Chronic pain is a complex condition shaped by long-standing alterations in both physiological and psychological processes. Rather than representing a simple continuation of acute nociceptive signaling, chronic pain is increasingly understood as the outcome of progressive dysregulation within distributed neural systems that govern sensation, affect, motivation, and cognitive control. Neuroimaging and electrophysiological studies indicate that this state is accompanied by extensive plastic changes in deep brain structures and large-scale networks. Beyond well-described central sensitization processes, chronic pain is characterized by disrupted oscillatory rhythms and altered connectivity within large-scale brain networks, including thalamo-cortical circuits and prefrontal-limbic-reward networks. These findings support a conceptual shift from viewing chronic pain as a focal, lesion-driven phenomenon toward recognizing it as a disorder of distributed network pathology. Pharmacological treatments remain central to clinical practice, yet their long-term efficacy is often limited and frequently accompanied by substantial side effects. The ongoing concerns about opioid-related risks and the inadequate therapeutic response in a subset of patients highlight the need for safe, non-pharmacological approaches that can address not only pain but also comorbid disturbances in mood, sleep, and social functioning. Neuromodulation provides a promising path toward mechanism-based and non-pharmacological management of chronic pain by employing physical or chemical stimulation to alter the excitability and synchrony of specific neural populations within central, peripheral, and autonomic systems. While invasive deep brain stimulation demonstrates that targeting deep brain structures can be effective, its clinical application is restricted by surgical risks and cost, highlighting the importance of non-invasive techniques capable of reaching deep targets. Current non-invasive approaches, such as transcranial electric stimulation, are constrained by limited penetration depth and insufficient spatial precision. These limitations hinder reliable engagement of deep regions implicated in pain, including the thalamus and nucleus accumbens, and tend to produce broad, non-specific modulation of cross-network oscillatory activity. Temporal interference (TI) stimulation has emerged as a means of overcoming these obstacles. By delivering interacting high-frequency currents that generate a low-frequency envelope within the head, TI enables focal stimulation of deep targets while minimizing superficial current delivery. Recent multiscale modeling and animal studies indicate that TI exploits the nonlinear rectification properties of neuronal membranes in response to high-frequency carriers, as well as their phase-locked responses to low-frequency envelopes, to generate “peak-focused” electric fields in deep regions under relatively low superficial current loads. Moreover, TI appears to exhibit potential advantages in terms of cell-type selectivity and rhythm-specific engagement, including differential responses across neuronal subtypes and distinct coupling to θ-, β-, and γ-band oscillations. These features suggest a promising avenue for correcting abnormal rhythms and network dynamics that contribute to chronic pain. This review summarizes current knowledge of the neural mechanisms underlying chronic pain and recent advances in TI research. It examines functional disturbances across key pain-related regions and networks, outlines the principles and technical characteristics of TI, and discusses potential deep-brain targets and stimulation strategies relevant to chronic pain. Evidence to date indicates that TI, with its non-invasiveness, tolerability, and capacity for precise deep brain modulation, holds great promise for the management of treatment-resistant chronic pain and may evolve into a new generation of precise and efficient non-pharmacological analgesic strategies.

Chronic pain is a complex condition shaped by long-standing alterations in both physiological and psychological processes. Rather than representing a simple continuation of acute nociceptive signaling, chronic pain is increasingly understood as the outcome of progressive dysregulation within distributed neural systems that govern sensation, affect, motivation, and cognitive control. Neuroimaging and electrophysiological studies indicate that this state is accompanied by extensive plastic changes in deep brain structures and large-scale networks. Beyond well-described central sensitization processes, chronic pain is characterized by disrupted oscillatory rhythms and altered connectivity within large-scale brain networks, including thalamo-cortical circuits and prefrontal-limbic-reward networks. These findings support a conceptual shift from viewing chronic pain as a focal, lesion-driven phenomenon toward recognizing it as a disorder of distributed network pathology. Pharmacological treatments remain central to clinical practice, yet their long-term efficacy is often limited and frequently accompanied by substantial side effects. The ongoing concerns about opioid-related risks and the inadequate therapeutic response in a subset of patients highlight the need for safe, non-pharmacological approaches that can address not only pain but also comorbid disturbances in mood, sleep, and social functioning. Neuromodulation provides a promising path toward mechanism-based and non-pharmacological management of chronic pain by employing physical or chemical stimulation to alter the excitability and synchrony of specific neural populations within central, peripheral, and autonomic systems. While invasive deep brain stimulation demonstrates that targeting deep brain structures can be effective, its clinical application is restricted by surgical risks and cost, highlighting the importance of non-invasive techniques capable of reaching deep targets. Current non-invasive approaches, such as transcranial electric stimulation, are constrained by limited penetration depth and insufficient spatial precision. These limitations hinder reliable engagement of deep regions implicated in pain, including the thalamus and nucleus accumbens, and tend to produce broad, non-specific modulation of cross-network oscillatory activity. Temporal interference (TI) stimulation has emerged as a means of overcoming these obstacles. By delivering interacting high-frequency currents that generate a low-frequency envelope within the head, TI enables focal stimulation of deep targets while minimizing superficial current delivery. Recent multiscale modeling and animal studies indicate that TI exploits the nonlinear rectification properties of neuronal membranes in response to high-frequency carriers, as well as their phase-locked responses to low-frequency envelopes, to generate “peak-focused” electric fields in deep regions under relatively low superficial current loads. Moreover, TI appears to exhibit potential advantages in terms of cell-type selectivity and rhythm-specific engagement, including differential responses across neuronal subtypes and distinct coupling to θ-, β-, and γ-band oscillations. These features suggest a promising avenue for correcting abnormal rhythms and network dynamics that contribute to chronic pain. This review summarizes current knowledge of the neural mechanisms underlying chronic pain and recent advances in TI research. It examines functional disturbances across key pain-related regions and networks, outlines the principles and technical characteristics of TI, and discusses potential deep-brain targets and stimulation strategies relevant to chronic pain. Evidence to date indicates that TI, with its non-invasiveness, tolerability, and capacity for precise deep brain modulation, holds great promise for the management of treatment-resistant chronic pain and may evolve into a new generation of precise and efficient non-pharmacological analgesic strategies.

Lutetium-177 (¹⁷⁷Lu)-prostate specific membrane antigen (PSMA)-617 is a small-molecule radioligand therapy (RLT) drug targeting PSMA. By selectively delivering the β^－ radiation emitted by ¹⁷⁷Lu to PSMA-positive prostate cancer cells, it induces tumor cell death. The agent has been approved in multiple nations and regions for the treatment of PSMA-positive metastatic castration-resistant prostate cancer, thereby expanding therapeutic options for this patient population. This review outlines the development, pharmacological properties, and current clinical applications of ¹⁷⁷Lu-PSMA-617, aiming to provide a theoretical basis for the clinical practice of RLT in prostate cancer treatment.

Objective To establish a chromatography-tandem mass spectrometry method for detecting chlorfenapyr and its metabolite tralopyril in blood,and to investigate the toxicokinetics in rats.Methods Chlorfenapyr(8 mg/kg)was administered orally to rats,and blood samples were collected from rats'canthus vein at 5 min,15 min,30 min,1 h,3 h,6 h,12 h,24 h and 48 h after administration.The blood samples were extracted using 100 μL of 5%formic acid solution and 400 μL of acetonitrile.Chlorfena-pyr was qualitatively and quantitatively detected by triple quadrupole gas chromatography-tandem mass spectrometry(GC-MS/MS)and tralopyril was detected by triple quadrupole liquid chromatography-tandem mass spectrometry(LC-MS/MS).The DAS 3.0 software was used to fit the toxicokinetic equa-tions and calculate the toxicokinetic parameters.Results Chlorfenapyr was detectable from 5 min to 24 h with a peak time of 1 h.Tralopyril was detectable from 15 min to 48 h with a peak time of 3 h.The toxicokinetic process of chlorfenapyr in rat blood conformed to a first-order absorption one-compartment open model,with the toxicokinetic equation described as C=e-0.265t-e-0.175t.Tralopyril con-formed to the first-order absorption three-compartment model,and the toxicokinetic equation was C=47 361.069e-2.209t-35 404.962e-1.486t+11 956.363e-0.512t.In the equations,C stands for the concentration of the target substance in the blood,e is the natural constant(≈2.718 28),and t stands for time.Conclu-sion This study optimized the detection method for chlorfenapyr and its metabolite tralopyril in blood.The toxicokinetic equations and parameters of chlorfenapyr and tralopyril can provide a reference for the estimation of oral intake time of chlorfenapyr.

Objective To investigate the effects of organophosphate flame retardant tri(2-chloroethyl)phosphate(TCPP)on reproductive function in male mice by the approach of non-targeted metabolomics.Methods A total of twelve 6-week-old SPF male CD-1 mice were randomly divided into control group and TCPP group,with 6 mice in each group.TCPP group was given TCPP(at the dose of 100 mg/kg/d)intragastrically,and control group was intragastrically adminis-trated with the same amount of corn oil(solvent control).After 6 weeks,the mice were killed,and the sperm were isolated from the epididymis.The sperm concentration and viability were analyzed.Testicular tissue sections were stained with he-matoxylin,and ki67 expression was detected by immunohistochemistry.Non-targeted metabolomics was used to detect the difference of metabolites in testicular tissue between the two groups,and to analyze the difference of metabolites and related pathway changes between the two groups.Results Compared with control group,the total sperm motility of mice in TCPP treatment group was significantly decreased(P＜0.05).HE staining showed irregular arrangement of spermatogenic tubule supporting cell layer in TCPP treatment group.The expression level of ki67 in testicular tissue of mice treated with TCPP was significantly decreased(P＜0.05).Non-targeted metabolomics detected 266 up-regulated metabolites with statistical difference.And 554 down-regulated metabolites with statistical difference,among which the largest difference multiples were organic acids and amino acid metabolites.The pathways with the highest concentration of differential metabolites in-cluded purine metabolism,nucleotide metabolism,amino acid metabolism,cofactor synthesis,etc.,which were mainly re-lated to basic cell life activities,pathophysiology and chemical carcinogenesis.Conclusion TCPP can significantly re-duce sperm motility and ki67 expression in mice at the dosage of 100 mg/kg/d,which might be related to its influence on key metabolic pathways such as purine,amino acid and pyruvate.

OBJECTIVES: To investigate the effect of monotropein on motor function recovery of mice with spinal cord injury (SCI) and explore the underlying mechanism. METHODS: Forty-five adult female C57BL/6 mice were randomized equally into sham operation group, SCI group, and SCI group with daily intraperitoneal monotropein injection. The mice in the former two groups received daily saline injections. Motor function of the mice was evaluated using BMS scores, slant plate test, and footprint analyses. Pathological changes and neuronal counts in the spinal cord were observed using HE, LFB, and Nissl staining. The biological functions of monotropein were explored using GO and KEGG enrichment analyses. NeuN/cleaved caspase-3 immunofluorescence assay and Western blotting were used to detect neuronal apoptosis in the spinal cord of the mice. In cultured HT22 cells, the effect of monotropein on TNF-α-induced cell apoptosis was evaluated using TUNEL staining and Western blotting. In monotropein-treated HT22 cells and SCI mice, the changes in the PI3K/AKT pathway were examined, and the effect of a PI3K/AKT pathway activator (IGF-1) on HT22 cell apoptosis and motor function recovery of SCI mice were observed. RESULTS: SCI mice with monotropein treatment showed significantly improved motor functions with reduced SCI areas and increased myelin retention and neuron counts in the spinal cord. Bioinformatics analysis suggested a role of PI3K/AKT signaling pathway in mediating the anti-apoptotic effects of monotropein. In SCI mice, monotropein obviously reduced apoptotic neurons, decreased expressions of cleaved caspase-3 and Bax and increased Bcl-2 expression in the spinal cord. In HT22 cells, monotropein significantly inhibited TNF-α-induced apoptosis and PI3K/AKT pathway activation. Treatment with IGF-1 obviously increased apoptosis of HT22 cells and exacerbated locomotor dysfunction in SCI mice. CONCLUSIONS Monotropein promotes motor function recovery in SCI mice by reducing neuronal apoptosis possibly by inhibiting the PI3K/AKT signaling pathway.
Animals ; Spinal Cord Injuries/metabolism* ; Apoptosis/drug effects* ; Signal Transduction/drug effects* ; Mice, Inbred C57BL ; Mice ; Proto-Oncogene Proteins c-akt/metabolism* ; Female ; Phosphatidylinositol 3-Kinases/metabolism* ; Neurons/pathology* ; Recovery of Function

OBJECTIVES: This study aims to evaluate the differences in shear bond strength, marginal adaptation, and nano-microleakage after aging among snowplow, layered filling, and lining techniques applied to the resin-bonded restoration of defective primary teeth. METHODS: In this study, 51 freshly extracted, crown-intact primary anterior teeth and 30 primary molars were collected. The experimental groups were as follows: layered filling group, lining group, and snowplow group. Experiments were performed to compare the differences in shear bond strength, marginal integrity, and silver ion nano-microleakage after aging among these groups. RESULTS: The median shear bond strength of the layered filling group, lining group, and snowplow group were 2.45, 5.72, and 9.43 MPa, respectively. The values for lining group and snowplow group were significantly higher than that for layered filling group (P<0.05). No statistically significant difference was found between lining group and snowplow group (P>0.05). The median overall margin integrity of the layered filling group, lining group, and snowplow group were 55.38%, 48.25%, and 65.63%, respectively. The difference among the three groups was not statistically significant (P>0.05). The median percentages of silver ion nano-microleakage in the layered filling group, lining group, and snowplow group were 11.71%, 9.47%, and 11.55%, respectively. The difference among the three groups was not statistically significant (P>0.05). CONCLUSIONS Applying the snowplow technique to restore defective primary teeth can improve the bond strength and margin integrity and reduce nano-microleakage.
Tooth, Deciduous ; Humans ; Dental Restoration, Permanent/methods* ; Dental Leakage ; Shear Strength ; Dental Bonding/methods* ; Molar ; Composite Resins ; Silver

Objective To explore the role of the protein kinase R-like endoplasmic reticulum kinase(PERK)-mediated endoplasmic reticulum stress pathway in a model of lipopolysaccharide(LPS)-induced microglia inflammation.Methods To investigate its effects on endoplasmic reticulum(ER)stress,an inflammation model of microglia was established by stimulating with LPS at gradient concentrations for 24 hours and with 1 mg/L LPS for different durations.Cell viability was assessed by the CCK-8 assay;The mRNA and protein expression levels of related inflammatory factors were measured by Real-time PCR and ELISA kits.Cellular oxidative stress was evaluated by detecting reactive oxygen species(ROS),and Real-time PCR and Western blotting were used to examine the mRNA and protein expression levels of ER stress pathway markers associated with inflammation.Results 1.The effects of different concentrations of LPS on cell viability and morphology were not statistically significant after acting on BV-2 cells for 24 hours(P＞0.05);2.1 mg/L LPS incubated with BV-2 cells for different times and the cell viability decreased with the increase of time;3.Compared with the 0 hour group,the levels of pro-inflammatory cytokine interleukin(IL)-1β,tumor necrosis factor-α(TNF-α)mRNA and protein expression increased significantly(P＜0.05)in the LPS-stimulated 9 hours,12 hours,and 24 hours groups,and the inflammation model was successfully established;4.Compared with the 0 hour group,the protein and mRNA expression levels of the endoplasmic reticulum stress pathway-related indexes in the LPS-stimulated 9 hours,12 hours,and 24 hours groups increased significantly(P＜0.01),which showed the time-dependence;5.After adding the PERK inhibitor GSK2606414,the mRNA and protein expression levels of endoplasmic reticulum stress-related indicators in the PERK inhibitor group were significantly reduced compared with those in the LPS group(P＜0.05);6.The mRNA and protein expression levels of pro-inflammatory cytokines and the fluorescence intensity of ROS in the PERK inhibitor group were significantly reduced compared with those in the LPS group(P＜0.01).Conclusion Targeting PERK-mediated endoplasmic reticulum stress inhibits LPS-induced inflammatory responses in microglia.

Objective To investigate the expression levels of serum microRNA-21(miR-21)and microRNA-23a(miR-23a)in patients with Parkinson's disease(PD)and their correlations with cognitive function and inflammatory responses.Methods A total of 120 PD patients admitted to the Second Affiliated Hospital of Hebei North University between December 2019 and January 2022 were enrolled,along with 115 healthy controls from the same period.Serum miR-21 and miR-23a levels were measured by quantitative real-time PCR,while serum levels of IL-6,CRP,and TNF-α were determined by ELISA.According to Mini-Mental State Examination(MMSE)scores,PD patients were classified into a cognitive impairment group(MMSE<26,n=72)and a normal cognition group(MMSE≥26,n=48).General characteristics in clinical and biochemical indicators levels were compared between the two groups.Spearman correlation analysis was used to assess the relationships of miRNAs and MMSE scores.Multivariate logistic regression analysis was employed to identify risk factors for cognitive impairment.The predictive value of miR-21 and miR-23a was evaluated using Receiver Operating Characteristic(ROC)curve analysis.Results Serum miR-21,miR-23a,IL-6,CRP,and TNF-α levels were significantly higher in the PD group than in the control group(P<0.01).The cognitive impairment group showed higher levels of miR-21,miR-23a,and inflammatory factor than the cognitively normal group(P<0.01).Correlation analysis revealed that miR-21 and miR-23a levels were negatively correlated with MMSE scores(r=-0.472,-0.514;P<0.001)and positively correlated with IL-6,CRP,and TNF-α(P<0.001).Multivariate Logistic regression analysis revealed that high expression of miR-21,miR-23a,and a higher UPDRS score,were independent risk factors for cognitive impairment in PD patients(P<0.05).Combined detection of miR-21 and miR-23a showed higher predictive accuracy for cognitive impairment than either marker alone(P<0.05).Conclusion Serum expression levels of miR-21 and miR-23a was upregulated in PD patients,which were associated with cognitive function and inflammatory response.Combined detection shows good predictive value for cognitive impairment..

AIM:Flow cytometry was used to evaluate the effects of short-term storage conditions(fresh,frozen at-80℃for 7 d,and stored at 4℃for 7 d)on the median fluorescence intensity(MFI)of antibodies and the percentage of immune cell subsets in mouse peripheral blood mononuclear cells(PBMCs)and splenocytes.METHODS:The PBMC and splenocyte suspensions from six male Kunming mice were collected and analyzed under three different processing con-ditions to compare differences in the antibody MFI and percentages of monocyte subsets(Ly-6clow/Ly-6cmedium/Ly-6chigh),macrophages(M1/M2),and dendritic cells.RESULTS:Both tissue and antibody specificity were demonstrated by changes in the antibody MFI values.Following storage at-80℃,the MFIs of certain antibodies(such as CD45 and F4/80 in PBMCs,and CD115,Ly-6c,F4/80,CD80 and MHC-II in the spleen)were similar to those of the fresh groups,where-as after storage at 4℃,the MFIs of other antibodies(such as 7-AAD,CD115,Ly-6c and MHC-II in PBMCs,and CD11b,CD206 and CD11c in the spleen)were closer to those of the fresh groups.The MFI of most of the examined anti-bodies varied significantly following storage.Both storage conditions significantly reduced the viability of PBMCs and sple-nocytes.In PBMCs stored at 4℃,the percentages of total monocytes,Ly-6cmedium/Ly-6chigh monocytes,total macrophages,and dendritic cells were similar to those in the fresh group.Compared with the fresh group,both storage groups presented significantly lower percentages of M1 macrophages and dendritic cells(P<0.05).There were no statistically significant differences in the percentages of total monocytes,Ly-6cmedium monocytes,Ly-6chigh monocytes,total macrophages,M1 and M2 macrophages,or dendritic cells in the spleen among the three groups(P>0.05).The percentage of Ly-6clow monocytes did not differ substantially(P>0.05)between the fresh and-80℃frozen groups but was significantly lower in the 4℃storage group than in the fresh group(P<0.05).CONCLUSION:The storage conditions of the samples had a substantial effect on the flow cytometry results(antibody MFI and cell subset percentages)of the PBMCs and splenic cells,with tissue specificity.If the percentage of immune cell subgroups(particularly monocytes/macrophages/dendritic cells)in PBMCs is highly important,storage at 4℃for 7 d is preferable.If the MFI values of specific antibodies(such as CD45 and F4/80)are important,freezing at-80℃may be more appropriate.If the MFI values of most antibodies or the percentages of criti-cal subgroups(such as total monocytes/Ly-6chigh/total macrophages/dendritic cells)in splenic cells need to be close to those of fresh samples,4 ℃ storage for 7 d is more effective.Freezing at-80℃is preferable if the MFI values of particular anti-bodies(such as CD115 and Ly-6c)need to be determined.