BACKGROUND:Laser therapy is a non-invasive and painless treatment that is considered to be an effective method suitable for the treatment of osteoarthritis due to its simplicity and non-invasive nature.Currently,the mechanism of action of laser therapy is unclear and the results of studies on its clinical application are controversial. OBJECTIVE:To review and summarize the latest research progress of laser therapy on chondrocytes,animal experiments and clinical efficacy,and to explore the possible mechanism of laser-mediated multi-pathway biological effects,so as to provide a theoretical basis for further research on the laser treatment of osteoarthritis of the knee joint. METHODS:A literature search was performed in CNKI,WanFang Data,VIP and PubMed databases for relevant literature published from 2018 to 2023,with"laser therapy,low level laser therapy,high level laser therapy,photobiomodulation,knee osteoarthritis,chondrocytes"as the search terms in Chinese and English,respectively.Together with 14 articles searched manually,70 articles were finally included for review. RESULTS AND CONCLUSION:Laser therapy in the treatment of knee osteoarthritis is mainly categorized into two types:low-level laser therapy and high-level laser therapy.Differences in laser parameters and treatment protocols have a direct impact on laser efficacy.When appropriate parameters are used,low-level lasers show positive effects in cellular experiments,animal models,and clinical efficacy.High-level lasers have been less studied in the treatment of knee osteoarthritis,but some preliminary clinical studies have shown positive results.Cell experiments have shown that low-level laser promotes chondrocyte proliferation and cartilage matrix synthesis,thereby reducing inflammatory response.Animal experiments have shown that low-level laser can reduce the release of pro-inflammatory factors,promote cartilage matrix synthesis,inhibit matrix degradation,and effectively improve the repair process of cartilage tissue.Low-level laser is also able to reduce oxidative stress damage and relieve pain in knee osteoarthritis.In clinical trials,both low-and high-level laser can reduce patients'pain and improve functional activities.The combination of laser therapy and exercise therapy modalities may improve the therapeutic effect.Lasers may affect intracellular signaling and cellular functions through photobiological or thermodynamic effects.This provides direct evidence that laser promotes articular cartilage regeneration.

Objective:To evaluate myocardial microcirculation perfusion with myocardial contrast echocardiography (MCE) in patients with acute myocardial infarction after percutaneous coronary intervention (PCI), and to explore the prognostic value of different types of myocardial microcirculation perfusion.Methods:This is a prospective cohort study. Patients with acute myocardial infarction who underwent successful PCI in Nanfang Hospital of Southern Medical University and Kanghua Hospital of Dongguan City from October 2019 to June 2021 were selected. All the enrolled patients completed MCE examination within 72 hours after PCI. According to the examination results, the patients were divided into normal microcirculation perfusion group, delayed microcirculation perfusion group, and blocked microcirculation perfusion group. Adverse cardiovascular events including all-cause death, cardiovascular death, and angina re-hospitalization were followed up, and left ventricular ejection fraction (LVEF) review results were collected at six months to one year after surgery. Kaplan-Meier survival curve was used to investigate the difference in the incidence of adverse cardiovascular events in different myocardial perfusion groups, and Cox regression analysis was used to evaluate the effect of myocardial perfusion on adverse cardiovascular events.Results:A total of 113 patients with acute myocardial infarction were included, aged (56.3±11.5) years, with 88(78%) males. There were 31 cases in the normal microcirculation perfusion group, 43 cases in the delayed microcirculation perfusion group and 39 cases in the blocked microcirculation perfusion group. LVEF was reviewed in 49 patients, and LVEF in the delayed microcirculation perfusion group was significantly improved compared with baseline at follow-up ((63.3±1.2) % vs. (58.6±1.8) %, P=0.043), and there was no statistically significant difference between the other two groups (all P>0.05). The median follow-up time was 473 days, during follow-up period 30 adverse cardiovascular events occurred. Kaplan-Meier survival curve analysis showed that there was a statistically significant difference in the incidence of adverse cardiovascular events among the three groups ( Plog-rank=0.029). Cox regression analysis showed that abnormal microcirculation perfusion (defined as delayed and blocked microcirculation perfusion) was an independent predictor of adverse cardiovascular events in patients with acute myocardial infarction after PCI ( HR=1.90, 95% CI1.16-3.12, P=0.011). Conclusions:Microcirculatory perfusion decrease or lost is common in patients with acute myocardial infarction after PCI. Timely restoration of blood flow reconstruction can save heart function when microcirculatory perfusion decreases. Microcirculatory perfusion is a predictor of adverse cardiovascular events in patients with acute myocardial infarction, and patients with poor myocardial perfusion are more likely to experience adverse cardiovascular events.

Objective To evaluate the effects of andrographolide on insulin resistance,dysbiosis and Notch/zinc finger protein transcription factor 1(Snail1)signaling pathway in diabetic rats.Methods A total of 70 male Wistar rats with SPF grade were selected,and 30 of them were selected for andrographolide LD50 test.After determining the lethal dose,50 mg/kg was selected for administration and observation,the remaining 40 rats,10 were used as the NC group,30 were established as the diabetes model,and a total of 28 rats were successfully modeled,which were divided into T2DM group(n=9),Metformin treatment group(Met,n=9),and andrographolide administration group(And,n=10).The NC group and T2DM group were not treated.The changes were evaluated after 14 days of intervention.Results Compared with NC group,HOMA-IR,the abundance levels of Bacteroidetes,Firmicute,mRNA and protein expression levels of Notch and Snail1,and positive expression rates were increased(P<0.05),while the abundance levels of Lactobacillus and Bifidobacterium were decreased in T2DM,Met and And group(P<0.05).Compared with T2DM group,HOMA-IR,the abundance levels of Bacteroidetes,Firmicute,mRNA and protein expression levels of Notch and Snail1,and positive expression rates were decreased,while the abundance levels of Lactobacillus and bifidobacterium were increased in Met and And group(P<0.05).Conclusions After andrographolide intervention,insulin resistance was alleviated,microbiota imbalance was improved,and Notch/Snail1 signaling pathway was suppressed in diabetic rats.

Objective To develop a pressure swing adsorption oxygen generating device that is workable at altitudes of 0 to 7000 meters.Methods The three-bed molecular sieve oxygen production process was adopted.The switching time of air circuit solenoid valve and the rotation speed of the compression pump were taken as controllable variables.The performance of the oxygen generating device was tested in a normal atmospheric environment and a low-pressure environment corresponding to altitudes of 0 to 7000 meters.The optimal values of controllable oxygen generating parameters corresponding to 10 low-pressure environments(89.9,79.7,69.7,65.0,62.0,57.7,53.8,47.6,43.0,41.0 kPa)were obtained.Results The oxygen concentration could reach 94％,oxygen flow rate was 9 L/min and oxygen outlet pressure stood at 44 kPa in a normal atmospheric environment(altitude 416 meters),compared with 94％,6.3 L/min and 30 kPa in a low-pressure environment of 41 kPa(altitude 7000 meters).Conclusion The oxygen generating device can meet the oxygen needs of two persons within the altitude range of 0 to 7000 meters.

To design an electronic sleep massager that can perform massage and sleep aid at the same time.It is powered by a 9 V battery,and a multivibrator is composed of a 555 timer as the core to generate an oscillation signal.The 0～180 V continuously adjustable electrical pulse was output to the massage electrode through the step-up transformer,and the low-frequency sound signal was output through the speaker to achieve massage and sleep assistance.The electronic sleep massager has simple design and excellent performance,and uses sound hypnosis and acupressure massage at the same time,which can achieve relatively good hypnosis and fatigue relief effects,and is a small electronic health care product suitable for home use,and has certain promotion and application value.

Objective To observe the effects of acupuncture at acupoints along the meridians on the expression of frontal lobe associated protein kinase in pchlorophenylalanine(PCPA)induced insomnia rats;To explore the mechanism of acupuncture in improving insomnia.Methods Totally 60 rats were randomly divided into blank group,model group,sham acupuncture group,acupuncture group and Western medicine group,with 12 rats in each group.An insomnia model rat was induced by intraperitoneal injection of PCPA.The acupuncture group received acupuncture at"Baihui","Shenmen"(bilateral),and"Sanyinjiao"(bilateral),while the sham acupuncture group only fixed the needle at the corresponding acupoints but did not penetrate the skin,while the model group was only fixed for 30 minutes,the Western medicine group was given a solution of estazolam by gavage for 7 consecutive days,the blank group was not treated.The pentobarbital sodium reversal experiment was used to detect the sleep latency and sleep time of rats,ELISA was used to detect the content of melatonin(MT)in plasma,RT-PCR was used to detect the mRNA expressions of calmodulin dependent protein kinase(CaMK)Ⅱ,protein kinase C(PKC)and p38 mitogen activated protein kinase(MAPK)in frontal lobe tissue,and Western blot was used to detect the protein expressions of CaMKⅡ,PKC and p38MAPK in frontal lobe tissue.Results Compared with the blank group,the sleep latency of the model group rats were significantly prolonged and the sleep time were significantly shortened(P<0.01),the content of MT in plasma was significantly reduced(P<0.01),and the mRNA and protein expressions of CaMKⅡ and PKC in frontal lobe tissue were significantly decreased(P<0.01),the mRNA and protein expressions of p38MAPK were significantly increased(P<0.01).Compared with the model group,the sleep latency were significantly shortened and the sleep time were significantly prolonged in the acupuncture group and the Western medicine group(P<0.01),the plasma MT content significantly increased(P<0.01),the mRNA and protein expressions of CaMKⅡ and PKC in frontal lobe tissue significantly increased(P<0.05),and the mRNA and protein expression of p38MAPK significantly decreased(P<0.01).Compared with the sham acupuncture group,the sleep latency shortened and sleep time were significantly prolonged in the acupuncture group and the Western medicine group(P<0.01),plasma MT content significantly increased(P<0.01),PKC mRNA expression in frontal lobe tissue significantly increased(P<0.01),and p38MAPK mRNA expression significantly decreased(P<0.01).There was no statistically difference in various indicators between the acupuncture group and the Western medicine group(P>0.05).Conclusion Acupuncture at acupoints along the meridians can shorten the sleep latency and prolong sleep time,improve sleep status by regulating the expression of associated protein kinase in frontal lobe of insomnia rats.

Objectives: . Using tissue-engineered materials for esophageal reconstruction is a technically challenging task in animals that requires bioreactor training to enhance cellular reactivity. There have been many attempts at esophageal tissue engineering, but the success rate has been limited due to difficulty in initial epithelialization in the special environment of peristalsis. The purpose of this study was to evaluate the potential of an artificial esophagus that can enhance the regeneration of esophageal mucosa and muscle through the optimal combination of a double-layered polymeric scaffold and a custom-designed mesenchymal stem cell-based bioreactor system in a canine model. Methods: . We fabricated a novel double-layered scaffold as a tissue-engineered esophagus using an electrospinning technique. Prior to transplantation, human-derived mesenchymal stem cells were seeded into the lumen of the scaffold, and bioreactor cultivation was performed to enhance cellular reactivity. After 3 days of cultivation using the bioreactor system, tissue-engineered artificial esophagus was transplanted into a partial esophageal defect (5×3 cm-long resection) in a canine model. Results: . Scanning electron microscopy (SEM) showed that the electrospun fibers in a tubular scaffold were randomly and circumferentially located toward the inner and outer surfaces. Complete recovery of the esophageal mucosa was confirmed by endoscopic analysis and SEM. Esophagogastroduodenoscopy and computed tomography also showed that there were no signs of leakage or stricture and that there was a normal lumen with complete epithelialization. Significant regeneration of the mucosal layer was observed by keratin-5 immunostaining. Alpha-smooth muscle actin immunostaining showed significantly greater esophageal muscle regeneration at 12 months than at 6 months. Conclusion . Custom-designed bioreactor cultured electrospun polyurethane scaffolds can be a promising approach for esophageal tissue engineering.

ObjectiveTo explore the barriers and facilitators of the adherence of formal practice after mindfulness-based cognitive therapy （MBCT） in psychological counseling outpatients. MethodsOne-on-one interview was conducted in 15 psychological counseling outpatients who attended MBCT at Shanghai Mental Health Center and had been out of treatment 5 months or more. Data was analyzed using thematic analysis. ResultsPoor mood， weak willpower， limited time and space， lack of companionship and supervision， and discomfort with the recording were the five factors that prevented the patients from sticking to their practice. Personality trait， trust， benefit， need for self-care， time/space arrangement， fellow practitioners， therapists， and ease and convenience of practice were the eight factors that promoted the patients to practice. ConclusionThe COM-B model helps therapists and individuals with practice needs to understand the mechanism of formal practice facilitators at a holistic level. Therapists and individuals with practice needs should be concerned about possible barriers on the adherence of formal practice.

The binding of talin-F0 domain to ras-related protein 1b (Rap1b) plays an important role in the formation of thrombosis. However, since talin is a force-sensitive protein, it remains unclear whether and how force regulates the talin-F0/Rap1b interaction. To explore the effect of force on the binding affinity and the dynamics mechanisms of talin-F0/Rap1b, molecular dynamics simulation was used to observe and compare the changes in functional and conformational information of the complex under different forces. Our results showed that when the complex was subjected to tensile forces, there were at least two dissociation pathways with significantly different mechanical strengths. The key event determining the mechanical strength difference between the two pathways was whether the β4 sheet of the F0 domain was pulled away from the original β1-β4 parallel structure. As the force increased, the talin-F0/Rap1b interaction first strengthened and then weakened, exhibiting the signature of a transition from catch bonds to slip bonds. The mechanical load of 20 pN increased the interaction index of two residue pairs, ASP ⁵⁴-ARG ⁴¹ and GLN ¹⁸-THR ⁶⁵, which resulted in a significant increase in the affinity of the complex. This study predicts the regulatory mechanism of the talin-F0/Rap1b interaction by forces in the intracellular environment and provides novel ideas for the treatment of related diseases and drug development.
Molecular Dynamics Simulation ; Talin

Medical Physics is an interdiscipline which is formed by applying the basic principles, methods, and techniques of physics to clinical medical research such as prevention, diagnosis, and treatment of human diseases, and it is a compulsory professional basic course for medical students. However, there are many medical students reflect that the content of this course is obscure and difficult to understand. Teaching effect is not ideal. The main reasons are that the teaching method is single and the reference materials are few. Based on the actual situation of the course, Hebei Medical University, China promotes formative evaluation from the content of teaching materials, teaching means, and other aspects. At the same time, by combining with the Internet, the digital construction has been realized, deepening the reform of the Medical Physics curriculum, and remarkable results have been achieved.