How health seeking behavior develops in patients with type 2 diabetes: a qualitative study based on health belief model in China.

Background: Type 2 diabetes(T2DM) is a global health problem which is accompanied with multi-systemic complications, and associated with long-term health burden and economic burden. Effective health seeking behavior (HSB) refers to reasonably utilize health resources, effectively prevent and treat diseases, and maintain health. Effective health seeking behavior (HSB) is vital to mitigate the risk of T2DM complications. However, health seeking behavior for T2DM patients remains sub-optimal worldwide. Objective: The study aimed to explore the internal logic of how health seeking behavior of T2DM patients develops and the influencing factors of health seeking behavior. With a view to provide a reference basis for improving the health seeking behavior situation of T2DM patients. Methods: This study was conducted at an integrated tertiary hospital in China. People who were diagnosed with T2DM, capable of expressing clearly and had no mental illness, were approached based on a purposive sampling. The experience of T2DM and health seeking behavior were collected via in-depth interviews. A theory-driven thematic analysis based on Health Belief Model (HBM) was applied for data analysis. Inductive reasoning was used to identify emerging themes which were not included in HBM. Results: 26 patients with T2DM were included in the current study. Seven themes were identified, including: (1) T2DM diagnosis and severity; (2) T2DM treatment and management; (3) Perceived susceptibility of diabetes progression; (4) Perceived severity of diabetes progression; (5) Perceived benefits of health seeking behavior; (6) Perceived barriers of health seeking behavior; (7) Perception of behavioral cues. Generally, patients with T2DM lacked reliable sources of information, considered T2DM to be slow-progressing and without posing an immediate threat to life. Consequently, they did not fully grasp the long-term risks associated with T2DM or the protective effects of health seeking behavior. Conclusion: This study highlighted the challenges in health seeking behavior for patients with T2DM. It suggested that future interventions and strategies should involve multi-faceted approaches, targeting healthcare providers (HCPs), patients with T2DM, and their support networks. This comprehensive strategy can help patients better understand their condition and the importance of effective health seeking behavior. Ultimately, enhancing their capacity for adopting appropriate health-seeking practices.

A qualitative study on inner experience of self-management behavior among elderly patients with type 2 diabetes in rural areas.

BACKGROUND: As a chronic metabolic disease, diabetes poses a serious threat to human health and has become a major public health problem in China and worldwide. In 2020, 30% of Chinese people (aged ≥ 60 years) reported having diabetes mellitus. Moreover, individuals with diabetes living in rural areas face a significantly higher mortality risk compared to those in urban areas. In this study, we explored the inner experience of self-management behaviors in elderly patients with type 2 diabetes in rural areas to inform targeted interventions. METHODS: A phenomenological research design was used to explore the inner experience of self-management in rural elderly diabetes. Ten elderly diabetic patients were sampled from December 2022 to March 2023 in rural areas of Yangcheng County, Jincheng City, ShanXi Province, China. The seven-step Colaizzi phenomenological was used to analyze the interview data and generate themes. RESULTS: Four themes emerged: "Insufficient self-management cognition", "Negative self-management attitude", "Slack self-management behavior", and "No time for self-management". CONCLUSION: The level of self-management among elderly patients with type 2 diabetes in rural areas is low. Healthcare professionals should develop targeted interventions aimed at enhancing their cognitive levels, modifying their coping styles, and improving their self-management abilities to improve their quality of life.

Body mass index influence on short-term perioperative results in robotic-assisted laparoscopic partial nephrectomy: a comprehensive systematic review and meta-analysis.

The objective of this meta-analysis was to evaluate the perioperative outcomes of robotic-assisted partial nephrectomy (RAPN) in obese and non-obese patients. Through March 2024, we executed an exhaustive search in internationally acclaimed databases such as PubMed, Cochrane Library, and Web of Science, limiting our scope to publications in English. We discarded review articles, protocols lacking empirical data, conference abstracts, and materials not pertinent to our research. Our analytical framework utilized the Cochran-Mantel-Haenszel method alongside a random-effects model for evaluating dichotomous variables' mean differences, expressed through odds ratios (OR) with 95% confidence intervals (CI). We established statistical significance at a P value below 0.05. The comprehensive meta-analysis incorporated data from eight cohort studies, collectively assessing 3657 patients. Findings indicated that, relative to individuals of normal weight, those in the obese category had prolonged operative durations (WMD - 25.68 95% CI - 42.07 to - 9.29; P = 0.002), increased estimated blood loss (WMD - 48.55ml, 95% CI - 78.27 to - 18.83; P = 0.001), and longer warm ischemia times (WMD - 1.11, 95% CI - 2.03 to - 0.19; P = 0.02). However, no significant disparities were observed in hospital stay duration, intraoperative and total postoperative complications, severe postoperative complications, or alterations in postoperative estimated glomerular filtration rate (eGFR). Our findings conclude that robotic-assisted partial nephrectomy (RAPN) represents a viable and safe surgical approach for obese patients. This assertion is backed by the observation that crucial metrics, including postoperative renal function alterations, surgical complication rates, and hospitalization duration, exhibit no substantial variances when juxtaposed with counterparts of normal weight.

A systematic review and meta-analysis of short-term outcomes comparing the efficacy of robotic versus laparoscopic colorectal surgery in obese patients.

This meta-analysis was conducted to evaluate and contrast the effectiveness of robotic-assisted and laparoscopic colorectal surgery in the treatment of obese patients. In February 2024, we carried out an exhaustive search of key global databases including PubMed, Embase, and Google Scholar, limiting our focus to studies published in English and Chinese. We excluded reviews, protocols lacking published results, articles derived solely from conference abstracts, and studies not relevant to our research objectives. To analyze categorical variables, we utilized the Cochran-Mantel-Haenszel method along with random-effects models, calculating inverse variances and presenting the outcomes as odds ratios (ORs) along with their 95% confidence intervals (CIs). Statistical significance was determined when p values were less than 0.05. In our final meta-analysis, we included eight cohort studies, encompassing a total of 5,004 patients. When comparing the robotic surgery group to the laparoscopic group, the findings revealed that the robotic group experienced a longer operative time (weighted mean difference (WMD) = 37.53 min, 95% (CI) 15.58-59.47; p = 0.0008), a shorter hospital stay (WMD = -0.68 days, 95% CI -1.25 to -0.10; p = 0.02), and reduced blood loss (WMD = -49.23 mL, 95% CI -64.31 to -34.14; p < 0.00001). No significant differences were observed between the two groups regarding overall complications, conversion rates, surgical site infections, readmission rates, lymph node yield, anastomotic leakage, and intestinal obstruction. The results of our study indicate that robot-assisted colorectal surgery offers benefits for obese patients by shortening the length of hospital stay and minimizing blood loss when compared to laparoscopic surgery. Nonetheless, it is associated with longer operation times and shows no significant difference in terms of overall complications, conversion rates, rehospitalization rates, and other similar metrics.

Pathological Characteristics and Classification of Unstable Coronary Atherosclerotic Plaques.

Important forensic diagnostic indicators of sudden death in coronary atherosclerotic heart disease, such as acute or chronic myocardial ischemic changes, sometimes make it difficult to locate the ischemic site due to the short death process, the lack of tissue reaction time. In some cases, the deceased died of sudden death on the first-episode, resulting in difficulty for medical examiners to make an accurate diagnosis. However, clinical studies on coronary instability plaque revealed the key role of coronary spasm and thrombosis caused by their lesions in sudden coronary death process. This paper mainly summarizes the pathological characteristics of unstable coronary plaque based on clinical medical research, including plaque rupture, plaque erosion and calcified nodules, as well as the influencing factors leading to plaque instability, and briefly describes the research progress and technique of the atherosclerotic plaques, in order to improve the study on the mechanism of sudden coronary death and improve the accuracy of the forensic diagnosis of sudden coronary death by diagnosing different pathologic states of coronary atherosclerotic plaques.

A New Residual Subsidence Prediction Method of Short Working Face Goaf for Safety Construction of Urban Viaduct.

The planned viaduct in Jining, Shandong is a priority project in the city. However, the 63 working faces of a mine in Jining is only 3 m away from the planned viaduct, posing a serious threat to the safety of the viaduct's construction. Consequently, it is essential to evaluate the stability of the planned viaduct's goaf area under the influence of the 63 working faces. However, the 63 working faces are short faces, and there is a lack of corresponding prediction of surface residual subsidence. To address this issue, this paper employs theoretical analysis and numerical simulation to uncover the foundation deformation mechanism and characteristics of fractured rock and soil mass in the short goaf. Subsequently, a residual subsidence prediction method for the short goaf was proposed for the viaduct mined-out area. This new approach was implemented for the planned viaduct in Jining, and its effectiveness was validated through InSAR and leveling monitoring results. The research findings offer technical support for viaduct construction in areas affected by underground mining.

Calcium transferring from ER to mitochondria via miR-129/ITPR2 axis controls cellular senescence in vitro and in vivo.

Senescent cells are known to be accumulated in aged organisms. Although the two main characteristics, cell cycle arrest (for dividing cells) and secretion of senescence-associated secretory phenotype (SASP) factors, have been well described, the lack of sufficient senescent markers and incomplete understanding of mechanisms have limited the progress of the anti-senescence field. Calcium transferred from the endoplasmic reticulum (ER) via inositol 1, 4, 5-trisphosphate receptor type 2 (ITPR2) to mitochondria has emerged as a key player during cellular senescence and aging. However, the internal regulatory mechanisms, particularly those of endogenous molecules, remain only partially understood. Here we identified miRNA-129 (miR-129) as a direct repressor of ITPR2. Interestingly, miR-129 controlled a cascade of intracellular calcium signaling, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), DNA damage, and consequently cellular senescence through ITPR2 and mitochondrial calcium uniporter (MCU). In addition, miR-129 was repressed in different senescence models and delayed bleomycin-induced cellular senescence. Importantly, intraperitoneal injection of miR-129 partly postponed bleomycin-accelerated lung aging and natural aging markers as well as reduced immunosenescence markers in mice. Altogether, these findings demonstrated that miR-129 regulated cellular senescence and aging markers via intracellular calcium signaling by directly targeting ITPR2.

Novel ratio-expressions of genes enables estimation of wound age in contused skeletal muscle.

Given that combination with multiple biomarkers may well raise the predictive value of wound age, it appears critically essential to identify new features under the limited cost. For this purpose, the present study explored whether the gene expression ratios provide unique time information as an additional indicator for wound age estimation not requiring the detection of new biomarkers and allowing full use of the available data. The expression levels of four wound-healing genes (Arid5a, Ier3, Stom, and Lcp1) were detected by real-time polymerase chain reaction, and a total of six expression ratios were calculated among these four genes. The results showed that the expression levels of four genes and six ratios of expression changed time-dependent during wound repair. The six expression ratios provided additional temporal information, distinct from the four genes analyzed separately by principal component analysis. The overall performance metrics for cross-validation and external validation of four typical prediction models were improved when six ratios of expression were added as additional input variables. Overall, expression ratios among genes provide temporal information and have excellent potential as predictive markers for wound age estimation. Combining the expression levels of genes with ratio-expression of genes may allow for more accurate estimates of the time of injury.

Related mechanisms and research progress in straight back syndrome.

Despite the high prevalence of straight back syndrome (SBS), there is still limited research on this condition, posing challenges for effective diagnosis and treatment. The disease has been known for a long time, but there have been few related studies, which mostly consist of case reports. These studies have not been systematically summarized, making it difficult to meet the current needs of diagnosis and treatment. This article summarized the existing literature and comprehensively reviewed the diagnosis, pathogenesis, treatment, and research status of mitral valve prolapse related to SBS. We specifically emphasized the mechanisms and prognosis of SBS combined with mitral valve prolapse and discussed the latest research progress in this disease.

Prevalence and risk factors of frailty in older patients with chronic heart failure: a systematic review and meta-analysis.

AIM: To provide a summary of the available evidence concerning prevalence and risk factors of frailty in elderly patients with CHF. METHODS: PubMed, Embase, Web of Science, CINAHL, The Cochrane Library, China National Knowledge Infrastructure Database (CNKI), Chinese Biomedical Database (Sinomed), Weipu Database (VIP), and Wanfang database were searched from inception to July 2023. This study strictly followed the PRISMA guidelines. The quality of the included studies was rated by the Agency for Healthcare and Research and Quality and the Newcastle-Ottawa Scale. RESULTS: A total of 21 original studies were included, involving 4,797 patients. Meta-analysis results showed that the prevalence of frailty in older patients with heart failure was 38% (95%CI: 0.32-0.44). Age, cardiac function grading, left atrial diameter, left ventricular ejection fraction, hemoglobin, polypharmacy, BNP, nutritional risk, and hospitalization day are the influential factors of frailty in older patients with CHF. CONCLUSION: The prevalence of frailty in older patients with CHF is high, and clinical medical personnel should identify and intervene early to reduce or delay the frailty in older patients with CHF as much as possible.

[Discussion on the location of Dazhui (GV 14) and Yaoyangguan (GV 3)].

Since the anatomical location of acupoints was recorded in The latest Practice of Western Acupuncture in 1915, and Lecture Notes on Advanced Acupuncture in 1931, the Japanese acupuncture works of Chinese translation version, the location of Dazhui (GV 14) (under the spinous process of the 7th cervical vertebra) and Yaoyangguan (GV 3) (under the spinous process of the 4th lumbar vertebra) had rarely been questioned for nearly a century. In order to confirm the above statement, the writers have reviewed ancient literature, combined with the modern anatomical knowledge and searched the evidences from the core arguments of the acupuncture Mingtang chart and the bronze acupuncture statue. It is believed that Dazhui （GV 14） should be positioned under the spinous process of the 1st thoracic vertebra, and Yaoyangguan（GV 3） be under the spinous process of the 5th lumbar vertebra. Accordingly, all of the other acupoints of these meridians should be moved down by 1 vertebra, i.e. those on the governor vessel from Dazhui (GV 14) to Yaoyangguan (GV 3), those on the 1st lateral line of the bladder meridian of foot-taiyang from Dazhu (BL 11) to Baihuanshu (BL 30) and those on the 2nd lateral line of the bladder meridian from Fufen (BL 41) to Zhibian (BL 54).

Zinc finger protein ZBTB17 controls cellular senescence via interacting with nuclear receptor RXRA and its downstream calcium signaling.

Cellular senescence is broadly known as a stable cell cycle arrest accompanied by a senescence-associated secretory phenotype (SASP). In the past decades, calcium signaling has emerged as a key mediator of cellular senescence. However, the transcriptional regulation of calcium signaling during cellular senescence remains partially understood. We have previously identified the nuclear receptor RXRA as a key senescence repressor through inhibiting the endoplasmic reticulum (ER) calcium release channel inositol 1,4,5-trisphosphate receptor, type 2 (ITPR2) mediated intracellular calcium signaling. Nevertheless, as a transcriptional recruiter, the mechanism by which RXRA inhibits ITPR2 during cellular senescence remains unclear. Here we identified the zinc finger protein ZBTB17 can interact with RXRA. Interestingly, knockdown of ZBTB17 induces a cascade of RXRA-dependent intracellular calcium signaling, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) accumulation, DNA damages, and ultimately cellular senescence. Moreover, the signaling and senescence phenotype induced by knocking down of ZBTB17 can also be abolished after silencing ITPR2. Altogether, our work provides a new mechanism controlling intracellular calcium signaling and cellular senescence and unveils novel insight toward the role of zinc finger proteins.

Pharmacological Activity of Matrine in Inhibiting Colon Cancer Cells VM Formation, Proliferation, and Invasion by Downregulating Claudin-9 Mediated EMT Process and MAPK Signaling Pathway.

Purpose: Matrine (Mat), the main active ingredient of traditional Chinese herbal plant Sophora flavescens Ait, has significant antitumor effects, but its pharmacological mechanism on colon cancer (CC) remains unclear. This study aimed to investigate the therapeutic effect of Mat on CC as well as the potential mechanism. Methods: The vasculogenic mimicry (VM) of CC cells was observed by three-dimensional (3D) Matrigel cell culture. Cell proliferation, apoptosis, migration, invasion, and actin filament integrity were detected by CCK8, flow cytometry, wound healing, Transwell and Phalloidin staining assays. qRT-PCR and Western blotting were applied to detect the expression of EMT factors. RNA-sequencing was conducted to screen differentially expressed genes (DEGs), and the GO and KEGG pathway enrichment analyses were performed. Then, the expression of the key MAPK pathway genes and the target gene Claudin-9 (Cldn9) were analyzed. RNA interference was used to silence Cldn9 expression, and the effects of Cldn9 silencing and simultaneous treatment with Mat on VM formation, proliferation, apoptosis, invasion, and migration were investigated. Finally, the expression of EMT factors and MAPK pathway key genes was detected. Results: CT26 cells formed the most typical VM structure. Mat disrupted the VM of CT26 cells, significantly suppressed their proliferation, migration, invasion, actin filament integrity, induced apoptosis, and inhibited EMT process. RNA-sequencing revealed 163 upregulated genes and 333 downregulated genes in Mat-treated CT26 cells, and the DEGs were significantly enriched in cell adhesion molecules and MAPK signaling pathways. Further confirmed that Mat significantly inhibited the phosphorylation levels of JNK and ERK, and the target gene Cldn9 was significantly upregulated in human CC tissues. Silencing Cldn9 markedly inhibited the VM, proliferative activity, invasiveness, and actin filament integrity of CT26 cells, blocked the EMT process, and downregulated the phosphorylation of JNK and ERK, whereas Mat intervention further strengthened the above trends. Conclusion: This study indicated that Mat may synergistically inhibit the EMT process and MAPK signaling pathway through downregulation Cldn9, thereby exerting pharmacological effects on inhibiting VM formation, proliferation, and invasion of CC cells.

Simple and Ultrasensitive Detection of Glioma-Related ctDNAs in Mice Serum by SERS-Based Catalytic Hairpin Assembly Signal Amplification Coupled with Magnetic Aggregation.

Purpose: Circulating tumor DNA (ctDNA) is more representative and accurate than biopsy and is also conducive to dynamic monitoring, facilitating accurate diagnosis and prognosis of glioma. Therefore, the present study aimed to establish and validate a novel amplified method for the detection of IDH1 R132H and BRAF V600E, which were associated with the genetic diagnosis of glioma. Patients and Methods: A dual-signal amplification method based on magnetic aggregation and catalytic hairpin assembly (CHA) was constructed for the simultaneous detection of ctDNAs. When target ctDNAs are present, the CHA reaction is initiated and leads to the assembly of Au-Ag nanoshuttles (Au-Ag NSs) onto magnetic beads (MBs). Further enrichment of MBs under an external magnetic field facilitated the dual-signal amplification of SERS. Results: The limit of detection (LOD) for IDH1 R132H and BRAF V600E in serum was as low as 6.01 aM and 5.48 aM. The reproducibility and selectivity of the proposed SERS analysis platform was satisfactory. Finally, the platform was applied to quantify IDH1 R132H and BRAF V600E in the serum of subcutaneous-tumor­bearing nude mice, and the results obtained by SERS were consistent with those from quantitative real-time polymerase chain reaction (qRT-PCR). Conclusion: The present study showed that the dual-signal amplification method is a simple and ultrasensitive strategy for gliomas-associated ctDNAs detection, which is crucial for early diagnosis and dynamic monitoring.

Exploring postmortem succession of rat intestinal microbiome for PMI based on machine learning algorithms and potential use for humans.

The microbial communities may undergo a meaningful successional change during the progress of decay and decomposition that could aid in determining the post-mortem interval (PMI). However, there are still challenges to applying microbiome-based evidence in law enforcement practice. In this study, we attempted to investigate the principles governing microbial community succession during decomposition of rat and human corpse, and explore their potential use for PMI of human cadavers. A controlled experiment was conducted to characterize temporal changes in microbial communities associated with rat corpses as they decomposed for 30 days. Obvious differences of microbial community structures were observed among different stages of decomposition, especially between decomposition of 0-7d and 9-30d. Thus, a two-layer model for PMI prediction was developed based on the succession of bacteria by combining classification and regression models using machine learning algorithms. Our results achieved 90.48% accuracy for discriminating groups of PMI 0-7d and 9-30d, and yielded a mean absolute error of 0.580d within 7d decomposition and 3.165d within 9-30d decomposition. Furthermore, samples from human cadavers were collected to gain the common succession of microbial community between rats and humans. Based on the 44 shared genera of rats and humans, a two-layer model of PMI was rebuilt to be applied for PMI prediction of human cadavers. Accurate estimates indicated a reproducible succession of gut microbes across rats and humans. Together these results suggest that microbial succession was predictable and can be developed into a forensic tool for estimating PMI.

Postmortem Interval Estimation Using Protein Chip Technology Combined with Multivariate Analysis Methods.

OBJECTIVES: To estimate postmortem interval (PMI) by analyzing the protein changes in skeletal muscle tissues with the protein chip technology combined with multivariate analysis methods. METHODS: Rats were sacrificed for cervical dislocation and placed at 16 ℃. Water-soluble proteins in skeletal muscles were extracted at 10 time points (0 d, 1 d, 2 d, 3 d, 4 d, 5 d, 6 d, 7 d, 8 d and 9 d) after death. Protein expression profile data with relative molecular mass of 14 000-230 000 were obtained. Principal component analysis (PCA) and orthogonal partial least squares (OPLS) were used for data analysis. Fisher discriminant model and back propagation (BP) neural network model were constructed to classify and preliminarily estimate the PMI. In addition, the protein expression profiles data of human skeletal muscles at different time points after death were collected, and the relationship between them and PMI was analyzed by heat map and cluster analysis. RESULTS: The protein peak of rat skeletal muscle changed with PMI. The result of PCA combined with OPLS discriminant analysis showed statistical significance in groups with different time points (P<0.05) except 6 d, 7 d and 8 d after death. By Fisher discriminant analysis, the accuracy of internal cross-validation was 71.4% and the accuracy of external validation was 66.7%. The BP neural network model classification and preliminary estimation results showed the accuracy of internal cross-validation was 98.2%, and the accuracy of external validation was 95.8%. There was a significant difference in protein expression between 4 d and 25 h after death by the cluster analysis of the human skeletal muscle samples. CONCLUSIONS: The protein chip technology can quickly, accurately and repeatedly obtain water-soluble protein expression profiles in rats' and human skeletal muscles with the relative molecular mass of 14 000-230 000 at different time points postmortem. The establishment of multiple PMI estimation models based on multivariate analysis can provide a new idea and method for PMI estimation.

Exenatide improves hypogonadism and attenuates inflammation in diabetic mice by modulating gut microbiota.

With the rising incidence of diabetes and its onset at a younger age, the impact on the male reproductive system has gradually gained attention. Exenatide is a glucagon-like peptide-1 receptor agonist effective in the treatment of diabetes. However, its role in diabetes-induced reproductive complications has rarely been reported. The study aimed to investigate the mechanism by which exenatide improved diabetic hypogonadism by regulating gut microbiota (GM) mediated inflammation. C57BL/6J mice were equally divided into normal control (NC), diabetic model control (DM) and exenatide-treated (Exe) groups. Testicular, pancreatic, colonic, and fecal samples were collected to assess microbiota, morphologic damage, and inflammation. Exenatide significantly reduced the fasting blood glucose (FBG) level in diabetic mice, increased the testosterone level, ameliorated the pathological morphological damage of islet, colon, and testes, and reduced the expression of pro-inflammatory factors, tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 in colon and testis. Furthermore, exenatide significantly reduced the abundance of some pathogenic bacteria, such as Streptococcaceae and Erysipelotrichaceae, and increased that of beneficial bacteria Akkermansia. Probiotics, such as Lactobacillus were negatively correlated with TNF-α, nuclear factor-kappa-B (NF-κB), IL-6, and FBG. Conditional pathogenic bacteria such as Escherichia/Shigella Streptococcus were positively correlated with TNF-α, NF-κB, IL-6, and FBG. The fecal bacteria transplantation experiment revealed that the abundance of pathogenic bacteria, Peptostreptococcaceae, significantly decreased from Exe group mice to pseudo-sterile diabetic mice, and the pathological damage to testes was also alleviated. These data suggested the protective effects of exenatide on male reproductive damage induced by diabetes by regulating GM.

Forensic identification of sudden cardiac death: a new approach combining metabolomics and machine learning.

The determination of sudden cardiac death (SCD) is one of the difficult tasks in the forensic practice, especially in the absence of specific morphological changes in the autopsies and histological investigations. In this study, we combined the metabolic characteristics from corpse specimens of cardiac blood and cardiac muscle to predict SCD. Firstly, ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UPLC-HRMS)-based untargeted metabolomics was applied to obtain the metabolomic profiles of the specimens, and 18 and 16 differential metabolites were identified in the cardiac blood and cardiac muscle from the corpses of those who died of SCD, respectively. Several possible metabolic pathways were proposed to explain these metabolic alterations, including the metabolism of energy, amino acids, and lipids. Then, we validated the capability of these combinations of differential metabolites to distinguish between SCD and non-SCD through multiple machine learning algorithms. The results showed that stacking model integrated differential metabolites featured from the specimens showed the best performance with 92.31% accuracy, 93.08% precision, 92.31% recall, 91.96% F1 score, and 0.92 AUC. Our results revealed that the SCD metabolic signature identified by metabolomics and ensemble learning in cardiac blood and cardiac muscle has potential in SCD post-mortem diagnosis and metabolic mechanism investigations.

A novel method for determining postmortem interval based on the metabolomics of multiple organs combined with ensemble learning techniques.

Determining postmortem interval (PMI) is one of the most challenging and essential endeavors in forensic science. Developments in PMI estimation can take advantage of machine learning techniques. Currently, applying an algorithm to obtain information on multiple organs and conducting joint analysis to accurately estimate PMI are still in the early stages. This study aimed to establish a multi-organ stacking model that estimates PMI by analyzing differential compounds of four organs in rats. In a total of 140 rats, skeletal muscle, liver, lung, and kidney tissue samples were collected at each time point after death. Ultra-performance liquid chromatography coupled with high-resolution mass spectrometry was used to determine the compound profiles of the samples. The original data were preprocessed using multivariate statistical analysis to determine discriminant compounds. In addition, three interrelated and increasingly complex patterns (single organ optimal model, single organ stacking model, multi-organ stacking model) were established to estimate PMI. The accuracy and generalized area under the receiver operating characteristic curve of the multi-organ stacking model were the highest at 93% and 0.96, respectively. Only 1 of the 14 external validation samples was misclassified by the multi-organ stacking model. The results demonstrate that the application of the multi-organ combination to the stacking algorithm is a potential forensic tool for the accurate estimation of PMI.

Application of Linear Regression Model of Gpnmb Gene in Rat Injury Time Estimation.

OBJECTIVES: To investigate the effects of injury time, postmortem interval (PMI) and postmortem storage temperature on mRNA expression of glycoprotein non-metastatic melanoma protein B (Gpnmb), and to establish a linear regression model between Gpnmb mRNA expression and injury time, to provide aimed at providing potential indexes for injury time estimation. METHODS: Test group SD rats were anesthetized and subjected to blunt contusion and randomly divided into 0 h, 4 h, 8 h, 12 h, 16 h, 20 h and 24 h groups after injury, with 18 rats in each group. After cervical dislocation, 6 rats in each group were collected and stored at 0 ℃, 16 ℃ and 26 ℃, respectively. The muscle tissue samples of quadriceps femoris injury were collected at 0 h, 12 h and 24 h postmortem at the same temperature. The grouping method and treatment method of the rats in the validation group were the same as above. The expression of Gpnmb mRNA in rat skeletal muscle was detected by RT-qPCR. The Pearson correlation coefficient was used to evaluate the correlation between Gpnmb mRNA expression and injury time, PMI, and postmortem storage temperature. SPSS 25.0 software was used to construct a linear regression model, and the validation group data was used for the back-substitution test. RESULTS: The expression of Gpnmb mRNA continued to increase with the prolongation of injury time, and the expression level was highly correlated with injury time (P<0.05), but had little correlation with PMI and postmortem storage temperature (P>0.05). The linear regression equation between injury time (y) and Gpnmb mRNA relative expression (x) was y=0.611 x+4.489. The back-substitution test proved that the prediction of the model was accurate. CONCLUSIONS: The expression of Gpnmb mRNA is almost not affected by the PMI and postmortem storage temperature, but is mainly related to the time of injury. Therefore, a linear regression model can be established to infer the time of injury.