BACKGROUND:Micro-robots have the characteristics of small size,flexibility,and strong targeting,and can complete complex tasks in a single or clustered manner in a narrow environment.With the continuous optimization of materials,preparation processes,and driving approaches,they have shown increasingly important application value in the field of biomedicine. OBJECTIVE:To analyze the application of field-driven micro-robots in medical field and to look forward to their application prospect. METHODS:Using"microrobots,nanorobots,drivers,biomedical,medical"as Chinese keywords and"microrobots,micro-robots,nanorobots,micromachine,microswimmer,medical"as English keywords,WanFang Data and PubMed databases were searched,respectively.The search time range was from January 2010 to January 2024,and a small number of long-term articles were included.Through reading the titles and preliminarily screening the abstracts,the repetitive studies,low-quality journals,and irrelevant literature were excluded.After reading the entire text,66 papers were finally included for review. RESULTS AND CONCLUSION:Field-driven medical micro-robots mainly include magnetic,optical,thermal,ultrasonic,and multi-mixed factor-driven robots.Field-driven robots have been used in intestinal diagnosis,drug targeting therapy,and stem cell therapy.Medical micro-robots are currently only used in a small number of clinical applications,but most of which are still in the theoretical and experimental stages.Medical micro-robots will face many challenges in future,such as large-scale preparation,precise control of micro-robots,recycling or degradation in vivo,whether the materials used will cause adverse reactions to the human body,and the related minimally invasive medical procedures.

Objective The aim of this study was to investigate the prospective association between physical activity (PA),independently or in conjunction with other contributing factors,and osteoporosis (OP) outcomes. Methods The Physical Activity in Osteoporosis Outcomes (PAOPO) study was a community-based cohort investigation. A structured questionnaire was used to gather the participants' sociodemographic characteristics. Bone mineral density (BMD) measurements were performed to assess OP outcomes,and the relationship between BMD and OP was evaluated within this cohort. Results From 2013 to 2014,8,471 participants aged 18 years and older were recruited from Tangshan,China's Jidong community. Based on their PA level,participants were categorized as inactive,moderately active,or very active. Men showed higher physical exercise levels than women across the activity groups. BMD was significantly higher in the very active group than in the moderately active and inactive groups. Individuals aged>50 years are at a higher risk of developing OP and osteopenia. Conclusion The PAOPO study offers promising insights into the relationship between PA and OP outcomes,encouraging the implementation of PA in preventing and managing OP.

Objective To study the population genetic structure and phylogenetic relationships by combining Y-STR haplotype genetic information from the Han population in Dalian with 32 domestic and foreign groups.Methods Blood samples of 958 Han male volunteers from Dalian were collected.Genetic typing of 42 genetic loci was completed using Y-STR fluorescent reagent kits and capillary electrophoresis.Related forensic parameters were calculated.Nei's standard genetic distances among 33 populations based on 17 Y-STR loci were computed,in order to create a principal coordinate analysis as well as construct a phylogenetic tree.Results The analysis of genetic polymorphisms at 42 Y-STR loci revealed 30 unconventional alleles at 10 loci.Genetic analysis of the population based on 17 Y-STR loci confirmed that Dalian's Han population had the closest genetic distance to the Anshan's Han population,followed by populations from Henan,Heilongjiang,Jilin,Shandong,and Chongqing.Furthermore,the genetic distances between the Han population in Dalian and the Qiang population in Beichuan or the Miao population in Guizhou were relatively closer than that to the Manchu population living in Liaoning.Conclusion The genetic distance between the Han population in Dalian and other groups is not entirely proportional to ethnicities and geographical proximity.Both population migration and ethnic assimilation or isolation may have influence on it.

Objective:To summarize the clinical manifestations, experiences in diagnosis and treatment of arrhythmogenic cardiomyopathy (ACM) in children.Methods:A retrospective analysis of the clinical manifestations, laboratory tests, radiological features, treatment and follow-up results was conducted in 11 children diagnosed with ACM at the center of congenital heart disease, Beijing anzhen hospital from May 2010 to March 2022.Results:A total of 11 patients aged 2 to 16 years, including 5 males and 6 females were diagnosed with ACM. The clinical manifestations included decreased activity tolerance (7 patients), heart failure (4 patients), syncope or sudden death (3 patients), palpitation (3 patients), and chest tightness and pain (3 patients). Electrocardiogram showed right bundle branch block in 9 cases, paroxysmal ventricular tachycardia in 4 cases, frequent premature ventricular contraction in 4 cases, ventricular pre-excitation in 1 case, left bundle branch block in 1 case, and first degree atrioventricular block in 2 cases. Echocardiography showed enlargement of the right heart, widening of the right ventricular outflow tract, and thinning and bulging of the local wall of the right ventricle with reduced pulsation. Ventricular thrombosis was found in 2 cases. Six children underwent cardiac magnetic resonance imaging, which mainly showed severe enlargement of the right heart, thin free wall of the right ventricle, decreased right heart function, enhanced right ventricular myocardium, and formation of right ventricular aneurysm. Two children underwent myocardial biopsy examination and presented with typical pathological changes of ACM. Genetic tests in five patients revealed DSG2 gene mutation in 2 cases, PKP2 gene mutation in 2 cases, and MYH6 gene mutation in 1 case. All patients received anti heart failure treatment and antiarrhythmic drugs. Two children received anticoagulant treatment due to ventricular thrombosis. Radiofrequency ablation was performed in 2 patients. Glenn procedure was performed in 4 patients, and heart transplantation was performed in 1 patient due to progressive heart failure. The follow-up period ranged from 6 months to 12 years. Two cases died of right heart failure, 6 cases had different degrees of heart failure, 1 case had intermittent chest tightness and pain, and 2 cases were stable.Conclusions:ACM is a progressive genetic cardiomyopathy characterized by decreased activity tolerance, cardiac failure and arrhythmia in pediatric patients. The diagnosis is mainly based on clinical manifestations, electrocardiogram, cardiac imaging changes, and genetic testing. Early detection, diagnosis, and personalized treatment can improve the prognosis.

Objective:To explore the effects of intrahippocampal injection of ferroptosis inducer Erastin on depressive- and anxiety-like behavior and the expression of ferroptosis-related proteins in rats.Methods:Forty 6-week-old healthy male Sprague-Dawley rats were randomly divided into five groups ( n=8/group): Control group, Erastin low-dose(200 ng/μL) group, Erastin medium-dose(400 ng/μL) group, Erastin high-dose group(600 ng/μL) and lipopolysaccharide (LPS, 10 μg/L) group.After the intrahippocampal injection of Erastin(2.5 μL per side), body weight, and behavioral tests, including sucrose preference test (SPT), forced swimming test (FST), open field test (OFT), and elevated plus maze (EPM), were performed to evaluate depressive- and anxiety-like phenotypes from the fourth day after injection.The levels of ferroptosis-related proteins and mRNA, including glutathione peroxidase 4 (GPX4), cyclo-oxygenase 2 (COX2), ferritin heavy polypeptide 1 (FTH1), long-chain fatty acyl-CoA synthetase 4 (ACSL4), solute carrier family 7 member 11 (SLC7A11) were measured using real-time quantitative PCR and Western blot analysis.SPSS 22.0 software was used for statistical analysis.One-Way ANOVA was used for multi-group comparison, and LSD was used for further pound-wise comparison. Results:(1)Body weight and behavioral tests: there were no statistically significant differences in baseline body weight and behavioral tests in these groups ( F=0.02-1.15, all P>0.05). After intrahippocampal injection, compared with the control group, medium-dose Erastin induced depression-like behaviors in rats more significantly, as indicated by reduced bodyweight ((245.20±5.24)g, (267.45±13.16)), sucrose preference in SPT ((32.14±8.51)%, (68.17±13.67)%), central time in OFT ((6.01±2.57)s, (16.49±7.21)s), percentage of time in open arm in EPM ((5.00±3.83)%, (19.63±5.91)%) and increased immobility time in FST ((37.00±7.58)s, (12.50±5.51)s) and percentage of time in closed arm in EPM ((89.43±4.77)%, (59.96±9.91)%), and there were statistically significant differences in these groups (all P<0.05). (2)The expression of ferroptosis-related indicators: after intrahippocampal injection, the expression of mRNA ( F=2.23, 8.37, 2.91, 7.60, 3.16, all P<0.05) and protein ( F=3.31, 40.13, 8.52, 3.70, 70.79, all P<0.05) of FTH1, GPX4, SLC7A11, COX2 and ACSL4 in hippocampus were statistically significant differences in the 5 groups.The mRNA and protein levels of FTH1, GPX4 and SLC7A11 in Erastin medium-dose group were lower than those in the control group (all P<0.05), while the mRNA and protein levels of COX2 and ACSL4 were higher than those in the control group (all P<0.05). Conclusion:Intrahippocampal microinjection of Erastin(400 ng/μL) can induce ferroptosis in hippocampus of rats and can also induce depressive-like behaviors in rats.

Acute pancreatitis often progresses rapidly, and if it is not controlled in time, it may lead to multiple organ injury and even death due to organ failure. At present, there is still a high proportion of patients with acute pancreatitis who died due to liver failure. The liver and the pancreas are interrelated physiologically and affect each other pathologically. This article elaborates on the molecular mechanism of liver injury in acute pancreatitis from the six aspects of the physiological relationship between the pancreas and the liver, cytokines, inflammatory response, oxidative stress, microcirculation disturbance, and intestinal flora translocation.

Depression is a common psychiatric disorder characterized by low mood with complex pathophysiological mechanisms and poor effect of pharmacological treatment.The animals were placed in greater sensory, physical and/or social stimuli than those of the standard feeding environment, so that they can obtain positive plasticity and adaptability.Environmental enrichment(EE) is a common intervention to improve brain function in laboratory.A large number of studies have shown that EE had significant ameliorative effects on various animal models of depression, but the mechanisms have not been yet fully understood with outcome heterogeneity in ethology.There was no universally accepted and unified paradigm and standard for EE due to its multi-dimensionality and complexity.Therefore, it is necessary to improve the structural components and implementation steps of EE by integrating the existing data.Combined with recent studies on animal models of depression, this paper reviewed the anti-depression mechanism of EE from promoting hippocampal neurogenesis, reducing neuroinflammation, regulating neuroendocrine and affecting epigenetic modifications, in order to provide new ideas for mechanisms research and treatment of depression.As the rise of precision medicine and individualized medicine brings human growing interest in exploring the sources and mechanisms of inter-individual differences and intra-group effects of depression, it will be a challenge to translate EE to the human society in a rational way.

Cryogels are a type of hydrogel material which are fabricated by cryopolymerization at subzero temperature. Due to their unique macroporous structure, shape memory properties and injectability, cryogels have gained significant interest in the fields of tissue engineering for encouraging the repair and regeneration of injured tissues. In this review, the basic concepts relevant to cryogels are introduced, and then the fabrication principle, the process parameters and the unique properties of cryogel are discussed. Next, the latest advances of cryogels as three-dimensional scaffold for various tissue engineering applications are given. Finally, this review summarizes the current limitations of cryogels, and strategies to further improve their properties for tissue engineering. The purpose of this article is to provide a reference guide for the researchers in related fields.
Cryogels ; Porosity ; Tissue Engineering ; Tissue Scaffolds

Objective:To report our experience in treatment of patients with orthopaedic trauma during COVID-19 epidemic.Methods:We retrospectively analyzed the 67 patients with orthopedic trauma who had been treated at Department of Orthopaedics, Peking Union Medical College Hospital from February 1 to March 31, 2020. After screening for COVID-19 infection was performed under strict protection, the patients were diagnosed and assigned to outpatient emergency treatment or hospitalization according to their specific condition. Twenty-six patients were treated at the outpatient emergency department. They were 8 males and 18 females with an average age of 69.5 years. Of them, 6 with vertebral compression fracture were placed on bed brakes, 14 with limb fracture immobilized after close reduction, 2 with skin laceration treated with debridement and suture, and 4 with hip fracture immobilized in bed. In the 41 hospitalized patients, there were 14 males and 27 females with an average age of 68.5 years. In them, hemiarthroplasty was performed for 7 femoral neck fractures, kyphoplasty for 5 vertebral compression fractures, total elbow arthroplasty for one humeral intercondylar fracture, exploration and suture for one case of Achilles tendon rupture, and internal fixation surgery for the remaining 27 cases.Results:Most of the patients had osteoporotic fractures which accounted for 61.5% (16/26) of the outpatients and 68.3% (28/41) of the inpatients, respectively. The duration from injury to surgery averaged 2.3 days and the length of hospitalization 4.5 days for the 41 hospitalized patients, decreased compared with the corresponding data (3.1 days and 11.5 days) for the similar inpatients in the same period last year. In the 41 inpatients, fever was observed upon hospitalization in 4 cases and after operation in 26 cases, and related to their primary injury or surgical trauma in all. Acute pulmonary embolism happened during operation in one patient with femoral shaft fracture.Conclusions:The prevention and control of COVID-19 should be continued. The awareness and behavior of health care providers are expected to be enhanced by strict screening protocol, protection and supervision. The proportion of elderly patients with osteoporotic fracture increased during the COVID-19 pandemic. Shortage of blood was the major problem affecting the treatment. Timely surgical treatment should be indicated for the patients with orthopedic trauma, especially those with lower extremity fracture.

Objective To evaluate the relationship between propofol anesthesia and postoperative delirium and inflammatory responses of aged rats.Methods Twenty-four adult male Sprague-Dawley rats,aged 18 months,weighing 550-650 g,were divided into 3 groups (n=8 each) using a random number table method:control group (group C),propofol anesthesia for 2 h group (group P2) and propofol anesthesia for 4 h group (group P4).In P2 and P4 groups,anesthesia was maintained with propofol at a rate of 24 mg· kg-1 · h-1 for 2 and 4 h,respectively,after anesthesia was induced with propofol.Morris water maze test was performed at 1 day before and after anesthesia.Blood and cerebrospinal fluid samples were collected after the end of Morris water maze test for determination of interleukin-1beta (IL-1β),IL-4,IL-6 and tumor necrosis factor-alpha (TNF-α) concentrations in plasma and cerebrospinal fluid by enzyme-linked immunosorbent assay.The hippocampus and cortex were removed for determination of Iba-1 positive cells.Results Compared with group C and the baseline value before anesthesia,no significant change was found in the escape latency or percentage of time of staying at the original platform quadrant in P2 and P4 groups (P＞0.05),the concentrations of IL-6 in cerebrospinal fluid and TNF-α in plasma were significantly decreased in group P2,the concentrations of IL-1β in cerebrospinal fluid and IL-4,IL-6 and TNF-α in plasma were significantly increased,and the concentrations of IL-1β in plasma and IL-4 in cerebrospinal fluid were decreased in group P4,and the number of hippocampal Iba-1 positive cells were significantly decreased in P2 and P4 groups (P＜0.05 or 0.01).Conclusion Propofol anesthesia dose not induce postoperative delirium and central inflammatory responses within 4 h,and propofol can induce peripheral inflammatory responses when anesthesia time is longer than 2 h.