Objective To design a test phantom for clinical routine quality control of magnetic resonance imaging (MRI).Methods The commonly used phantom such as Magphan SMR170 and Victoreen 76-903 were used for experiments with the same parameters,and the test data of all the modules were compared.The advantages and disadvantages of all the modules were analyzed,and an optimization scheme was proposed accordingly.Results The phantom could be applied to the detection of high-image-quality MRI machine,and solved the problems in positioning,size matching and etc.Conclusion The new phantom meets the demand of magnetic resonance imaging clinical routine testing,and provides a certain reference for phantom optimization design.

Objective To assess iron bioavailability of three iron-biofortified maizes using an in vitro digestion/ Caco-2 cell culture model. Method Three maize varieties rich in iron (Zhongtie 2, 3 and 4) and two maize varieties with lower content of iron (Zhengda 818 and 619) were pulverized, and the content of iron and phosphorus in each maize variety was measured. After digestion the iron bioavailability per g food was determined by using Caco-2 cell ferritin formation per mg cell protein as indicator. Results The iron content (33.250 mg/kg), iron bioavailability and the iron bioavailability per g food of Zhongtie 2 maize was the highest among all varieties, but its phosphorus content was lower. The maize varieties with the next higher iron bioavailability were Zhongtie 3 and Zhengda 818, and the lowest was Zhengda 619. Conclusion Zhongtie 2 maize contained the hightest content and bioavailability of iron,so it was optimal to use for the following human trials.

Objective To develop a ribbed,oxygen-enriched and inflatable tent to fulfill the requirements for mobile enriched oxygen supply under plateau conditions.Methods The tent was developed with ribbed skeleton,PVC material,nested structure,buffer door,channel for fresh air dispersion,exhaust recovery pipeline and etc,and the self-developed plateau oxygen enrichers were involved in to establish a mobile oxygen-enriched room.The enrichers were divided into four grades of 20,50,70 and 100 m3/h,which were used to execute 8-h oxygen-enriched fresh air dispersion in the tent.The change curves of the fractions for oxygen and carbon dioxide were compared and analyzed at 5 disperse points in the tent.Results Optimal effect was acquired with 20 m3/h oxygen enricher,the oxygen concentration reached 27％ in the tent after 8-h dispersion,while the carbon dioxide fraction was 1 800 ppm (1 ppm=l×l0-6) and it took 3-h to raise oxygen concentration to 25％.Conclusion The tent combined with 20 m3/h oxygen enricher decreases the equivalent altitude from 5 000 m to less than 3 000 m,and is hopeful to be spreaded in the plateau troops after improvement.

The factors for the undergraduate thesis design in biomedical engineering specialty were analyzed from the as-pects of tutor, student and administration, and some suggestions were proposed accordingly to enhance the undergraduate thesis design in biomedical engineering specialty.

Objective: In order to understand temporal and spatial distributions of alternating electromagnetic field (AEMF) of a coil thoroughly, the 3-D finite-element models of this kind of Biomagnetic Fields are established and analyzed for the research on bioeffect of magnetic field on microcirculation. Methods: Designing CAD models, setting boundary conditions, meshing models and obtaining numerical solutions were completed all within Comsol Multiphysics in terms of the theory of electromagnetic field. Results: Axial and radial plot of spatial attenuation rate of the AEMF, which were accordance with measured data, were simulated while the temporal and spatial distributions of AEMF were acquired. Conclusion: Models of 3-D finite-element of this kind of biomagnetic fields which appeared to exactly simulate the real magnetic field were first established systematically, and solved the placing problem of magnetic fields for the research on bioeffect of magnetic field on microcirculation and provided platforms for the simulation of hemodynamic of blood flow in the magnetic field.

Objective To develop a novel stress fracture animal model system based on dynamic cyclic mechanical loading.Methods Ulnae and tibiae of rats were respectively fixed using differently shaped fixtures (including a fixed holder and a movable holder).The axial mechanical loading was applied via a linear actuator based on LabVIEW control program.During the loading process,a load cell and a laser displacement transducer were used to detect the force and displacement changes in the limbs,respectively.The two signals were sampled at real time by PC-based LabVIEW data acquisition program.A compressive loading test (peak force of 50 N) was conducted to examine the consistency and reliability of cyclic loads after completing the loading system.The loading system and an ElectroForce 3220 mechanical testing machine were respectively used to measure and compare the Young's modulus of a standard ultra-high molecular weight polyethylene (UHMWPE)cylinder to calibrate the loading system.Results The compressive loading test (peak force of 50 N) demonstrated that the mechanical loading system was able to apply consistent loads with controllable intensity and time.The calibration experiment indicated the accuracy of the loading system.Conclusion The novel mechanical loading device has characteristics of precision,scientificity and reliability,and it is approaching the real development situation of stress fracture,which may provide a reliable experimental base for exploring the precautionary measures of stress fracture.

English for science and technology (EST) is the language medium for academic communication among scientists and technologists. The expression of EST is characterized by concise-ness, correctness, objectiveness and understandability. The EST course is regarded as a key process for the undergraduate students to reinforce the English foundation and improve the capacity of English application after their College English study. In this paper, the authors introduced an interest-motivated, output-dominated, snowballing and interactive teaching strategy, according to the accumulated experi-ence of EST teaching in the past few years coupled with the unique medicine-engineering combined characteristics for the major of biomedical engineering.

ObjectiveTo picture the trajectory of changes in glucose and lipid metabolism among schizophrenic patients in long-term hospitalization. MethodsA total of 109 inpatients of Shenzhen Kangning Hospital from 2014 to 2022， who were diagnosed with schizophrenia based on the International Classification of Diseases， tenth edition （ICD-10） criteria， were recruited as subjects. Real-world follow-up data on longitudinal glucose metabolism （fasting blood glucose， glycosylated hemoglobin， C-peptide） and lipid metabolism （triglycerides， low density lipoprotein， high density lipoprotein， total cholesterol） were observed. The frequency of visit was once a year， with a total of 9 visits over 8 years. ResultsIn terms of glucose metabolism parameters， fasting blood glucose level decreased to 4.87 mmol/L at the 7^th visit， lower than the baseline level （P<0.01）. Glycated hemoglobin level was 6.08% at the 9^th visit， higher than the baseline level （P<0.05）. C-peptide level was 3.14 ng/mL at the 7^th visit， higher than the baseline level （P<0.01）. As for the trajectory of lipid metabolism parameters， high-density lipoprotein level were significantly lower than baseline level at the second visit （P<0.01） and stayed basically stable thereafter. Total cholesterol levels at the last three visits were 4.06， 4.07 and 3.95 mmol/L， respectively， all lower than the baseline level （P<0.01）. ConclusionThe changes of glycolipid metabolism parameters in long-term inpatients with schizophrenia were generally smooth during the 8-year follow-up period.

Objective:To analyze the clinical characteristics of elderly acute pulmonary thromboembolism(APE)patients complicated with preexisting atrial fibrillation(AF)and the impact of preexisting AF on in-hospital adverse outcomes in elderly patients with APE.Methods:A retrospective analysis was performed on elderly APE patients with preexisting AF hospitalized in Beijing Anzhen Hospital, Capital Medical University between January 1, 2008 and December 31, 2021.We compared the comorbidities, symptoms, signs, laboratory test results and echocardiographic features, simplified pulmonary embolism severity index(sPESI)scores and adverse in-hospital outcomes between the preexisting AF group and the non-AF group.Logistic regression was used to analyze the risk factors of in-hospital adverse outcomes in elderly patients with APE.Results:A total of 240 patients diagnosed with APE were enrolled.There were 120 patients in the AF group and 120 patients in the non-AF group.For patients in the AF group and the non-AF group, the proportions with chronic heart failure were 38.3%(46/120)and 15.8%(19/120), the proportions with lower extremity deep vein thrombosis(DVT)were 36.7%(44/120)and 65.8%(79/120), the left ventricular ejection fractions(LVEF)were(59±10)% and(62±7)%, and hospital stays were(15±7)and(11±4)days, respectively, and the differences were statistically significant( χ2=15.381, 20.429, t=2.527, -4.710, all P<0.05). The incidences of in-hospital adverse outcomes in the AF group and the non-AF group were 4.2%(5/120)and 3.3%(4/120), respectively, with no significant difference( χ2=0.000, P=1.000). The overall incidence of in-hospital adverse outcomes was 3.8%(9/240). Multivariate Logistic regression analysis showed that elevated lactic acid was an independent risk factor for in-hospital adverse outcomes( OR=2.753, 95% CI: 1.367-5.542, P=0.005). However, AF( OR=2.880, 95% CI: 0.587-14.141, P=0.192)and sPESI score( OR=2.056, 95% CI: 0.904-4.673, P=0.086)were not associated with in-hospital adverse outcomes. Conclusions:Elderly APE patients with preexisting AF have a relatively low incidence of DVT, but a higher proportion have concurrent chronic heart failure and need a longer hospital stay.Elevated lactic acid is an independent risk factor for in-hospital adverse outcomes of elderly APE patients with preexisting AF.However, preexisting AF has no predictive value for in-hospital adverse outcomes in elderly patients with APE.

BackgroundThe incidence of delirium in critically ill psychiatric patients is high， and there are many factors affecting delirium occurrence. At present， epidemiological studies on delirium among critically ill patients in psychiatric hospitals are limited. ObjectiveTo explore the risk factors for delirium in critically ill patients in a psychiatric hospital， so as to guide the clinical management of delirium in psychiatric hospitals. MethodsThis retrospective study included 427 critically ill patients who were admitted to Shenzhen Kangning Hospital from January 1， 2019 to May 31， 2021. The delirium situation， gender， age， pre-admission course of illness （duration from the onset of acute mental state changes to in-patient registration at a psychiatric hospital）， history of mental illness， history of cognitive dysfunction， history of using psychoactive substances， history of using sedative and hypnotic drugs， number of combined chronic diseases， number of combined drugs and type of disease were examined as potential risk factors for delirium. Single Logistic regression was used to analyze the potential risk factors for delirium， and the potential risk factors were incorporated into the multi-factor Logistic regression analysis model so as to gradually screen out the risk factors for delirium in critically ill psychiatric patients. ResultsDelirium was present in 33.49% （143/427） of critically ill patients. Multi-factor Logistic regression analysis demonstrated that the presence of delirium was associated with mental and behavioral disorders caused by psychoactive substances （OR=8.949， P<0.01）， absent history of mental illness （OR=4.202， P<0.01）， number of combined chronic diseases （OR=1.249， P<0.01）， age （OR=1.031， P<0.01） and pre-admission course of illness （OR=0.942， P<0.01） . ConclusionDelirium was present in nearly 1/3 critically ill patients in the psychiatric hospital. The risk factors for delirium included short course of illness before admission， age， more combined chronic diseases， absent history of mental illness， mental and behavioral disorders caused by psychoactive substances. ［Funded by Shenzhen Fund for Guangdong Provincial High-level Clinical Key Specialties （number， SZGSP013）］