First Principles Study on the Mechanism of Nitrobenzene Hydrogenation by a Ni₁/CeO_2‑x(111) Single-Atom Catalyst

Ceria (CeO2) exhibits superior catalytic activity and selectivity in the hydrogenation of nitrobenzene via combination with other transition metals. However, the reaction mechanism of nitrobenzene hydrogenation by those CeO2-based catalysts is still unclear. Herein, a density functional theory study was performed to investigate the mechanism of nitrobenzene hydrogenation by a Ni1/CeO2‑x single-atom catalyst. The dominant pathway of H2 dissociation on the Ni1/CeO2(111) and Ni1/CeO2‑x(111) surfaces and the oxygen vacancy formation on the Ni1/CeO2(111) surface were proposed. The direct route and condensation route of nitrobenzene hydrogenation on the Ni1/CeO2‑x(111) surface were further studied, in which the direct route includes the single H-induced dissociation pathway, the double H-induced dissociation pathway, and the single–double H-induced mixed dissociation pathway. The calculated results indicate that the single–double H-induced mixed dissociation pathway (PhNO2* → PhNOOH* → PhNO* → PhNHO* → PhNHOH* → PhNH* → PhNH2*) is the most favorable pathway for the hydrogenation of nitrobenzene to aniline by Ni1/CeO2‑x(111). The rate-determining step of the overall reaction, using H2 as the hydrogen source, is the fourth hydrogen transfer step (PhNHO* + H* → PhNHOH*), which has an energy barrier of 1.24 eV. This might provide theoretical insights into the nature of nitrobenzene hydrogenation to aniline by CeO2-based catalysts

Influence of CO₂ Exposure on High-Pressure Methane and CO₂ Adsorption on Various Rank Coals: Implications for CO₂ Sequestration in Coal Seams

There exist complex interactions between coal and CO₂ during the process of CO₂ sequestration in coal seams with enhanced coalbed methane recovery (CO₂-ECBM). This work concentrated on the influence of CO₂ exposure on high-pressure methane and CO₂ (up to 10 MPa) adsorption behavior of three types of bituminous coal and one type of anthracite. The possible mechanism of the dependence of CO₂ exposure on adsorption performance of coal was also provided. The results indicate that the maximum methane adsorption capacities of various rank coals after CO₂ exposure increase by 3.45%–10.37%. However, the maximum CO₂ adsorption capacities of various rank coals decrease by 9.99%–23.93%. TG and pore structure analyses do not observe the obvious changes on the inorganic component and pore morphology of the coals after CO₂ exposure. In contrast, CO₂ exposure makes changes in surface chemistry of the coals, according to the results from FTIR analysis, which is the main reason for increases in the maximum adsorption capacity of methane and decreases in the maximum adsorption capacity of CO₂ for the coals after CO₂ exposure. The different role of CO₂ exposure on methane and CO₂ adsorption is detrimental to CO₂-ECBM. Thus, the implementation of CO₂-ECBM must take into account the influence of CO₂ exposure on the adsorption performance of the target coal seams

Influences of SO₂, NO, and CO₂ Exposure on Pore Morphology of Various Rank Coals: Implications for Coal-Fired Flue Gas Sequestration in Deep Coal Seams

Carbon dioxide (CO₂) sequestration in deep coal seams with enhanced coal-bed methane recovery is a promising way to store the main anthropogenic greenhouse gas, CO₂, in geologic time. Recently, injection of CO₂ mixed with coal-fired flue gas components, i.e., SO₂ and NO_<i>x</i>, into coal seams has gained attention because it offers great advantages in reducing the cost of CO₂ capture, flue gas desulfuration, and denitration. As a preliminary investigation on the feasibility of coal-fired flue gas sequestration in deep coal seams, the influences of SO₂, NO, and CO₂ exposures on the pore morphology of various rank coals are addressed in this work. Considering the optimum coal reservoir conditions for flue gas sequestration, the interaction of CO₂ with coals was studied at a temperature of 45 °C and a pressure of 12 MPa. The results show that both CO₂ exposure and SO₂ exposure lead to decreases in both the specific surface area and pore volume of micropores of various rank coals. The micropore morphology of both Hulunbuir coal and Shenmu coal after NO exposure exhibits degradation, while the opposite trend is found for Erdos coal and Yangquan coal. The average micropore size of all the coals after contact with CO₂, NO, and SO₂ decreases. The CO₂, NO, and SO₂ dependences of the meso- and macropore surface area and volume of coals are complex and strongly related to the coal rank. Fractal analyses show that the pore surfaces of coals after CO₂, NO, and SO₂ exposures become smooth, as indicated by the surface fractal dimension determined from the Neimark model, which is consistent with the increasing trend of the average meso- and macropore size. Generally, the influences of SO₂, NO, and CO₂ exposures on pore morphology of various rank coals may play an important role in the diffusion and adsorption performance of fluid within the target coal reservoir. Thus, comprehensive evaluation of the dependence of coal pore morphology on fluid exposure is needed for the practical coal-fired flue gas sequestration in deep coal seams

Detection of the JCV T-antigen sequence in samples from CRC patients.

<p>(A) The 110 bp fragment was amplified from DNA isolated from matched samples of colorectal cancer (upper) and normal tumor adjacent tissues (lower) with nested PCR. M: DL 2,000 DNA Marker (TaKaRa); P: positive control; N1: first-round negative control; N2: second-round negative control. (B) Images from JCV nested-PCR product arrays. Nested-PCR products of tumor tissues (left) and normal tumor adjacent tissues (right) were spotted onto surfaces of aminosilane slides as three replicates, hybridized with TAMRA-labeled oligonucleotide probe and finally visualized by AXON scanner. (C) The numbers of JCV-positive samples in 137 matched pairs of tumor tissue, non-cancerous adjacent tumor tissue and PB samples from CRC patients.</p

Factors associated with JCV infection among CRC patients.

a<p>, No tobacco exposure was defined as never having smoked cigarettes daily for more than 1 year.</p>b<p>, No alcohol use was defined as never having consumed 1 drink or more per month.</p>c<p>, by Fisher's exact test. d, Chemotherapy was used before surgery within 3 months.</p

Additional file 5 of Microbiota and metabolites alterations in proximal and distal gastric cancer patients

Additional file 5: Figure S4. Metabolite composition and difference between Proximal N and Distal N. A, B OPLS-DA showed that Proximal N and Distal N were not separated into two clusters. Test for OPLS-DA model showed that the OPLS-DA model for this study was valid

Additional file 1 of Microbiota and metabolites alterations in proximal and distal gastric cancer patients

Additional file 1: Table S1. Clinicopathological characteristics of patients with gastric cancer in this study. Table S2. Different microorganisms in Proximal T and Distal T compared to their respective non tumor samples. Table S3. Significant differences in metabolites between Distal T and Distal N. Table S4. Significant differences in metabolites between Proximal T and Proximal N. Table S5. Metabolic pathway enrichment of differential metabolites between Distal T and Distal N. Table S6. Metabolic pathway enrichment of differential metabolites between Proximal T and Proximal N

DataSheet_1_The human oral – nasopharynx microbiome as a risk screening tool for nasopharyngeal carcinoma.zip

Nasopharyngeal carcinoma (NPC) is a common head and neck cancer with a poor prognosis. There is an urgent need to develop a simple and convenient screening tool for early detection and risk screening of NPC. 139 microbial samples were collected from 40 healthy people and 39 patients with nasopharyngeal biopsy. A total of 40 and 39 oral, eight and 27 nasal cavity, nine and 16 nasopharyngeal microbial samples were collected from the two sets of individuals. A risk screening tool for NPC was established by 16S rDNA sequencing and random forest. Patients with nasopharyngeal biopsy had significantly lower nasal cavity and nasopharynx microbial diversities than healthy people. The beta diversity of the oral microbiome was significantly different between the two groups. The NPC screening tools based on nasopharyngeal and oral microbiomes have 88% and 77.2% accuracies, respectively. The nasopharyngeal biopsy patients had significantly higher Granulicatella abundance in their oral cavity and lower Pseudomonas and Acinetobacter in the nasopharynx than healthy people. This study established microbiome-based non-invasive, simple, no radiation, and low-cost NPC screening tools. Individuals at a high risk of NPC should be advised to seek further examination, which might improve the early detection of NPC and save public health costs.</p