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.

A centrifugation-free,single-reaction colorimetric method for detection of glucose,utilizing a dual nanozyme cascade system based on gold nanoparticles(AuNPs)and iron-doped carbon dots(FeCDs),was developed in this work.The AuNPs exhibited glucose oxidase-like activity to catalyze glucose oxidation for generation of H2O2,while the FeCDs demonstrated peroxidase-like activity to subsequently catalyze the H2O2-mediated oxidation of 3,3',5,5'-tetramethylbenzidine(TMB).To prevent interference from the blue signal generated by self-aggregation of AuNPs in subsequent quantitative detection,the reaction system was terminated with HCl,converting oxTMB into a stable yellow product.Based on changes in the absorbance at 450 nm of this yellow solution,a quantitative relationship was established between glucose concentration and absorbance at 450 nm(A450).Experimental results demonstrated that this sensor achieved a linear detection range of 44 μmol/L to 11.11 mmol/L(R2=0.993)with a detection limit of 30.68 μmol/L and spiked recoveries of 97.9%-104.7%.By integrating smartphone-based color recognition capabilities,a rapid visual detection platform was established for quantification of glucose through RGB analysis.The validation experimental results using commercial glucose injection samples further confirmed the practical application potential of this methodology.

Objective To explore the acceptability of routine biochemical test results for serum samples with varying degrees of chylous high triglyceride(TG).Methods Blood samples of 69 patients with different degrees of lipids were collected,including 33 patients with mild to moderate lipids(1.7 mmol/L≤TG<5.6 mmol/L)and 36 patients with severe lipids(TG≥5.6 mmol/L).Twenty-nine biochemical tests were detected before and after high-speed centrifugation.The result acceptability before high speed centrifugation of serum was compared with the results after high speed centrifugation as the gold standard[TG and total cholesterol(TC)before centrifugation].The acceptable criteria were subject to the following three conditions at the same time.Firstly,correlation coefficient(R2)was greater than or equal to 0.95.Secondly,the slope of linear re-gression equation was 1.00±0.05.Thirdly,for the same index,the number of samples whose result bias be-fore and after centrifugation was less than 1/2 total allowable error(TEa)in more than 90%of the total sam-ple numbers.Results Firstly,in the mild to moderate lipemia group,22 tests met the criteria,7 tests did not,including total protein(TP),albumin(ALB),TG,aspartate aminotransferase(AST),carbon dioxide(CO2),α-L-fucosidase(AFU),lactate dehydrogenase(LDH)(bias<10%),and the coincidence rate was 75.9%.In the severe lipemia group,12 tests met the criteria,17 tests did not,including pre-albumin(PA),AFU,γ-glu-tamyltransferase(γ-GT),LDH,AST,TC,direct bilirubin(DBIL),CO2,5'-nucleotidase(5'-NT),small and low-density lipoprotein cholesterol(sd-LDL-C),high density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),adenosine deaminase(ADA),cystatin C(CysC),glycosylated albumin(GA),total bilirubin(TBIL)(bias>10%),the coincidence rate was 41.4%,and there was a statistically sig-nificant difference in the coincidence rate between the two groups(P<0.05).Secondly,there was no statisti-cally significant difference in the acceptability of results between continuous monitoring method and endpoint method detection methods(P>0.05).Conclusion Most test results of direct determination with mild or moderate lipemia samples are acceptable,and the bias of unacceptable tests is small(<10%),so it is recom-mended to issue a test report without further sample treatment.However,due to the large number of unacceptable tests and larger bias(>10%),severe lipemia samples should be determined after high-speed centrifugation.

Objective:To investigate the effects of Zhibai Dihuang Pills on neurons of cognitive dysfunction in D-galactose (D-gal) model mice.Methods:Totally 60 male mice were divided into four groups using a random number table method: control group, model group, donepezil group, and Zhibai Dihuang Pills group, with 15 mice in each group. Except for the control group, the other groups were subcutaneously injected with D-galactose solution at a dosage of 125 mg/kg once a day for 8 weeks to prepare the aging model. Mice in the donepezil group were intragastrically administered donepezil solution at a dosage of 0.65 mg/kg, and those in the Zhibai Dihuang Pills group were intragastrically administered Zhibai Dihuang Pills solution at a dosage of 1.56 g/kg. The control group was intragastrically administered an equal volume of physiological saline once a day for 8 weeks. The object recognition test and Morris Water Maze were used to assess object recognition memory and spatial learning memory abilities of mice in each group, respectively. Hematoxylin-Eosin (HE) staining and Nissl staining were employed to observe the morphology of neurons in the hippocampal region; Golgi staining was used to observe neuronal dendritic spines; Western Blot was used to detect the protein expression levels of PI3K, p-Akt/Akt, glycogen synthase kinase 3β (GSK3β), postsynaptic density protein-95 (PSD-95), and synaptophysin (SYP) in the hippocampus region; RT-qPCR was performed to detect mRNA expression of PI3K, Akt and GSK3β in the hippocampus region.Results:Compared with the model group, the recognition index in both the donepezil group and the Zhibai Dihuang Pills group increased ( P<0.05), the escape latency was shortened ( P<0.05), the platform crossings times and the target quadrant dwell time increased ( P<0.05), the number of nerve cells in the hippocampal region increased, arranged closely, the number of Nissl bodies increased, the morphology returned to normal, and the density of dendritic spines increased; the protein expressions of PI3K, PSD-95, and SYP in the hippocampal region and the ratio of p-Akt/Akt increased ( P<0.01), the mRNA level of PI3K increased ( P<0.01 or P<0.05), and the protein and mRNA levels of GSK3β decreased ( P<0.01 or P<0.05). Conclusion:Zhibai Dihuang Pills can improve the learning and memory ability and rescue neuronal damage in D-gal model mice, and the mechanism may be related to the activation of PI3K/Akt pathway and the restoration of synaptic connections.

Objective To observe the clinical efficacy of filiform-heated needle stimulation on myofascial trigger points(MTrPs)based on the"pivot mechanism"theory in treating neck-shoulder myofascial pain syndrome(MPS).Methods Sixty-four patients diagnosed with neck-shoulder MPS from the Acupuncture Department(inpatient and outpatient)of Guangzhou University of Chinese Medicine Dongguan Hospital between January 2023 and September 2023 were selected and randomly divided into a control group and an observation group using a random number table,with 32 cases per group.The control group received oral administration of Celecoxib Capsules,while the observation group received additional filiform-heated needle therapy.The treatment duration was 2 weeks and 1 course per week.Clinical efficacy was evaluated after 2 weeks,with observing the changes in the Short-Form McGill Pain Questionnaire(SF-MPQ)scores,Neck Disability Index(NDI)scores.The cervical range of motion(ROM)was compared between the two groups.Results(1)After treatment,the SF-MPQ scores of the two groups of patients were significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving the SF-MPQ scores,and the difference was statistically significant(P＜0.05).(2)After treatment,the NDI scores of patients in the two groups were significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving the NDI scores,and the difference was statistically significant(P＜0.05).(3)After treatment,the cervical joint mobility of patients in the two groups was significantly improved(P＜0.05),and the observation group was significantly superior to the control group in improving cervical joint mobility,with a statistically significant difference(P＜0.05).(4)The total effective rate was 96.88%(31/32)in the observation group and 84.38%(27/32)in the control group.The efficacy of the observation group was superior to that of the control group,and the difference was statistically significant(P＜0.05).Conclusion Filiform-heated needle stimulation on MTrPs based on the"pivot mechanism"theory significantly alleviates pain,improves soft tissue injury,and enhances neck-shoulder mobility in patients with neck-shoulder MPS,demonstrating remarkable clinical efficacy.

Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

This study aims to explore the role and mechanism of berberine in promoting the expression of aquaporin 4(AQP4) in astrocytes by regulating the expression of miR-383-5p in HepG2 cell-derived exosomes under insulin resistance(IR). The IR-HepG2 cell model was established with 1×10~(-6) mol·L~(-1) insulin. With metformin as the positive control, the safe concentrations of berberine and metformin were screened by cell counting kit-8(CCK-8) and lactate dehydrogenase(LDH) leakage assays, and the effect of berberine on the IR of HepG2 cells was evaluated by glucose consumption. NanoSight was used to measure the particle size and concentration of exosomes secreted by HepG2 cells in each group. HepG2 cell-derived exosomes in each group were incubated with astrocytes for 24 h, and the protein and mRNA levels of AQP4 in HA1800 cells were determined by Western blot and qRT-PCR, respectively. qRT-PCR was performed to determine the expression of miR-383-5p in HepG2 cell-derived exosomes and HA1800 cells after co-incubation. Western blotting was employed to determine the expression levels of miRNAs and proteins associated with exosome production and release in HepG2 cells. The results showed that 10 μmol·L~(-1) berberine and 1 mmol·L~(-1) metformin significantly alleviated the IR of HepG2 cells and reduced the concentration of exosomes in HepG2 cells. The exosomes of HepG2 cells treated with berberine and metformin significantly up-regulated the protein and mRNA levels of AQP4 in HA1800 cells. The mRNA level of miR-383-5p in HepG2 cell exosomes and HA1800 cells co-incubated with berberine and metformin decreased significantly. The intervention with berberine and metformin significantly down-regulated the expression of proteins associated with the production of miRNAs(Dicer, Drosha) as well as the production(Alix, Vps4A) and release(Rab35, VAMP3) of exosomes in IR-HepG2 cells. In conclusion, berberine can promote the expression of AQP4 in astrocytes by inhibiting the production and release of miR-383-5p in HepG2-derived exosomes under IR.
Humans ; MicroRNAs/metabolism* ; Berberine/pharmacology* ; Hep G2 Cells ; Exosomes/genetics* ; Aquaporin 4/metabolism* ; Insulin Resistance ; Astrocytes/drug effects*

This study aims to explore the effects of Buzhong Yiqi Decoction(BYD) on the cyclic guanosine monophosphate-adenosine monophosphate synthase(cGAS)-stimulator of interferon genes(STING) signaling pathway in the mouse model of autoimmune thyroiditis(AIT) and the mechanism of BYD in alleviating the immune injury. Forty-eight NOD.H-2~(h4) mice were assigned into normal, model, low-, medium-, and high-dose BYD, and selenium yeast tablets groups(n=8). Mice of 8 weeks old were treated with 0.05% sodium iodide solution for 8 weeks for the modeling of AIT and then administrated with corresponding drugs by gavage for 8 weeks before sampling. High performance liquid chromatography was employed to measure the astragaloside Ⅳ content in BYD. Hematoxylin-eosin staining was employed to observe the pathological changes in the mouse thyroid tissue. Enzyme-linked immunosorbent assay was employed to measure the serum levels of thyroid peroxidase antibody(TPO-Ab), thyroglobulin antibody(TgAb), and interferon-γ(IFN-γ). Flow cytometry was employed to detect the distribution of T cell subsets in the spleen. The immunohistochemical method was used to detect the expression of cGAS, STING, TANK-binding kinase 1(TBK1), and interferon regulatory factor 3(IRF3). Real-time PCR and Western blot were employed to determine the mRNA and protein levels, respectively, of markers related to the cGAS-STING signaling pathway in the thyroid tissue. The results showed that the content of astragaloside Ⅳ in BYD was(7.06±0.08) mg·mL~(-1). Compared with the normal group, the model group showed disrupted structures of thyroid follicular epithelial cells, massive infiltration of lymphocytes, and elevated levels of TgAb and TPO-Ab. Compared with the model group, the four treatment groups showed intact epithelial cells, reduced lymphocyte infiltration, and lowered levels of TgAb and TPO-Ab. Compared with the normal group, the model group showed increases in the proportions of Th1 and Th17 cells, a decrease in the proportion of Th2 cells, and an increase in the IFN-γ level. Compared with the model group, the four treatment groups presented decreased proportions of Th1 and Th17 cells and lowered levels of IFN-γ, and the medium-dose BYD group showed an increase in the proportion of Th2 cells. Compared with the normal group, the modeling up-regulated the mRNA levels of cGAS, STING, TBK1, and IRF3 and the protein levels of cGAS, p-STING, p-TBK1, and p-IRF3. Compared with the model group, the four treatment groups showed reduced levels of cGAS, STING, TBK1, and IRF3-positive products, down-regulated mRNA levels of cGAS, STING, and TBK1, and down-regulated protein levels of cGAS and p-STING. The high-dose BYD group showed down-regulations in the mRNA level of IRF3 and the protein levels of p-TBK1 and p-IRF3. The above results indicate that BYD can repair the imbalance of T cell subsets, alleviate immune injury, and reduce thyroid lymphocyte infiltration in AIT mice by inhibiting the cGAS-STING signaling pathway.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Signal Transduction/drug effects* ; Thyroiditis, Autoimmune/metabolism* ; Mice ; Membrane Proteins/metabolism* ; Mice, Inbred NOD ; Humans ; Female ; Nucleotidyltransferases/metabolism* ; Male ; Disease Models, Animal

This paper aims to evaluate the pharmacodynamic effect and mechanism of Zhifuxin in the prevention and treatment of vascular dementia(VD), providing a theoretical basis for later development. Bilateral common carotid artery ligation in male Wistar rats was conducted to replicate the long-term hypoperfused VD model, and the drug was given to groups after one month. The rats were fed daily with nimodipine of 20 mg·kg~(-1), Zhifuxin of 50, 100, and 200 mg·kg~(-1), or the same volume of solvent for four weeks. 24 hours after the last dose, Morris water maze experiments were performed to detect the learning and memory abilities of rats. Hematoxylin-eosin(HE) staining was used to observe the pathological changes in the brain tissue of rats; the immunohistochemical method was used to detect the expression of muscarinic acetylcholine receptors M1 and M4 in rats and determine the content of acetyl choline(Ach), acetylcholin esterase(AchE), malondialdehyde(MDA), choline acetyl transferase(ChAT), and dimethyl arginine hydrolase 1(DDAH1) in the cerebral cortex of rats. Western blot was employed to detect protein expression of endothelial nitric oxide synthase(eNOS), caveolin-1, monoamine oxidase A(MAO-A), and monoamine oxidase B(MAO-B). RT-qPCR was utilized to detect mRNA expression of eNOS, caveolin-1, MAO-A, and MAO-B. The results showed that compared with the model group, the different doses of Zhifuxin were able to shorten the latency of VD rats in the water maze positioning navigation test, increase the number of crossing platforms in the space exploration test, and alleviate cone cell contracture in the hippocampus of VD rats. The expression of biochemical indicators related to the cholinergic system in the cerebral cortex: M1 and M4 receptors increased, as well as ChAT activity, and AchE activity significantly decreased. The protein and mRNA expression of indicators related to the eNOS/NO pathway: DDAH1 content, eNOS, and caveolin-1 increased, and that of indicators related to monoamine oxidase(MAO): MAO-A and MAO-B significantly decreased. The results show that Zhifuxin can improve cognition ability in long-term hypoperfused VD rats, and its mechanism of action may be related to its ability to modulate the cholinergic system and the eNOS/NO pathway and inhibit MAO expression.
Animals ; Dementia, Vascular/metabolism* ; Male ; Rats, Wistar ; Rats ; Drugs, Chinese Herbal/administration & dosage* ; Maze Learning/drug effects* ; Nitric Oxide Synthase Type III/genetics* ; Acetylcholinesterase/metabolism* ; Humans ; Choline O-Acetyltransferase/genetics* ; Disease Models, Animal