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.

OBJECTIVE To investigate the effects and mechanisms of Lycium ruthenicum Murr. in improving sleep. METHODS Network pharmacology was employed to identify the active components of L. ruthenicum and their associated disease targets， followed by enrichment analysis. A caffeine‑induced zebrafish model of sleep deprivation was established ， and the zebrafish were treated with L. ruthenicum Murr. extract （LRME） at concentrations of 0.1， 0.2 and 0.4 mg/mL， respectively； 24 h later， behavioral changes of zebrafish and pathological alterations in brain neurons were subsequently observed. The levels of inflammatory factors [interleukin-6 （IL-6）， IL-1β， IL-10， tumor necrosis factor-α （TNF-α）]， oxidative stress markers [superoxide dismutase （SOD）， malondialdehyde （MDA）， glutathione peroxidase （GSH-Px）， catalase （CAT）]， and neurotransmitters [5- hydroxytryptamine （5-HT）， γ-aminobutyric acid （GABA）， glutamic acid （Glu）， dopamine （DA）， and norepinephrine （NE）] were measured. The protein expression levels of protein kinase B1 （AKT1）， phosphorylated AKT1 （p-AKT1）， epidermal growth factor receptor （EGFR）， B-cell lymphoma 2 （Bcl-2）， sarcoma proto-oncogene，non-receptor tyrosine kinase （SRC）， and heat shock protein 90α family class A member 1 （HSP90AA1） in the zebrafish were also determined. RESULTS A total of 12 active components and 176 intersecting disease targets were identified through network pharmacology analysis. Among these， apigenin， naringenin and others were recognized as core active compounds， while AKT1， EGFR and others served as key targets； EGFR tyrosine kinase inhibitor resistance signaling pathway was identified as the critical pathway. The sleep improvement rates in zebrafish of LRME low-， medium-， and high-dose groups were 54.60%， 69.03% and 77.97%， 开发。E-mail：hjp_yft@163.com respectively， while the inhibition ratios of locomotor distance were 0.57， 0.83 and 0.95， respectively. Compared with the model group， the number of resting counts， resting time and resting distance were significantly increased/extended in LRME medium- and high-dose groups （P＜0.05）. Neuronal damage in the brain was alleviated. Additionally， the levels of IL-6， IL-1β， TNF-α， MDA， Glu， DA and NE， as well as the protein expression levels of AKT1， p-AKT1， EGFR， SRC and HSP90AA1， were markedly reduced （P＜0.05）， while the levels of IL-10， SOD， GSH-Px， CAT， 5-HT and GABA， as well as Bcl-2 protein expression， were significantly elevated （P＜0.05）. CONCLUSIONS L. ruthenicum Murr. demonstrates sleep-improving effects， and its specific mechanism may be related to the regulation of inflammatory responses， oxidative stress， neurotransmitter balance， and the EGFR tyrosine kinase inhibitor resistance signaling pathway.

Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

AIM To prepare anisamide-modified ursolic acid self-assembled nanoparticles,and to evaluate their anti-drug resistance effect of enzalutamide on prostate cancer.METHODS Nanoparticle precipitation method was adopted in the preparation of anisamide-modified and non-anisamide-modified self-assembled nanoparticles,respectively,after which the particle size,Zeta potential and encapsulation efficiency were determined,and the morphology was observed under transmission electron microscope.The intake of cancer-associated fibroblasts(CAFs)was investigated,after which the model for enzalutamide resistance in prostate cancer was established,CCK8 assay was applied to analyzing the sensitization effect of self-assembled nanoparticles on enzalutamide,and Western blot was used for the detection of NRG1,HER3,AKT expressions.RESULTS The anisamide-modified self-assembled nanoparticles demonstrated the average particle size,Zeta potential and encapsulation efficiency of(195.13±8.06)nm,(-29.07±0.55)mV and(94.58±0.84)％,respectively.CAFs displayed higher intake in the anisamide-modified self-assembled nanoparticles than that in the non-modified preparation and free Cy5(P＜0.05).Meanwhile,anisamide-modified self-assembled nanoparticles were able to inhibit enzalutamide resistance caused by CAFs,reduce NRG1 expression on CAFs,and anisamide-modified self-assembled nanoparticles-treated conditioned medium of CAFs could reduce HER3 and AKT expression on LNCaP cells(P＜0.05,P＜0.01).CONCLUSION Anisamide-modified ursolic acid self-assembled nanoparticles can enhance the targeting of CAFs,alleviate the drug resistance effect of enzalutamide on prostate cancer caused by CAFs,and reduce NRG1 expression in CAFs.

Objective To explore the characteristics of Xin'an doctors in the syndrome differentiation and treatment of liver cirrhosis from the dimensions of symptoms,syndromes and medication using data mining methods.Methods Medical cases and prescriptions for liver cirrhosis were collected from Xin'an medical literature.Data mining was performed using frequency analysis,complex network analysis,Louvain clustering analysis and factor analysis to investigate syndromes,symptoms,and medicines.Results A total of 363 prescriptions were analyzed,involving 15 syndromes and 325 kinds of Chinese materia medica,with 33 identified as core medications.Tonifying herbs were the most frequently used;the primary syndromes were liver qi stagnation and water retention;core symptoms of liver qi stagnation included emotional distress,reduced appetite and hypochondriac pain,with core medications such as Bupleuri Radix and Poria;core symptoms of water retention included lower limb edema and abdominal distension,with core medications such as Pinelliae Rhizoma,Citri Reticulatae Pericarpium,Magnoliae Officinalis Cortex and Poria.Factor analysis of core medications identified 12 common factors.Conclusion The pathogenesis of liver cirrhosis involves deficiency in nature and excess in superficiality,primarily affecting the liver and closely related to the spleen and kidneys.Xin'an doctors emphasize treating the symptoms with qi-regulating,blood-activating,dampness-drying and heat-clearing strategies,while simultaneously addressing the root with qi-tonifying,spleen-strengthening,liver-nourishing and kidney-replenishing therapies.

BACKGROUND:Spine osteoarthritis is a chronic inflammatory disease of the spine,articular ligaments,and tendons,and is the main cause of chronic low back pain.Artificial tiger bone powder has anti-inflammatory and pain-relieving biological effects,so it is expected to provide a new strategy for targeted therapy of spinal osteoarthritis.OBJECTIVE:To investigate the mechanism of artificial tiger bone meal in regulating the expression level of interleukin-23/interleukin-17 immune axis in improving spine osteoarthritis in rats.METHODS:Sixty SD rats were randomly divided into blank control group,model group,artificial tiger bone meal low-,medium-and high-dose groups,with 12 rats in each group.Except for the blank control group,osteoarthritis models were established in the other groups by injecting 0.1 mL of iodoacetic acid into the joint cavity of the lumbar vertebral joint capsule of the rats.15 days after modeling,the artificial tiger bone meal low,medium and high dose groups were treated by intragastric administration of 120,240 and 480 mg/kg per day respectively.The blank control group and model group were given the same volume of normal saline by gavage.After 21 days of treatment,the expression levels of interleukin-17,interleukin-23,matrix metalloproteinase-3,and chemokine receptor-6 in rat spinal articular cartilage were measured by western blot assay.The expression levels of related inflammatory factors in rat serum were detected by ELISA.The degree of joint injury and degeneration in rats was observed by hematoxylin-eosin staining and safranin O-fast green staining.RESULTS AND CONCLUSION:(1)The results of western blot assay showed that the expression levels of interleukin 17,interleukin 23,matrix metalloproteinase 3,and chemokine receptor 6 in the articular cartilage of rats in the artificial tiger bone meal high-dose group were significantly lower than those in the model group(P＜0.05).(2)ELISA results showed that compared with the model group,the artificial tiger bone meal medium-and high-dose groups had a significant down-regulating effect on the levels of serum interleukin 17,tumor necrosis factor α,interleukin 1β,and matrix metalloproteinase 3(P＜0.05).(3)Hematoxylin-eosin staining and saffron O-solid green staining showed that the infiltration and proliferation of synovial inflammatory cells in each treatment group of artificial tiger bone meal were significantly improved compared with the model group,and the pathological inflammation Osteoarthritis Research Society International score and Mankin's score in the medium-and high-dose groups of artificial tiger bone meal were significantly reduced(P＜0.05).(4)It is suggested that artificial tiger bone meal could significantly improve the inflammation and degeneration of spinal facet joints caused by iodoacetic acid chemical stimulation.Among them,the effect of the high-dose group was more significant.The mechanism may be to inhibit the expression of interleukin-23/interleukin-17 immune axis-related inflammatory factors and improve the immune microenvironment of articular cartilage.

BACKGROUND:During the treatment of posterolateral tibial plateau fractures through the fibular head approach,the gap between the fibular head and the lateral plateau cannot accommodate the posterior placement of a plate for all patients.OBJECTIVE:To analyze,via finite element analysis,the differences in fixation strength resulting from varying the angles and quantities of horizontal arm variable angle screws in the plate during the treatment of posterolateral tibial plateau fractures through the fibular head approach.METHODS:A finite element model was established based on CT images of the knee to ankle joints of a 30-year-old healthy adult male volunteer.The models were divided into two categories:posteriorly placed group and non-posteriorly placed group based on whether the lateral locking compression plate was posteriorly placed.The posteriorly placed group was further subdivided into groups A-D based on the offset angle of the two variable angle screws(0°,5°,10°,and 15°).The non-posteriorly placed group was subdivided into groups E and F based on offset angles(0° and 15°).Finite element analysis was used to evaluate the von Mises stress distribution,maximum von Mises stress,and compressive displacement under loads of 250,500,and 750 N,exploring the mechanical differences between the groups.RESULTS AND CONCLUSION:(1)Finite element analysis results showed that under a 750 N load,the maximum compressive displacement trend of the internal fixation device was D＜B=C=F＜A＜E.The trend for maximum von Mises stress was B＜C＜A＜D＜F＜E.The trend for maximum compressive displacement on the bone was C=D＜B＜A＜F＜E,and for maximum von Mises stress,it was B＜C＜A＜F＜D＜E.The displacement and stress trends for the six models were similar under loads ranging from 250 N to 750 N.(2)These results suggest that for posterolateral tibial plateau fractures fixed through the fibular head approach,posterior placement of the plate should aim to accommodate two screws.If only one screw can be fixed during surgery,variable angle screws should be offset in the range of 0-15° to increase the probability of securing two screws.

Aim To evaluate the role of the glucose transporter protein 1(GLUT1)-dependent glycolytic in the attenuation of oxygen-glucose deprivation-reoxygen-ation(OGD/R)injury in HK-2 cells by dexmedetomi-dine(Dex).Methods C57/BL6 mice were random-ly divided into three groups(n=6),namely,sham operation group(Sham group),renal ischemia reper-fusion group(I/R group)and Dex group(I/R+Dex group).Serum creatinine(Cr)and urea nitrogen(BUN)were measured,while the levels of key glyco-lytic enzymes HK2,PFKFB3 and GLUT1 were meas-ured.HK-2 cells were cultured and randomised into seven groups(n=6),which was treated with OGD/R,overexpression or interference with GLUT1,Dex and glycolysis inhibitor 2-DG.CCK-8 and LDH activi-ty were used to detect cellular damage.Glycolysis lev-els were detected by lactate and ECAR.The inflamma-tory level was reflected by qRT-PCR for IL-6 and TNF-α.qRT-PCR and Western blot were performed to de-tect the levels of GLUT1,HK2,and PFKFB3.Results Dex significantly ameliorated kidney injury and HK-2 cell injury(P＜0.05).Dex inhibited the OGD/R-induced rise in lactate and extracellular acidification rate(ECAR),as evidenced by suppression of the ex-pression of GLUT1,HK2 and PFKFB3(P＜0.05).In vitro experiments showed that GLUT1 knockdown sig-nificantly improved OGD/R-induced cellular damage.Lactate,ECAR,glycolysis-related mRNAs and pro-teins were inhibited by GLUT1 knockdown(P＜0.05).Significantly,there were no significant differ-ences in above indexes after Dex treatment based on GLUT1 knockdown.Overexpression of GLUT1 abroga-ted the protective effects of Dex,while reversing the inhibitory effects of Dex on the expression of GLUT1,HK2,and PFKFB3(P＜0.05).Conclusions Dexmedetomidine attenuates OGD/R induced injury in HK-2 cells by inhibiting GLUT1-dependent glycolysis.

BACKGROUND:Our previous studies found that decreased expression of connexin 43 and its Ser368 phosphorylation after myocardial hypothermic ischemia-reperfusion was closely associated with decreased cardiac conduction velocity and reperfusion arrhythmia.OBJECTIVE:To observe the effect of changes in membrane-type matrix metalloproteinase 2,matrix metalloproteinase 2 and collagen type Ⅳ on the expression of connexin 43 and its Ser368 phosphorylation and electrical conduction in the myocardial extracellular matrix after hypothermic ischemia-reperfusion.METHODS:Sixteen Langendorff extracorporeal cardiac perfusion models were successfully established from SD rats and randomly divided into a control group(n=8)and a hypothermic ischemia-reperfusion group(n=8).The control group was balanced perfused with 37 ℃ Krebs-Henseleit solution for 15 minutes and then continued to be perfused with 37 ℃ Krebs-Henseleit solution for 90 minutes.The hypothermic ischemia-reperfusion group was balanced perfused with 37 ℃ Krebs-Henseleit solution for 15 minutes,and then the heart was arrested for 60 minutes by injection of 4 ℃ Thomas solution.During the cardiac arrest,the periphery was protected by 4 ℃ Krebs-Henseleit solution.Half-volume 4 ℃ Thomas solution was reperfused 30 minutes after the arrest.After stopping the arrest,the heart was reperfused with 37 ℃ Krebs-Henseleit solution for 30 minutes.The occurrence of arrhythmias,rebeating time,and the duration of arrhythmias were recorded from the immediate time point to the end of the reperfusion period.Conduction velocity,absolute inhomogeneity,and inhomogeneity index were measured using the Mapping Lab multi-channel electrophysiological mapping system at the time of balanced perfusion for 15 minutes(T1),reperfusion for 15 minutes/continuous perfusion for 90 minutes(T2),and reperfusion for 30 minutes/continuous perfusion for 105 minutes(T3).The relative expression levels of membrane-type matrix metalloproteinase 2,matrix metalloproteinase 2,collagen type Ⅳ,connexin 43,and its Ser368 phosphorylation in ventricular tissue were detected by western blot assay.RESULTS AND CONCLUSION:(1)No arrhythmia occurred in the control group.There were six cases of arrhythmia in the hypothermic ischemia-reperfusion group during reperfusion.Rebeating time and duration of arrhythmias were(25.38+12.02)and(158.67±67.68)seconds,respectively.(2)The conduction sochronal diagrams at T1,T2,and T3 in the control group were uniform and regular in direction,and the conduction velocity at T2 and T3 was not different from that at T1(P＞0.05).The conduction isochronal diagrams at T2 and T3 in the hypothermic ischemia-reperfusion group were uneven and irregular in direction,and the conduction velocity was slower than that at T1(P＜0.01).The conduction velocity at T2 and T3 in the hypothermic ischemia-reperfusion group was slower than that in the control group(P＜0.01).Conduction dispersion was greater in the hypothermic ischemia-reperfusion group than that in the control group at T2 and T3(P＜0.05).(3)Compared with the control group,the protein expressions of membrane-type matrix metalloproteinase 2 and matrix metalloproteinase 2 in the hypothermic ischemia-reperfusion group were increased(P＜0.05 or P＜0.01),and the protein expression levels of type Ⅳ collagen,connexin 43 and its Ser368 phosphorylation were decreased(P＜0.05 or P＜0.01).(4)The results indicate that after hypothermic ischemia-reperfusion,myocardial extracellular matrix remodeling may mediate the downregulation of myocardial connexin 43 and its Ser368 phosphorylation,slowed conduction velocity and increased conduction dispersion,thereby increasing the risk of arrhythmia.