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 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: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.

Lipopolysaccharides (LPS) are major outer membrane components of Gram-negative bacteria. Unlike most Gram-negative bacteria, Acinetobacter baumannii can still survive and acquire polymyxin resistance after complete loss of LPS. Previous studies of LPS-deficient Acinetobacter baumannii mostly focused on LPS-deficient strains induced by polymyxin, whose background was complex and unstable. To investigate LPS loss-mediated polymyxin resistant-Acinetobacter baumannii, this study constructed a stable and clear background LPS-deficient strain by knocking out lpxC gene in Acinetobacter baumannii ATCC 19606 with CIRSPR/Cas9, and then studied the phenotypic changes of the lpxC-deficient strain including morphology, growth rate, antibiotic susceptibility, virulence, membrane permeability, and membrane potential. Animal experiments were approved by the Animal Care and Welfare Committee Institute of Medicinal Biotechnology, CAMS and PUMC (approval number: IMB-20240119D₉). The results indicated that the lpxC gene of Acinetobacter baumannii ATCC 19606 was successfully knocked out. After losing the lpxC, the strain underwent the morphological change from rod-shaped to spherical. Furthermore, it leads to reduced growth rate, enhanced membrane permeability, decreased membrane potential, lower virulence, and increased antibiotic susceptibility to β-lactams, quinolones, aminoglycosides, macrolides, glycopeptides. The lpxC deletion results in significant changes in membrane homeostasis and adaptability of Acinetobacter baumannii. Understanding the phenotypic changes of colistin-resistant Acinetobacter baumannii mediated by LPS loss is useful for exploring the resistance mechanism of Acinetobacter baumannii and developing new therapeutic strategies.

Objective:To investigate the influence of changes in the cognitive load of anesthesia residents on the teaching effectiveness of high-fidelity scenario simulation.Methods:Eighty-seven anesthesia residents in a grade-A tertiary hospital from February to November 2022 were divided into groups A, B, and C according to the random number method. Three cases were selected from the anesthesia crisis resource teaching case library for high-fidelity simulation training for the three groups, respectively, using the crossover design to control the order of the cases. Each round of training consisted of pre-training instruction, simulation teaching, and post-training summarization and analysis. After three rounds of simulation teaching, cognitive load, anxiety status, test scores, and non-technical skills were evaluated for all the study participants. SPSS 20.0 was used to perform analysis of variance with repeated measures and Pearson's correlation analysis.Results:All the three groups showed significantly higher cognitive load and anxiety scores during the first-round simulation training than during the second-round and third-round simulation trianing. The test scores were significantly lower in the first round [(87.07±5.66), (88.38±5.41), (89.07±6.17)] than in the second round [(95.69±2.29), (96.10±2.08), (96.07±2.60)] and the third round [(96.34±1.45), (96.38±1.50), (96.17±1.73); all P<0.05]. The non-technical skill scores were also significantly lower in the first round [(37.24±7.58), (38.69±7.27), (39.24±8.74)] than in the second round [(46.17±5.55), (47.07±5.59), (47.59±6.74)] and the third round [(47.17±5.21), (48.48±5.38), (48.24±6.83); all P<0.05]. For simulations with the same cases, the trainees showed significantly higher cognitive load and anxiety scores and significantly lower test scores and non-technical skill scores in the first round than in the second and third rounds ( P<0.05). Conclusions:Anesthesia residents have higher levels of cognitive load and anxiety in the first scenario simulation training, which can reduce learning outcomes, and repeated simulation training can reduce trainees' cognitive load and anxiety.

Heterotypic cell-in-cell structures(heCICs)mediate unique non-autonomous cell death,which are widely involved in a variety of important pathological processes,such as tumorigenesis,pro-gression and clinical prognosis.Methylenetetrahydrofolata dehydrogenase 2(MTHFD2),one of the key enzymes of one-carbon metabolism,is highly expressed in a variety of tumor cells.In this study,in order to investigate the effect of MTHFD2 on the formation of heCICs,liver cancer cells and immune cells were first labeled separately by live cell dyes,and the heCIC model was established by using fluorescence mi-croscopy for cell imaging and analysis.After transiently knocking down MTHFD2 in cells by RNAi,we found that the ability of PLC/PRF/5 and Hep3B to form heCICs with immune cells was significantly in-creased(all P＜0.01).MTHFD2 recombinant expression plasmid was constructed by the homologous re-combination method,and MTHFD2 overexpression cell lines were further constructed.Then,the effect of MTHFD2 overexpression on the ability to form heCICs was detected by co-culturing the overexpression cell lines with immune cells.The results showed that the rate of heCIC formation was significantly re-duced after overexpression of MTHFD2(all P＜0.001).In conclusion,this study demonstrated that MTHFD2 is a negative regulator of heCIC formation,providing a research basis for targeting MTHFD2 to promote heCIC formation and enhance the in-cell killing of immune cells.

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.

Humans ; Neoplasms, Second Primary/epidemiology* ; Neoplasms/epidemiology* ; Risk Factors ; Prognosis

Radiotherapy is widely used in the management of advanced colorectal cancer (CRC). However, the clinical efficacy is limited by the safe irradiated dose. Sensitizing tumor cells to radiotherapy via interrupting DNA repair is a promising approach to conquering the limitation. The BRCA1-BARD1 complex has been demonstrated to play a critical role in homologous recombination (HR) DSB repair, and its functions may be affected by HERC2 or BAP1. Accumulated evidence illustrates that the ubiquitination-deubiquitination balance is involved in these processes; however, the precise mechanism for the cross-talk among these proteins in HR repair following radiation hasn't been defined. Through activity-based profiling, we identified PT33 as an active entity for HR repair suppression. Subsequently, we revealed that BAP1 serves as a novel molecular target of PT33 via a CRISPR-based deubiquitinase screen. Mechanistically, pharmacological covalent inhibition of BAP1 with PT33 recruits HERC2 to compete with BARD1 for BRCA1 interaction, interrupting HR repair. Consequently, PT33 treatment can substantially enhance the sensitivity of CRC cells to radiotherapy in vitro and in vivo. Overall, these findings provide a mechanistic basis for PT33-induced HR suppression and may guide an effective strategy to improve therapeutic gain.