Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Objective:To establish a fluorescent quantitative RT-PCR assay based on N_sgRNA of SARS-CoV-2 and preliminarily apply it on real samples.Methods:Recombinant plasmid, specific primers and probes of N_sgRNA were designed and synthesized based on Wuhan-Hu-1/2019_MN908947 and synthesis mechanism of subgenomic RNA (sgRNA). Using recombinant plasmid as amplification templates, the optimal reaction conditions and reaction system were screened according to the Ct value, fluorescence intensity, and shape of amplification curve and was evaluated for sensitivity, reproducibility, and specificity. Meanwhile, the possibility of practical application of the method was explored by testing 172 clinical samples and 256 municipal wastewater samples. Results:A qRT-PCR assay for N_sgRNA in SARS-CoV-2 was initially established. The detection limit of the assay was 20 copies/mL, and the variation coefficients of in-batch (0.002%~0.767%) and batch to batch repetition (0.016%~0.752%) were less than 1%. Only N_sgRNA recombinant plasmid was detected in the specificity assay. So the method is more highly sensitive, specific and reproducible. The RatiosgRNA/ gRNA of clinical samples HK.3, EG.5.1, JN.1 and their sub-lineages and their corresponding urban sewage samples in epidemic period were significantly different ( P<0.05). There is a strong correlation between the median of RatiosgRNA/ gRNA in clinical samples and sewage samples in the same period (correlation coefficient r=1.000, P=0.010). Conclusions:In this study, a qRT-PCR method for detecting N_sgRNA of SARS-CoV-2 was established and the method has the characteristics of higher sensitivity, stronger specificity and better repeatability, and it can be used to detect SARS-CoV-2 infectivity.

Objective To explore the feasibility and corresponding implementation methods of constructing a sample resource bank based on individual-level data of completed clinical trials and using it to construct external controls for drug/device clinical trials.Methods Taking the pre-marketing clinical trial of transcatheter active valve replacement(TAVR)for the treatment of aortic valve stenosis as an example,the individual-level databases of multiple trials were standardized to form a sample bank.The original data of any trial in the sample bank were selected as the experimental group,and the remaining samples were selected as the control group.The potential confounding was handled by using the propensity score matching and stratification methods to clarify the process of constructing external controls based on the sample bank of individual-level data of clinical trials.Results This study included individual-level data of single-group trials of 4 TAVR devices,with a total of 569 subjects(59.2%male).The number of subjects in Trials 1 to 4 was 120,120,163,and 166,respectively.Propensity score matching enabled the matching of 113,117,125,and 147 subjects with comparable or similar characteristics from individual-level data from other trials,respectively,demonstrating a high matching success rate.The PS score distribution plot after stratification showed that the proportions of subjects in the experimental and control groups in strata 1 to 5 in scheme 1 were 4/103,11/103,22/92,32/87,and 51/64,respectively.For all constructed external controlled trials,a certain number of control samples with similar baseline characteristics to the experimental groups were distributed within each propensity score stratum.The results of the simulation test also reflected the potential differences between different devices in the 12-month all-cause mortality rate.Conclusions The sample bank constructed with individual-level data from clinical trials,as a high-quality data source,can serve as a source of external control for single-arm trials in the same field,and as a useful supplement to the external control scenario of real-world evidence to support drug and device development.At the same time,targeted research on research methods and bias control measures in related fields is also needed.

The pregnant woman was 30 years old,G2P0.This singleton pregnancy at 22 weeks of gestation was screened for second-trimester ultrasound malformations,suggesting fetal aortic valve atresia,aortic stenosis with reverse blood flow,mitral valve atresia,and markedly enlarged left ventricle,which was considered for the diagnosis of hypoplastic left heart syndrome(HLHS).The pregnancy was terminated at our hospital and subsequently underwent genetic testing with results of heterozygous variants in the NOTCH1 gene,which can cause aortic valve disease type 1.The findings of the fetal autopsy were aortic valve atresia,mitral valve widening and thickening,and left ventricular enlargement with myocardial infarction.This report focuses on the ultrasound characteristics of HLHS with left ventricular enlargement and its hemodynamic changes in order to improve clinicians'understanding of the progressive changes in the disease phenotype of HLHS.

Objective To explore the debridement effects of 3 types of plasma scalpels for the animal model of explosion injury,and to compare them with the steel scalpel and high-frequency electrosurgical scalpel.Methods Firstly,blast wounds were constructed in the right inguinal regions of 9 Landrace pigs by high-pressure gas impact combined with preset metal shrapnel.Secondly,debridement was carried out in experimental groups with wide-,arrow-or needle-type plasma scalpel and in control groups with steel and high-frequency electrisurgical scalpel,with the operating temperature and debridement time recorded during the procedure and trauma specimens analyzed pathologically after the debridement;comparisons were performed among the five types of scalpels in terms of debridement effect,and among the four ones in terms of maximum operating temperature and depth of tissue thermal damage under electrocutaneous cutting and electrocoagulation modes with the steel scalpel excluded because it did not generate any heat.GraphPad Prism 9.5.1 software was used for statistical analysis.Results There were no significant differences in debridement effect found between the three plasma scalpels and the steel and high-frequency electrosurgical scalpels(P＞0.05).The three types of plasma scalpels had the maximum operating temperature lower significantly than that of the high-frequency electrosurgical scalpel during debridement(P＜0.05).Under electrosection and electrocoagulation modes the three plasma scalpels had the depths of tissue thermal damage statistically less than that by the high-frequency electrosurgical scalpel under electrosection and electrocoagulation modes(P＜0.05).The depths of tissue thermal damage by the four scalpels under electrocoagulation mode were obviously greater than those under electrosection mode(P＜0.05).Conclusion Multi shapes of plasma scalpels behave well in debridement with low operating temperature,little tissue thermal damage and high efficiency for wound protection and the same efficacy with the steel scalpel and high-frequency electrosur-gical scalpel.[Chinese Medical Equipment Journal,2025,46(2):31-38]

Objective:To establish a fluorescent quantitative RT-PCR assay based on N_sgRNA of SARS-CoV-2 and preliminarily apply it on real samples.Methods:Recombinant plasmid, specific primers and probes of N_sgRNA were designed and synthesized based on Wuhan-Hu-1/2019_MN908947 and synthesis mechanism of subgenomic RNA (sgRNA). Using recombinant plasmid as amplification templates, the optimal reaction conditions and reaction system were screened according to the Ct value, fluorescence intensity, and shape of amplification curve and was evaluated for sensitivity, reproducibility, and specificity. Meanwhile, the possibility of practical application of the method was explored by testing 172 clinical samples and 256 municipal wastewater samples. Results:A qRT-PCR assay for N_sgRNA in SARS-CoV-2 was initially established. The detection limit of the assay was 20 copies/mL, and the variation coefficients of in-batch (0.002%~0.767%) and batch to batch repetition (0.016%~0.752%) were less than 1%. Only N_sgRNA recombinant plasmid was detected in the specificity assay. So the method is more highly sensitive, specific and reproducible. The RatiosgRNA/ gRNA of clinical samples HK.3, EG.5.1, JN.1 and their sub-lineages and their corresponding urban sewage samples in epidemic period were significantly different ( P<0.05). There is a strong correlation between the median of RatiosgRNA/ gRNA in clinical samples and sewage samples in the same period (correlation coefficient r=1.000, P=0.010). Conclusions:In this study, a qRT-PCR method for detecting N_sgRNA of SARS-CoV-2 was established and the method has the characteristics of higher sensitivity, stronger specificity and better repeatability, and it can be used to detect SARS-CoV-2 infectivity.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.

Objective: To evaluate the feasibility of dynamic contrast-enhanced MRI (DCE-MRI) in differentiating tumor deposits (TDs) from metastatic lymph nodes (MLNs) in rectal cancer. Materials and Methods: A retrospective analysis was conducted on 70 patients with rectal cancer, including 168 lesions (70 TDs and 98 MLNs confirmed by histopathology), who underwent pretreatment MRI and subsequent surgery between March 2019 and December 2022. The morphological characteristics of TDs and MLNs, along with quantitative parameters derived from DCE-MRI (K trans , kep, and v e) and DWI (ADCmin, ADCmax, and ADCmean), were analyzed and compared between the two groups.Multivariable binary logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of significant individual quantitative parameters and combined parameters in distinguishing TDs from MLNs. Results: All morphological features, including size, shape, border, and signal intensity, as well as all DCE-MRI parameters showed significant differences between TDs and MLNs (all P < 0.05). However, ADC values did not demonstrate significant differences (all P > 0.05). Among the single quantitative parameters, v e had the highest diagnostic accuracy, with an area under the ROC curve (AUC) of 0.772 for distinguishing TDs from MLNs. A multivariable logistic regression model incorporating short axis, border, v e, and ADC mean improved diagnostic performance, achieving an AUC of 0.833 (P = 0.027). Conclusion The combination of morphological features, DCE-MRI parameters, and ADC values can effectively aid in the preoperative differentiation of TDs from MLNs in rectal cancer.