A combined radiomic model distinguishing GISTs from leiomyomas and schwannomas in the stomach based on endoscopic ultrasonography images.

BACKGROUND: Endoscopic ultrasonography (EUS) is recommended as the best tool for evaluating gastric subepithelial lesions (SELs); nonetheless, it has difficulty distinguishing gastrointestinal stromal tumors (GISTs) from leiomyomas and schwannomas. GISTs have malignant potential, whereas leiomyomas and schwannomas are considered benign. PURPOSE: This study aimed to establish a combined radiomic model based on EUS images for distinguishing GISTs from leiomyomas and schwannomas in the stomach. METHODS: EUS images of pathologically confirmed GISTs, leiomyomas, and schwannomas were collected from five centers. Gastric SELs were divided into training and testing datasets based on random split-sample method (7:3). Radiomic features were extracted from the tumor and muscularis propria regions. Principal component analysis, least absolute shrinkage, and selection operator were used for feature selection. Support vector machine was used to construct radiomic models. Two radiomic models were built: the conventional radiomic model included tumor features alone, whereas the combined radiomic model incorporated features from the tumor and muscularis propria regions. RESULTS: A total of 3933 EUS images from 485 cases were included. For the differential diagnosis of GISTs from leiomyomas and schwannomas, the accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve were 74.5%, 72.2%, 78.7%, and 0.754, respectively, for the EUS experts; 76.8%, 74.4%, 81.0%, and 0.830, respectively, for the conventional radiomic model; and 90.9%, 91.0%, 90.6%, and 0.953, respectively, for the combined radiomic model. For gastric SELs <20 mm, the accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve of the combined radiomic model were 91.4%, 91.6%, 91.1%, and 0.960, respectively. CONCLUSIONS: We developed and validated a combined radiomic model to distinguish gastric GISTs from leiomyomas and schwannomas. The combined radiomic model showed better diagnostic performance than the conventional radiomic model and could assist EUS experts in non-invasively diagnosing gastric SELs, particularly gastric SELs <20 mm.

[Effects of consecutive application of composted sewage sludge on active organic nitrogen fractions in the sandy fluvo-aquic soil.] / è¿žç»­æ–½ç”¨æ— å®³åŒ–æ±¡æ³¥å †è‚¥å¯¹æ²™è´¨æ½®åœŸæ´»æ€§æœ‰æœºæ°®ç»„åˆ†çš„å½±å“.

A field experiment was conducted with sandy fluvo-aquic soil under wheat-maize rotation system during 2012 to 2016 in Henan Province, with four treatments: Chemical fertilizer (CK), composted sewage sludge (CS) 15 t·hm-2(CS1), 30 t·hm-2(CS2), 45 t·hm-2(CS3). We investigated the effects of CS on soil active organic nitrogen and its allocation ratio. Results showed that CS significantly enhanced soil water content, decreased soil pH, increased contents of soil organic carbon and total nitrogen (TN) and available nutrients. Soil TN was increased by 93.1%-284.3%. The CS3 treatment significantly improved the content of light fraction organic nitrogen (LFON), particulate organic nitrogen (PON) and microbial biomass nitrogen (MBN). CS treatments promoted the allocation of PON/TN and MBN/TN. with an enhancement of 12.3% and 539.9% in the CS2 treatment, respectively. The distributions of LFON/TN and DON/TN were decreased by 17.3%-40.1% and 38.5%-71.3%, respectively. The contribution of soil active organic nitrogen fractions to TN was: PON>LFON>DON>MBN. Results from the principal component analysis showed that organic nitrogen and their distribution had high load value in CS2 and CS3 treatments. Results from redundancy analysis showed that positive correlations existed between the soil physicochemistry, enzymatic activity and soil active organic nitrogen as well as their distribution. In summary, CS had positive impacts on soil organic matter, soil properties, and the formation of active organic nitrogen. The rates of 30 and 45 t·hm-2 CS application had significant effects on soil fertility, which could be an effective way to improve sandy fluvo-aquic soil quality.

[Influence of the Application of Non-Hazardous Sewage Sludge on the Evolution of Soil Carbon Pool and Carbon Pool Management Index].

The products of non-hazardous commercial sewage sludge were utilized in the accordance of the national standard in the experiment with sandy fluvo-aquic soil under wheat-maize rotation system during 2013 to 2015. The experiment focused on the effects of the use of non-hazardous sewage sludge on soil carbon pool and carbon pool management index to provide theoretical and technical basis for the resource utilization of non-hazardous sewage sludge. The results showed that compared with CK, soil amended sludge significantly improved soil total organic carbon (TOC), soil microbial biomass carbon (SMBC), labile organic carbon (LOC),and dissolved organic carbon (DOC) to 8.40-14.74 g·kg-1, 164.45-257.45 mg·kg-1, 3.58-4.88 g·kg-1and 81.16-101.58 mg·kg-1, soil amended sludge significantly enhanced SMBC, LOC and DOC by 84.00%-188.07%, 26.26%-58.03%, and 109.58%-185.39% (P<0.05) respectively, and 45 t·hm-2 sewage sludge (W3) had the most significant impact on soil carbon pool. The soil microbial entropy (SMBC/TOC), and utilization of labile organic carbon (LOC/TOC) increased by 8.02%-2.77% and 13.75%-46.48% respectively, and the utilization of dissolved organic carbon (DOC/TOC) significantly decreased by 153.45%-195.40% (P<0.05). SMBC/TOC, LOC/TOC, and DOC/TOC declined in treatments of soil amended sludge due to increased application of sewage sludge, which indicated that soil amended with 45 t·hm-2 of the sewage sludge improved the content of stable carbon resulting in the decease of the ratio. L and LI decreased with the increasing amount of sewage sludge indicating that soil amended with 45 t·hm-2 of the sewage sludge improved the content of stable carbon and was conducive to the accumulation of organic carbon. Soil amended with sludge significantly increased carbon pool management index (CMPI) by 153.45%-195.40% (P<0.05), and W3 had the most significant effect on CMPI. Compared with TOC, CMPI could be more sensitive and direct to reflect the dynamic changes of soil nutrients and carbon pools through the correlation analysis and redundancy analysis. In summary, the application of 15-45 t·hm-2 sewage sludge could significantly enhance the soil carbon pool and carbon pool management index, especially 45 t·hm-2 sewage sludge (W3).