Vanadium Extraction from the Flotation Concentrate of Vanadium-Bearing Shale by Process of Non-Roasting Enhanced Acid Leaching and Thermodynamics.

The purpose of this work is to significantly improve the vanadium grade of vanadium-bearing shale after flotation preconcentration, which is conducive to reducing the acid consumption and industrial costs in the subsequently enhanced acid leaching of vanadium. Vanadium concentrate from vanadium-bearing shale enriched by flotation is used for acid-leaching feed. The leaching effects of two kinds of acid-leaching systems were compared, and the mechanism of acid leaching on the mineral structure was also described. The difficulty of spontaneous reactions of vanadium-bearing minerals such as garnet in an acid-leaching system was studied through thermodynamics. Additionally, several characterization methods were used to evaluate the improvement of leaching performance. The addition of oxidants and fluorinating aids strengthens the acid-leaching process, which greatly destroys the structure of a garnet, which is conducive to the extraction of vanadium in a flotation concentrate. The leaching efficiency can reach 94.86%, and the acid consumption is also reduced. Through the mechanism study of the leaching system, it is expected that when the enhanced acid-leaching process is put into industrial production, the effective leaching of vanadium can be accurately controlled, and the difficulty of subsequent vanadium enrichment and purification can be reduced.

A Novel Multicolor Flow Cytometry Scoring System for the Diagnosis and Prognostic Stratification of Myelodysplastic Syndromes.

BACKGROUND: Myelodysplastic syndromes (MDS) are a class of myeloid neoplasms featuring inefficient maturation and differentiation of hematopoietic cells, blood cytopenia, and a high risk of leukemia onset. The diagnosis of MDS remains a challenging task owing to its complexity, heterogeneity, and the lack of specific characteristics. METHODS: To look for an easy and inexpensive diagnostic method for MDS, we tried to establish an FCM scoring systems (FCSS) with a combination of antibodies for diagnosis and prognostic stratification of MDS. This FCSS adopted four parameters; i.e., the frequency of myeloblasts in nucleated cells, the ratio between pro-B cells and CD117+ cells, the ratio of CD45 mean fluorescence intensity between lymphocytes and myeloblasts, and the ratio of SSC peak values between mature granulocytes and lymphocytes. RESULTS: We tested the correlation between the total FCSS score with conventional IPSS-R. Additionally, the correlation between the score of each FCSS parameter and IPSS-R was also evaluated. We found that total FCSS score had a positive correlation with IPSS-R, while FCSS parameter 1 and 4 were also correlated with IPSS-R. Furthermore, this FCSS had a sound sensitivity and specificity in the diagnosis of MDS. CONCLUSIONS: The FCSS represents a convenient and affordable approach for the diagnosis and prognostic stratification of MDS.

A new prenylated coumarin and a new anthranilamide derivative from Evodia lepta.

A new prenylated coumarin (1) and a new anthranilamide derivative (2) were isolated from the aerial parts of Evodia lepta. Compound 2 represents the first anthranilamide derivative from the Evodia genus. Their structures were elucidated by spectroscopic data analysis (MS, UV, IR, and NMR). Compound 1 exhibited certain inhibition on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 macrophages with an IC50 value of 37.96 ± 1.7 µM.

Two new naphthoate derivatives from Morinda officinalis.

Two new naphthoate derivatives, including a symmetrical dimer (1) and a monomer (2), were separated from the roots of Morinda officinalis var. hirsuta. Their structures were characterized on the basis of spectroscopic means especially MS and NMR methods. Biological evaluations revealed that the two compounds did not show inhibition against both cholinesterases AChE and BChE, while the dimer (1) did exhibit moderate growth inhibitory activity toward one human osteosarcoma cell line U2OS with an IC50 value of 18.5 ± 1.1 µM.

Metals source apportionment in farmland soil and the prediction of metal transfer in the soil-rice-human chain.

China is facing serious heavy metal pollution in farmland soil, which is a major pressing concern for food safety and human health. This research delivers an integrated methodology for pollution source apportionment and a soil-rice-human model to predict heavy metal transfer in the farmland soil, rice grain and human blood chain. The source identification integrated positive matrix factorization (PMF), cluster analysis (CA) and the life cycle assessment (LCA) survey of agricultural and industrial production and consumption. Based on the case analysis of Shaoxing, this method showed very good performance through the illustration of the source contributions by PMF and LCA at county level and the identification of the pollution sources using CA and LCA at field scale. According to the overall evaluation, the integrated method was superior for the farmland metals pollution source identification comparing to existing source apportionment methods. To predict metal transformation in soil-rice-human chain, a set of models of metals (As, Pb, Cd, Hg, Cr) accumulation ability in rice grain and human blood has been established by literature review and monitoring data. The models showed adequate predictability for the metal content of rice grains at both the field and regional scale, and plausible simulation of the metal concentration in human blood throughout the whole study region. Therefore, this study provides valuable tools for farmland soil heavy metal pollution source identification and for the prediction of heavy metal transformation in soil-rice-human chain; and it can highlight the need to take mitigating action to reduce farmland metal pollution risks in specific regions.

Cp*Co(III)-Catalyzed Dearomative [3 + 2] Spiroannulation of 2-Alkenylphenols with Ynamides via C-H Activation.

An oxidative [3 + 2] C-H spiroannulation reaction of 2-alkenylphenols with ynamides has been developed toward the synthesis of spiro[4,5]decane derivatives. This dearomative reaction employs earth-abundant cobalt as the metal catalyst and occurs under rather mild reaction conditions (room temperature). The use of ynamides confers unique reactivity and exclusive regioselectivity. The products bearing an all-carbon quaternary stereogenic center were constructed in generally good yields with good functional group tolerance being observed. Experimental mechanistic studies were conducted, and a possible reaction mechanism is proposed.

Zn/N/S Co-doped hierarchical porous carbon as a high-efficiency oxygen reduction catalyst in Zn-air batteries.

Zn-N-C catalysts have garnered attention as potential electrocatalysts for the oxygen reduction reaction (ORR). However, their intrinsic limitations, including poor activity and a low density of active sites, continue to hinder their electrocatalytic performance. In this study, we have devised a dual-template strategy for the synthesis of Zn, N, S co-doped nanoporous carbon-based catalysts (Zn-N/S-C(S, Z)) with a substantial specific surface area and a graded pore structure. The introduction of S enhances electron localization around the Zn-Nx active centers, facilitating interactions with oxygen-containing substances. The resulting Zn-N/S-C(S, Z) sample exhibits outstanding performance in an alkaline solution, demonstrating a half-wave potential of 0.89 V. This value surpasses that of commercial Pt/C by 40 mV. Furthermore, when combined with RuO2 (Zn-N/S-C(S, Z) + RuO2), the catalyst demonstrates exceptional performance in a Zn-air battery, offering an open-circuit voltage (OCV) of 1.47 V and a peak power density of 290.8 mW cm-2. This study paves the way for the development of highly dispersed and highly active Zn-metal site catalysts, potentially replacing traditional Pt-based catalysts in various electrochemical devices.

High-Quality N-Doped Graphene with Controllable Nitrogen Bonding Configurations Derived from Ionic Liquids.

Controllable nitrogen doping is an effective way to regulate the electronic properties of graphene and further to facilitate its wider application. However, the synthesis of high-quality nitrogen-doped graphene (NG) with a controllable nitrogen configuration still faces considerable challenges. In this work, we present for the first time a simple method for the one-step synthesis of NG with ionic liquids (ILs) as precursors, which avoids the defects introduced by secondary doping and simplifies the process. Using 1-Ethyl-3-methylimidazolium dicyanamide (EMIM-dca) as the precursor, we obtained a high-quality NG with few defects (ID /IG is 0.83), nitrogen content (4.11 at%), and graphite-N proportion of 92% at a growth temperature of 1000 °C and field effect transistors (FETs) fabricated on SiO2 /Si substrates using the NG exhibited typical n-type semiconductor behavior in air. Our findings bring more inspiration for the controllable growth of high-quality graphitic N-doped graphene, thereby promoting its application possibilities in numerous fields.

Three new bioactive diterpenoids from the roots of Croton crassifolius.

Phytochemical investigation of Croton crassifolius led to the isolation of two new halimane diterpenoids (1 and 2), a new nor-clerodane diterpenoid (3), along with three known analogues (4-6). Their structures including absolute configurations were elucidated by spectroscopic analysis, single-crystal X-ray diffraction, and CD analysis. All isolates were evaluated for their inhibitory effects on the nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 macrophage cells, and compound 1 exhibited moderate inhibition of NO production with an IC50 value of 25.8 ± 0.9 µM.

Improving the precision of modeling the incidence of hemorrhagic fever with renal syndrome in mainland China with an ensemble machine learning approach.

OBJECTIVE: Hemorrhagic fever with renal syndrome (HFRS), one of the main public health concerns in mainland China, is a group of clinically similar diseases caused by hantaviruses. Statistical approaches have always been leveraged to forecast the future incidence rates of certain infectious diseases to effectively control their prevalence and outbreak potential. Compared to the use of one base model, model stacking can often produce better forecasting results. In this study, we fitted the monthly reported cases of HFRS in mainland China with a model stacking approach and compared its forecasting performance with those of five base models. METHOD: We fitted the monthly reported cases of HFRS ranging from January 2004 to June 2019 in mainland China with an autoregressive integrated moving average (ARIMA) model; the Holt-Winter (HW) method, seasonal decomposition of the time series by LOESS (STL); a neural network autoregressive (NNAR) model; and an exponential smoothing state space model with a Box-Cox transformation; ARMA errors; and trend and seasonal components (TBATS), and we combined the forecasting results with the inverse rank approach. The forecasting performance was estimated based on several accuracy criteria for model prediction, including the mean absolute percentage error (MAPE), root-mean-squared error (RMSE) and mean absolute error (MAE). RESULT: There was a slight downward trend and obvious seasonal periodicity inherent in the time series data for HFRS in mainland China. The model stacking method was selected as the best approach with the best performance in terms of both fitting (RMSE 128.19, MAE 85.63, MAPE 8.18) and prediction (RMSE 151.86, MAE 118.28, MAPE 13.16). CONCLUSION: The results showed that model stacking by using the optimal mean forecasting weight of the five abovementioned models achieved the best performance in terms of predicting HFRS one year into the future. This study has corroborated the conclusion that model stacking is an easy way to enhance prediction accuracy when modeling HFRS.

Comparison of ARIMA model and XGBoost model for prediction of human brucellosis in mainland China: a time-series study.

OBJECTIVES: Human brucellosis is a public health problem endangering health and property in China. Predicting the trend and the seasonality of human brucellosis is of great significance for its prevention. In this study, a comparison between the autoregressive integrated moving average (ARIMA) model and the eXtreme Gradient Boosting (XGBoost) model was conducted to determine which was more suitable for predicting the occurrence of brucellosis in mainland China. DESIGN: Time-series study. SETTING: Mainland China. METHODS: Data on human brucellosis in mainland China were provided by the National Health and Family Planning Commission of China. The data were divided into a training set and a test set. The training set was composed of the monthly incidence of human brucellosis in mainland China from January 2008 to June 2018, and the test set was composed of the monthly incidence from July 2018 to June 2019. The mean absolute error (MAE), root mean square error (RMSE) and mean absolute percentage error (MAPE) were used to evaluate the effects of model fitting and prediction. RESULTS: The number of human brucellosis patients in mainland China increased from 30 002 in 2008 to 40 328 in 2018. There was an increasing trend and obvious seasonal distribution in the original time series. For the training set, the MAE, RSME and MAPE of the ARIMA(0,1,1)×(0,1,1)12 model were 338.867, 450.223 and 10.323, respectively, and the MAE, RSME and MAPE of the XGBoost model were 189.332, 262.458 and 4.475, respectively. For the test set, the MAE, RSME and MAPE of the ARIMA(0,1,1)×(0,1,1)12 model were 529.406, 586.059 and 17.676, respectively, and the MAE, RSME and MAPE of the XGBoost model were 249.307, 280.645 and 7.643, respectively. CONCLUSIONS: The performance of the XGBoost model was better than that of the ARIMA model. The XGBoost model is more suitable for prediction cases of human brucellosis in mainland China.

[One stage thyroidectomy and bilateral neck dissection for well-differentiated thyroid carcinoma].

OBJECTIVE: To investigate the indications, safety and difficulties of one stage thyroidectomy and bilateral neck lymph node dissection for well-differentiated thyroid carcinoma. METHODS: A retrospective review was carried out in 36 well-differentiated thyroid carcinoma patients so treated from 1990 to 2004. Various incisions including H, L and modified Kocher types were selected according to the location of primary tumor and status of cervical lymph node metastasis. Either total thyroidectomy or sub-total thyroidectomy combined with bilateral neck lymph node dissection according to the principles of modified radical neck lymph node dissection: preserving the internal jugular vein, spinal accessory nerve and sternocleidomastoid muscles. RESULTS: There was no operative death in this group. Postoperative complications included: 2 wound bleeding, 3 recurrent laryngeal nerve resection due to tumor involvement, 1 recurrent laryngeal nerve injury, 2 unilateral internal branch of superior laryngeal nerve injury, 9 unilateral external branch of superior laryngeal nerve injury, 3 unilateral accessory nerve injury, 5 unilateral sympathetic nerve injury, 2 unilateral phrenic nerve injury, 6 chylus fistula, 13 temporary hypoparathyroidism, 2 permanent hypoparathyroidism. The dissected lymph nodes were found to be positive from 0 to 21 in each patient with a mean of 8.3. Of the 36 patients: 31 had bilateral positive lymph nodes; 3 unilateral positive; 2 bilateral negative lymph nodes. The follow up period ranged from 1 to 13 years, Three patients died of distant metastasis, 1 died of cerebral vascular accident. 7 patients lost in follow-up. Totally, 25 patients are still alive, 3 patients had local relapse and were surgically treated again. CONCLUSION: The procedure of one-stage thyroidectomy and bilateral neck lymph node dissection for well-differentiated thyroid carcinoma is safe, as it is mandatory that at least one unilateral internal jugular vein should be preserved; one unilateral recurrent laryngeal nerves and accessory nerves should not be injured. Well-differentiated thyroid carcinoma patients whose bilateral cervical lymph nodes are clinically suspected to be positive (obviously enlarged, hard, purplish grapelike lymph node) or are confirmed pathologically to be positive are indications for one-stage thyroidectomy and bilateral neck lymph node dissection. Total or sub-total thyroidectomy should be undertaken with emphasis that at least one parathyroid with blood supply should be preserved. It is of utmost importance that not only the cancer be completely resected but the function of the organs be preserved.