基于增强CT深度学习影像组学术前预测胸腺瘤风险分类

目的:探讨基于增强CT深度学习影像组学术前预测胸腺瘤风险分类的价值。方法:收集2015年1月至2023年1月皖南医学院弋矶山医院139例胸腺瘤患者为训练集,池州市人民医院与芜湖市第二人民医院81例患者为外部验证集。其中低风险组(A、AB、B1型)137例、高风险组(B2、B3型)83例。基于CT静脉期图像分别提取手工影像组学(hand-crafted radiomics,HCR)特征与深度学习(deep learning,DL)特征,构建影像组学标签评分(Radscore)。单因素与多因素Logistic回归分析筛选预测胸腺瘤高风险的影像学独立影响因素,利用逻辑回归(Logistic regression,LR)、随机森林(random forest,RF)、决策树(decision tree,DT)及支持向量机(support vector machine,SVM)机器学习建模。选择最佳模型为输出模型,构建模型列线图、校准曲线及临床决策曲线(decision curve analysis,DCA)。受试者工作特征(receiver operating characteristics,ROC)曲线下面积(area under the curve,AUC)及净重新分类指数(net reclassification index,NRI)用于评估模型效能。结果:LR、RF、DT及SVM构建预测模型的AUC分别为训练集0.899、0.835、0.897、0.860,外部验证集0.889、0.830、0.905、0.858。由于训练集LR模型效能最佳,作为本研究输出模型,校准曲线及DCA表明模型具有较高的校准度及临床适用性。列线图与Radscore比较效能有改善,NRI训练集为7.5%(P=0.007),外部验证集为5.3%(P=0.020)。结论:基于增强CT深度学习影像组学术前实现了胸腺瘤准确风险分类,列线图能够提供个性化预测结果。

Thermodynamic parameters of 135 gaseous PCDF calculated with DFT

Numerous thermal processes （e.g. waste incineration, steel and nonferrous industry, wastes recycling plants, hot dip galvanizing etc. ） have been identified as emission sources of PolyChlorinated Dibenzo-p-Dioxins （PCDD） and PolyChlorinated DibenzoFurans （PCDF）, which are named in brief ＂dioxins＂ The processes by which such dioxins （PCDD/F） are formed are still incompletely understood and probably proceed catalytically by multiple and parallel pathways. However, two major pathways of formation have been identified during final stages of the combustion process： The first one is the precursor route, i.e. the formation of PCDD/F from related structures, such as simple or chlorinated benzenes, phenols, biphenyls, and polycyclic aromatic hydrocarbons （PAH）, and the second one is the de novo synthesis of PCDD/F from macromolecular solid carbon （ or other structures unrelated to dioxins）, organic and inorganic chlorine, oxygen, etc. Knowledge of the relevant thermodynamic parameters is essential for predicting possible stability domains of PCDD/F during combustion processes and their equilibrium distribution at emission sources. In the previous study, thermodynamic parameters of PCDDi predicted with density functional theory （DFF） method have been reported. A comprehensive thermodynamic database of the standard entropy （ S^0 ）, specific heat （Cp）, enthalpy of formation （ΔfH^0） and Gibbs free energy of formation （ΔfG^0） for 135 gaseous PCDF （including dibenzofuran） was studied. From the enthalpies of formation the order of stability of individual congeners is reported. Additionally, the results obtained in this study are compared with values determined by other electronic structural methods.

Calculation of thermodynamic parameters of 75 gaseous PCDDs using the density functional theory

In this paper, the thermodynamic parameters are calculated for all gaseous Poly Chlorinat Dibenzo-p-dioxins （PCDDs） using the Density Functional Theory （DFF） method and both the enthalpy of formation （ΔfH^0） and Gibbs free energy of formation （Δf G^0） are derived, from which the order of stability of individual congeners is then predicted. All these properties, together with the calculated entropies （ S^0） and heat capacities （ Cp）, are presented as a function of the number of chlorine atoms in the various PCDD molecules. The accuracy of the method used here, is evaluated by comparing the thermodynamic parameters of gaseous chlorobenzenes with experimental values collected from literature.

Bifunctional organocatalyst-catalyzed dynamic kinetic resolution of hemiketals for synthesis of chiral ketals via hydrogen bonding control

Herein,we report the dynamic kinetic resolution asymmetric acylation ofγ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts,and a series of ketals were obtained in high yields(up to 95%)and excellent enantioselectivities(up to 99%).In terms of synthetic utility,the reaction can be performed on a gram scale,and the product can be converted into potential biological nucleoside analog.

Operating condition influences on PCDD/Fs emissions from sinter pot tests with hot flue gas recycling

This study was designed to clarify the influence of operating conditions on the formation and emissions of polychlorinated-p-dibenzodioxins and dibenzofurans （PCDD/Fs） from a sintering process with hot flue gas recycling. A pilot scale sinter pot with simulated flue gas recycling was developed, and four key operational parameters, including temperature, oxygen content of the simulated waste flue gas, the coke rate of the sintering mixture, and the quicklime quality, were selected for exploring PCDD/Fs formation. The results showed that the temperature of the recycled flue gas had a major affect on PCDD/Fs formation, and a high temperature could significantly increase their formation during sintering. A clear linear correlation between the temperature of recycling flue gas and PCDD/Fs emission （r = 0.93） was found. PCDD/Fs could be reduced to a certain extent by decreasing the level of oxygen in the recycled flue gas, while sintering quality was unchanged. The coke rate had no significant influence on the formation of PCDD/Fs, but the quality of quicklime used in the sintering mixture could affect not only the amount of PCDD/Fs emissions but also the sintering productivity. Compared with a benchmark sinter pot test, PCDD/Fs emissions markedly decreased with improvements to quicklime quality. However, the reduction in PCDD/Fs emissions realized by using high-quality quicklime was limited by the temperature of the inlet gas. The highest reduction achieved was 51% compared with conventional quicklime when the temperature of the inlet gas was 150°C.

Outcomes of patients awaiting lung transplantation after the implementation of donation after brain death at a single Chinese center

oluntary contribution has become the only source of donor lungs in China since 2015.To elaborate the outcomes of patients awaiting lung transplantation(LTx)after the implementation of donation after brain death,we performed a retrospective study that encompassed 205 patients with end-stage lung disease who registered for LTx at Shanghai Pulmonary Hospital from January 1,2015 to January 1,2021.A total of 180 patients were enrolled in the study.The median waiting time was 1.25 months.Interstitial lung disease(ILD)(103/180,57.2%)and chronic obstructive pulmonary disease(COPD)(56/180,31.1%)were the most common diseases in our study population.The mean pulmonary artery pressure(mPAP)of patients in the died-waiting group was higher than that of the survivors(53.29+21.71 mmHg vs.42.11+18.58 mmHg,P-0.002).The mortality of patients with ILD(34/103,33.00%)was nearly twice that of patients with COPD(10/56,17.86%)while awaiting LTx(P-0.041).In the died-waiting group,patients with ILD had a shorter median waiting time than patients with COPD after being listed(0.865 months vs.4.720 months,P-0.030).ILD as primary disease and mPAP>35 mmHg were two significant independent risk factors for waitlist mortality,with hazard ratios(HR)of 3.483(95%CI 1.311-9.111;P-0.011)and 3.500(95%CI 1.435-8.536;P=0.006).Hence,LTx is more urgently needed in patients with ILD and pulmonary hypertension.