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The part of responses that is absent in the nonequivalent groups with anchor test (NEAT) design can be managed to a planned missing scenario. In the context of small sample sizes, we present a machine learning (ML)-based imputation technique called chaining random forests (CRF) to perform equating tasks within the NEAT design. Specifically, seven CRF-based imputation equating methods are proposed based on different data augmentation methods. The equating performance of the proposed methods is examined through a simulation study. Five factors are considered: (a) test length (20, 30, 40, 50), (b) sample size per test form (50 versus 100), (c) ratio of common/anchor items (0.2 versus 0.3), and (d) equivalent versus nonequivalent groups taking the two forms (no mean difference versus a mean difference of 0.5), and (e) three different types of anchors (random, easy, and hard), resulting in 96 conditions. In addition, five traditional equating methods, (1) Tucker method; (2) Levine observed score method; (3) equipercentile equating method; (4) circle-arc method; and (5) concurrent calibration based on Rasch model, were also considered, plus seven CRF-based imputation equating methods for a total of 12 methods in this study. The findings suggest that benefiting from the advantages of ML techniques, CRF-based methods that incorporate the equating result of the Tucker method, such as IMP_total_Tucker, IMP_pair_Tucker, and IMP_Tucker_cirlce methods, can yield more robust and trustable estimates for the "missingness" in an equating task and therefore result in more accurate equated scores than other counterparts in short-length tests with small samples.

Ferroptosis is a new type of cell death proposed in recent years, and its main characteristics are iron overload and lipid peroxidation. Ferroptosis is involved in the occurrence and development of non-alcoholic fatty liver disease(NAFLD). Iron overload can generate a large amount of reactive oxygen species through the Fenton reaction. Under the action of lipoxygenase, the unsaturated fatty acids on the liver cell membrane undergo lipid peroxidation, which induces liver cell death and leads to the occurrence of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis. Blocking ferroptosis may provide one of the therapeutic strategies to protect liver cells.

Objective To investigate the effects of metformin(Met) on the proliferation of pancreatic cancer cells under different glucose concentration culture conditions, and to find the potential role of miR-139-5p in the process. Methods PANC-1 cells were treated with different concentrations of metformin(0/5/10/20 mmol/L) in 25 mmol/L(high-glucose group,HG) or 5 mmol/L(normal-glucose group,NG) glucose culture, cell proliferation, apoptosis, migration and cell cycle were detected after 48 h. The expression of miR-139-5p was quantitatively detected by RT-qPCR, and the miR-139-5p mimics were transfected into PANC-1 cells to clarify the role of miR-139-5p. Results Metformin inhibited the proliferation, promoted apoptosis, and induced S phase and G2/M phase arrest of PANC-1 cells under in high glucose and normal glucose culture conditions, and its anti-proliferation and pro-apoptosis effects were more significant in the normal glucose groups. The expression of miR-139-5p was up-regulated by metformin treatment in normal but not in high glucose culture. Further studies showed that miR-139-5p mimics inhibited of PANC-1 cells proliferation without metformin pre-incubation and enhanced the anti-proliferation effect of 5 mmol/L metformin. The pro-apoptotic effect of 10 mmol/L metformin in normal glucose culture conditions. Conclusions In normal-glucose culture conditions, metformin can inhibit proliferation, induce apoptosis and cell cycle arrest of PANC-1 cells more significantly than in higher-glucose culture, which may be partly related to the up-regulation of miR-139-5p.

Previous studies have established a link between fluctuations in climate and increased mortality due to coronary artery disease (CAD). However, there remains a need to explore and clarify the evidence for associations between meteorological changes and hospitalization incidences related to CAD and its subtypes, especially in cold regions. This study aimed to systematically investigate the relationship between exposure to meteorological changes, air pollutants, and hospitalization for CAD in cold regions.

Objective To explore how to integrate the history of Peking Union Medical College (PUMC) into the teaching of diabetes in internal medicine, in order to develop an ideological and political theory-based course with PUMC characteristics. Methods The students in '4+4' medical doctor program of PUMC were enrolled into this study. Diabetes mellitus course combined with ideological and political theories course (including the history of insulin development, the life and contribution of Prof. WU Xian and Prof. LIN Kesheng, and the contributions of Prof. CHI Zhisheng, Prof. PAN Xiaoren and Prof. XIANG Hongding to the prevention and treatment of diabetes) was used for the teaching. Feedback (including the level of the political teaching knowledge before and after the course, the effectiveness of the political teaching by students after the course) was collected by questionnaire online, and statistical analysis was conducted. Results A total of 62 students (32 in grade 2020 and 30 in grade 2021) were included in the '4+4' pilot class of clinical medicine at PUMC. A total of 58 questionnaires were collected (30 in grade 2020 and 28 in grade 2021), with a rate of 93.5%(58/62). Before teaching, 55.2%~100% of the students had no knowledge of the course, and after teaching, all students had a general understanding, with the level of understanding significantly better than before (P < 0.001). According to the survey, 82.8% of the students thought that the course increased their interest in learning, 86.2% of the students were satisfied with the overall effect of the course, 89.7% thought that it allowed them to better understand the history of PUMC, 77.6% thought it deepened their understanding of the spirit of medical science, 82.8% thought it increased their understanding of the spirit of professional service to the country and patriotism, and 72.4% thought it increased their sense of social responsibility. Conclusions Integrating the history of PUMC into clinical medicine education is the unique advantage of PUMC medical education. It is conducive to students understanding of ideological and political theories, inculcation of correct values, method ology and humanistic qualities, and cultivation of the truth-seeking and pragmatic spirit of medical science.

Objective To investigate the clinical characteristics of different subtypes of type 1 diabetes mellitus(T1DM) patients and to analyze the risk of macrovascular diseases in different subtypes of T1DM patients. Methods The clinical data among 79 T1DM patients who treated in the Endocrinology Department of Beijing Puren Hospital from March 2002 to July 2021 were retrospectively analyzed. There were 21 patients with idiopathic T1DM and 58 patients with autoimmune T1DM. Excluding 14 patients because of data missing, 65 patients were divided into macrovascular disease group (n=13) and non-macrovascular disease group (n=52). Results 1)Patients with idiopathic T1DM manifested a longer diabetic course,a higher high density lipoprotein cholesterol(HDL-c)level, a lower body mass index(BMI), hemoglobin A1c(HbA1c) and fasting C peptide(FC-P)level. 2)Compared with the group non-macrovascular disease, the macrovascular disease group was elder with higher prevalence of idiopathic T1DM and lower estimated glomerular filtration rate(eGFR) level and incidence of diabetic ketoacidosis(DKA) at the beginning of disease. 3)Macrovascular lesions were positively correlated with age(r=0.432) and diabetic course (r=0.245)(P＜0.05), were negatively correlated with eGFR(r=-0.392), positive islet autoantibody (r=-0.268) and DKA incidence at the beginning of disease(r=-0.313)(P＜0.05). 4)Multivariate regression analysis showed that negative auto-antibody finding was a risk factor for macrovascular disease (OR=0.03, 95% CI:0.001-0.858, P＜0.05) after age, diabetic course, BMI, eGFR, HDL-c and incidence of DKA at onset were adjusted. Conclusions Patients with idiopathic T1DM show a higher risk of macrovascular disease risk than those with autoimmune T1DM.