ObjectiveThe rapid advancement of bioanalytical technologies has heightened the demand for high-throughput, label-free, and real-time cellular analysis. Electrochemical impedance spectroscopy (EIS) operating in the GHz frequency range (GHz-EIS) has emerged as a promising tool for characterizing cell suspensions due to its ability to rapidly and non-invasively capture the dielectric properties of cells and their microenvironment. Although GHz-EIS enables rapid and label-free detection of cell suspensions, significant challenges remain in interpreting GHz impedance data for complex samples, limiting the broader application of this technique in cellular research. To address these challenges, this study presents a novel method that integrates GHz-EIS with deep learning algorithms, aiming to improve the precision of cell suspension concentration identification and quantification. This method provides a more efficient and accurate solution for the analysis of GHz impedance data. MethodsThe proposed method comprises two key components: dielectric property dataset construction and backpropagation (BP) neural network modeling. Yeast cell suspensions at varying concentrations were prepared and separately introduced into a coaxial sensor for impedance measurement. The dielectric properties of these suspensions were extracted using a GHz-EIS dielectric property extraction method applied to the measured impedance data. A dielectric properties dataset incorporating concentration labels was subsequently established and divided into training and testing subsets. A BP neural network model employing specific activation functions (ReLU and Leaky ReLU) was then designed. The model was trained and tested using the constructed dataset, and optimal model parameters were obtained through this process. This BP neural network enables automated extraction and analytical processing of dielectric properties, facilitating precise recognition of cell suspension concentrations through data-driven training. ResultsThrough comparative analysis with conventional centrifugal methods, the recognized concentration values of cell suspensions showed high consistency, with relative errors consistently below 5%. Notably, high-concentration samples exhibited even smaller deviations, further validating the precision and reliability of the proposed methodology. To benchmark the recognition performance against different algorithms, two typical approaches—support vector machines (SVM) and K-nearest neighbor (KNN)—were selected for comparison. The proposed method demonstrated superior performance in quantifying cell concentrations. Specifically, the BP neural network achieved a mean absolute percentage error (MAPE) of 2.06% and an R² value of 0.997 across the entire concentration range, demonstrating both high predictive accuracy and excellent model fit. ConclusionThis study demonstrates that the proposed method enables accurate and rapid determination of unknown sample concentrations. By combining GHz-EIS with BP neural network algorithms, efficient identification of cell concentrations is achieved, laying the foundation for the development of a convenient online cell analysis platform and showing significant application prospects. Compared to typical recognition approaches, the proposed method exhibits superior capabilities in recognizing cell suspension concentrations. Furthermore, this methodology not only accelerates research in cell biology and precision medicine but also paves the way for future EIS biosensors capable of intelligent, adaptive analysis in dynamic biological research.

Nine compounds were isolated and purified from 90% ethanol extract of Alstonia mairei Lévl by using various chromatographic methods, including silica gel, SephadexLH-20, MCI Gel and ODS column chromatography, combined with semi-preparative liquid phase separation methods. Modern spectroscopic methods (1D and 2D NMR, UV, IR, MS, etc.) were used to identify the structures of the isolated compounds. They were identified as mairoside A (1), 3′,6-di-O-sinaloylsucrose (2), myristic acid (3), methyl myristate (4), ethyl myristate (5), 3,4,5-trimethoxycinnamic acid (6), 3,4,5-trimethoxybenzoic acid (7), vinoline (8), kaempferol-3-O-rutinoside (9), among which compound 1 is a new glycoside, compounds 4 and 5 are new natural products, and the nuclear magnetic data of compound 4 were reported for the first time.

Objective To compare the effectiveness of TiRobot assisted F screw technique and inverted triangle parallel nail internal fixation in the treatment of unstable femoral neck fractures.Methods A retrospective analysis was conducted on 72 patients with unstable femoral neck fractures who were treated with percutaneous cannulated screw fixation assisted with TiRobot Orthopaedic robot from December 2019 to April 2021.Among them,37 patients were treated with F screw internal fixa-tion,including 16 males and 21 females,aged47 to 64years old with an average of(53.87±5.28)years old;According to Pauwels classification,there were 1 case of type Ⅰ,19 cases of type Ⅱ,17 cases of type Ⅲ;8 cases of combined medical diseases;17 cases of falling,8 cases of traffic accident and 12 cases of falling from height;The time from injury to operation was 29 to 49 hours with average of(35.00±7.34)hours.Another 35 cases used internal fixation with an inverted triangle parallel nail,including 13 males and 22 females with an average age of 46 to 63 years old(52.36±5.05)years old;According to the Pauwels injury classifi-cation:there were 2 cases of type Ⅰ,21 cases of type Ⅱ,12 cases of type Ⅲ;6 cases of medical diseases,15 cases of falling in-jury,9 cases of traffic accident,11 cases of falling injury;The time from injury to operation was 30 to 45 hours with an average of(33.00±6.83)h.The intraoperative blood loss,operation time,intraoperative fluoroscopy times,follow-up time,fracture healing time,postoperative complications were observed and compared between the two groups.The hip joint function was e-valuated by Harris score at 6 months and 12 months after operation.Results There was no significant difference in operation time,intraoperative blood loss,intraoperative fluoroscopy times and other intraoperative data between two groups(P＞0.05).Both groups were followed up regularly,and the follow-up time was 12 to 16 months.The fracture healing time and Harris score of the F screw internal fixation group were better than those of the inverted triangle parallel nail internal fixation group(P＜0.05).There was 1 case of femoral neck shortening in the F screw internal fixation group,1 case of nonunion,1 case of nail withdrawal,and 1 case of lower extremity deep vein thrombosis in the inverted triangle internal fixation group.The incidence of complications in the F screw internal fixation group was lower than that in the inverted triangle parallel nail internal fixation group(P＜0.05).Conclusion Percutaneous cannulated F screw technique using Tirobot navigation positioning system is a safe and effective treatment for patients with unstable femoral neck fractures.It can significantly shorten the fracture healing time,reduce the incidence of postoperative complications,significantly improve hip joint function,and improve the quality of life.

Mitral annular calcification(MAC)is an age-related,chronic,degenerative change in localized fibrous support structures,and current research suggests that it is a process similar to the active onset of atherosclerosis and aortic valve calcification,both of which are accompanied by the deposition of lipoprotein(α)[Lp(α)]and the formation of chronic inflammatory foci.Among them,Lp(α)is the hot spot of research.In recent years,the relationship between Lp(α)and aortic valve calcification has received extensive attention.A large number of studies have demonstrated that elevated Lp(α)and its associated oxidized phospholipids(OxPL)can promote aortic valve calcification and stenosis through multiple calcium-regulated pathways,but the pathophysiological process of MAC is much more complex and unclear,and there has been a preliminary exploration of the relationship between Lp(α)and MAC.To make the current relationship between the two clearer,and thus provide new possibilities for preventing or delaying MAC,the paper will review the three aspects of MAC,Lp(α),and the research progress between the two.

Objective:To change the current situation that immune molecules presented only by schematic diagram or static model in the textbook of Medical Immunology,and to present the specific and vivid molecular morphology and functions to students.And set up corresponding elective course to let students personally explore the structure and function of immune molecules.Methods:On one hand,the teaching team applied the molecular simulation technology of scientific research to the production of teaching materi-als for the specific morphology,structural characteristics and functions of immune molecules,which were used in the teaching of medi-cal immunology for medical undergraduates majoring in clinical,oral and preventive medicine.On the other hand,a related elective course research on the love of molecule was opened to give students the opportunity to operate relevant software by themselves and learn the structure and function of immune molecules.Results:The application of molecular simulation in teaching improved teachers'teaching ability,strengthened teachers'immunology knowledge,enhanced the interaction between teachers and students,and achieved good teaching results.Conclusion:It is feasible to apply molecular simulation technology to medical immunology teaching for undergraduates,which can improve the teaching quality.

Objective:To investigate the clinical efficacy and safety of ixazomib-containing regimens in the treatment of patients with multiple myeloma(MM).Methods:A retrospective analysis was performed on the clinical efficacy and adverse reactions of 32 MM patients treated with a combined regimen containing ixazomib in the Hematology Department of the First People's Hospital of Lianyungang from January 2020 to February 2022.Among the 32 patients,15 patients were relapsed and refractory multiple myeloma(R/RMM)(R/RMM group),17 patients who responded to bortezomib induction therapy but converted to ixazomib-containing regimen due to adverse events(AE)or other reasons(conversion treatment group).The treatment included IPD regimen(ixazomib+pomalidomide+dexamethasone),IRD regimen(ixazomib+lenalidomide+dexamethasone),ICD regimen(ixazomib+cyclophosphamide+dexamethasone),ID regimen(ixazomib+dexamethasone).Results:Of 15 R/RMM patients,overall response rate(ORR)was 53.3％(8/15),among them,1 achieved complete response(CR),2 achieved very good partial response(VGPR)and 5 achieved partial response(PR).The ORR of the IPD,IRD,ICD and ID regimen group were 100％(3/3),42.9％(3/7),33.3％(1/3),50％(1/2),respectively,there was no statistically significant difference in ORR between four groups(x2=3.375,P=0.452).The ORR of patients was 50％after first-line therapy,42.9％after second line therapy,60％after third line therapy or more,with no statistically significant difference among them(x2=2.164,P=0.730).In conversion treatment group,ORR was 88.2％(15/17),among them,6 patients achieved CR,5 patients achieved VGPR and 4 patients achieved PR.There was no statistically significant difference in ORR between the IPD(100％,3/3),IRD(100％,6/6),ICD(100％,3/3)and ID(60％,3/5)regimen groups(x2=3.737,P=0.184).The median progression-free survival(PFS)time of R/RMM patients was 9 months(95％CI:6.6-11.4 months),the median overall survival(OS)time was 18 months(95％CI:11.8-24.4 months).The median PFS time of conversion treatment group was 15 months(95％CI:7.3-22.7 months),the median OS time not reached.A total of 10 patients suffered grade 3-4 adverse event(AE).The common hematological toxicities were leukocytopenia,anemia,thrombocytopenia.The common non-hematological toxicities were gastrointestinal symptoms(diarrhea,nausea and vomit),peripheral neuropathy,fatigue and infections.Grade 1-2 peripheral neurotoxicity occurred in 7 patients.Conclusion:The ixazomib-based chemotherapy regimens are safe and effective in R/RMM therapy,particularly for conversion patients who are effective for bortezomib therapy.The AE was manageable and safe.

Objective To compare regional pulmonary ventilation and perfusion and ventilation/perfusion(V/Q)matching in different body positions using electrical impedance tomography(EIT).Methods Ten healthy experimental pigs were selected to collect their EIT lung ventilation and perfusion data in supine,prone,left lateral and right lateral positions.The EIT data underwent analysis and image reconstruction using MATLAB R2022b and EIDORS v3.9.The effective regions with ventilation and perfusion were determined and the V/Q matching regions were computed with the maximum pixel value 20％as the threshold.Comparisons were carried out over the V/Q matching indexes including V/Q match％,dead space％and shunt％and ventilation and perfusion distribution in regions of interest(ROIs)including ROI1,ROI2,ROI3 and ROI4 in different body positions.Results The differences in V/Q match％,dead space％and shunt％of the experimental animals in varied positions were not statistically significant(P＞0.05).The regional distribution of pulmonary ventilation and perfusion changed in different positions,and the regional distributions differed in ROIl,ROI2 and ROI3 for ventilation(P＜0.05)and in ROI1 and ROI2 for perfusion(P＜0.05).The ventilation and perfusion regions were distributed consistently with the gravity-dependent areas in supine and prone positions whereas conversely in the right and left lateral positions.Conclusion The V/Q matching indexes of one subject have high test consistency in different body positions;gravity-dependent areas varied with the changes of the body positions,which affected the distribution of pulmonary ventilation and perfusion regions;EIT can be used for measuring the changed pulmonary ventilation and perfusion due to different positions and determining the influences of position changes on pulmonary ventilation and perfusion and V/Q matching.[Chinese Medical Equipment Journal,2024,45(5):1-7]

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.

Objective:To explore the value of the imaging nomogram model based on preoperative CT features of patients with small intestinal stromal tumor (SIST) in predicting pathological risk classification.Methods:This was a cohort study. The patients who were diagnosed as primary SIST by postoperative pathology in Cancer Hospital, Chinese Academy of Medical Sciences from January 2014 to October 2023 were retrospectively included. According to the modified 2008 National Institutes of Health classification criteria, the patients were divided into a pathological intermediate/high-risk group (86 cases) and a very low/low-risk group (56 cases). The features of preoperative enhanced CT images of SIST were analyzed, including tumor boundary, necrosis, intra-tumoral hemorrhage, intra-tumoral calcification, growth pattern, enhancement pattern, enhancement degree, enlarged vessels feeding or draining the mass (EVFDM), and tumor location. Patients were followed up to determine the recurrence-free survival (RFS). Univariate and multivariate logistic regression were used to screen the independent predictors of SIST with pathological medium/high-risk group. The independent predictors were combined to construct an imaging prediction model, and a nomogram was drawn. The receiver operating characteristic curve was used to evaluate the predictive efficacy of the model. The Kaplan-Meier method was used to draw the survival curve, and the log-rank test was used to compare the differences in RFS.Results:Univariate logistic regression results showed that tumor shape, necrosis, intra-tumoral hemorrhage, EVFDM, and tumor location were potentially related to medium/high-risk SIST. Multivariate logistic regression results showed that tumor shape ( OR=3.92, 95% CI 1.58-9.71, P=0.003), necrosis ( OR=4.60, 95% CI 1.91-11.09, P<0.001), and EVFDM ( OR=6.25,95% CI 1.74-22.47, P=0.005) were independent predictors of pathological intermediate/high-risk SIST. The area under the curve of the imaging predictive model combining the three predictors to predict the intermediate/high-risk SIST was 0.835 (95% CI 0.769-0.901), the sensitivity was 0.810, the specificity was 0.839, and the accuracy was 0.789. Taking the cut-off value (0.810) as the boundary value, the patients were divided into the high-risk group (74 cases) and the low-risk group (68 cases) according to the prediction results. The median RFS of the predicted high-risk group was poorer than that of the predicted low-risk group, and the difference was statistically significant ( χ2=5.20, P=0.023). Conclusions:The imaging nomogram model based on preoperative CT image features shape, necrosis, and EVFDM can effectively predict the pathological intermediate/high-risk SIST before surgery and has important predictive value for postoperative recurrence.

Objective To analyze the characteristics of adult anomalous aortic origin of coronary artery(AAOCA)and the causes of missed diagnosis by transthoracic echocardiography(TTE)so as to facilitate TTE in diagnosing adult AAOCA.Methods A total of 37 adult patients with AAOCA diagnosed by non-invasive coronary CT angiography(CCTA)and/or invasive coronary angiography(ICA)were selected as research samples at some hospital from January 2019 to December 2022,and their clinical symptoms and the findings of 12-lead electrocardiogram,cardiac enzymes and TTE were summarized;the patients were typed according to the site of origin of coronary artery anomalies,and the causes for the missed diagnosis of TTE were eplored.Chi-square test was used to compare the differences in TTE missed diagnoses.Results Of the 37 patients,31 ones had no or only mild symptoms;most ones had negative results in terms of 12-lead electrocardiography,cardiac enzymes,changes in the size of the cardiac chambers,segmental ventricular wall motion abnormalities and left ventricular systolic function.The patients with anomalous origin of the right coronary artery from left sinus(ARCA-L)gained the largest proportion of 59.45％(22/37);21 patients were diagnosed with anomalous origin of coronary artery arising from the opposite sinus(ACAOS)in the two examinations of TTE,of whom there were 19 cases of ARCA-L,and the detection rate of ACAOS by TTE was 87.5％;all the 13 patients origins in branches and high-grade openings were missed by TTE.The detection rate of ACAOS by TTE was significantly higher than that of coronary artery anomalies originating in branches and in high openings,and the difference was statistically significant(21/24 vs 0/13,P＜0.001).Conclusion Most adult AAOCA patients lack specificity in symptoms and related examination results.TTE has a high detection rate of ACAOS,while it is easy to miss the diagnosis of coronary artery anomalies originating from branches and high openings.Ultrasonographers have to identify false negative AAOCA by multi-section and multi-angle scanning and color Doppler flow imaging in order to reduce the rate of missed diagnosis.[Chinese Medical Equipment Journal,2024,45(1):71-75]