in M.tb and B.pertussis.It systematically outlines the molecular mechanisms and pathogenic functions of TA sys-tems in these two pathogens.M.tb relies on type Ⅱ TA systems(e.g.,VapBC,MazEF)to drive persis-ter formation and antibiotic tolerance through toxin-mediated ribonuclease activity that cleaves host nucle-ic acids or DarT/DarG-mediated DNA modification.In contrast,B.pertussis utilizes a unique tempera-ture-sensing PhtA/PhtB system to release adenylate cyclase toxin,which targets the host cAMP signaling pathway to achieve immune evasion.Both pathogens employ TA toxins to suppress host defenses-such as VapC cleaving tRNA and RelE degrading NF-κB components.Their high-frequency mutation sites(e.g.,the VapC47-Ser46Leu mutation frequency＞50 000 in M.tuberculosis)reveal strong positive selec-tion pressure,closely associated with persister phenotypes and virulence evolution.This review further discusses therapeutic strategies,including small-molecule inhibitors targeting toxin-antitoxin interactions,TA-deletion attenuated vaccines,and antitoxin-based immunization approaches.Finally,it highlights the need for future research to elucidate TA-host interaction networks and develop nanocarrier delivery tech-nologies to advance breakthroughs in precision therapy for tuberculosis and pertussis.

Toxin-antitoxin(TA)systems serve as central hubs of bacterial adaptive regulation and play critical roles in the pathogenesis of Mycobacterium tuberculosis(M.tb)and Bordetella pertussis(B.per-tussis).This review summarizes the functional evolution and therapeutic potential of TA systems in M.tb and B.pertussis.It systematically outlines the molecular mechanisms and pathogenic functions of TA sys-tems in these two pathogens.M.tb relies on type Ⅱ TA systems(e.g.,VapBC,MazEF)to drive persis-ter formation and antibiotic tolerance through toxin-mediated ribonuclease activity that cleaves host nucle-ic acids or DarT/DarG-mediated DNA modification.In contrast,B.pertussis utilizes a unique tempera-ture-sensing PhtA/PhtB system to release adenylate cyclase toxin,which targets the host cAMP signaling pathway to achieve immune evasion.Both pathogens employ TA toxins to suppress host defenses-such as VapC cleaving tRNA and RelE degrading NF-κB components.Their high-frequency mutation sites(e.g.,the VapC47-Ser46Leu mutation frequency＞50 000 in M.tuberculosis)reveal strong positive selec-tion pressure,closely associated with persister phenotypes and virulence evolution.This review further discusses therapeutic strategies,including small-molecule inhibitors targeting toxin-antitoxin interactions,TA-deletion attenuated vaccines,and antitoxin-based immunization approaches.Finally,it highlights the need for future research to elucidate TA-host interaction networks and develop nanocarrier delivery tech-nologies to advance breakthroughs in precision therapy for tuberculosis and pertussis.

Although teniposide(VM26)is widely used in the treatment of lymphoma,its poor water sol-ubility,low bioavailability and systemic toxicities still limit its clinical application.Nano-delivery systems are effective in increasing the bioavailability and reducing the toxicity of VM26,but there is an urgent need to overcome the problem of its non-specific targeting.Therefore,in this paper,we designed and constructed a hyaluronic acid-modified teniposide-targeted nano-delivery system(VM26-TNDS),and characterised its drug encapsulation rate,particle size and zeta potential.We also investigated the effects of VM26-TNDS on B-cell lymphoma cells with different expression of CD44 receptor,in terms of cellular targeting,inhibitory effect of proliferation,and induction of apoptosis and necrosis.The results showed that the drug encapsulation efficiency of VM26-TNDS exceeded 85％,and its liquid formulation could be stably stored at 4 ℃ for more than 6 months without precipitation.Based on CD44 receptor expression,Granta-519(high expression),Raji(medium-low expression)and SU-DHL-4(almost no expression)were screened for cellular experiments.Compared with VM26-NDS,the targeted modification could effec-tively reduce the uptake of VM26-TNDS by RAW264.7 and increase the uptake of VM26-TNDS by CD44 receptor-expressing lymphoma cells.The inhibitory proliferative effect and apoptotic necrosis-inducing a-bility of VM26-TNDS were stronger than those of VM26-NDS for Granta-519 and Raji cells,whereas there was no significant difference in the inhibitory effect on proliferation and ability to induce apoptosis and necrosis between VM26-NDS and VM26-TNDS in SU-DHL-4 cells,reflecting the targeting advantage for VM26-TNDS,as expected.However,its toxic effect on B-cell lymphoma cells only reflected the targeting advantage at some concentrations(0.25 μmol/L and 0.5 μmol/L),which met the expectation.The a-bove results indicate that a teniposide-targeted nano-delivery system,VM26-TNDS,has been successfully prepared in this study.VM26-TNDS improves the delivery efficiency of VM26 by targeting human B-cell lymphoma cells expressing the CD44 receptor,thus killing human B-cell lymphoma cells more effectively and overcoming the problem of non-specific targeting in drug delivery to improve the therapeutic effect.Its biological therapeutic effects and mechanisms still need to be proved by more in vitro and in vivo ex-perimental evidence.