Supercooling preservation technology, as a groundbreaking innovation in the field of organ preservation, significantly reduces the metabolic rate of cells and inhibits ice crystal formation by placing organs in a low-temperature environment near or below the freezing point. This technology extends the preservation time of organs and maintains their biological activity. Compared with the traditional low-temperature preservation at 4 °C, supercooling preservation effectively avoids cell damage and the accumulation of metabolic products, demonstrating significant advantages in the preservation of cells, tissues and organs. In recent years, important progress has been made in the optimization of cryoprotectants, the application of antifreeze proteins, the improvement of vitrification technology, and the development of nanotechnology-based rewarming techniques. These advancements provide new pathways to address the challenges of toxicity, ice crystal formation and uneven rewarming rates during supercooling preservation. This review summarizes the basic principles of supercooling preservation, the application of key technologies, and their practical effects in organ transplantation. It also analyzes the challenges of toxicity and rewarming efficiency, aiming to provide theoretical support and research directions for the future optimization of organ low-temperature preservation technology and its clinical application.

Objective: To evaluate the bone repair effect of 3D-printed magnesium (Mg)-loaded polycaprolactone (PCL) scaffolds in a rat skull defect model. Methods: PCL scaffolds mixed with Mg microparticles were prepared by using 3D printing technology, as were pure PCL scaffolds. The surface morphologies of the two scaffolds were observed by scanning electron microscopy (SEM), and the surface elemental composition was analyzed via energy dispersive spectroscopy (EDS). The physical properties of the scaffolds were characterized through contact angle measurements and an electronic universal testing machine. This study has been reviewed and approved by the Ethics Committee. A critical size defect model was established in the skull of 15 Sprague-Dawley (SD) rats, which were divided into the PCL group, PCL-Mg group, and untreated group, with 5 rats in each group. Micro-CT scanning was performed to detect and analyze skull defect healing at 4 and 8 weeks after surgery, and samples from the skull defect area and major organs of the rats were obtained for histological staining at 8 weeks after surgery. Results: The scaffolds had a pore size of (480 ± 25) μm, a fiber diameter of (300 ± 25) μm, and a porosity of approximately 66%. The PCL-Mg scaffolds contained 1.0 At% Mg, indicating successful incorporation of Mg microparticles. The contact angle of the PCL-Mg scaffolds was 68.97° ± 1.39°, indicating improved wettability compared to that of pure PCL scaffolds. Additionally, compared with that of pure PCL scaffolds, the compressive modulus of the PCL-Mg scaffolds was (57.37 ± 8.33) MPa, demonstrating enhanced strength. The PCL-Mg group exhibited the best bone formation behavior in the skull defect area compared with the control group and PCL group at 4 and 8 weeks after surgery. Moreover, quantitative parameters, such as bone volume (BV), bone volume/total volume (BV/TV), bone surface (BS), bone surface/total volume (BS/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N) and bone mineral density (BMD), of skull defects were better than those in the other groups, indicating the best bone regeneration effect. H&E, Goldner, and VG staining revealed more mineralized new bone formation in the PCL-Mg group than in the other groups, and H&E staining of the major organs revealed good biosafety of the material. Conclusion PCL-Mg scaffolds can promote the repair of bone defects and have clinical potential as a new scaffold material for the repair of maxillofacial bone defects.

In the past few decades, microbubbles were widely used as ultrasound contrast agents in the field of tumor imaging. With the development of research, ultrasound targeted microbubble destruction technology combined with drug-loaded microbubbles can achieve precise drug release and play a therapeutic role. As a micron-scale carrier, microbubbles are difficult to penetrate the endothelial cell space of tumors, and nano-scale drug delivery system—nanobubbles came into being. The structure of the two is similar, but the difference in size highlights the unique advantages of nanobubbles in drug delivery. Based on the classification principle of shell materials, this review summarized micro/nanobubbles used for ultrasound diagnosis or treatment and discussed the possible development directions, providing references for the subsequent development.

Objective:To construct a teaching ability evaluation system for diversified general medicine course teachers under the guidance of "one practice and three learning".Methods:A research group was established to search for relevant documents and literature. A framework of evaluation index system was established through drafting and repeated discussion and modification by members of the group, as well as further discuss and modification by experts in general medicine. The framework was used to develop an expert consultation questionnaire on the teaching ability evaluation system for diversified general medicine course teachers under the guidance of "one practice and three learning". Through two rounds of expert consultation, a teaching ability evaluation system for diversified general medicine teachers under the guidance of "one practice and three learning" was constructed. A questionnaire was developed according to the system. The rationality and scientificity of the evaluation index system were verified by questionnaire survey.Results:The teaching ability evaluation system for diversified general medicine teachers under the guidance of "one practice and three learning" included 3 first-level indicators, 15 second-level indicators, and 41 third-level indicators. The general medicine curriculum evaluation questionnaire developed on the system showed that the Cronbach's α coefficient of the overall evaluation system was 0.981. The Cronbach's α coefficients of first-level indicators, including general medicine teaching plan, diversified theory and practice teaching, and comprehensive ability cultivation under the guidance of "one practice and three learning" ideology, were 0.920, 0.919, and 0.923, respectively. The content validity index (S-CVI) of the system was 0.981, and the content validity index (I-CVI) of indicators were 0.826-1.000. The correlation coefficients of first-level indicators and the system were 0.837-0.942 (all P<0.05). The correlation coefficients of second-level indicators and their corresponding first-level indicators were 0.586-0.971 (all P<0.05). The correlation coefficients of third-level indicators and their corresponding first-level indicators were 0.412-0.904 (all P<0.05). Conclusions:Under the guidance of "one practice and three learning", the teaching ability evaluation indicators for diversified general medicine course teachers have high specificity, rationale structure, high feasibility, high reliability, and high practicability. This evaluation system can provide theoretical reference for the training of undergraduate students in general medicine.

Circadian rhythms are self-sustaining oscillations within biological systems that play key roles in a diverse multitude of physiological processes.The circadian clock mechanisms in brain and peripheral tissues can oscillate independently or be synchronized/disrupted by external stimuli.Dental enamel is a type of mineralized tissue that forms the exterior surface of the tooth crown.Incremental Retzius lines are readily observable microstructures of mature tooth enamel that indicate the regulation of amelogenesis by circadian rhythms.Teeth enamel is formed by enamel-forming cells known as ameloblasts,which are regulated and orchestrated by the circadian clock during amelogenesis.This review will first examine the key roles of the circadian clock in regulating ameloblasts and amelogenesis.Several physiological processes are involved,including gene expression,cell morphology,metabolic changes,matrix deposition,ion transportation,and mineralization.Next,the potential detrimental effects of circadian rhythm disruption on enamel formation are discussed.Circadian rhythm disruption can directly lead to Enamel Hypoplasia,which might also be a potential causative mechanism of amelogenesis imperfecta.Finally,future research trajectory in this field is extrapolated.It is hoped that this review will inspire more intensive research efforts and provide relevant cues in formulating novel therapeutic strategies for preventing tooth enamel developmental abnormalities.

Background Type 2 diabetes mellitus is one of the most prevalent diseases,which imposes a heavy burden on patients' families and the society.Sleep disorders are recognized as risk factors for the development of diabetes,which may affect the onset and development of diabetes through neuro-endocrino-metabolic pathways,so identifying the factors responsible for the sleep quality of diabetic patients is of great importance in improving their sleep quality.Objective To investigate the relationship among fear of disease progression,executive function and sleep quality in patients with type 2 diabetes mellitus,so as to provide references for improvement of sleep quality in patients with type 2 diabetes mellitus.Methods A sample of 197 patients with type 2 diabetes mellitus who were admitted to the Endocrinology Department of the Second Affiliated Hospital of the Air Force Military Medical University from January to May 2023 and met the criteria defined in the Guideline for the Prevention and Treatment of Type 2 Diabetes Mellitus in China(2020 edition)were consecutively selected.All subjects were assessed using Fear of Progression Questionnaire-Short Form(FoP-Q-SF),Behavior Rating Inventory of Executive Function-Adult version(BRIEF-A)and Pittsburgh Sleep Quality Index(PSQI).Then the Process macro for SPSS(Model 4)and Bootstrap technique were applied to examine the mediating effect of executive function on the relationship between fear of disease progression and sleep quality in patients with type 2 diabetes mellitus.Results ①75 patients(38.07%)with type 2 diabetes mellitus were found to have sleep problems.②PSQI score in patients with type 2 diabetes mellitus was positively correlated with FoP-Q-SF score and BRIEF-A score(r=0.159,0.287,P<0.01).③Executive function mediated the relationship between fear of disease progression and sleep quality,the indirect value was 0.076(95%CI:0.022～0.146),accounting for 39.58%of the total effect.Conclusion Sleep disorders are common in patients with type 2 diabetes mellitus,and executive function may play a medicating role in the relationship between fear of disease progression and sleep quality.

Objective To explore the metastasis rate and related risk factors of T1 stage colonic neuroendocrine tumor(C-NET),and to compare the long-term survival outcomes of patients with non-metastatic(T1N0M0 stage)C-NET after local excision(LE)or radical surgery(RS).Methods Clinical information of 433 patients diagnosed with C-NET in the SEER database from January 1,2004 to December 31,2015 were analyzed.Cox regression was used to analyze the influencing factors of metastasis of C-NET.The patients without metastasis were divided into LE group and RS group,and assigned in a 1∶1 ratio using propensity score matching(PSM)according to gender,age,tumor largest diameter,and infiltration depth,with a caliper value set to 0.02.Kaplan-Meier survival curve was used to analyze 5-year cancer-specific survival(CSS)and overall survival(OS)of patients.Cox regression analysis was used to evaluate the influence of metastasis on survival.Results Among 419 C-NET patients,19(4.52%)had distant metastases.Cox regression analysis showed that 11-20 mm of tumor large diameter(HR=9.264,95%CI 3.322-25.835,P＜0.001),right colon location(HR=0.116,95%CI 0.042-0.321,P＜0.001),and submucosal invasion(HR=5.842,95%CI 1.858-18.371,P=0.003)were independent risk factors for distant metastasis of T1 stage C-NET.The 5-year OS rates of non-metastatic and metastatic patients were 94.5%and 47.4%,respectively(χ2=79.762,P＜0.001),and their 5-year CSS rates were 99.5%and 55.7%,respectively(χ2=164.604,P＜0.001).Before PSM,the 5-year OS rates of non-metastatic C-NET patients after LE and RS were 95.8%and 90.1%(χ2=2.679,P=0.063),and the 5-year CSS rates were 100.0%and 97.2%(χ2=0.579,P=0.038);after PSM,the 5-year OS rates of non-metastatic patients after LE and RS were 96.8%and 92.1%(χ2=3.606,P=0.058),and the 5-year CSS rates were 100.0%and 98.5%(χ2=1.015,P=0.314).After PSM,there was no significant difference in the 5-year OS and CSS of patients with defferent tumor location,tumor large diameter,or submucosal invasion between the LE and RS groups.Conclusions 11-20 mm of tumor diameter,right colon location,and submucosal invasion might be independent risk factors for distant metastasis of T1 stage C-NET,and LE could be an appropriate treatment option for non-metastatic C-NET.

The present study was aimed to investigate the role and mechanism of glutaminolysis of cardiac fibroblasts (CFs) in hypertension-induced myocardial fibrosis. C57BL/6J mice were administered with a chronic infusion of angiotensin II (Ang II, 1.6 mg/kg per d) with a micro-osmotic pump to induce myocardial fibrosis. Masson staining was used to evaluate myocardial fibrosis. The mice were intraperitoneally injected with BPTES (12.5 mg/kg), a glutaminase 1 (GLS1)-specific inhibitor, to inhibit glutaminolysis simultaneously. Immunohistochemistry and Western blot were used to detect protein expression levels of GLS1, Collagen I and Collagen III in cardiac tissue. Neonatal Sprague-Dawley (SD) rat CFs were treated with 4 mmol/L glutamine (Gln) or BPTES (5 μmol/L) with or without Ang II (0.4 μmol/L) stimulation. The CFs were also treated with 2 mmol/L α-ketoglutarate (α-KG) under the stimulation of Ang II and BPTES. Wound healing test and CCK-8 were used to detect CFs migration and proliferation respectively. RT-qPCR and Western blot were used to detect mRNA and protein expression levels of GLS1, Collagen I and Collagen III. The results showed that blood pressure, heart weight and myocardial fibrosis were increased in Ang II-treated mice, and GLS1 expression in cardiac tissue was also significantly up-regulated. Gln significantly promoted the proliferation, migration, mRNA and protein expression of GLS1, Collagen I and Collagen III in the CFs with or without Ang II stimulation, whereas BPTES significantly decreased the above indices in the CFs. α-KG supplementation reversed the inhibitory effect of BPTES on the CFs under Ang II stimulation. Furthermore, in vivo intraperitoneal injection of BPTES alleviated cardiac fibrosis of Ang II-treated mice. In conclusion, glutaminolysis plays an important role in the process of cardiac fibrosis induced by Ang II. Targeted inhibition of glutaminolysis may be a new strategy for the treatment of myocardial fibrosis.
Rats ; Mice ; Animals ; Rats, Sprague-Dawley ; Angiotensin II/pharmacology* ; Fibroblasts ; Mice, Inbred C57BL ; Fibrosis ; Collagen/pharmacology* ; Collagen Type I/metabolism* ; RNA, Messenger/metabolism* ; Myocardium/pathology*

Objective:To analyze the MRI findings of tendinopathy of the common extensor tendon (CET) and common flexor tendon (CFT) and to explore its application for injury classification.Methods:Sixty-two patients with elbow tendinopathy of CET and/or CFT who were examined in the Radiology Department of Beijing Jishuitan Hospital from August 2019 to April 2022 were enrolled as the case group, and 20 healthy subjects (40 elbows) were recruited as the control group. The clinical data of patients and MRI findings of elbow joint of all subjects were reviewed. The MRI of tendinopathy of CFT and CET were read by 2 senior radiologists independently, and the consistency was tested by the κ test. The MRI manifestations for injury classification were discussed. Results:The κ values of CFT, CET, medial collateral ligament complex and lateral collateral ligament complex were 0.645, 0.657, 0.615 and 0.653 respectively. MRI clearly showed the anatomical structure of CFT, CET and surrounding soft tissue. The CFT and CET of the elbow of 20 normal volunteers (40 sides) in the control group showed thin line or banded low signal in each MRI sequence, and the muscle fibers were continuous. In 27 patients with classification Ⅰ injury of CFT and/or CET of elbow joint, MRI showed thickening or thinning of tendons and increased signal intensity on fat suppression T2-weighted imaging. In 27 cases of classification Ⅱ injury, MRI showed that the fluid signal involved 20% to 80% of the tendon thickness. In 8 cases of classification Ⅲ injury, MRI showed that the fluid signal involved more than 80% of the tendon thickness. Conclusions:Tendinopathy of CFT and CET of elbow joint has its characteristic MRI manifestations, indicating that MRI can be used for the diagnosis of tendinopathy. In addition, MRI can also be used for the injury classification.

Purpose/Significance The current situation of internet diagnosis and treatment in medical institutions in Beijing is ana-lyzed and studied to provide references for further promoting internet diagnosis and treatment and improving supervision of internet diagno-sis and treatment in medical institutions.Method/Process By using the methods of literature analysis,questionnaire survey and on-site interview,the current situation of internet diagnosis and treatment in medical institutions that have been qualified for internet diagnosis and treatment in Beijing is investigated.Result/Conclusion The internet diagnosis and treatment has been attached great importance by medical institutions in Beijing and has developed rapidly.However,it is also necessary to further optimize the internal and external envi-ronment for the development of internet diagnosis and treatment,strengthen supervision,and improve the public's acceptance.