1.Three-dimensional Electrical Impedance Tomography for Monitoring Gastric Hemorrhage
Zi-Han ZHAO ; Bo SUN ; Jing-Shi HUANG ; Zhi-Wei LI ; Yang WU ; Nan LI ; Jia-Feng YAO ; Tong ZHAO
Progress in Biochemistry and Biophysics 2026;53(4):1062-1075
ObjectiveGastric hemorrhage is one of the most common and life-threatening emergencies of the upper digestive tract. Early identification and continuous monitoring are essential for reducing rebleeding rates and mortality, particularly within the critical early hours after onset. Although endoscopy and radiological imaging can accurately localize bleeding sites, these approaches are invasive, resource-intensive, and unsuitable for continuous bedside monitoring. Electrical impedance tomography (EIT), as a noninvasive and radiation-free functional imaging technique, offers real-time visualization of conductivity distribution and has the potential for detecting intragastric bleeding based on the electrical contrast between blood and surrounding gastric tissues. In this study, a three-dimensional gastric EIT (3D-gEIT) framework is proposed to achieve noninvasive, real-time, and dynamic monitoring of gastric hemorrhage, with emphasis on spatial localization and quantitative volume assessment. MethodsA three-dimensional upper-abdominal simulation model incorporating the stomach, gastric wall, gastric contents, and surrounding tissues was established. Three electrode configurations, namely the dual layer ring, the four layer staggered ring, and the opposed dual plane array, were designed and systematically compared to evaluate their influence on depth sensitivity and spatial resolution. Based on the Tikhonov-Noser hybrid regularization scheme, a region-clustering constraint was introduced to develop the TK-Noser-RCC algorithm. This approach aggregates spatially adjacent elements with similar conductivity variations, thereby enhancing structural continuity and suppressing isolated noise artifacts. To validate the proposed framework, an upper-abdominal physical phantom was constructed using agar to simulate background tissue conductivity. Hemispherical high-conductivity inclusions with volumes ranging from 10 ml to 50 ml were attached to the inner gastric wall to mimic localized bleeding under different gastric filling states. Boundary voltages were acquired under a 120 kHz excitation current and reconstructed using the TK-Noser-RCC algorithm. Furthermore, an in vivo animal experiment was performed using a porcine model with adult-scale abdominal dimensions. A total of 100 ml of autologous blood was injected incrementally into the stomach to simulate progressive gastric hemorrhage, and time-difference EIT reconstruction was conducted at each injection stage to assess the dynamic system response under physiological conditions. ResultsSimulation results demonstrated that the opposed dual-plane electrode array achieved superior depth sensitivity distribution and spatial resolution. For a 40 ml hemorrhage model, the average ICC and SSIM improved by 55.9% and 38.8% compared with the dual-layer ring configuration, and by 64.0% and 39.5% compared with the four-layer staggered configuration. The proposed region-clustering constraint significantly enhanced reconstruction stability. Under added Gaussian noise of 40 dB and 30 dB, ICC values remained approximately 0.85, indicating effective artifact suppression and preservation of boundary integrity. In physical phantom experiments, reconstructed hemorrhage volumes increased approximately linearly with the preset hemispherical volumes, and the reconstructed high-conductivity regions closely matched the actual bleeding locations. Both empty-stomach and full-stomach conditions were evaluated, demonstrating that the opposed dual-plane configuration maintained stable imaging performance across varying gastric contents. In the animal experiment, reconstructed low-impedance regions expanded progressively with increasing injected blood volume. The spatial localization of the hemorrhage remained stable throughout the procedure, and no significant artifacts were observed. Quantitative analysis showed that reconstructed volume and average conductivity variation exhibited an approximately linear growth trend with injected blood volume, confirming the sensitivity of the system to dynamic intragastric conductivity changes. ConclusionThe proposed 3D-gEIT framework enables quantitative reconstruction of gastric hemorrhage volume and spatial distribution with improved depth sensitivity, structural continuity, and noise robustness compared with conventional EIT approaches. By integrating optimized electrode configuration and a region-clustering-constrained reconstruction algorithm, the system provides stable dynamic monitoring under both controlled phantom conditions and in vivo physiological environments. This method offers a noninvasive, real-time, and low-cost imaging strategy for early diagnosis, postoperative monitoring, and bedside surveillance of gastric bleeding.
2.Proteomic Preparation Techniques for Formalin-Fixed Paraffin-Embedded Tissue Samples
Ao LU ; Bo MENG ; Jia-Wei ZHAO ; Huan-Yue LIAO ; Zi-Hong YE ; Xiang FANG ; Yang ZHAO
Chinese Journal of Analytical Chemistry 2025;53(1):84-93,中插4-中插8
Twelve pre-processing protocols for formalin-fixed paraffin-embedded(FFPE)tissue samples were developed by orthogonal experimental design,incorporating different dewaxing buffers(Triton X-100 and xylene),lysis buffers(TFE and RapiGest),and enzyme digestion methods(iST,SP3,and FASP)to explore the optimal experimental conditions.These protocols were assessed based on protein and peptide identification depth,identification stability,and quantitative levels of protein abundance.The results indicated that Triton X-100 and xylene minimally impacted proteomics identification,whereas the TFE lysis buffer and iST digestion method significantly enhanced the proteomics analysis of FFPE samples.Considering the potential toxicity of xylene,the TTI protocol based on Triton X-100,TFE,and iST was determined to be the optimal choice.This protocol exhibited the best repeatability and stability,and a higher number of proteins associated with significant biological functions were identified.In conclusion,the established TTI protocol offered an efficient and comprehensive approach for proteomic analysis of FFPE samples,significantly enhancing the repeatability and stability of protein identification.
3.Study on Influence of Endogenous Derivatives on Chemical Sensing Performance of Carbon Dots
Ying-Xi QIN ; Yu WANG ; Li-Hua YANG ; Zi-Wei LIU ; Ai-Miao QIN ; Liang FENG
Chinese Journal of Analytical Chemistry 2025;53(1):94-103
The blue fluorescent carbon dots(TMCDs)and cyan fluorescent carbon dots(TMCDs-H2O)were synthesized fromm-phenylenediamine and tricarballylic acid through air-assisted melting polymerization and one-step hydrothermal method,respectively.Air purging could effectively inhibit the side reactions and reduce the derivative structures in the carbon dots product.The structure and morphology of these two materials were systematically characterized using liquid nuclear magnetic resonance spectroscopy(NMR),mass spectrometry(MS),and transmission electron microscopy.Compared to TMCDs-H2O((3.12±0.63)nm),TMCDs showed a smaller average particle size(approximately(1.85±0.02)nm).The NMR and MS analysis revealed that although the main structure of both types of carbon dots was similar,TMCDs exhibited a simpler structure with higher degree of polymerization.These results suggested that supramolecular interactions might introduce numerous small molecule derivatives into TMCDs-H2O particles,resulting in lower polymerization degree,multiple substructures,and larger particle size characteristics for this material.When employed as chemical sensors for metal ion detection,in the linear range of 1×10-5-5×10-4 mol/L,the detection limits of Fe3+by TMCDs and TMCDs-H2O were 3.3×10-6 mol/L and 3.8×10-6 mol/L,respectively.The experimental results demonstrated that the recoveries of CDs and inductively coupled plasma optical emission spectrometer(ICP-OES)were similarity,whereas TMCDs displayed a considerable relative standard deviation.This study demonstrated that endogenously derived structures in CDs could enhance the performance of metal ion sensing.
4.Fluorescence Method for Determination of Metolazone and Valsartan in Human Serum and Urine:A Comparison from Zero-order to Second-order Calibration Method
Zi-Wei DING ; Hai-Long WU ; Xiao-Zhi WANG ; Tong WANG ; Hao-Ran LIU
Chinese Journal of Analytical Chemistry 2025;53(2):224-234
A second-order calibration method combined with excitation-emission matrix(EEM)fluorescence spectroscopy was presented for simultaneous quantitative analysis of two anti-hypertensive drugs,metolazone(MET)and valsartan(VAL),in human serum and urine,and the quantitative results were compared with the results obtained by zero-and first-order calibration methods.The results indicated that the methods based on zero-and first-order calibration were inadequate for accurately quantifying the components of interest in cases where severe spectral overlap and unknown interferences coexisted.However,it was possible to obtain satisfactory results with the second-order calibration method based on alternating normalization-weighted error(ANWE)algorithm because of its strong"mathematical separation",even when the fluorescence spectra of the target analytes and unknown interferents considerably overlapped.Correlation coefficients for both analytes were greater than 0.99,with mean recoveries of 104.9%±5.7%and 107.8%±9.2%for MET and VAL in human serum,and 103.7%±8.9%and 94.7%±3.8%in human urine,respectively.In addition,the sensitivity,selectivity,limit of detection,limit of quantification,repeatability,and reproducibility of the proposed second-order calibration method were thoroughly examined.All results indicated that the established method was capable of achieving simultaneous and accurate quantification of MET and VAL in human body fluids,which was expected to be applied to analysis of both drugs in clinical settings.
5.Investigation of Proteomic Mechanisms of Luteolin's Inhibition on Growth of Colorectal Cancer SW620 Cells
Jia-Wei ZHAO ; Bo MENG ; Ao LU ; Zi-Xing HAN ; Zi-Hong YE ; Yang ZHAO
Chinese Journal of Analytical Chemistry 2025;53(2):258-268,中插18-中插19
With the continuous rise in the incidence of colorectal cancer and the trend towards younger patient population,the existing treatment options,while able to prolong survival,are difficult to avoid significant side effects.It is imperative to develop new treatment strategies.Luteolin(LUT),as a natural herbal active ingredient,has been proved to have broad-spectrum anti-tumor effects in studies of multiple cancer types.However,the mechanism of LUT action in colorectal cancer has not been systematically elucidated.In this study,for the first time,the molecular mechanism of LUT on colorectal cancer SW620 cells from the perspective of proteomics-glycoproteomics co-regulation was revealed.Proteomic analysis identified 472 differentially expressed proteins.Functional enrichment analysis showed that down-regulated proteins were mainly involved in oxidative stress response,mRNA processing,RNA splicing,and actin filament organization among key biological processes,involving oxidative phosphorylation and peroxisome pathways.Up-regulated proteins were mainly involved in DNA replication,protein folding,and rRNA metabolism,closely related to DNA replication and protein processing pathways in the endoplasmic reticulum.At the level of glycoproteomics,231 differentially expressed intact N-glycopeptides were identified.Functional enrichment analysis of corresponding glycoproteins indicateed that LUT might exert biological effects by regulating biological processes such as nuclear organization,nuclear membrane organization,and Fc receptor-mediated signaling pathways,as well as endoplasmic reticulum protein processing and N-glycan biosynthesis pathways.Analysis of key interaction networks revealed 5 core target proteins namely RPS15A,WDR43,FBL,UTP18,and UTP11.The loss of these proteins had been confirmed to inhibit the proliferation and migration of various tumor cells.Notably,altered glycosylation modifications of the lysosome-associated membrane proteins LAMP1 and LAMP2 suggested that LUT might affect tumor metastatic potential by regulating organelle dynamics.It was found that LUT could inhibit the malignant phenotype of colon cancer cells through a dual mechanism of specifically regulating protein expression networks and glycosylation modification patterns,providing new molecular targets and theoretical basis for precise treatment of colorectal cancer based on natural products.
6.Research Progress on Electrochemical Sensing Techniques for Detection of Telomerase Activity
Hai-Tang YANG ; Peng-Hua SHU ; Wen-Lin LIU ; Wen-Bo MA ; Zi-Jun YANG ; Zhi-Feng DENG ; Xin-Yun ZHANG ; Wei WEI
Chinese Journal of Analytical Chemistry 2025;53(6):864-874
The telomere structure in the cell nucleus is crucial for maintaining the stability and functions of chromosomes.Telomerase is a ribonucleoprotein reverse transcriptase,which catalyzes the elongation of telomeres using its own RNA as a template,thereby counteracting the shortening of telomeres caused by chromosome replication and cell division.Due to its overexpression in over 85%of malignant tumor cells,telomerase has emerged as a highly promising biomarker and a novel target for cancer therapy.In recent years,given the importance of precise quantification of telomerase activity in guiding medical diagnosis and treatment strategies,researchers have developed various high-performance telomerase detection techniques.Among these,electrochemical biosensing technique has cause much attention due to its high sensitivity,operational convenience,rapid response,and ease of miniaturization.This paper focused on the latest advances in electrochemical sensing technique for detection of telomerase activity,aiming to provide inspiration for designing novel telomerase activity detection strategies by elucidating three unique properties of telomerase primer extension products.
7.Determination of Lipid Components in Fingerprints by Gas Chromatography-Mass Spectrometry and Gender Recognition of Fingerprint Donors by Machine Learning
Zi-Chen YI ; Wen-Ji ZHANG ; Zi-Yong ZHU ; Wei YI ; Jia-Si JIANG ; Zi-Hua LI
Chinese Journal of Analytical Chemistry 2025;53(8):1290-1299,中插19-中插22
Gender recognition based on the analysis of fingerprint residue can assist investigators in narrowing down the scope of investigation and play an important role in the field of criminal investigation.This study established a quantitative analysis method for lipid substances in fingerprints based on gas chromatography-mass spectrometry(GC-MS).Fatty acids in fingerprints were methylated using sulfuric acid methanol derivatization reagent(7%,V/V),the extraction reagent was dichloromethane-methanol(1∶1,V/V)solution,the reaction temperature was 70℃and the heating time was 45 min.Quantitative analysis of the relative content of 23 kinds of fatty acids and squalene in fingerprints residue by different genders was conducted,and orthogonal partial least squares-discriminant analysis(OPLS-DA)was used to reduce the dimensionality of the quantitative results.A total of 13 kinds of components in the fingerprints were selected to maximize the difference in relative content between male and female fingerprints.Three machine learning models,including binary logistic regression(BLR),support vector machine(SVM)and random forest(RF),were further used as feature variables to classify the gender of fingerprints.The classification performance of each model was compared through five indicators,and it was found that the most suitable model for binary classification of fingerprint gender was SVM model.The results showed that the SVM fingerprint residual gender binary classification model established based on the relative content data of 13 kinds of lipid substances in fingerprints achieved a classification accuracy of 90%and an area under the receiver operating characteristic curve(AUC)value of 0.98.This study provided a new research method for detecting lipid components in fingerprints and a methodological basis for gender recognition of fingerprints.
8.Determination of Decabromodiphenyl Ether and Decabromodiphenyl Ethane in Sediments by High-Performance Liquid Chromatography Coupled with Inductively Coupled Plasma-Mass Spectrometry
Xiao-Fei WEI ; Jing WU ; Zhuo HAN ; Yu-Zhu ZHANG ; Zi-Juan PENG ; Peng-Hui LI ; Shan-Jun SONG
Chinese Journal of Analytical Chemistry 2025;53(9):1526-1535
Decabromodiphenyl ether(BDE-209)and decabromodiphenyl ethane(DBDPE)are widely used brominated flame retardants,which have been detected in the atmosphere,water,soil,and various organisms.In this study,a method based on high-performance liquid chromatography-inductively coupled plasma-mass spectrometry(HPLC-ICP-MS)was developed for determination of BDE-209 and DBDPE in sediment.Firstly,the target compounds in the sediments were extracted by accelerated solvent extraction(ASE),and the extraction solvent was hexane/dichloromethane(1∶1,V/V).The extract was concentrated by rotary evaporation and purified by a composite silica gel column(6 g neutral silica gel,8 g acidic silica gel,and 4 g anhydrous sodium sulfate),concentrated by nitrogen blowing,and then re-dissolved with 1 mL of toluene for instrumental determination.The chromatographic separation was carried out on a TC-C18(2)column(250 mm×4.6 mm)with isocratic elution using methanol-isopropanol-water(89∶6∶5,V/V)as the mobile phase,and the samples were separated within 20 min.Further,the Br element was quantified by ICP-MS to realize the detection of the target.The results showed that the method established in this study exhibited good linearity(R2>0.999)in the range of 100-10000 ng/mL,and the limits of quantification(LOQs)of the method were 2.0 ng/g for BDE-209 and 10.0 ng/g for DBDPE,with the relative standard deviations(RSDs,n=3)lower than 10%,and the recoveries were in the acceptable range(80.9%-120.7%).The matrix effect was effectively controlled within 10%.In addition,by analyzing the actual sediment samples from Guangxi,a background point,and Taizhou,Zhejiang,a typical contaminated area,it was found that neither BDE-209 nor DBDPE was detected in the sediment from Guangxi,while the concentrations of BDE-209 and DBDPE in the sediment from Zhejiang ranged from 1591.8 to 3362.9 ng/g,which further demonstrated the applicability and reliability of the method for analyzing actual environmental samples.This study provided a strong technical support for the accurate detection of POPs in the environment.
9.Estimate the Age of Han Adult Based on the Pulp Chamber Volume and Pulp Dentinal Index of Right First Molars Using Oral and Maxillofacial CBCT
Yan-Jie DING ; Xiao ZHANG ; Wen-Li SHI ; Zi-Yi LI ; Wei WANG ; Shi-Lin ZHANG ; Gen-Jie YANG ; A-Ji GUO ; Bo JIN
Journal of Forensic Medicine 2025;41(1):59-65
Objective To explore the correlation between the actual age and the pulp chamber volume(PCV)and pulp dentinal index(PDI)of the right first molars based on cone beam computed tomog-raphy(CBCT)technology,and to construct an accurate and convenient model for age estimation.Methods CBCT image data of 1 857 Han adults(883 males and 974 females)from the Department of Stomatology,Affiliated Hospital of North Sichuan Medical College were collected.The data were di-vided into training and validation sets at a ratio of 8∶2.A total of 1 485 training samples were used to construct the age estimation model,and 372 samples were used to validate the accuracy of the model.The Mimics 21.0 software was used to measure the PCV and calculate the PDI of the right first molars.Their correlations with age and the differences between different sexes and tooth positions were analyzed.Results Both the PCV and the PDI of the first molars showed strong negative correla-tions with the actual age(r values ranged from 0.82 to 0.89).The differences in PCV and PDI be-tween different sexes and tooth positions were statistically significant(P<0.05).The age estimation model based on PDI was superior to that based on PCV.The model based on the PDI values of the two right first molars(y=73.72-44.15 x3-28.27 x4,where x3 and x4 are the PDI values of the right maxil-lary and mandibular first molars,respectively)was the best,with the R2 of 0.79 and the mean abso-lute error of 4.90 years.Conclusion Both PCV and PDI of the first molars are effective indicators for age estimation.The age estimation model based on the PDI is more convenient and accurate than that based on the PCV,providing a more effective method for age estimation in forensic practice.
10.Synergistic neuroprotective effects of main components of salvianolic acids for injection based on key pathological modules of cerebral ischemia.
Si-Yu TAN ; Ya-Xu WU ; Zi-Shu YAN ; Ai-Chun JU ; De-Kun LI ; Peng-Wei ZHUANG ; Yan-Jun ZHANG ; Hong GUO
China Journal of Chinese Materia Medica 2025;50(3):693-701
This study aims to explore the synergistic effects of the main components in salvianolic acids for Injection(SAFI) on key pathological events in cerebral ischemia, elucidating the pharmacological characteristics of SAFI in neuroprotection. Two major pathological gene modules related to endothelial injury and neuroinflammation in cerebral ischemia were mined from single-cell data. According to the topological distance calculated in network medicine, potential synergistic component combinations of SAFI were screened out. The results showed that the combination of caffeic acid and salvianolic acid B scored the highest in addressing both endothelial injury and neuroinflammation, demonstrating potential synergistic effects. The cell experiments confirmed that the combination of these two components at a ratio of 1∶1 significantly protected brain microvascular endothelial cells(bEnd.3) from oxygen-glucose deprivation/reoxygenation(OGD/R)-induced reperfusion injury and effectively suppressed lipopolysaccharide(LPS)-induced neuroinflammatory responses in microglial cells(BV-2). This study provides a new method for uncovering synergistic effects among active components in traditional Chinese medicine(TCM) and offers novel insights into the multi-component, multi-target acting mechanisms of TCM.
Brain Ischemia/metabolism*
;
Neuroprotective Agents/pharmacology*
;
Animals
;
Drugs, Chinese Herbal/administration & dosage*
;
Benzofurans/pharmacology*
;
Mice
;
Drug Synergism
;
Caffeic Acids/pharmacology*
;
Polyphenols/pharmacology*
;
Humans
;
Alkenes/pharmacology*
;
Endothelial Cells/drug effects*
;
Depsides

Result Analysis
Print
Save
E-mail