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To evaluate the effects of biochar on pH buffering capacity (pHBC) of paddy soils, rice straw biochar (RC) was modified by hydrogen peroxide (H2O2) and nitric acid/sulphuric acid (HNO3/H2SO4), respectively, and then added to the paddy soils developed from sandy Ultisol, clay Ultisol and granite Ultisol at the same proportion. After submerging and draining incubation, soil pHBC, soil pH and the available cadmium (Cd) extracted with calcium chloride were determined. The results indicated that the two modified biochars effectively promoted pHBC of three paddy soils and HNO3/H2SO4 modified biochar (HNO3/H2SO4-RC) led to greater increase in soil pHBC. Compared with control, HNO3/H2SO4-RC apparently increased pHBC of the paddy soils from sandy Ultisol, clay Ultisol and granite Ultisol by 32.7%, 37.4% and 25.3%, respectively. Correspondingly, soil pH increased by 1.59, 1.15 and 0.88 units, and the available Cd decreased by 74.1%, 67.5% and 75.0% in the paddy soils due to the incorporation of HNO3/H2SO4-RC. HNO3/H2SO4 modification significantly increased the carboxyl groups on the surface of RC. The dissociation of these functional groups produced a large number of organic anions, which could consume exogenous protons, and thus retarding the decline of soil pH and decreased soil available Cd. [ABSTRACT FROM AUTHOR]

Objective: To externally validate the Ovarian‐adnexal Reporting and Data System (O‐RADS) and evaluate its performance in differentiating benign from malignant adnexal masses (AMs) compared with the Gynecologic Imaging Reporting and Data System (GI‐RADS) and Assessment of Different NEoplasias in the adneXa (ADNEX). Methods: A retrospective analysis was performed on 734 cases from the Second Affiliated Hospital of Fujian Medical University. All patients underwent transvaginal or transabdominal ultrasound examination. Pathological diagnoses were obtained for all the included AMs. O‐RADS, GI‐RADS, and ADNEX were used to evaluate AMs by two sonologists, and the diagnostic efficacy of the three systems was analyzed and compared using pathology as the gold standard. We used the kappa index to evaluate the inter‐reviewer agreement (IRA). Results: A total of 734 AMs, including 564 benign masses, 69 borderline masses, and 101 malignant masses were included in this study. O‐RADS (0.88) and GI‐RADS (0.90) had lower sensitivity than ADNEX (0.95) (P <.05), and the PPV of O‐RADS (0.98) was higher than that of ADNEX (0.96) (P <.05). These three systems showed good IRA. Conclusion: O‐RADS, GI‐RADS, and ADNEX showed little difference in diagnostic performance among resident sonologists. These three systems have their own characteristics and can be selected according to the type of center, access to patients' clinical data, or personal comfort. [ABSTRACT FROM AUTHOR]

Polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer, or Soluplus®, is a relatively new copolymer and a promising carrier of amorphous solid dispersions. Knowledge on the inherent properties of Soluplus® (e.g. cloud points, critical micelle concentrations, and viscosity) in different conditions is relatively inadequate, and the application characteristics of Soluplus®-based solid dispersions made by microwave methods still need to be clarified. In the present investigation, the inherent properties of a Soluplus® carrier, including cloud points, critical micelle concentrations, and viscosity, were explored in different media and in altered conditions. Ibuprofen, a BCS class II non-steroidal anti-inflammatory drug, was selected to develop Soluplus®-based amorphous solid dispersions using the microwave-quench cooling (MQC) method. Scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Raman spectroscopy (RS), and Fourier transform infrared spectroscopy (FT-IR) were adopted to analyze amorphous properties and molecular interactions in ibuprofen/Soluplus® amorphous solid dispersions generated by MQC. Dissolution, dissolution extension, phase solubility, equilibrium solubility, and supersaturated crystallization inhibiting experiments were performed to elucidate the effects of Soluplus® on ibuprofen in solid dispersions. This research provides valuable information on the inherent properties of Soluplus® and presents a basic understanding of Soluplus® as a carrier of amorphous solid dispersions. [ABSTRACT FROM AUTHOR]

An efficient procedure for the synthesis of biaryls was catalyzed by Pd(CH3CN)4(BF4)2 is reported. This Pd-catalyzed cross-coupling reaction of aryltrifluoroborates with sodium arenesulfinates was developed under mild and environmentally benign conditions, in water without any ligand or additive. The reaction gave a range of structurally diverse unsymmetrical bi-aryl molecules with excellent yields, in which the byproduct was sulfur dioxide. It is worth noting that this protocol is also applicable to many heterocyclic aromatics such as thiophene, furan, pyridine, quinoline, isoquinoline and indole. [ABSTRACT FROM AUTHOR]

Biochar was prepared from rice straw and modified with 15% H 2 O 2 and 1:1 HNO 3 /H 2 SO 4 , respectively. The unmodified biochars and HCl treated biochars for carbonate removal were used as control. The biochars were added to the acid paddy soil collected from Langxi, Anhui Province, China at the rate of 30 g/kg. The paddy soil was flooded and then air-dried, and soil pH and Eh were measured in situ with pH electrode and platinum electrode during wet-dry alternation. Soil pH buffering capacity (pHBC) was determined by acid-base titration after the wet-dry treatment. Then, the simulated acidification experiments were carried out to study the changing trends of soil pH, base cations and exchangeable acidity. The results showed that soil pHBC was effectively increased and the resistance of the paddy soil to acidification was apparently enhanced with the incorporation of H 2 O 2 - and HNO 3 /H 2 SO 4 -modified biochars. Surface functional groups on biochars were mainly responsible for enhanced soil resistance to acidification. During soil acidification, the protonation of organic anions generated by dissociation of these functional groups effectively retarded the decline of soil pH. The modification of HNO 3 /H 2 SO 4 led to greater increase in carboxyl functional groups on the biochars than H 2 O 2 modification and thus HNO 3 /H 2 SO 4 -modified biochars showed more enhancement in soil resistance to acidification than H 2 O 2 -modified biochars. After a wet-dry cycle, the pH of the paddy soil incorporated with HNO 3 /H 2 SO 4 -modified biochar increased apparently. Consequently, the addition of HNO 3 /H 2 SO 4 -modified biochar can be regarded as a new method to alleviate soil acidification. In short, the meaning of this paper is to provide a new method for the amelioration of acid paddy soils., (Copyright © 2021 Elsevier Ltd. All rights reserved.)