Effects of iron oxides on the anaerobic codigestion performances of the Pennisetum hybrid and kitchen waste

The addition of iron oxides in anaerobic digestion can increase conversion efficiency. In this study, we investigated the effects of the addition of Fe2O3, Fe2O3 nanoparticles, Fe3O4, and Fe3O4 nanoparticles with different concentrations (0.5%–1.5%) on the anaerobic codigestion of a Pennisetum hybrid and kitchen waste in a batch-mode mesophilic experiment. The results indicated that the additives with different valence states and particle sizes had different effects on the anaerobic codigestion of the Pennisetum hybrid and kitchen waste. The addition of 0.5% Fe2O3 [with a biogas production of 286.0±61.8  mL/g volatile solid (VS)] and 0.5% Fe3O4 (with a biogas production of 309.1±22.3  mL/g VS) improved the cumulative biogas yield by 23.5% and 37.9%, respectively, compared with that of the control group (with a biogas production of 237.2±30.1  mL/g VS). Further correlation analysis showed that pH and total ammonia nitrogen were positively correlated with cumulative biogas yield, whereas bicarbonate alkalinity concentration/volatile alkalinity concentration and volatile fatty acids were negatively correlated with cumulative biogas yield. This study provided insights on anaerobic codigestion of the Pennisetum hybrid and kitchen waste in the presence of iron oxides, which will be beneficial for further studies in the field of renewable energy production

Evaluation of a Novel Biphasic Culture Medium for Recovery of Mycobacteria: A Multi-Center Study

on L-J slants. Automated liquid culture systems are expensive. A low-cost culturing medium capable of rapidly indicating the presence of mycobacteria is needed. The aim of this study was to develop and evaluate a novel biphasic culture medium for the recovery of mycobacteria from clinical sputum specimens from suspected pulmonary tuberculosis patients.<0.001).

Predictive model and risk analysis for peripheral vascular disease in type 2 diabetes mellitus patients using machine learning and shapley additive explanation

BackgroundPeripheral vascular disease (PVD) is a common complication in patients with type 2 diabetes mellitus (T2DM). Early detection or prediction the risk of developing PVD is important for clinical decision-making.PurposeThis study aims to establish and validate PVD risk prediction models and perform risk factor analysis for PVD in patients with T2DM using machine learning and Shapley Additive Explanation(SHAP) based on electronic health records.MethodsWe retrospectively analyzed the data from 4,372 inpatients with diabetes in a hospital between January 1, 2021, and March 28, 2023. The data comprised demographic characteristics, discharge diagnoses and biochemical index test results. After data preprocessing and feature selection using Recursive Feature Elimination(RFE), the dataset was split into training and testing sets at a ratio of 8:2, with the Synthetic Minority Over-sampling Technique(SMOTE) employed to balance the training set. Six machine learning(ML) algorithms, including decision tree (DT), logistic regression (LR), random forest (RF), support vector machine(SVM),extreme gradient boosting (XGBoost) and Adaptive Boosting(AdaBoost) were applied to construct PVD prediction models. A grid search with 10-fold cross-validation was conducted to optimize the hyperparameters. Metrics such as accuracy, precision, recall, F1-score, G-mean, and the area under the receiver operating characteristic curve (AUC) assessed the models’ effectiveness. The SHAP method interpreted the best-performing model.ResultsRFE identified the optimal 12 predictors. The XGBoost model outperformed other five ML models, with an AUC of 0.945, G-mean of 0.843, accuracy of 0.890, precision of 0.930, recall of 0.927, and F1-score of 0.928. The feature importance of ML models and SHAP results indicated that Hemoglobin (Hb), age, total bile acids (TBA) and lipoprotein(a)(LP-a) are the top four important risk factors for PVD in T2DM.ConclusionThe machine learning approach successfully developed a PVD risk prediction model with good performance. The model identified the factors associated with PVD and offered physicians an intuitive understanding on the impact of key features in the model

Iron-fortified Anaerobic Co-digestion Performance of Kitchen Waste and Pennisetum Hybrid

Element iron as an essential trace metal has the function of facilitating the process of anaerobic digestion and consequently improving the biogas yield. Accordingly, the mixture ratio of kitchen waste and Pennisetum hybrid was optimized for the codigestion system, and the effects of iron powder (IP), iron protoxide (FeO), and zero valent iron (nZVI) on the performance of the co-digestion system were studied under the batch mode and mesophilic condition. The results showed that the mixture ratio of 0.5:9.5 of kitchen waste and Pennisetum hybrid achieved a higher specific biogas yield of 338.32 +/- 10.44 mL/g VS, which increased by 52.60% in comparison with that of the mono-digestion of Pennisetum hybrid. Based on the results, adding IP, FeO, and nZVI to the co-digestion system improves the biogas yield. Among them, a maximum specific biogas yield of 406.73 +/- 61.28 mL/g VS was obtained by adding IP at the dosage of 0.5% and increased by 39.50% in comparison with the control system. For the co-digestion system with nZVI and FeO addition, an increase of 0.64% and 29.60% in specific biogas yields was achieved at the same dosage 0.5%

Conventional and unconventional petroleum “orderly accumulation”: Concept and practical significance

Based on the latest global conventional-unconventional petroleum development situation and the conclusion of petroleum geology theory and technology innovation in recent 10 years, the connotation of conventional and unconventional petroleum “orderly accumulation” connotation is formulated. This concept indicates that, unconventional petroleum occurs in the hydrocarbon supply direction of conventional petroleum, and conventional petroleum may appear in the outer space of unconventional petroleum. Proper evaluation methods and engineering technology are important to push the conventional-unconventional petroleum co-development, and the petroleum finding thought from outer-source into inner-source. Unconventional petroleum evaluation focuses on source rocks characteristics, lithology, physical property, brittleness, oil-gas possibility and stress anisotropy. Taking shale gas for examples, in China, these six properties are TOC>2%, laminated silicious calcareous shale or calcareous silicious shale, porosity 3%-8%, brittle minerals content 50%-80%, gas content 2.3-4.1 m3/t, pressure coefficient 1.0-2.3, natural fractures; in north America, these six properties are TOC>4%, silicious shale or calcareous shale or marl, porosity 4%-9%, brittle minerals content 40%-70%, gas content 2.8-9.9 m3/t, pressure coefficient 1.3-1.85, natural fractures. “Sweet spot area” assessment, “factory-like” operation pattern and other core evaluation methods and technologies are discussed. And 8 key elements of unconventional “sweet spot area” are proposed, 3 of them are TOC>2% (for shale oil S1>2 mg/g), higher porosity (for tight oil & gas >10%, shale oil & gas >3%), and microfractures. Multiple wells “factory-like” operation pattern is elaborated, and its implementation needs 4 elements, i.e. batch well spacing, standard design, flow process, and reutilization. Through horizontal well volume fractures in directions, “man-made reservoirs” with large-scale fracture systems can be formed underground. For “shale oil revolution” in future, non-water “gas in critical state” and etc. fracturing fluid and matching technology should be stressed to be industrially tested and encouraged to be low cost developed. Key words: unconventional petroleum, “orderly accumulation”, co-development, “sweet spot area” assessment, “factory-like” operation pattern, “man-made reservoir”, tight oil, shale oil, shale gas, tight gas, petroleum exploration into source rock

Rates of recovery of mycobacteria by biphasic medium, L-J medium and MGIT 960 culture system.

<p>Rates of recovery of mycobacteria by biphasic medium, L-J medium and MGIT 960 culture system.</p

Growth of mycobacteria in L-J and biphasic medium scenarios with acid-fast bacilli (AFB) smear microscopy and status of the source respiratory specimen.

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036331#s3" target="_blank">Results</a> are shown for 830 AFB smear-negative respiratory specimens and 362 AFB smear-positive respiratory specimens that were found positive for <i>M. tuberculosis</i> by both L-J and biphasic medium (B–P). L-J, culture on L-J medium; B–P, culture in biphasic medium.</p

Growth of H37Rv culture on and in different culture media.

<p>For L-J (0.1), biphasic medium (0.1), and MGIT (0.1), a mean 0.1 ml of inocula were incubated. For biphasic medium (0.5) and MGIT (0.5), a mean 0.5 ml of inocula were incubated.</p