The modification mechanism of low-molecular-weight organic acids on a single-chain silicate mineral (wollastonite) was investigated through a leaching method. Solid and liquid samples were analyzed using atomic absorption spectrophotometer (AAS), X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier-transform infrared spectroscopy (FTIR). After 720 h of reaction, the results revealed that the dissolution concentration of Si (2200 μmol/L) in citric acid solution is more than that (1950 μmol/L) in oxalic acid.
View Article and Find Full Text PDFFeldspar is a high-abundance mineral in the earth's crust, and its natural weathering and dissolution processes are an important phenomenon on the earth's surface. This study focused on the dissolution behavior of silicon (Si) and aluminum (Al) in feldspar minerals (microcline and albite) when exposed to low-molecular-weight organic acids (LMWOAs). Various analytical techniques, including atomic absorption spectrophotometer, X-ray diffraction, scanning electron microscope, and Fourier-transform infrared spectroscopy, were employed to investigate these processes.
View Article and Find Full Text PDFThe interaction between low-molecular-weight organic acids (LMWOAs) and minerals in nature has been widely studied; however, limited research has been conducted on the dissolution mechanism of sillimanite in the presence of different organic acids. In this study, the interaction between the sillimanite sample and LMWOAs (citric acid, oxalic acid, and citric/oxalic mixture) at the same pH was investigated. The dissolution rate of Si and Al was high during the initial reaction time, then slowed down in the presence of LMWOAs.
View Article and Find Full Text PDFThe organization of the brain follows a topological hierarchy that changes dynamically during development. However, it remains unknown whether and how cognitive training administered over multiple years during development can modify this hierarchical topology. By measuring the brain and behavior of school children who had carried out abacus-based mental calculation (AMC) training for five years (starting from 7 years to 12 years old) in pre-training and post-training, we revealed the reshaping effect of long-term AMC intervention during development on the brain hierarchical topology.
View Article and Find Full Text PDF6-Thioguanine (6-TG) is a purine analog anticancer drug used to treat childhood acute leukemia and inflammatory bowel disease; however, the over-dosage use of 6-TG can cause serious adverse effects. Therefore, monitoring the free 6-TG concentration in the human body is critical during drug therapy. In this work, a highly sensitive and rapid fluorescent nanoprobe based on Cu/Ag nanoclusters (NCs) for the detection of 6-TG was developed.
View Article and Find Full Text PDFA high sintering temperature is usually required to acquire excellent performance in the ceramic industry, but it results in high fuel consumption and high pollution. To reduce the sintering temperature and to toughen the porcelain, a self-produced sintering additive of citric acid activated kaolinite was added to the raw material; X-ray powder diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and thermal gravity analysis and differential scanning calorimetry (TG-DSC) were used to characterize the samples, and the toughening mechanism was discussed. The citric acid activated kaolinite obtained high activity and a large specific surface area.
View Article and Find Full Text PDFFront Comput Neurosci
April 2022
Functional magnetic resonance imaging (fMRI) is one of the best techniques for precise localization of abnormal brain activity non-invasively. Machine-learning approaches have been widely used in neuroimaging studies; however, few studies have investigated the single-voxel modeling of fMRI data under cognitive tasks. We proposed a hybrid one-dimensional (1D) convolutional neural network (1D-CNN) based on the temporal dynamics of single-voxel fMRI time-series and successfully differentiated two continuous task states, namely, self-initiated (SI) and visually guided (VG) motor tasks.
View Article and Find Full Text PDFHierarchy is a fundamental organizational principle of the human brain network. Whether and how the network hierarchy changes in Alzheimer's disease (AD) remains unclear. To explore brain network hierarchy alterations in AD and their clinical relevance.
View Article and Find Full Text PDFOur brains do not mechanically process incoming stimuli; in contrast, the physiological state of the brain preceding stimuli has substantial consequences for subsequent behavior and neural processing. Although previous studies have acknowledged the importance of this top-down process, it was only recently that a growing interest was gained in exploring the underlying neural mechanism quantitatively. By utilizing the attentional blink (AB) effect, this study is aimed to identify the neural mechanism of brain states preceding T2 and predict its behavioral performance.
View Article and Find Full Text PDFThe aim of thisstudy was to explore the effects of malonic acid (MA), manganese dioxide (MnO), malonic acid combined with manganese dioxide (MA + MnO) additionon reducing CO emission and promoting humic substance (HS) formation during composting. The result showed that the addition of MA and MnO were an efficient way to reduce CO emission. Meanwhile, the CO emissions in the MA + MnO treatment was 36.
View Article and Find Full Text PDFIt is a difficult task to determine the cause of death for decomposed bodies found in water. Diatom test has been shown to provide supportive evidence for the diagnosis of drowning. According to our previous studies, the ratio of diatom content in lung tissue to diatom content in drowning medium (L/D ratio) is a very useful indicator to distinguish between drowning and postmortem immersion.
View Article and Find Full Text PDFObjectives: This study was performed to identify the differences in incidence, clinicopathological features, and survival in esophageal cancer among ethnic groups in the United States and to determine the reasons for the differences.
Result: A total of 49,766 patients were included. Black and Asian groups had a higher proportion of squamous cell carcinoma (ESCC) (85.
2D hand-like structured α-MoO porous nanosheets were grown in-situ onto a capillary by a simple hydrothermal route, on which titanium dioxide seed layer was sol-dip-coated in advance. The α-MoO porous nanosheets array exhibits an exceptional lead ion uptake capacity up to 1450.0mg·g, and can effectively reduce Pb concentration from 20mg·L to a low level of smaller than 3μg·L, well below the acceptable limits in drinking water standards (10μg·L) and can efficiently remove 99.
View Article and Find Full Text PDFWe developed a novel, low-cost and simple method for the fabrication of microfluidic paper-based analytical devices (μPADs) by silanization of filter cellulose using a paper mask having a specific pattern. The paper mask was penetrated with trimethoxyoctadecylsilane (TMOS) by immersing into TMOS-heptane solution. By heating the filter paper sandwiched between the paper mask and glass slides, TMOS was immobilized onto the filter cellulose via the reaction between cellulose OH and TMOS, while the hydrophilic area was not silanized because it was not in contact with the paper mask penetrated with TMOS.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
October 2013
In the title compound, [CoRu(C5H5)(C16H9)(C17H14P)2]PF6, the Ru(II) atom is coordinated by a cyclo-penta-dienyl ring in an η(5)-mode, one C atom from a 4,4'-diethynyl-1,1'-biphenyl ligand and two P atoms from a chelating 1,1'-bis-(di-phenyl-phosphan-yl)cobaltocenium ligand, giving a three-legged piano-stool geometry. In the crystal, weak C-H⋯F hydrogen bonds link the complex cations and hexa-fluorido-phosphate anions into a three-dimensional supra-molecular structure.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
February 2014
The adsorption of Cr(VI) and As(III) by amino-functionalized SBA-15 (NH2-SBA-15) from single and binary systems were investigated in this work. The effects of pH and temperature on the adsorption of NH2-SBA-15 were studied. Adsorption kinetics, isotherm model, and thermodynamics were studied to analyze the experimental data.
View Article and Find Full Text PDFAdvanced oxidation techniques are efficient processes to dispose of organic contaminants in industrial wastewater with low secondary pollution. The solution plasma technique was featured as an advanced oxidation technique with low secondary pollution and high efficiency. However, the solution plasma technique reported previously could only treat wastewater of less than 200 mL owing to the limited plasma generated by only one pair of electrodes.
View Article and Find Full Text PDFThe potential of using two different kinds of air drying of activated sludge (aerobic activated sludge and anaerobic activated sludge) for the removal of Cu(2+), Mn(2+), Zn(2+), and Fe(3+) from aqueous solutions was assessed. Results indicated that the maximum biosorption occurred at pH = 5.0 for Cu(2+), Zn(2+), and Mn(2+) and pH = 3.
View Article and Find Full Text PDFNovel N,O-chelated naphthyridine-BF(2) complexes with push-pull structures have been synthesized and characterized. Spectral investigations on these complexes reveal that photoinduced intramolecular charge transfer occurs and results in a large Stokes shift, which is further supported by density functional theory based theoretical calculations.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
April 2013
This study evaluates the behavior of coconut charcoal (AC) to adsorb Cr(VI), As(III), and Ni(II) in mono- and multicomponent (binary and ternary) systems. Batch experiments were carried out for mono- and multicomponent systems with varying metal ion concentrations to investigate the competitive adsorption characteristics. The adsorption kinetics followed the mechanism of the pseudo-second-order equation in both single and binary systems, indicating chemical sorption as the rate-limiting step of adsorption mechanism.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
September 2012
Purpose: The potential of using waste Saccharomyces cerevisiae as adsorbent for the adsorption of As(III) from aqueous solution was assessed.
Methods: The biosorbent was characterized by Fourier transform infrared (FTIR) spectroscopy analysis. Various parameters including pH, biosorbent dosage, contact time, and temperature were systematically investigated.
A field survey was conducted to identify potential Zn accumulators from an artisanal Zn smelting area in southwest China's Guizhou Province. Hydroponic and soil culture experiments were performed to investigate the accumulation ability of Zn in Corydalis davidii. Zn concentrations in roots, stems and leaves of C.
View Article and Find Full Text PDFHuman exposure to harmful ultraviolet (UV) radiation has important public health implications. Actual human exposure to solar UV radiation depends on ambient UV irradiance, and the latter is influenced by ground reflection. In urban areas with higher reflectivity, UV exposure occurs routinely.
View Article and Find Full Text PDFA novel structural pattern: two-dimensional, five-membered ring-like boron hydride system B(6)H(5)(+), which contains both planar tetra- and pentacoordinated boron (ptB and ppB) was designed and investigated at [B3LYP, MP2(Full) and CCSD(T,FC)]/6-311+G(d,p) theoretical levels. The results indicate that both degenerate ppB B(6)H(5)(+) configurations A (D(5H),(1)A(1)') and B (C(2nu),(1)A(1)) are energetically favorable, sharing the lowest energy comparison with other isomers considered in this work. The computed considerably large smallest vibrational frequencies [197.
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