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.

Objective:To enhance comprehension of undifferentiated embryonal sarcoma of the liver(UESL)in children by analyzing ultra-sound,CT,and MRI imaging features.Methods:A retrospective analysis was conducted on 11 cases of UESL in children,confirmed through surgery and pathology,at the Children's Hospital,Affiliated Capital Institute of Pediatrics from December 2009 to December 2021.We ana-lyzed the ultrasound,CT,and MRI imaging features of all patients and summarized their characteristics.Results:All 11 cases presented with solitary hepatic masses ranging from 11.5 to 19.8 cm in diameter.Imaging manifestations of UESL correlated with component proportion and distribution within the masses.Lesions displayed clear boundaries in all cases.CT scans revealed mixed low density in 11 cases,with ir-regular floc soft tissue density shadows observed at the edge of cystic density areas or around partitions in a few cases.Ultrasound images of all six cases showed solid space-occupying masses,with varying sizes of anechoic regions within the solid mass.MRI T1WI showed mixed low intensity signal in three cases and strip/large high intensity signal areas in the lesion.T2WI revealed mixed high intensity signal and strip low intensity signal areas in 3 lesions.In the arterial phase,lesions displayed slightly to moderately heterogeneous strip/patch enhancement,primarily marginal enhancement in nine cases and thickened,tortuous arterial shadows in eight cases.In the delayed phase,lesions showed continuous uneven enhancement,with enhancement at the edge and peripheral-to-central filling observed in eight cases.Additionally,the enhancement range continuously increased in eight cases,with the false capsule sign identified in eight cases in the delayed stage.Conclu-sions:Imaging features of UESL in children exhibit distinct characteristics.Understanding these features,in conjunction with clinical findings,may aid in early diagnosis.

Objective:To explore the MR enterography (MRE) features of intestinal Behcet disease (BD) and Crohn disease (CD) in pediatric patients.Methods:This study was a cross-sectional study. The BD patients and CD patients were retrospectively enrolled from Children′s Hospital Affiliated to Capital Institute of Pediatrics from January 2019 to October 2022. There were 17 children with intestinal BD, including 6 males and 11 females, aged 5-12 (8.4±2.6) years, and 23 children with CD, including 15 males and 8 females, aged 7-15 (10.2±2.7) years. The MRE images were observed, and the evaluation contents included the diseased intestine (terminal ileum, ileum+ascending colon, ileum+ascending colon+transverse colon, whole colon), the form of intestinal wall thickening (uniform/eccentric thickening), MRI signal (fat suppression T 2WI, DWI), the enhancement mode (uniform/layered enhancement), intestinal stenosis, intestinal dilatation, mesentery comb sign, mesentery fatty fibrosis, lymph node enlargement, and the extraintestinal complication (anal fistula, fluid collection). The comparison of MRE signs between groups was performed using the χ2 test or Fisher exact test. Results:All children were completed MRE examination with good intestinal filling, and no adverse reactions. The significant differences were found in the scope of the diseased bowel, the form of intestinal wall thickening, DWI signal, intestinal dilatation, lymph node enlargement, anal fistula and fluid collection between the intestinal BD and CD patients ( P<0.05), while no significant differences were found in the fat suppression T 2WI signal, enhancement mode of the lesion, intestinal stenosis, mesentery comb sign, and mesentery fatty fibrosis ( P>0.05). Conclusion:MRE is safe and effective, and there are certain significantly different MRE features between children with intestinal BD and CD.

OBJECTIVE To investigate the HRCT and MRI characteristic of external auditory canal cholesteatoma(EACC)in children.METHODS A total of 40 patients(45 lesions)with EACC confirmed by pathology were retrospectively analyzed with HRCT and MRI characteristics and clinical therapeutic value.Imaging findings of 40 patients(45 lesions)with EACC were retrospectively analyzed.RESULTS Soft tissues were found in all the external auditory canal(EAC).Of the forty-five soft tissues,7 manifested as inhomogeneous strip soft tissues and 38 as lesions solid soft tissues;30 located in medial part of the EAC and covered the tympanic membrane,while the other 15 presented as tympanic membrane perforation and involved the tympanic cavity.The MRI of the 3 ears showed high signal on T2/T1 iso-intensity,high signal on DWI,and low signal on ADC.Normal whole bony EAC was observed in 17 cases and enlarged medial EAC in 28 cases.Seven cases only involved in the superior wall,but 38 cases displayed as multiple bone wall involved,of which 6 involved in circumferential walls.Thirty-three cases displayed atactic ear bone margin,11 displayed blunted or disappeared drum shield plate.Destroy of long crus of incus and manubrium mallei occurred in 15 cases,of short crus of incus in 8 cases,of stapes in 2 cases,and mastoiditis in 5 cases.According to the pneumatization degree of mastoid air cell,37 cases were classified into pneumatic type,7 cases into mixed type,and the last one into diploic type.CONCLUSION The children EACC tends to be limited and rarely involved in middle ear and mastoid process.No patient with peri-ear infection was found.Application of HRCT and MRI help accurate location and determination of cholesteatoma.According to the extent of the lesion,selecting the appropriate surgical method is an effective method to remove cholesteatoma,improve hearing and reduce recurrence.

Objective A simple,sensitive and rapid ultra high performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS)method was developed and validated for the determination of ertapenem in human plasma.Methods Using ertapenem-D4 as internal standard,the protein in plasma was precipitated with acetonitrile;chromatographic column:ACQUITY HSS T3(2.1 mm × 50.0 mm,1.8 μm);the mobile phase was 0.1％formic acid aqueous solution(containing 2 mmol·L-1 ammonium formate)-acetonitrile(0.1％formic acid),using a gradient elution;flow rate:0.4 mL·min-1,injection volume:1 μL,column temperature:45 ℃,the analysis time was 4.5 min,the scanning mode is positive ion selective reaction monitoring mode(SRM)with an electric spray ion source(ESI).The specificity,standard curve and lower limit of quantification,precision and recovery,matrix effect,dilution effect and stability were investigated.Results Ertapenem had a good linearity within 0.5-80.0μg·mL-1,and the standard curve was y=4.25 × 10-1x-2.64× 10-2(r2=0.999 0),the lower limit of quantification was 0.5 μg·mL-1,the relative standard deviation within and between batches is 1.39％-4.15％.The extraction recovery rate was 58.36％-64.57％,and the relative standard deviation of dilution effect was 3.30％,and the matrix effect was 99.71％-103.23％.The relative standard deviation of room temperature,repeated freeze-thaw,4 ℃,and long-term stability are all less than 10％.Conclusion The method is sensitive,rapid and specific,which is suitable for clinical monitoring of Ertapenem.

Objective:To explore the clinical outcomes of locking compression plating (LCP) in the treatment of periprosthetic fracture (PPF) of the distal femur in the aged patients.Methods:A retrospective study was performed to analyze the 31 aged patients who had been treated at Department of Orthopedic Surgery, The Affiliated Hospital to Nantong University for PPF of the distal femur with LCP between June 2012 and May 2023. There were 27 females and 4 males with an age of (80.2±6.1) years. According to the Unified Classification System (UCS), 18 PPFs were classified as type Ⅴ.3B1 and 6 PPFs as type Ⅴ.3B2 after total knee arthroplasty and 7 PPFs as type Ⅳ.3C after total hip arthroplasty. The patients were fixated with a lateral single plate in 25 cases, and with lateral and medial dual plates in 6 cases. The surgical time, intraoperative blood loss, hospitalization time, postoperative weight-bearing time, fracture healing time, and knee joint function and complications during follow-up were recorded.Results:For the 25 patients undergoing fixation with a lateral single plate, the surgical time was (58.7±7.9) minutes, the intraoperative blood loss (78.0±15.1) mL, the hospitalization time (6.9±1.6) days, the postoperative weight-bearing time (5.9±1.4) days, and the follow-up time 37 (15, 51) months. For the 6 patients undergoing fixation with lateral and medial dual plates, the surgical time was (186.6±9.8) minutes, the intraoperative blood loss (1,256.7±231.2) mL, the hospitalization time (17.8±3.3) days, the postoperative weight-bearing time (3.6±0.6) days, and the follow-up time 17 (16, 21) months. The fracture healing time was (14.9±2.0) and (18.7±2.6) weeks, respectively, for patients fixed with single and double steel plates. By the scoring criteria of the American Hospital for Special Surgery (HSS), the knee joint function was evaluated at the last follow-up as excellent in 10 cases and as good in 15 cases for the 25 patients undergoing fixation with a lateral single plate, and as good for all the 6 patients undergoing fixation with lateral and medial dual plates. No patient experienced such complications as incision infection, bone nonunion, or internal fixation failure during the follow-up period.Conclusions:LCP fixation can achieve satisfactory outcomes in the treatment of PPF of the distal femur in the aged patients. As fixation with a single lateral femoral plate is suitable for most of the aged patients with PPF of the distal femur, it can be used as the first choice. Fixation with dual plates can provide stronger stability, but its indications should be strictly controlled.

Purpose To explore the application value of computed tomography enterography(CTE)in differentiating active staging of pediatric Crohn disease.Materials and Methods The clinical data of 83 pediatric Crohn disease children performed by CTE examination and conducted with pediatric Crohn disease activity index(PCDAI)from January 2019 to October 2022 were selected.According to their different PCDAI scores,the patients were divided into four groups,which were remission stage(11 cases),mild activity period(47 cases),moderate activity period(14 cases)and severe activity period(11 cases),and the parameters of CTE were analyzed.Then the results associated with CTE and the stages of pediatric Crohn disease activity were analyzed.Results The CTE images of different clinical PCDAI activity stages were manifested in the scope of the diseased intestine(χ2=49.934),the enhancement mode of diseased intestinal wall(χ2=56.561),the degree of intestinal cavity stenosis(χ2=31.932),the degree of intestinal wall thickened(χ2=46.535),lymph node enlargement(χ2=17.330);in which there was a significantly difference(P<0.05),respectively.With the aggravation of PCDAI activity stages,the extent of diseased intestinal canal(more than 50 mm,31 cases,37.3%),the layered reinforcement of diseased intestinal wall(27 cases,32.5%),the luminal stenosis(less than 5 mm,19 cases,22.9%),the thickening of intestinal wall(more than 5.0 mm,54 cases,65.1%)were more common.The proportion of occurrence in the enlargement of lymph nodes(more than 7 mm,16 cases,19.3%)was high,with significant statistical significance(P<0.05).Spearman correlation analysis showed that there was a significant positive correlation between pediatric Crohn disease clinical activity stage(all P<0.01)and the extent of the lesion intestinal canal(r=0.500),the enhancement mode of the lesion intestinal wall(r=0.574),the luminal stenosis(r=0.316),the thickening of intestinal wall(r=0.533).Conclusion With the extent of diseased intestinal canal,the degree of the luminal stenosis,the enhancement mode of diseased intestinal wall and intestinal wall thickened increase,and the clinical stage gradually increase.The above four parameters use as characteristic indicators to reflect the activity stage of pediatric Crohn disease.

This study aims to investigate the mechanism of Linderae Radix water extract(LRWE) in the prevention and treatment of diarrhea-predominant irritable bowel syndrome(IBS-D) based on serum metabolomics. Eighteen 2-week-old male SD rats were randomized into control, IBS-D model, and LRWE groups. The rats in other groups except the control group received gavage of senna concentrate combined with restraint stress for the modeling of IBS-D. The rats in the LRWE group were administrated with LRWE(5.4 g·kg~(-1)) by gavage, and those in the control and IBS-D model groups with an equal volume of distilled water for a total of 14 days. The visceral sensitivity was evaluated by the abdominal withdrawal reflex(AWR) score, and the degree of diarrhea was assessed by the fecal water content(FWC). The morphological changes of the colon and the morphology and number of goblet cells were observed by hematoxylin-eosin(HE) and periodic acid-schiff(PAS) staining, respectively. Ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) was used for the screening of the potential biomarkers in the rat serum and their related metabolic pathways. The results showed that LRWE reduced the AWR score, decreased FWC, and alleviated visceral sensitivity and diarrhea symptoms in IBS-D rats. HE and PAS staining showed that LRWE mitigated low-grade intestinal inflammation and increased the number of mature secretory goblet cells in the colonic epithelium of IBS-D rats. A total of 25 potential biomarkers of LRWE in treating IBS-D were screened out in this study, which were mainly involved in riboflavin, tryptophan, glycine, serine and threonine metabolism, glyoxylate and dicarboxylate metabolism, and cysteine and methionine metabolism. The regulatory effects were the most significant on the riboflavin and tryptophan metabolism pathways. LRWE may alleviate the visceral hypersensitivity by promoting energy metabolism and amino acid metabolism, enhancing intestinal barrier function, and improving intestinal immune function in IBS-D rats.
Rats ; Male ; Animals ; Irritable Bowel Syndrome/metabolism* ; Water ; Chromatography, Liquid ; Tryptophan ; Rats, Sprague-Dawley ; Tandem Mass Spectrometry ; Diarrhea/drug therapy* ; Biomarkers ; Riboflavin

Objective:To assess the clinical outcome of patients with spinal tumors who received en bloc resection in our center and to provide theoretical basis for developing novel surgical technique in en bloc resection for spinal tumor.Methods:We retrospectively reviewed the clinical and follow-up data of 113 patients who received en bloc resection for spinal tumors in Musculoskeletal Tumor Center, Peking University People's Hospital from Jan. 2007 to Dec. 2021. There were 68 males and 45 females with an average age of 38.7±16.7 (10-79) years. Primary malignant spinal tumors, primary aggressive spinal tumors and solitary metastatic spinal tumors were diagnosed in 55, 27 and 31 patients, respectively. The surgeries were planned according to the surgical classification for en bloc resection for spinal tumors proposed by Boriani et al, which classified the en bloc resection for spinal tumor into 7 types. The general condition (gender, age, histological diagnosis, location of the lesion, number of involved vertebrae, pre-operative neurological function), surgical procedure (type of surgery, stage of surgery, reconstruction method for anterior structure, duration of surgery, intra-operative haemorrhage, surgical margin), peri- and post-operative complication (intra- and peri-operative complication, post-operative neurological function), and survival [overall survival (OS), recurrence-free survival (RFS) and implant survival (IS)] of patients were retrospectively analyzed.Results:All surgeries accomplished uneventfully except one intra-operative death owing to the haemorrhagic shock caused by injury of major blood vessel. Mean duration of surgery and volume of intra-operative haemorrhage was 517.6±267.4 min and 3802.7±3039.4 ml, respectively. R0 resection was achieved in 48 patients. Three patients died in peri-operative period. Intra- and peri-operative complications were identified in 44 patients (38.9%). 109 patients were followed up with a mean time of 39.4±35.2 months. 27 patients died during follow-up period. The average post-operative overall survival (OS) was 115.4[95% CI (97.9, 133.0)]months and the 5-year OS rate was 64.1%[95% CI (52.3%, 75.9%)]. In patients with primary malignant spinal tumors, the OS of patients with R2 resection was significantly poorer than that of patients with R0/R1 resection ( P=0.024); in patients with metastatic tumors, no difference of OS was observed in patients with different surgical margins ( P=0.612). There were 29 recurrences, and the mean RFS was 105.8 [95% CI (87.5, 124.1)] months. In patients with primary malignant and aggressive spinal tumors, the RFS of patients underwent R2 resection was significantly lower than that of patients underwent R0/R1 resection ( P=0.008, P=0.027); in patients with metastatic spinal tumors, no significant difference of RFS was found in patients with different surgical margin (P=0.707). Conclusion:Although en bloc resection for spinal tumors indicates high morbidity, it significantly improves the OS of patients with primary malignant spinal tumors and the local control of primary malignant and aggressive spinal tumors.

Objective:To investigate the combination of internal fixation for periprosthetic fractures of the proximal femur (PFFF) after hip arthroplasty.Methods:The data of 58 patients with periprosthetic fractures after hip arthroplasty from May 2008 to March 2022 were retrospectively analyzed, including 31 males and 27 females. The average age was 75.5±18.2 years (range, 35-95 years). There were 39 total hip arthroplasty and 19 hemiarthroplasty; 37 biological prosthesis and 21 cemented prosthesis. Intraoperative periprosthetic fractures occurred in 6 cases and 52 cases postoperatively. Unified classification system (UCS): UCS IV.3A1 type 2 cases, 3A2 type 1 case, 3B1.1 type 19 cases, 3B2.1 type 25 cases, 3B3 type 2 cases, 3C type 9 cases. Fracture site: 3 cases in zone A (greater trochanter), 46 cases in zone B (around the femoral stem), and 9 cases in zone C (distal to the tip of the femoral stem. Internal fixation is composed of primary and secondary fixation, the main fixation method was the cerclage of steel wire or titanium cable, locking compression plate, and locking attachment plate fixation. The secondary fixation method was the cerclage of titanium cable, which was required to cover three zones A, B and C to form an overall balanced fixation. The modified Harris hip scores (mHHS), plate length, working length and screw number of different internal fixation combinations were compared.Results:The follow-up time was 54.2±21.6 months (range, 11-86 months). All patients showed signs of fracture healing at 10.2±1.5 weeks (range, 7-13 weeks) after operation, and bony union was observed at 19.6±1.3 weeks (range, 17-22 weeks) after operation. No delayed union or nonunion was observed. After operation, one case had a stress fracture and was revised with double-plate internal fixation; one case had a failed internal fixation and was revised with double-plate internal fixation and a large allograft bone graft. The mHHS score of UCSIV.3B2.1 group (80.3±4.6) was the lowest at 6 months after operation, and the difference between the groups of different types was statistically significant ( F=256.72, P<0.001). The score of simple internal fixation group (91.6±4.2) was higher than that of revision combined with internal fixation group (81.9±4.1), and the difference was statistically significant ( t=8.32, P<0.001). The plate length and working length were 24.9±2.5 cm and 12.6±1.7 cm for UCS IV.3B1.1, 25.4±2.6 cm and 13.6±1.8 cm for 3B2.1 and 28.1±2.5 cm and 4.9±1.9 cm for 3C, respectively ( F=5.33, P=0.005; F=6.78, P<0.001). The number of screws in zone A was significant difference among different UCS types ( F=52.67, P<0.001); UCS IV.3B1.1 (6.5±2.3) and 3B2.1 (6.7±2.2) were more than 3B3 (3.5±1.5) and 3C (3.7±1.6). The number of screws in zone B was significant difference among different UCS types ( F=42.15, P<0.001); The number of UCS IV.3B1.1 (2.3±1.6) and 3B2.1 (2.8±1.9) were significantly more than that of 3B3 (1.0±0.5) and 3C (1.2±0.6). The number of screws in zone C was significant differences among different UCS types ( F=39.62, P<0.001); The number of UCS IV.3B1.1 (3.8±1.9) and 3B2.1 (3.9±1.7) were more than that of 3B3 (2.0±0.5), the difference was statistically significant ( P<0.05). Conclusion:The function of hip after simple internal fixation of proximal femoral periprosthetic fractures was better than that of those who underwent revision at the same time; the number of screws of UCSIV.B1 and B2 is more than that of B3.