Modification and application of coking coal by alkali pretreatment in wastewater adsorption

<p>Coking coal has been employed for coking wastewater adsorption treatment. The modification and adsorption of coking coal pretreated by alkali solution is discussed and compared in this study. Results demonstrated OH- could react with -COOH, -OH and minerals, which resulted in coal surface variations. As the hydroxide concentration is increased, surface hydrophobility increased and the zeta potential became less negative. A coal sample pretreated by 0.1 mol/L NaOH solution had the highest surface area and pore volume. The adsorption ability of the samples was improved significantly as surface changes. The coal sample pretreated by 0.1 mol/L NaOH solution had the highest adsorption capacity, and followed pseudo-second-order kinetics.</p

NO Reduction by H₂ on the Rh(111) and Rh(221) Surfaces: A Mechanistic and Kinetic Study

Periodic density functional theory (DFT) was used to investigate the selective catalytic reduction of NO by H₂ (H₂ SCR) on Rh(111) and stepped Rh(221) surfaces. The stepped Rh(221) surface exhibits a higher reactivity for NO reduction than the Rh(111) surface. NO dissociation on the Rh(221) surface exhibits almost no effect in the presence of H₂, whereas predosed H atoms slightly inhibit NO dissociation on Rh(111). Microkinetic calculations further predicted the product selectivity for H₂ SCR at different temperatures and pressures. It was found that, under ultrahigh-vacuum (UHV) conditions, NH₃ is the only N-containing product on Rh(111), consistent with the experimental observations, whereas on the Rh(221) surface, N₂O formation is predominant at low temperatures, and N₂ becomes main product above 480 K. Under near-atmospheric-pressure conditions, the product selectivity on the Rh(111) surface exhibits almost no change, whereas N₂O is the dominant product on Rh(221) throughout the whole temperature range. The present study indicates that the NO dissociation activity and product selectivity are strongly dependent on both the Rh surface structure and the experimental conditions

Effect of Subsurface Oxygen on Selective Catalytic Reduction of NO by H₂ on Pt(100): A First-Principles Study

The mechanisms of NO reduction by H₂ on the Pt(100) surface and the surface modified with subsurface oxygen atoms (Md-Pt(100)) are studied by first-principles calculations. Similar catalytic activity toward NO dissociation is found on both surfaces with barriers of 0.86 and 0.96 eV, respectively. The pathway of N + N → N₂ rather than NO + N → N₂ + O is the N₂ formation pathway on the Pt(100) surface, while these two pathways are competitive on the Md-Pt(100) surface. The NH₃ formation is almost negligible, and reductant hydrogen can effectively remove the surface oxygen on both surfaces. The microkinetic analysis further confirms that, compared to the high selectivity toward N₂O (almost 100% at 300–500 K) on the clean surface, higher N₂ low-temperature selectivity (larger than 90%) is achieved on the Md-Pt(100) surface under lower pressure. The present study shows that subsurface oxygen has an enhanced effect for improving the N₂ selectivity of NO reduction on Pt catalysts

Data_Sheet_1_Exposure to heavy metals and trace elements among pregnant women with twins: levels and association with twin growth discordance.docx

BackgroundTwin growth discordance is one of the leading causes of perinatal mortality in twin pregnancies. Whether prenatal exposure to heavy metals and trace elements is associated with twin growth discordance has not been studied yet.ObjectiveTo evaluate the prenatal level of heavy metals and trace elements in twin pregnancy and its relationship with twin growth discordance.MethodsThis study involving 60 twin pairs and their mothers was conducted in Zhejiang Province, China, in 2020–2021. The concentration of heavy metals and trace elements in maternal blood, umbilical cord, and placenta were collected at delivery and measured by inductively coupled plasma tandem mass spectrometer. The association of prenatal level with twin growth discordance was evaluated using conditional logistic regression.ResultsHigh levels of heavy metal elements (thallium in maternal blood and umbilical cord blood of larger twins, vanadium in the placenta of larger twins) and trace elements (iodine in the placenta of larger twins) during pregnancy, as well as low levels of heavy metal elements (strontium in the umbilical cord blood of larger twins, strontium and chromium in the umbilical cord blood of smaller twins, strontium in the placenta of larger twins, molybdenum and lead in the placenta of smaller twins and difference of molybdenum in the placenta of twins), are associated with intertwin birthweight discordance. Univariate regression analyses showed a significant effect of gestational age at delivery and eleven trace element data on intertwin birthweight discordance. Multivariable logistic regression analysis with transformed variables as dichotomous risk factors combined with baseline demographic characteristics showed Tl in maternal blood as an independent risk factor. The model constructed by combining Tl in maternal blood (OR = 54.833, 95% CI, 3.839–83.156) with the gestational week (OR = 0.618, 95% CI, 0.463–0.824) had good predictive power for intertwin birthweight discordance (AUC = 0.871). The sensitivity analysis results indicate that the effect of maternal blood thallium on intertwin birthweight discordance is stable and reliable.ConclusionTo our knowledge, ours is the first case–control study to investigate the association between elevated maternal thallium levels before delivery and twin growth discordance.</p

Circulating MicroRNAs as a Novel Class of Diagnostic Biomarkers in Gastrointestinal Tumors Detection: A Meta-Analysis Based on 42 Articles

<div><p>Objective</p><p>MicroRNAs (miRNAs) have become the focus of most recent efforts in cancer research. However, there have been inconsistencies in the literature regarding the suitability of circulating miRNAs for early detection of gastrointestinal cancers. This study aims to assess the diagnostic performance of circulating miRNAs in detection of gastrointestinal cancer through a meta-analysis.</p><p>Methods</p><p>Eligible studies were selected by conducting a systematic literature search of public databases. The sensitivity and specificity were used to plot the summary receiver operator characteristic (SROC) curve and calculate the area under the SROC curve (AUC). The between-study heterogeneity was evaluated by <i>Q</i> test and <i>I</i>² statistics. Subgroup analyses and meta-regression were further performed to explore the potential sources of heterogeneity. All analyses were performed using the STATA 12.0 software.</p><p>Results</p><p>A total of 107 studies from 42 articles were included for the meta-analysis according to the inclusion criteria. The overall analysis of all gastrointestinal cancers showed that circulating miRNAs have a relatively good diagnostic performance in gastrointestinal cancers, with a sensitivity of 0.75, a specificity of 0.81 and an AUC of 0.85. In addition, subgroup analyses based on different type of miRNA assay suggested that single-miRNA assay displayed a relatively low diagnostic performance with the AUC values of 0.84 for gastric cancer (GC) and 0.79 for colorectal cancer (CRC), while multiple-miRNAs assay significantly improved the diagnosing accuracy with AUC rising to 0.92 for GC and 0.89 for CRC. Another interesting finding was that plasma-based miRNA assay reach a higher accuracy compared with serum-based one for GC, while opposite conclusion was drawn for CRC.</p><p>Conclusions</p><p>In conclusion, circulating miRNAs, particularly the combination of multiple miRNAs, may present as promising biomarkers for the diagnosis of gastrointestinal cancers. Further large-scale prospective studies are necessary to validate their potential applicability in human cancer diagnosis.</p></div

Main characteristics of 42 studies included in meta-analysis.

a<p>miR-221, -744, -376c, -27a, -27b, -222, -191.</p>b<p>miR-18a, -20a, -21, -29a, -92a, -106b, -133a, -143, -145, -181b, -342-3p, -532-3p.</p>c<p>miR-10a, -22, -100, -148b, -223, -133a, -127-3p.</p><p>NA, not available; GC, gastric cancer; CRC, colorectal cancer; EC, esophageal cancer; QUADAS-2, the revised Quality Assessment of Diagnostic Accuracy Studies.</p><p>Main characteristics of 42 studies included in meta-analysis.</p

Overall quality assessment of included studies using the QUADAS-2 criteria (a: risk of bias; b: applicability).

<p>Overall quality assessment of included studies using the QUADAS-2 criteria (a: risk of bias; b: applicability).</p

Forest plots of multivariable meta-regression analyses for sensitivity and specificity (a: single-miRNA assay; b: multiple-miRNAs assay).

<p>Forest plots of multivariable meta-regression analyses for sensitivity and specificity (a: single-miRNA assay; b: multiple-miRNAs assay).</p

SROC curve with pooled estimates of sensitivity, specificity and AUC on the diagnostic value of circulating miRNAs in CRC detection (a: single-miRNA assay; b: multiple-miRNAs assay; c: plasma-based assay; d: serum-based assay).

<p>SROC curve with pooled estimates of sensitivity, specificity and AUC on the diagnostic value of circulating miRNAs in CRC detection (a: single-miRNA assay; b: multiple-miRNAs assay; c: plasma-based assay; d: serum-based assay).</p

SROC curve with pooled estimates of sensitivity, specificity and AUC (a: overall studies on gastrointestinal cancers; b: GC; c: CRC; d: EC).

<p>SROC curve with pooled estimates of sensitivity, specificity and AUC (a: overall studies on gastrointestinal cancers; b: GC; c: CRC; d: EC).</p