Intratumoral and peritumoral radiomics based on contrast-enhanced MRI for preoperatively predicting treatment response of transarterial chemoembolization in hepatocellular carcinoma.

BACKGROUND: Noninvasive and precise methods to estimate treatment response and identify hepatocellular carcinoma (HCC) patients who could benefit from transarterial chemoembolization (TACE) are urgently required. The present study aimed to investigate the ability of intratumoral and peritumoral radiomics based on contrast-enhanced magnetic resonance imaging (CE-MRI) to preoperatively predict tumor response to TACE in HCC patients. METHODS: A total of 138 patients with HCC who received TACE were retrospectively included and randomly divided into training and validation cohorts at a ratio of 7:3. Total 1206 radiomics features were extracted from arterial, venous, and delayed phases images. The inter- and intraclass correlation coefficients, the spearman's rank correlation test, and the gradient boosting decision tree algorithm were used for radiomics feature selection. Radiomics models on intratumoral region (TR) and peritumoral region (PTR) (3 mm, 5 mm, and 10 mm) were established using logistic regression. Three integrated radiomics models, including intratumoral and peritumoral region (T-PTR) (3 mm), T-PTR (5 mm), and T-PTR (10 mm) models, were constructed using TR and PTR radiomics scores. A clinical-radiological model and a combined model incorporating the optimal radiomics score and selected clinical-radiological predictors were constructed, and the combined model was presented as a nomogram. The discrimination, calibration, and clinical utilities were evaluated by receiver operating characteristic curve, calibration curve, and decision curve analysis, respectively. RESULTS: The T-PTR radiomics models performed better than the TR and PTR models, and the T-PTR (3 mm) radiomics model demonstrated preferable performance with the AUCs of 0.884 (95%CI, 0.821-0.936) and 0.911 (95%CI, 0.825-0.975) in both training and validation cohorts. The T-PTR (3 mm) radiomics score, alkaline phosphatase, tumor size, and satellite nodule were fused to construct a combined nomogram. The combined nomogram [AUC: 0.910 (95%CI, 0.854-0.958) and 0.918 (95%CI, 0.831-0.986)] outperformed the clinical-radiological model [AUC: 0.789 (95%CI, 0.709-0.863) and 0.782 (95%CI, 0.660-0.902)] in the both cohorts and achieved good calibration capability and clinical utility. CONCLUSIONS: CE-MRI-based intratumoral and peritumoral radiomics approach can provide an effective tool for the precise and individualized estimation of treatment response for HCC patients treated with TACE.

Effects of Wearing Face Masks on Exercise Capacity and Ventilatory Anaerobic Threshold in Healthy Subjects During the COVID-19 Epidemic.

BACKGROUND Face masks have become an important part of the COVID-19 prevention approach. This study aimed to explore the effect of wearing masks on exercise ability and ventilatory anaerobic threshold (VAT). MATERIAL AND METHODS Thirty-four young, healthy volunteers were included in this study, consisting of 18 men and 16 women. The subjects were randomized to perform 2 cardiopulmonary exercise tests (CPET) on a cycle ergometer with gas exchange analysis, one with and another without wearing a face mask (cross-over design). The general data for all subjects and indicators from the 2 exercise tests performed with and without wearing a face mask were collected. RESULTS In cardiopulmonary exercise tests, wearing a mask significantly (P<0.05) decreased peak indexes (eg, work rate (WR), oxygen consumption per kg body weight (VO2/kg), heart rate (HR), ventilation per minute (VE) and carbon dioxide ventilation equivalent (VE/VCO2)) and anaerobic threshold indexes (eg, WR, HR, VE, breath frequency (BF), dead space ratio (VD/VT), and VE/VCO2). However, the PETCO2 at peak was significantly higher. There was a positive linear correlation between WR difference and VO2 difference at VAT (abbreviated as deltaWR@VAT and deltaVO2@VAT, respectively) (r=0.495, P=0.003). Subgroup analysis of the VAT indexes showed that WR, VO2/kg, and VE were significantly decreased in the advanced VAT group with mask compared with the stable VAT group with mask (P<0.05). Logistic regression showed that deltaVE, deltaBF, and deltaVE/VCO2 had independent influences on VAT. CONCLUSIONS Wearing masks advances VAT in healthy young subjects during CPET. The advanced VAT was associated with changes in VE, BF, and VE/VCO2 while wearing masks.

Quantification of Hepatic Fat Fraction in Patients With Nonalcoholic Fatty Liver Disease: Comparison of Multimaterial Decomposition Algorithm and Fat (Water)-Based Material Decomposition Algorithm Using Single-Source Dual-Energy Computed Tomography.

METHODS: Hepatic fat fractions were quantified by noncontrast (HFFnon-CE) and contrast-enhanced single-source dual-energy computed tomography in arterial phase (HFFAP), portal venous phase (HFFPVP) and equilibrium phase (HFFEP) using MMD in 19 nonalcoholic fatty liver disease patients. The fat concentration was measured on fat (water)-based images. As the standard of reference, magnetic resonance iterative decomposition of water and fat with echo asymmetry and least-squares estimation-iron quantification images were reconstructed to obtain HFF (HFFIDEAL-IQ). RESULTS: There was a strong correlation between HFFnon-CE, HFFAP, HFFPVP, HFFEP, fat concentration and HFFIDEAL-IQ (r = 0.943, 0.923, 0.942, 0.952, and 0.726) with HFFs having better correlation with HFFIDEAL-IQ. Hepatic fat fractions did not significantly differ across scanning phases. The HFFs of 3-phase contrast-enhanced computed tomography had a good consistency with HFFnon-CE. CONCLUSIONS: Hepatic fat fraction using MMD has excellent correlation with that of magnetic resonance imaging, is independent of the computed tomography scanning phases, and may be used as a routine technique for quantitative assessment of HFF.

Bamboo Tar as a Novel Fungicide: Its Chemical Components, Laboratory Evaluation, and Field Efficacy Against False Smut and Sheath Blight of Rice and Powdery Mildew and Fusarium Wilt of Cucumber.

The application of agricultural and forest residues can benefit the environment and the economy; however, they also generate a large amount of byproducts. In this study, bamboo tar (BT), a waste product of bamboo charcoal production, was dissolved in natural ethanol and the surfactant alkyl glucoside to manufacture a 50% (wt/wt) BT emulsifiable concentrate (BTEC) biopesticide. BTEC was screened for fungicidal activity against pathogens. The greatest activity was seen against Ustilaginoidea virens with a half-maximal effective concentration (EC50) value of 6 mg/liter. Four phytopathogenic fungi, Podosphaera xanthii, Rhizoctonia solani, Fusarium oxysporum, and Botrytis cinerea, showed EC50 values of <60 mg/liter. Greenhouse tests in vivo showed 2,000 mg/liter BTEC had a 78.4% protective effect against U. virens, and replicated treatments had an 80.6% protective effect. In addition, replicated 2-year field trials were conducted in two geographic locations with four plant diseases: false smut (U. virens), rice sheath blight (Thanatephorus cucumeris [Frank] Donk), cucumber powdery mildew (P. xanthii), and cucumber Fusarium wilt (F. oxysporum). Results showed that 1,000 to 2,000 mg/liter BTEC significantly inhibited these diseases. Gas chromatography-mass spectrometry analysis showed that the total phenolic mass fractions of two BT samples were 45.39 and 48.26%. Eleven components were detected, and their percentage content was as follows (from high to low): 2,6-dimethoxyphenol > 2- or 4-ethylphenol > 2- or 4-methylphenol > phenol > 4-ethylguaiacol > dimethoxyphenol > 4-methylguaiacol > 4-propenyl-2,6-dimethoxyphenol > 2,4-dimethylphenol. Some of the phenolic compounds identified from the tar might be fungicidally active components. BT is a biochar waste, which has potential as a biofungicide and has promise in organic agriculture. The value of this tar may not be because of any fundamental physical differences from other synthetic fungicides but rather caused by reduced production expenses and more efficient use of waste products.

The value of single-source dual-energy CT imaging for discriminating microsatellite instability from microsatellite stability human colorectal cancer.

OBJECTIVES: To demonstrate the value of single-source dual-energy computed tomography (ssDECT) imaging for discriminating microsatellite instability (MSI) from microsatellite stability (MSS) colorectal cancer (CRC). METHODS: Thirty-eight and seventy-six patients with pathologically proven MSI and MSS CRC, respectively, were retrospectively selected and compared. These patients underwent contrast-enhanced abdominal ssDECT scans before any anti-cancer treatment. Effective atomic number (Eff-Z) in precontrast phase, slope k of spectral HU curve in precontrast (k-P), arterial (k-A), venous (k-V), and delayed phase (k-D), normalized iodine concentration in arterial (NIC-A), venous (NIC-V), and delayed phase (NIC-D), of tumors in two groups were measured by two reviewers. Consistency of measurements was tested by intra-class correlation coefficients (ICC). Mann-Whitney U test or Student's t test was used to compare above values between MSI and MSS. Multivariate logistic regression was used to analyze multiple parameters. Receiver operating characteristic curves were calculated to assess diagnostic efficacies. RESULTS: Interobserver agreement was excellent (ICC > 0.80). MSI CRC had significantly lower values in all measurements (NIC-A, V, D; k-P, A, V, D; Eff-Z) than MSS CRC. For discriminating MSI from MSS CRC, the area under curve (AUC) using k-A was the highest (AUC, 0.803; sensitivity, 72.4%; specificity, 76.3%). The multivariate logistic regression (selection method, Enter) with combined ssDECT parameters (NIC-A, NIC-V, NIC-D, Eff-Z, k-P, k-A, k-V, k-D) significantly improved diagnostic capability with AUC of 0.886 (sensitivity, 81.6%; specificity, 81.6%). CONCLUSIONS: The combination of multiple parameters in ssDECT imaging by multivariate logistic regression provides relatively high diagnostic accuracy for discriminating MSI from MSS CRC. KEY POINTS: • ssDECT generates multiple parameters for discriminating CRC with MSI from MSS. • ssDECT measurements for MSI CRC were significantly lower than MSS CRC. • Combination of ssDECT parameters further improves diagnostic capability for differentiation.

Radiomics-based classification of hepatocellular carcinoma and hepatic haemangioma on precontrast magnetic resonance images.

BACKGROUND: To evaluate the feasibility of using radiomics with precontrast magnetic resonance imaging for classifying hepatocellular carcinoma (HCC) and hepatic haemangioma (HH). METHODS: This study enrolled 369 consecutive patients with 446 lesions (a total of 222 HCCs and 224 HHs). A training set was constituted by randomly selecting 80% of the samples and the remaining samples were used to test. On magnetic resonance (MR) images of HCC and HH obtained with in-phase, out-phase, T2-weighted imaging (T2WI), and diffusion-weighted imaging (DWI) sequences, we outlined the target lesions and extracted 1029 radiomics features, which were classified as first-, second-, higher-order statistics and shape features. Then, the variance threshold, select k best, and least absolute shrinkage and selection operator algorithms were explored for dimensionality reduction of the features. We used four classifiers (decision tree, random forest, K nearest neighbours, and logistic regression) to identify HCC and HH on the basis of radiomics features. Two abdominal radiologists also performed the conventional qualitative analysis for classification of HCC and HH. Diagnostic performances of radiomics and radiologists were evaluated by receiver operating characteristic (ROC) analysis. RESULTS: Valuable radiomics features for building a radiomics signature were extracted from in-phase (n = 22), out-phase (n = 24), T2WI (n = 34) and DWI (n = 24) sequences. In comparison, the logistic regression classifier showed better predictive ability by combining four sequences. In the training set, the area under the ROC curve (AUC) was 0.86 (sensitivity: 0.76; specificity: 0.78), and in the testing set, the AUC was 0.89 (sensitivity: 0.822; specificity: 0.714). The diagnostic performance for the optimal radiomics-based combined model was significantly higher than that for the less experienced radiologist (2-years experience) (AUC = 0.702, p < 0.05), and had no statistic difference with the experienced radiologist (10-years experience) (AUC = 0.908, p>0.05). CONCLUSIONS: We developed and validated a radiomics signature as an adjunct tool to distinguish HCC and HH by combining in-phase, out-phase, T2W, and DW MR images, which outperformed the less experienced radiologist (2-years experience), and was nearly equal to the experienced radiologist (10-years experience).

Difference in Diffusion-Weighted Magnetic Resonance Imaging and Diffusion Tensor Imaging Parameters Between Endometrioid Endometrial Adenocarcinoma and Uterine Serous Adenocarcinoma: A Retrospective Study.

OBJECTIVE: This study aimed to elucidate the difference in diffusion-weighted magnetic resonance imaging (DWI) and diffusion tensor imaging (DTI) parameters between endometrioid endometrial adenocarcinoma (EEA) and uterine serous adenocarcinoma (SA). METHODS: Data of patients with pathologically confirmed EEA or SA who underwent DWI and DTI scanning between May 2013 and July 2016 were retrospectively analyzed. Apparent diffusion coefficient (ADC) value from DWI and ADC from DTI (ADC) map and fractional anisotropy (FA) values from DTI were analyzed and compared statistically. The correlation between ADC and ADC was analyzed by Pearson correlation analysis. Apparent diffusion coefficient, ADC, and FA between the 2 groups were compared using independent t test. The effect of ADC, ADC, and FA in distinguishing EEA and SA was evaluated by receiver operator characteristic curve. RESULT: Thirty-three patients were enrolled into the study, including 13 cases of SA and 20 cases of EEA. Pearson correlation analysis suggested that the value of ADC was highly related with ADC in both the SA group (r = 0.812, P = 0.001) and the EEA group (r = 0.858, P < 0.001). The value of ADC and ADC in the SA group was significantly lower than that in the EEA group; FA was significantly higher than that in the EEA group. Receiver operator characteristic curve analysis showed that ADC and ADC have high sensitivity and specificity; FA has low sensitivity and high specificity. CONCLUSIONS: We suggest that both DWI and DTI could be used in distinguishing EEA from SA. Apparent diffusion coefficient and ADC possess potential diagnostic value with high sensitivity and specificity.

Two new tenvermectins from a genetically engineered strain Streptomyces avermitilis MHJ1011.

Two new tenvermectins, tenvermectins C (1) and D (2), were isolated from Streptomyces avermitilis MHJ1011. Their structures were determined by extensive spectroscopic analysis and by comparison with a related known compound, tenvermectin A. Compounds 1 and 2 exhibited potent nematocidal and acaricidal activities against Bursaphelenchus xylophilus and Tetranychus cinnabarinus.

New macrocyclic lactones with acaricidal and nematocidal activities from a genetically engineered strain Streptomyces bingchenggensis BCJ60.

Two new macrocyclic lactones, 4,25-diethyl-4,25-demethyl-milbemycin ß3 (1) and 27-formaldehyde-milbemycin ß14 (2), were isolated from a genetically engineered strain Streptomyces bingchenggensis BCJ60. Their structures were determined on the basis of spectroscopic analysis, including 1D and 2D NMR techniques as well as ESI-MS and comparison with data from the literature. The acaricidal and nematocidal capacities of compounds 1 and 2 were evaluated against Tetranychus cinnabarinus and Bursaphelenchus xylophilus, respectively. The results showed that the two new macrocyclic lactones 1 and 2 possessed potent acaricidal and nematocidal activities.

Three new 16-membered macrolide compounds from a genetically engineered strain S. avermitilis MHJ1011.

Three new 16-membered macrolide compounds, 13α-O-α-l-oleandrosyl milbemycin ß3 (1), 13α-O-α-l-oleandrosyl-25-ethyl milbemycin ß3 (2), 13α-O-α-l-oleandrosyl-25-isopropyl milbemycin ß3 (3), were isolated from the genetically engineered strains Streptomyces avermitilis MHJ1011. Their structures were determined on the basis of spectroscopic analysis, including 1D and 2D NMR techniques as well as ESI-MS and comparison with data from the literature. Both compounds 1-3 displayed impressive acaricidal activity against larval mites with the IC50 values of 0.0327, 0.0276 and 0.0235mg/L, respectively, which are higher than those of 13α-hydroxy milbemycin ß3 and 13α-hydroxy-25-ethyl milbemycin ß3.

Perspectives on biologically active camptothecin derivatives.

Camptothecins (CPTs) are cytotoxic natural alkaloids that specifically target DNA topoisomerase I. Research on CPTs has undergone a significant evolution from the initial discovery of CPT in the late 1960s through the study of synthetic small-molecule derivatives to investigation of macromolecular constructs and formulations. Over the past years, intensive medicinal chemistry efforts have generated numerous CPT derivatives. Three derivatives, topotecan, irinotecan, and belotecan, are currently prescribed as anticancer drugs, and several related compounds are now in clinical trials. Interest in other biological effects, besides anticancer activity, of CPTs is also growing exponentially, as indicated by the large number of publications on the subject during the last decades. Therefore, the main focus of the present review is to provide an ample but condensed overview on various biological activities of CPT derivatives, in addition to continued up-to-date coverage of anticancer effects.

Gene Replacement for the Generation of Designed Novel Avermectin Derivatives with Enhanced Acaricidal and Nematicidal Activities.

Avermectin (AVM) and ivermectin (IVM) are potent pesticides and acaricides which have been widely used during the past 30 years. As insect resistance to AVM and IVM is greatly increasing, alternatives are urgently needed. Here, we report two novel AVM derivatives, tenvermectin A (TVM A) and TVM B, which are considered a potential new generation of agricultural and veterinary drugs. The molecules of the TVMs were designed based on structure and pharmacological property comparisons among AVM, IVM, and milbemycin (MBM). To produce TVMs, a genetically engineered strain, MHJ1011, was constructed from Streptomyces avermitilis G8-17, an AVM industrial strain. In MHJ1011, the native aveA1 gene was seamlessly replaced with milA1 from Streptomyces hygroscopicus. The total titer of the two TVMs produced by MHJ1011 reached 3,400 mg/liter. Insecticidal tests proved that TVM had enhanced activities against Tetranychus cinnabarinus and Bursaphelenchus xylophilus, as desired. This study provides a typical example of exploration for novel active compounds through a new method of polyketide synthase (PKS) reassembly for gene replacement. The results of the insecticidal tests may be of use in elucidating the structure-activity relationship of AVMs and MBMs.

Apparent diffusion coefficient measurement by diffusion weighted magnetic resonance imaging is a useful tool in differentiating renal tumors.

BACKGROUND: To determine the clinical value of apparent diffusion coefficient (ADC) measurement by diffusion weighted magnetic resonance imaging (DW-MRI) in differentiating renal tumors. METHODS: Electronic databases were searched using combinations of keywords and free words relating to renal tumor, ADC and DW-MRI. Based on carefully selected inclusion and exclusion criteria, relevant case-control studies were identified and the related clinical data was acquired. Statistical analyses were performed using STATA 12.0 (Stata Corporation, College station, TX). RESULTS: Sixteen case-control studies were ultimately included in the present meta-analysis. These 16 high quality studies contained a combined total of 438 normal renal tissues and 832 renal tumor lesions (597 malignant and 235 benign). The results revealed that ADC values of malignant renal tumor tissues were markedly lower than normal renal tissues and benign renal tumor tissues. ADC values of benign renal tumor tissues were also significantly lower than normal renal tissue. CONCLUSIONS: ADC measurement by DW-MRI provided clinically useful information on the internal structure of renal tumors and could be an important radiographic index for differentiation of malignant renal tumors from benign renal tumors.

Synthesis, biological activities, and quantitative structure-activity relationship (QSAR) study of novel camptothecin analogues.

In continuation of our program aimed at the development of natural product-based pesticidal agents, three series of novel camptothecin derivatives were designed, synthesized, and evaluated for their biological activities against T. Cinnabarinus, B. brassicae, and B. xylophilus. All of the derivatives showed good-to-excellent activity against three insect species tested, with LC50 values ranging from 0.00761 to 0.35496 mmol/L. Remarkably, all of the compounds were more potent than CPT against T. Cinnabarinus, and compounds 4d and 4c displayed superior activity (LC50 0.00761 mmol/L and 0.00942 mmol/L, respectively) compared with CPT (LC50 0.19719 mmol/L) against T. Cinnabarinus. Based on the observed bioactivities, preliminary structure-activity relationship (SAR) correlations were also discussed. Furthermore, a three-dimensional quantitative structure-activity relationship (3D-QSAR) model using comparative molecular field analysis (CoMFA) was built. The model gave statistically significant results with the cross-validated q2 values of 0.580 and correlation coefficient r2 of 0.991 and  of 0.993. The QSAR analysis indicated that the size of the substituents play an important in the activity of 7-modified camptothecin derivatives. These findings will pave the way for further design, structural optimization, and development of camptothecin-derived compounds as pesticidal agents.

[Virtual unehanced image in the single-source dual energy CT for evaluation of renal cell carcinoma:a preliminary study].

OBJECTIVE: To qualitatively and quantitatively evaluate the feasibility of CT virtual unenhanced (VUE) spectral imaging in renal cell carcinoma. METHOD: Thirty-six patients with histopathologically proven renal cell carcinoma underwent gemstone spectral imaging (GSI) including ture unenhanced (TUE), arterial, cortex and medullary phase acquisitions. The triphasic GSI dataset was sent to workstation and 3 sets of VUE images (including VUE a, VUE c, VUE m) were obtained by subtract iodine from iodine-water images in the triphasic enhanced GSI images, respectively. The quality of VUE s and TUE images was evaluated on a five-point scale.Interobserver agreement with regard to image quality was assessed using Cohen's Kappa, and four groups of image quality was compared with ANOVA analysis. The contrast-to-noise ratio (CNR) of mass-to-kidney in the TUE and VUE s images was calculated, and difference between these four datasets was compared with ANOVA analysis. Using appearance of masses on triphasic images as a standard, the masses detection ratio of four groups was calculated and compared with chi-square test. RESULTS: Interobserver agreement with regard to image quality was excellent (κ>0.600). There was no significant difference among the image quality of TUE and triphasic images of VUEs (P>0.05). The CNR of TUE (0.7 ± 0.6) was significant worse than that of triphasic images (1.7 ± 1.0, 1.9 ± 1.2, 2.5 ± 1.4, respectively) (P<0.05). There was no significant difference among the CNR of triphasic images (P>0.05). CONCLUSION: VUE images obtain from triphasic phases may be a surrogate for conventional unenhanced scan in renal cell carcinoma diagnosis.

[Optimal monochromatic images of abdominal arteries with low concentrations of contrast agents in spectral computed tomography imaging].

OBJECTIVE: To explore the application of optimal monochromatic images according to computed tomography (CT) values of conventional CT scans with high concentration contrast agent and the feasibility in guiding abdominal arteries imaging with low concentration contrast. METHODS: From March 2013 to February 2014, 160 patients of suspected celiac disease with a body mass index (BMI) of >25 kg/m(2) underwent spectral CT scan. And they were randomly divided into two groups. In group A (n = 61), 270 mgI/ml low concentrations of contrast agents and spectral CT imaging; in group B (n = 99), 350 mgI/ml high concentrations of contrast agents and 120 kVp scan. For CT values of the first measurement of abdominal aorta B group of patients, the average CT value was calculated . The optimal monochromatic images of group A according to CT values of group B were reconstructed and 70 keV images (group C) also reconstructed. The CT values of hepatic, splenic, right renal and superior mesenteric arteries were measured and contrast to noise ratios (CNRs) calculated. CT values and CNR were compared through t test on independent samples. P > 0.05 indicated no significant difference. RESULTS: Mean CT value of abdominal aorta was (422 ± 65) HU in group B. And optimal keV was (67 ± 5) keV in group A. CT values of abdominal aorta and its branches showed no statistical significance; the CNRs of abdominal aorta and its branches showed statistical significance. The scoring consistency between two observers was excellent and the score (4.1 ± 0.9 vs 4.2 ± 0.7) showed no significant difference (P > 0.05). CONCLUSION: GSI abdominal scans with low concentration contrast may obtain better image qualities compared to conventional CTA of high concentration. And (67 ± 5) keV is recommended.

T1 Mapping and Amide Proton Transfer Weighted Imaging for Predicting Lymph Node Metastasis in Patients with Rectal Cancer.

BACKGROUND: Accurate preoperative judgment of lymph node (LN) metastasis is a critical step in creating a treatment strategy and evaluating prognosis in rectal cancer (RC) patients. OBJECTIVE: This study aimed to explore the value of T1 mapping and amide proton transfer weighted (APTw) imaging in predicting LN metastasis in patients with rectal cancer. METHODS: In a retrospective study, twenty-three patients with pathologically confirmed rectal adenocarcinoma who underwent MRI and surgery from August 2019 to August 2021 were selected. Then, 3.0T/MR sequences included conventional sequences (T1WI, T2WI, and DWI), APTw imaging, and T1 mapping. Patients were divided into LN metastasis (group A) and non-LN metastasis groups (group B). The intra-group correlation coefficient (ICC) was used to test the inter-observer consistency. Mann-Whitney U test was used to compare the differences between the two groups. Spearman correlation analysis was performed to evaluate the correlation between T1 and APT values. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the differential performance of each parameter and their combination. The difference between AUCs was compared using the DeLong test. RESULTS: The APT value in patients with LN metastasis was significantly higher than in those without LN metastasis group (P=0.020). Also, similar results were observed for the T1 values (P=0.001). The area under the ROC curve of the APT value in the prediction of LN metastasis was 0.794; when the cutoff value was 1.73%, the sensitivity and specificity were 71.4% and 88.9%, respectively. The area under the ROC curve of the T1 value was 0.913; when the cutoff value was 1367.36 ms, the sensitivity and specificity were 78.6% and 100.0%, respectively. The area under the ROC curve of T1+APT was 0.929, with a sensitivity of 78.6% and specificity of 100.0%. CONCLUSION: APT and T1 values show great diagnostic efficiency in predicting LN metastasis in rectal cancer.

Nomogram based on dual-energy CT-derived extracellular volume fraction for the prediction of microsatellite instability status in gastric cancer.

Purpose: To develop and validate a nomogram based on extracellular volume (ECV) fraction derived from dual-energy CT (DECT) for preoperatively predicting microsatellite instability (MSI) status in gastric cancer (GC). Materials and methods: A total of 123 patients with GCs who underwent contrast-enhanced abdominal DECT scans were retrospectively enrolled. Patients were divided into MSI (n=41) and microsatellite stability (MSS, n=82) groups according to postoperative immunohistochemistry staining, then randomly assigned to the training (n=86) and validation cohorts (n=37). We extracted clinicopathological characteristics, CT imaging features, iodine concentrations (ICs), and normalized IC values against the aorta (nICs) in three enhanced phases. The ECV fraction derived from the iodine density map at the equilibrium phase was calculated. Univariate and multivariable logistic regression analyses were used to identify independent risk predictors for MSI status. Then, a nomogram was established, and its performance was evaluated by ROC analysis and Delong test. Its calibration performance and clinical utility were assessed by calibration curve and decision curve analysis, respectively. Results: The ECV fraction, tumor location, and Borrmann type were independent predictors of MSI status (all P < 0.05) and were used to establish the nomogram. The nomogram yielded higher AUCs of 0.826 (0.729-0.899) and 0.833 (0.675-0.935) in training and validation cohorts than single variables (P<0.05), with good calibration and clinical utility. Conclusions: The nomogram based on DECT-derived ECV fraction has the potential as a noninvasive biomarker to predict MSI status in GC patients.

Opportunistic screening for osteoporosis using enhanced images based on dual-energy computed tomography material decomposition: a comparison with quantitative computed tomography.

Background: Many patients with malignant tumors require chemotherapy and radiation therapy, which can result in a decline in physical function and potentially influence bone mineral density (BMD). Furthermore, these treatments necessitate enhanced computed tomography (CT) scans for determining disease staging or treatment outcomes, and opportunistic screening with available imaging data is beneficial for patients at high risk for osteoporosis if existing imaging data can be used. The study aimed to investigate the feasibility of opportunistic screening for osteoporosis using enhanced CT based on a dual-energy CT (DECT) material decomposition technique. Methods: We prospectively enrolled 346 consecutive patients who underwent abdominal unenhanced and triphasic contrast-enhanced CT (arterial, portal venous, and delayed phases) between June 2021 and June 2022. The BMD, and the density of hydroxyapatite (HAP) on HAP-iodine images and calcium (Ca) on Ca-iodine images were measured on the L1-L3 vertebral bodies. The iodine intake was recorded. Pearson analysis was conducted to assess the correlation between iodine intake and the density values in three phases and the correlation between BMD and the densities of HAP and Ca. Furthermore, linear regression was employed for quantitative evaluation. Bland-Altman analysis was used to evaluate the agreement between calculated BMD derived from DECT (BMD-DECT) and reference BMD derived from quantitative CT (BMD-QCT). Receiver operating characteristic (ROC) analysis was applied to assess the diagnostic efficacy. Results: The HAP and Ca density of the L1-L3 vertebral bodies did not differ significantly among the three phases of contrast-enhanced CT (F=0.001-0.049; P>0.05). Significant positive correlations were found between HAP, Ca densities, and BMD (HAP-BMD: r=0.9472, R2=0.8973; Ca-BMD: r=0.9470, R2=0.8968; all P<0.001). Bland-Altman plots showed high agreement between BMD-DECT and BMD-QCT. The area under the curve (AUC) using HAP and Ca measurements was 0.963 [95% confidence interval (CI): 0.937-0.980] and 0.964 (95% CI: 0.939-0.981), respectively, for diagnosing osteoporosis and was 0.951 (95% CI: 0.917-0.973) and 0.950 (95% CI: 0.916-0.973), respectively, for diagnosing osteopenia. Conclusions: The HAP and Ca density measurements generated through the material decomposition technique in DECT have good diagnostic performances in assessing BMD, which offers a new perspective for opportunistic screening of osteoporosis on contrast-enhanced CT.

Design, Synthesis, Nematicidal, and Fungicidal Activities of Novel Azo and Azoxy Compounds.

Bursaphelenchus xylophilus (B. xylophilus) and Meloidogyne are parasitic nematodes that have caused severe ecological and economic damage in pinewood and crops, respectively. Jietacins (jietacin A and B) were found to have excellent biological activity against B. xylophilus. Based on our tremendous demand for chemicals against B. xylophilus, a novel scaffold based on the azo and azoxy groups was designed, and a series of compounds were synthesized. In the bioassay, Ia, IIa, IIc, IId, and IVa exhibited higher activity against B. xylophilus in vitro than avermectin (LC50 = 2.43 µg·mL-1) with LC50 values of 1.37, 1.12, 0.889, 1.56, and 1.10 µg·mL-1, respectively. Meanwhile, Ib, Ic, IIc, and IVa showed good inhibition effects against Meloidogyne in vivo at the concentrations of 80 and 40 µg·mL-1 with inhibition rates of 89.0% and 81.6%, 95.6% and 75.7%, 96.3% and 41.2%, and 86.8% and 78.7%, respectively. In fungicidal activity in vitro, IIb and IVa exhibited excellent effect against Botryosphaeria dothidea with the inhibition of 82.59% and 85.32% at the concentration of 10 µg·mL-1, while the inhibition of Ia was 83.16% against Rhizoctonia solani at the concentration of 12.5 µg·mL-1. Referring to the biological activity against B. xylophilus, a 3D-QASR model was built in which the electron-donating group and small group at the 4-phenylhydrazine were favorable for the activity. In general, the novel azoxy compounds, especially IIc possess great potential for application in the prevention of B. xylophilus.