With the deepening application of artificial intelligence (AI) technology in the field of medical devices, pre-trained models have increasingly become a crucial engine driving innovation in intelligent healthcare due to their efficiency, generalization capability, and transfer learning performance. However, potential risks associated with pre-trained models—such as issues related to source diversity and quality controllability —pose new challenges to the safety and effectiveness of AI-based medical devices. Against this background, the National Medical Products Administration (NMPA) released the sectoral standard YY/T 1833.5-2024 Artificial Intelligence Medical Devices—Quality Requirements and Evaluation-Part 5: Pre-trained Models in September 2024. This standard provides essential technical guidance and a regulatory framework for standardizing the application of pre-trained models in medical devices, marking a milestone in ensuring the safety and efficacy of AI-powered medical products. This article offers an in-depth interpretation and analysis of the standard's background, orientation, and key technical consideration. It elucidates specific requirements regarding documentation for pre-trained models, definitions of critical quality attributes, and conformity assessment pathways. Furthermore, the practical and far-reaching implications of the standard are discussed, including its role in enhancing quality assurance throughout the entire lifecycle of AI-based medical devices and guiding technological innovation and healthy development within the industry. Additionally, by dissecting the standard, this article aims to support the industry in conducting prudent evaluations during model selection phases, thereby reducing the application of low-quality and high-risk models.

Objective:To investigate the effects of blood pressure variability (BPV), serum reactive oxygen species (ROS) and superoxide dismutase (SOD) levels on cognitive function in patients with subcortical ischemic vascular disease (SIVD).Methods:A total of 133 patients with SIVD confirmed by craniocranial MRI admitted to Department of Neurology, Red Flag Hospital Affiliated to Mudanjiang Medical University from October 2021 to October 2022 were selected. According to Montreal Cognitive Assessment scores, they were divided into SIVD without cognitive impairment group (SIVD-NC group, n=39) and subcortical vascular cognitive impairment group (SVCI group, n=94); and 23 healthy volunteers with normal cognition who had normal brain MRI in the Physical Examination Center during the same period were chosen as control group. General data of all subjects and vascular risk factors in each group were collected, routine biochemical indexes of peripheral blood were detected, 24 h ambulatory blood pressure monitoring was performed, and serum ROS and SOD levels were detected by enzyme-linked immunosorbent assay. Statistical methods were used to analyze the risk factors for cognitive impairment, correlations of independent risk factors with cognitive function, and diagnostic value of risk factors in cognitive impairment in patients with SIVD. Results:(1) Compared with control group, SIVD-NC group had significantly increased percentages of patients with hypertension history or lacunar stroke history, and significantly increased hypersensitive C-reactive protein (hs-CRP) level ( P<0.05). Compared with control group and SIVD-NC group, patients in SVCI group had significantly older age, lower years of education, higher proportion of patients with lacunar stroke history, and increased hs-CRP level ( P<0.05). Compared with control group, SVCI group had significantly higher proportion of patients with hypertension history ( P<0.05). (2) SIVD-NC group had significantly higher ROS level than control group ( P<0.05); Compared with control group and SIVD-NC group, SVCI group had significantly increased ROS level ( P<0.05). (3) SIVD-NC group had significantly increased nighttime systolic blood pressure (nSBP) compared with control group ( P<0.05); SVCI group had significantly increased 24 h SBP, nSBP and nSBP-variable coefficient (CV) compared with control group and SIVD-NC group ( P<0.05). Compared with SIVD-NC group, SVCI group had significantly increased 24 h SBP-CV ( P<0.05). (4) The nSBP, nSBP-CV, serum hs-CRP and ROS, and lacunar stroke history were independent risk factors for cognitive impairment in SIVD patients ( OR=1.096, P<0.001, 95% CI: 1.042-1.154; OR=1.231, P=0.010, 95% CI: 1.050-1.443; OR=2.303, P=0.004, 95% CI: 1.311-4.039; OR=1.026, P<0.001, 95% CI: 1.014-1.039; OR=2.954, P=0.041, 95% CI: 1.045-8.348), and education level was a protective factor for that ( P<0.05). (5) Serum ROS and hs-CRP, nSBP, and nSBP-CV were negatively correlated with MoCA scores in SIVD patients ( r s=-0.336, P<0.001; r s=-0.503, P<0.001; r s=-0.204, P=0.018; r s=-0.309, P=0.001). (6) Serum ROS and hs-CRP, nSBP, and nSBP-CV had high diagnostic values in cognitive impairment in SIVD patients (areas under the curves: 0.874, 0.847, 0.804 and 0.702, P<0.05); combined diagnosis efficacy of multiple indexes was better (area under the curve: 0.948, P<0.05). Conclusion:Serum ROS and hs-CRP, nSBP and nSBP-CV are highly likely to be hemodynamic and serological monitoring indexes for screening of cognitive impairment in SIVD patients.

Objective To preliminarily study and establish a method for measurement of the transuranic nuclide ²⁴¹Am in fecal samples, and to provide technical support for internal radiation monitoring of staff. Methods Fecal samples were collected with a self-made stool sampler and treated with a self-made carbonization and ashing furnace. DGA resin was used to separate and purify ²⁴¹Am from fecal samples. With ²⁴³Am as the tracer, the orthogonal method was used for condition optimization. Results The optimum conditions for separation and purification were: the acidity of HNO₃ added into the column, 6 mol/L; column flow rate, 0.6 mL/min; and the volume of analytical solution,12 mL. The method based on inductively coupled plasma mass spectrometry showed a detection limit of 9.79×10⁻⁴ Bq for ²⁴¹Am in fecal samples, which was satisfactory and feasible. Conclusion This method fills the vacancy of ²⁴¹Am measurement in fecal samples to some extent, which is of practical significance for internal radiation monitoring and protection for analysts.

Ulcerative colitis(UC)is a chronic inflammatory bowel disease caused by many factors including colonic inflammation and microbiota dysbiosis.Previous studies have indicated that celastrol(CSR)has strong anti-inflammatory and immune-inhibitory effects.Here,we investigated the effects of CSR on colonic inflammation and mucosal immunity in an experimental colitis model,and addressed the mechanism by which CSR exerts the protective effects.We characterized the ther-apeutic effects and the potential mechanism of CSR on treating UC using histological staining,intestinal permeability assay,cytokine assay,flow cytometry,fecal microbiota transplantation(FMT),16S rRNA sequencing,untargeted metabolomics,and cell differentiation.CSR administra-tion significantly ameliorated the dextran sodium sulfate(DSS)-induced colitis in mice,which was evidenced by the recovered body weight and colon length as well as the decreased disease activity index(DAI)score and intestinal permeability.Meanwhile,CSR down-regulated the production of pro-inflammatory cytokines and up-regulated the amount of anti-inflammatory mediators at both mRNA and protein levels,and improved the balances of Treg/Thl and Treg/Th1 7 to maintain the colonic immune homeostasis.Notably,all the therapeutic effects were exerted in a gut microbiota-dependent manner.Furthermore,CSR treatment increased the gut microbiota diversity and changed the compositions of the gut microbiota and metabolites,which is probably associated with the gut microbiota-mediated protective effects.In conclusion,this study provides the strong evidence that CSR may be a promising therapeutic drug for UC.

Xylanase is a high-profile glycoside hydrolase with applications in brewing, feed, pharmacy and bioenergy industries, but most of xylanases are in active below 30 ℃. In order to obtain low temperature active xylanase, a xylanase gene, XYN11A, was cloned from Penicillium sp. L1 and expressed in Pichia pastoris GS115. After purification and enzyme assay, optimal pH and temperature were determined to be 3.5 to 4.0 and 55 ℃. This enzyme was stable at acid and neutral condition (pH 1.0 to 7.0) or under the treatment of 40 ℃ for 1 hour. This xylanase displayed strong resistance to all tested ions and chemicals. Noteworthily, XYN11A maintained a higher activity of 6 700 U/mg than a lot of GH11 xylanase, and demonstrated higher activity (24% to 58%) at lower temperature from 20 to 40 ℃. After beechwood xylan hydrolysis for 16 h, the hydrolysates consisted mainly of xylobiose, xylotriose and xylotetraose and barely of xylose, thus XYN11A could be used for the production of prebiotic xylooligosaccharide. Possessing the features of acidophilic, highly active at lower temperature and oligosaccharide production, XYN11A demonstrated great potential in food and feed industrials.

There are some common problems such as recurrent symptoms and poor compliance among patients with chronic diseases. Although scientific knowledge and skills have been learned from traditional health education, patients with chronic diseases cannot improve their life style continuously. At present, many researches abroad have proved that health coaching contributes to setting feasible goals and encourages continuously behavior change of patients. In China, health coaching is in the stage of becoming familiar with its scientific definition, intervention effect and application characteristics. And health coaching also needs evidences from high-level evidence-based studies. Along with continuous improvement of intervention techniques on health management, health coaching will get further development and standardization.

Objective To compare the curative effect and biomechanical performance of cannulated compression screw (CCS) and dynamic hip screw-blade (DHS-B) in the treatment of patients with femoral neck fracture.Methods Between February 2010 and February 2014,102 patients with femoral neck fracture were treated with CCS or DHS-B at our department.They were 54 males and 48 females,aged from 15 to 86 years.There were 30 subcapital fractures,51 transcervical ones and 21 base ones.CCS was used in 60 patients and DHS-B in 42.In-hospital data were collected retrospectively to compare the curative effects in 2 groups.Furthermore,femoral neck fracture models were established using 12 adult cadaveric femoral specimens.The 12 models were randomized into 2 equal groups (n =6).Group A was subjected to fixation by 3 CCSs and group B to fixation by DHS-B.The 2 groups were compared in terms of axial loading test,rotation test and destructive axial loading test.Results The operation time (59.4 ± 20.2 min),incision size (4.1 ±0.6 cm) and intraoperative blood loss (25.9 ±9.9 mL) in the CCS group were significantly less than those in the DHS-B group (88.6±22.9 min,12.1 ±1.2cmand 156.7±107.1 mL) (P ＜0.05).The Harris hip score for the DHS-B group (91.9±9.8) was significantly higher than that for the CCS group (87.2 ± 9.2) (P ＜ 0.05).There were no significant differences between the 2 groups in hospital stay,partial weight-bearing time,or postoperative complications (P ＞ 0.05).At 500 N vertical loading,the stress values at both medial and lateral sides of the femur in group A were significantly smaller than those in group B (P ＜ 0.05).There were no significant differences between groups A and B in the average sinking displacement of femoral head or the torque at a torsion angle of 6° (P ＞ 0.05).The maximum load in group A (2,135 ±120 N) was significantly smaller than that in group B (2,986 ± 98 N) (P ＜ 0.05).Conclusion In treatment of femoral neck fracture,DHS-B fixation is obviously superior to CCS fixation,because the former is in better agreement with the femoral biomechanical property,and performs better in anti-rotation and anti-compression,leading to better functional recovery of the affected hip.

Objective:To investigate the expression and significance of Gab 2 in colorectal cancer tissues .Methods:Immuno-histochemistry was used to detect the expression of Gab 2 in 78 cases of colorectal cancer tissues and 46 cases of the adjacent tissues and to analyze the association of Gab2 expression with the clinicopathologic features of colorectal cancer;The expression of Gab2 in samples from 10 cases of colorectal cancer tissues and matched adjacent nontumorous tissues was detected by Western blot .Results: The results of immunohistochemistry demonstrated that the Gab 2 protein positive expression rate in 78 cases of colorectal cancer was 53.85%;whereas was negative expression or weak in the adjacent tissues , showing a significant difference of comparison within this result (P<0.001) .The expression of Gab2 in colorectal cancer was related with TNM stage and lymph node metastasis (P<0.05) , but no relation with the size and differentiation of tumor (P>0.05) .Western blot showed that the Gab2 protein expression of colorectal cancer cases was significantly higher than that of matched adjacent nontumorous tissues ( P<0.05 ).Conclusion: Gab2 was overexpressed in colorectal cancer .Gab2 maybe play an important role in carcinogenesis and progression of colorectal carcinoma .

Objective To explore the expression level of Tim-3,the marker of activated T_H 1 cells.in T lymphocytes in different sites from recipients with acute rejection.Methods The model of cervical heterotopic heart transplantation was established in mice Two groups were get up:the isograft group(C57BL/6→C57BL/6) and the allograft group (Balb/c→C57BL/6).Lymphocytes were isolated from peripheral blood,spleens,draining lymph nodes and grafts 3 or 6 days after transplantation.The expression of TIM-3 in CD4~+ and CD8~+ T subsets was detected by flow cytometry.Results There was no significant difference in Tim-3~+/CD4~+ and Tim-3~+/CD8~+ ratio in peripheral blood or spleens between two groups.As compared with the isograft group,the proportion of Tirn-3~+/CD4~+ cells was slightly elevated in draining lymph node(P<0.05),but the percentage of Tim-3~+/CD4~+ cells had no significant change between 3 days and 6 days in the allograft group(P>0.05).The expression of Tim-3 in CD4~+ and CD8~+ of graft infiltrating T cells was obviously increased in allograft group(P<0.01),and it was significantly (P<0.01) up-regulated on the 6th day as compared with that on the 3rd day.Conclusion The dynamic changes of Tim-3 expression in T lymphocytes in draining lymph node and graft were correlated with the progresston oi acute rejection in mice.

To identify acute renal allograft rejection biomarkers in human serum, two-dimensional differential in-gel electrophoresis (2-D DIGE) and reversed phase high-performance liquid chromatography (RP-HPLC) followed by electrospray ionization mass spectrometry (ESI-MS) were used. Serum samples from renal allograft patients and normal volunteers were divided into three groups: acute rejection (AR), stable renal function (SRF) and normal volunteer (N). Serum samples were firstly processed using Multiple Affinity Removal Column to selectively remove the highest abundance proteins. Differentially expressed proteins were analyzed using 2-D DIGE. These differential protein spots were excised, digested by trypsin, and identified by RP-HPLC-ESI/MS. Twenty-two differentially expressed proteins were identified in serum from AR group. These proteins included complement C9 precursor, apolipoprotein A-IV precursor, vitamin D-binding protein precursor, beta-2-glycoprotein 1 precursor, etc. Vitamin D-binding protein, one of these proteins, was confirmed by ELISA in the independent set of serum samples. In conclusion, the differentially expressed proteins as serum biomarker candidates may provide the basis of acute rejection noninvasive diagnosis. Confirmed vitamin D-binding protein may be one of serum biomarkers of acute rejection. Furthermore, it may provide great insights into understanding the mechanisms and potential treatment strategy of acute rejection.