Visualizing the Birth and Monitoring the Life of a Bimetallic Methanation Catalyst.

Well-defined bimetallic heterogeneous catalysts are not only difficult to synthesize in a controlled manner, but their elemental distributions are also notoriously challenging to define. Knowledge of these distributions is required for both the as-synthesized catalyst and its activated form under reaction conditions, where various types of reconstruction can occur. Success in this endeavor requires observation of the active catalyst via in situ analytical methods. As a step toward this goal, we present a composite material composed of bimetallic nickel-ruthenium nanoparticles supported on a protonated zeolite (Ni-Ru/HZSM-5) and probe its evolution and function as a photoactive carbon dioxide methanation catalyst using in situ X-ray absorption spectroscopy (XAS). The working Ni-Ru/HZSM-5, as a selective and durable photothermal CO2 methanation catalyst, comprises a corona of Ru nanoparticles decorating a Ni nanoparticle core. The specific Ni-Ru interactions in the bimetallic particles were confirmed by in situ XAS, which reveals significant electron transfer from Ni to Ru. The light-harvesting Ni nanoparticle core and electron-accepting Ru nanoparticle corona serve as the CO2 and H2 dissociation centers, respectively. These Ni and Ru nanoparticles also promote synergistic photothermal and hydrogen atom transfer effects. Collectively, these effects enable an associative CO2 methanation reaction pathway while hindering coking and fostering high selectivity toward methane.

Solar-Driven Reforming of Methane and Nitrogen to Methanol and Ammonium on Iron-Modified Zeolite under Ambient Conditions in Water.

Artificial photosynthesis from selective methane oxidation or nitrogen reduction to value-added chemicals provides a promising pathway for the sustainable chemical industry, while still remaining a great challenge due to the extreme difficulty in C-H and N≡N bond cleavage under ambient conditions. Catalysts that can cocatalyze these two reactions simultaneously are rarely reported. Here, Fe-ZSM-5 with highly dispersed extra-framework Fe-oxo species enables efficient and selective photocatalytic conversion of methane and nitrogen to coproduce methanol and ammonia using H2O as the redox reagent under ambient conditions. The optimized Fe-ZSM-5 photocatalyst achieves up to 0.88 mol/molFe·h of methanol products with 97% selectivity. Meanwhile, the productivity of ammonia is 0.61 mol/molFe·h. In situ EPR and DRIFT studies disclose that water serves as a redox reagent to provide hydroxyl radicals for methane oxidation and protons for nitrogen hydrogenation. Quantum chemical calculations revealed that Fe-oxo species play a significant role in the coactivation of methane and nitrogen molecules, which lowers the energy barriers of rate-determining steps for methanol and ammonia generation.

TLR2 mediates autophagy through ERK signaling pathway in Chlamydia psittaci CPSIT_p7 protein-stimulated RAW264.7 cells.

Chlamydia psittaci is a zoonotic pathogen found in birds and humans. Macrophages, major components of the innate immune system, can resist chlamydial infections and trigger adaptive immune responses. However, the molecular mechanisms underlying the action of macrophages against C. psittaci infection are not well understood. This study investigated the roles and mechanisms of plasmid-encoded protein CPSIT_p7 of C. psittaci in regulating autophagy in RAW264.7 cells. The results demonstrated that stimulation of RAW264.7 with C. psittaci plasmid protein CPSIT_p7 induced the expressions of the autophagy signaling primary regulators LC3 and Beclin1, which could also significantly induce the phosphorylation levels of ERK, JNK, p38, and Akt. Next, siRNA knockdown of TLR2 resulted in significant downregulation of CPSIT_p7-triggered autophagy in RAW264.7 cells. Moreover, the extracellular regulated protein kinase (ERK) inhibitor PD98059 markedly reduced autophagy in CPSIT_p7-stimulated macrophages. In summary, these results indicated that TLR2 plays an essential role in the induction of autophagy through the ERK signaling pathway in CPSIT_p7-stimulated RAW264.7 cells.

Solar Hydrocarbons: Single-Step, Atmospheric-Pressure Synthesis of C2 -C4 Alkanes and Alkenes from CO2.

Cobalt ferrite (CoFe2 O4 ) spinel has been found to produce C2 -C4 hydrocarbons in a single-step, ambient-pressure, photocatalytic hydrogenation of CO2 with a rate of 1.1 mmol g-1 h-1 , selectivity of 29.8 % and conversion yield of 12.9 %. On stream the CoFe2 O4 reconstructs to a CoFe-CoFe2 O4 alloy-spinel nanocomposite which facilitates the light-assisted transformation of CO2 to CO and hydrogenation of the CO to C2 -C4 hydrocarbons. Promising results obtained from a laboratory demonstrator bode well for the development of a solar hydrocarbon pilot refinery.

Mycoplasma genitalium Protein of Adhesion Suppresses T Cell Activation via CypA-CaN-NFAT Pathway.

Mycoplasma genitalium is a prokaryotic microorganism that causes urogenital tract infections. M. genitalium protein of adhesion (MgPa) was essential for M. genitalium attachment and subsequent invasion into host cells. Our prior research confirmed that Cyclophilin A (CypA) was the binding receptor for MgPa and MgPa-CypA interaction can lead to the production of inflammatory cytokines. In this study, we revealed that the recombinant MgPa (rMgPa) could inhibit the CaN-NFAT signaling pathway to reduce the level of IFN-γ, IL-2, CD25, and CD69 in Jurkat cells by binding to the CypA receptor. Moreover, rMgPa inhibited the expressions of IFN-γ, IL-2, CD25, and CD69 in primary mouse T cells. Likewise, the expressions of these T cells activation-related molecules in CypA-siRNA-transfected cells and CypA-/- mouse primary T cell was strengthened by rMgPa. These findings showed that rMgPa suppressed T cell activation by downregulating the CypA-CaN-NFAT pathway, and as a result, acted as an immunosuppressive agent. IMPORTANCE Mycoplasma genitalium is a sexually transmitted bacterium that can co-infect with other infections and causes nongonococcal urethritis in males, cervicitis, pelvic inflammatory disease, premature birth, and ectopic pregnancy in women. The adhesion protein of M. genitalium (MgPa) is the primary virulence factor in the complicated pathogenicity of M. genitalium. This research proved that MgPa could interact with host cell Cyclophilin A (CypA) and prevent T cell activation by inhibiting Calcineurin (CaN) phosphorylation and NFAT nuclear translocation, which clarified the immunosuppression mechanism of M. genitalium to host T cells. Therefore, this study can provide a new idea that CypA can be used for a therapeutic or prophylactic target for M. genitalium infection.

Synthesis of Coal-Fly-Ash-Based Ordered Mesoporous Materials and Their Adsorption Application.

A feasible approach was developed for the synthesis of ordered mesoporous SBA-15-type materials using coal fly ash (CFA) as raw material. In the proposed approach, CFA was, firstly, activated by subcritical water with the addition of NaOH, which allowed an efficient extraction of silicon species from CFA under strong acidic conditions at near room temperature. Subsequently, in the synthesis system, using silicon extraction solution as the silicon precursor, the introduction of anhydrous ethanol as a co-solvent effectively inhibited the polymerization of silanol species and promoted their collaborative self-assembly with surfactant molecules by enhancing the hydrogen bond interactions. The resultant SBA-15 material had a high purity, high specific surface area (1014 m2/g) and pore volume (1.08 cm3/g), and a highly ordered mesostructure, and, therefore, exhibited an excellent removal efficiency (90.5%) and adsorption capacity (160.8 mg/g) for methylene blue (MB) from simulated wastewater. Additionally, the generation of surface acid sites from the homogenous incorporation of Al atoms onto the mesoporous walls of SBA-15 combined with the perfect retention of the ordered mesostructure endowed the obtained Al-SBA-15 material with a further boost in the removal performance of MB. The MB removal efficiency can reach ~100%, along with a maximum adsorption capacity of 190.1 mg/g.

Chlamydia psittaci hypothetical inclusion membrane protein CPSIT_0842 evokes a pro-inflammatory response in monocytes via TLR2/TLR4 signaling pathways.

Chlamydia psittaci (C. psittaci) is an obligate intracellular pathogen that resides within a membrane-bound compartment known as the inclusion. Upon entering the host cell, Chlamydiae secrete numerous proteins to modify the inclusion membrane. Inclusion membrane (Inc) proteins are important pathogenic factors in Chlamydia and play crucial roles in the growth and development of Chlamydia. In the present study, the C. psittaci protein, CPSIT_0842, was identified and shown to localize to the inclusion membrane. Temporal analysis revealed that CPSIT_0842 is an early expression protein of Chlamydia. Moreover, this protein was shown to induce the expression of pro-inflammatory cytokines IL-6 and IL-8 in human monocytes (THP-1 cells) via the TLR2/TLR4 signaling pathway. CPSIT_0842 increases the expression of TLR2, TLR4, and adaptor MyD88. Suppression of TLR2, TLR4, and MyD88 markedly attenuated CPSIT_0842-induced production of IL-6 and IL-8. MAP kinases and NF-κB, important downstream molecules of TLR receptors in inflammatory signaling pathways, were also confirmed to be activated by CPSIT_0842. CPSIT_0842-induced production of IL-6 was reliant on activation of the ERK, p38, and NF-κB signaling pathways while IL-8 expression was regulated by the ERK, JNK, and NF-κB signaling pathways. Specific inhibitors of these signaling pathways significantly decreased CPSIT_0842-mediated expression of IL-6 and IL-8. Together these findings demonstrate that CPSIT_0842 upregulates the expression of IL-6 and IL-8 via TLR-2/TLR4-mediated MAPK and NF-κB signaling pathways in THP-1 cells. Exploring these molecular mechanisms enhances our understanding of C. psittaci pathogenesis.

Omentin inhibits the resistin-induced hypertrophy of H9c2 cardiomyoblasts by inhibiting the TLR4/MyD88/NF-κB signaling pathway.

The recently identified adipocytokine omentin was previously found to be expressed mainly in human omental and visceral adipose tissues. As such, reduced plasma concentrations of omentin were revealed to be associated with increased risks of cardiovascular diseases. Omentin has also been previously demonstrated to exert anti-inflammatory effects. By contrast, resistin is a protein that has been associated with obesity and type-2 diabetes mellitus, and the serum concentration of resistin is increased significantly in these populations. Resistin is involved in mediating inflammation development, where they can promote cardiac hypertrophy in humans through toll-like receptor 4 (TLR4)-related signaling. In the present study, the potential effects of omentin on resistin-induced hypertrophy in H9c2 cardiomyoblasts were investigated. In the absence/presence of omentin, H9c2 cardiomyoblasts were treated with resistin. Omentin was found to significantly inhibit resistin-induced increases in the surface area of H9c2 cardiomyoblasts as determined by immunofluorescence. In addition, omentin significantly inhibited resistin-induced increases in the mRNA expression of atrial natriuretic factor, brain natriuretic peptide, ß-myosin heavy chain (which is a characteristic feature of cardiac hypertrophy) and TLR4, which was determined using reverse-transcription-quantitative PCR. According to western blotting results, omentin significantly inhibited resistin-induced ERK phosphorylation, which is an important mediator of cardiomyoblast hypertrophy. Furthermore, omentin significantly inhibited resistin-induced protein expression of TLR4, myeloid differentiation factor 88 (MyD88) and NF-κB phosphorylation, both of which are important members of inflammatory signaling. To conclude, data from the present study suggest that omentin can inhibit resistin-induced H9c2 cardiomyoblast hypertrophy through inhibition of the TLR4/MyD88/NF-κB signaling pathway. Therefore, omentin serve as an attractive therapeutic target against resistin-induced cardiac hypertrophy.

Chlamydia psittaci Plasmid-Encoded CPSIT_P7 Elicits Inflammatory Response in Human Monocytes via TLR4/Mal/MyD88/NF-κB Signaling Pathway.

The chlamydial plasmid, an essential virulence factor, encodes plasmid proteins that play important roles in chlamydial infection and the corresponding immune response. However, the virulence factors and the molecular mechanisms of Chlamydia psittaci are not well understood. In the present study, we investigated the roles and mechanisms of the plasmid-encoded protein CPSIT_P7 of C. psittaci in regulating the inflammatory response in THP-1 cells (human monocytic leukemia cell line). Based on cytokine arrays, CPSIT_P7 induces the expression of interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1) in THP-1 cells. Moreover, the expression levels of IL-6, IL-8, and MCP-1 stimulated by CPSIT_P7 declined after silencing of the Toll-like receptor 4 (TLR4) gene using small interfering RNA and transfection of a dominant negative plasmid encoding TLR4 (pZERO-hTLR4). We further demonstrated that transfection with the dominant negative plasmid encoding MyD88 (pDeNy-hMyD88) and the dominant negative plasmid encoding Mal (pDeNy-hMal) could also abrogate the expression of the corresponding proteins. Western blot and immunofluorescence assay results showed that CPSIT_P7 could activate nuclear factor κB (NF-κB) signaling pathways in THP-1 cells. Altogether, our results indicate that the CPSIT_P7 induces the TLR4/Mal/MyD88/NF-κB signaling axis and therefore contributes to the inflammatory cytokine response.

Surgical management of Boerhaave's syndrome with early and delayed diagnosis in adults: a retrospective study of 88 patients

BACKGROUND: spontaneous esophageal rupture (Boerhaave's syndrome) is a rare and challenging clinical condition. OBJECTIVE: to evaluate the outcome of different surgical treatments for patients with Boerhaave's syndrome with an early diagnosis (< 24 h) and delayed diagnosis (> 24 h), using a retrospective cohort study in a tertiary referral center. PATIENTS AND METHODS: eighty-eight patients with Boerhaave's syndrome who underwent surgical treatment were identified from March 1994 to March 2019 in the First Hospital of Shanxi Medical University. Subsequently, they were retrospectively divided into two groups according to time from symptom onset to diagnosis (group 1, < 24 h, n = 16; group 2, > 24 h, n = 72). Primary suture repair was used in group 1 and reinforcement with a vascular muscle flap was used in group 2, in order to reduce the incidence of fistula. Patients in group 2 were further divided into two subgroups according to reinforcement using diaphragmatic flaps (subgroup 1) or intercostal muscle flaps (subgroup 2). RESULTS: the duration of hospitalization and stay in Intensive Care Unit (ICU) was significantly shorter in group 1 (p = 0.027 and p = 0.001). Group 1 had fewer postoperative esophageal leaks (p = 0.037) compared to group 2. Various aspects were compared in the two subgroups and the differences were not statistically significant (p > 0.05). CONCLUSIONS: it is very important to establish an early diagnosis for patients with Boerhaave's syndrome. Early (< 24 h) and primary suture repair is superior to delayed (> 24 h) primary repair, even for those reinforced with vascular muscle flaps. Furthermore, repair reinforcement with different muscle flaps appears to render similar results for patients with delayed diagnosis

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Flash Solid-Solid Synthesis of Silicon Oxide Nanorods.

1D silicon-based nanomaterials, renowned for their unique chemical and physical properties, have enabled the development of numerous advanced materials and biomedical technologies. Their production often necessitates complex and expensive equipment, requires hazardous precursors and demanding experimental conditions, and involves lengthy processes. Herein, a flash solid-solid (FSS) process is presented for the synthesis of silicon oxide nanorods completed within seconds. The innovative features of this FSS process include its simplicity, speed, and exclusive use of solid precursors, comprising hydrogen-terminated silicon nanosheets and a metal nitrate catalyst. Advanced electron microscopy and X-ray spectroscopy analyses favor a solid-liquid-solid reaction pathway for the growth of the silicon oxide nanorods with vapor-liquid-solid characteristics.

Effect of Thermal Annealing on Conformation of MEH-PPV Chains in Polymer Matrix: Coexistence of H- and J-Aggregates.

In diluted solid solution using poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) and polymethyl methacrylate (PMMA) or polystyrene (PS), both aggregated and extended conformations could be formed according to the weight ratio. Aggregated conformation in as-cast MEH-PPV/PMMA film presented a J-aggregate-like photoluminescence (PL) emission. After annealing at 160 °C, its PL showed characteristics of both J- and H-aggregates at the same time; however, extended conformation showed an oligomer-like emission, which was not sensitive to either measurement temperature or annealing temperature. Thus, the conformation transition between aggregated and extended is unlikely to happen in MEH-PPV/PMMA blends during thermal annealing. On the contrary, in MEH-PPV/PS blends, extended conformation dominated in as-cast film with oligomer-like emissions; after annealing at 160 °C, both J- and H- aggregate-like PL emissions were observed, indicating the conformation transitioned from extended to aggregated. Therefore, our work may suggest a new method to manipulate photophysical properties of conjugated polymers by combining appropriate host matrix and thermal annealing processes.

Synthesis of Ordered Mesoporous Zr-Al Composite Oxides with Excellent Structural and Textural Properties and Extremely High Stability.

Ordered mesoporous Zr-Al composite oxide materials (denoted as OMZA-x) with different Zr contents have been synthesized by a solvent evaporation-inducing self-assembly procedure associated with a thermal treatment at 100 °C. A cooperative co-assembly process of amphiphilic triblock copolymer F127 molecules and inorganic hydroxyl species originated from the hydrolysis of Zr and Al precursors was proposed to explain the synthesis of OMZA-x. Compared to ordered mesoporous alumina prepared without introducing Zr species, the resultant OMZA-x exhibited a much more ordered mesostructure combined with a distinct increase in the pore volume and specific surface area. The highly homogenous doping of Zr into the mesopore walls together with the formation of Zr-O-Al bonds can effectively enhance the thermal and hydrothermal stability of OMZA-x. For instance, the ordered mesostructure and excellent textural properties of OMZA-6 prepared with the optimum atomic ratio of Al to Zr of 6 could be well maintained even after a high-temperature treatment at 1000 °C for 1 h or a hydrothermal treatment at 100 °C for 6 h.

Surgical management of Boerhaave's syndrome with early and delayed diagnosis in adults: a retrospective study of 88 patients.

BACKGROUND: spontaneous esophageal rupture (Boerhaave's syndrome) is a rare and challenging clinical condition. OBJECTIVE: to evaluate the outcome of different surgical treatments for patients with Boerhaave's syndrome with an early diagnosis (< 24 h) and delayed diagnosis (> 24 h), using a retrospective cohort study in a tertiary referral center. PATIENTS AND METHODS: eighty-eight patients with Boerhaave's syndrome who underwent surgical treatment were identified from March 1994 to March 2019 in the First Hospital of Shanxi Medical University. Subsequently, they were retrospectively divided into two groups according to time from symptom onset to diagnosis (group 1, < 24 h, n = 16; group 2, > 24 h, n = 72). Primary suture repair was used in group 1 and reinforcement with a vascular muscle flap was used in group 2, in order to reduce the incidence of fistula. Patients in group 2 were further divided into two subgroups according to reinforcement using diaphragmatic flaps (subgroup 1) or intercostal muscle flaps (subgroup 2). RESULTS: the duration of hospitalization and stay in Intensive Care Unit (ICU) was significantly shorter in group 1 (p = 0.027 and p = 0.001). Group 1 had fewer postoperative esophageal leaks (p = 0.037) compared to group 2. Various aspects were compared in the two subgroups and the differences were not statistically significant (p > 0.05). CONCLUSIONS: it is very important to establish an early diagnosis for patients with Boerhaave's syndrome. Early (< 24 h) and primary suture repair is superior to delayed (> 24 h) primary repair, even for those reinforced with vascular muscle flaps. Furthermore, repair reinforcement with different muscle flaps appears to render similar results for patients with delayed diagnosis.

Evaluation of a tandem Chlamydia psittaci Pgp3 multiepitope peptide vaccine against a pulmonary chlamydial challenge in mice.

Chlamydia psittaci is the pathogen of psittacosis, and it has emerged as a significant public health threat. Because most infections are easily overlooked, a vaccine is recognized as the best solution to control the spread of C. psittaci. Our previous study showed that Pgp3 protein is efficacious as a subunit vaccine while not the best candidate due to the negative effects. Thus, in this study, we tested the ability of a tandem epitope vaccine candidate designated SP based on Pgp3-dominant epitopes to induce protective immunity against pulmonary chlamydial infection. BALB/c mice were intraperitoneally inoculated with multiepitope peptide antigens followed by intranasal infection with C. psittaci. We found that the multiepitope peptide antigens induced strong humoral and cellular immune responses with high Th1-related (IFN-γ and IL-2) and proinflammatory (IL-6) cytokine levels. Meanwhile, the pathogen burden and inflammatory infiltration were significantly reduced in lungs of SP-immunized mice after chlamydial challenge. In addition, the IFN-γ and IL-6 secretion levels in the infected lungs were substantially reduced. Overall, our findings demonstrate that the peptide vaccine SP plays a significant role with good immunogenicity and protective efficacy against C. psittaci lung infection in BALB/c mice, providing important insights towards understanding the potential of peptide vaccines as new vaccine antigens for inducing protective immunity against chlamydial infection.

The next big thing for silicon nanostructures - CO2 photocatalysis.

Silicene is a relatively new member of the growing family of two-dimensional single-element materials. Both top-down and bottom-up approaches provide access to silicene, the former via vapor deposition on a substrate and the latter via exfoliation of the layered CaSi2 precursor. Most top-down research has been concerned with understanding the various electronic, optical, magnetic, mechanical, electrical, thermal transport and gas-adsorption properties of silicene. By contrast, the focus on bottom-up silicene has primarily been on its synthesis, structure and chemical properties as they relate to its function and utility. Herein, emphasis is placed on the bottom-up strategy because of its scalability and the ease of subsequent silicene modification, with both qualities being important prerequisites for heterogeneous catalysis applications. In this context, synthetic freestanding silicene exists as single sheets or multilayer assemblies, depending on the CaSi2 exfoliation synthesis conditions. The structure of a sheet comprises three connected chair-configuration silicon 6-rings. This connectivity creates buckled sheets in which the hybridization around the unsaturated silicon atoms is sp2-sp3. By adjusting the CaSi2 exfoliation synthesis conditions, either layered silane (Si6H6) or siloxene (Si6H3(OH)3) nanosheets can be obtained. In our studies, we have explored the nucleation and growth of different transition metal nanoparticles on and within the layer spaces of these nanosheets, and explored their thermochemical and photochemical reactivity in CO2 hydrogenation reactions. An overview of these findings, related works and a new-and-optimized catalyst are provided in this article.

Simultaneous Intramuscular And Intranasal Administration Of Chitosan Nanoparticles-Adjuvanted Chlamydia Vaccine Elicits Elevated Protective Responses In The Lung.

BACKGROUND: Chlamydia psittaci is a zoonotic bacteria closely associated with psittacosis/ornithosis. Vaccination has been recognized as the best way to inhibit the spread of C. psittaci due to the majority ignored of infections. The optimal Chlamydia vaccine was obstructed by the defect of single immunization route and the lack of availability of nontoxic and valid adjuvants. METHODS: In this study, we developed a novel immunization strategy, simultaneous (SIM) intramuscular (IM) and intranasal (IN) administration of a C. psittaci antigens (Ags) adjuvanted with chitosan nanoparticles (CNPs). And SIM-CNPs-Ags were used to determine the different types of immune response and the protective role in vivo. RESULTS: CNPs-Ags with zeta-potential values of 13.12 mV and of 276.1 nm showed excellent stability and optimal size for crossing the mucosal barrier with high 71.7% encapsulation efficiency. SIM-CPN-Ags mediated stronger humoral and mucosal responses by producing meaningfully high levels of IgG and secretory IgA (sIgA) antibodies. The SIM route also led to Ags-specific T-cell responses and increased IFN-γ, IL-2, TNF-α and IL-17A in the splenocyte supernatants. Following respiratory infection with C. psittaci, we found that SIM immunization remarkably reduced bacterial load and the degree of inflammation in the infected lungs and made for a lower level of IFN-γ, TNF-α and IL-6. Furthermore, SIM vaccination with CNPs-Ags had obviously inhibited C. psittaci disseminating to various organs in vivo. CONCLUSION: SIM immunization with CNPs-adjuvanted C. psittaci Ags may present a novel strategy for the development of a vaccine against the C. psittaci infection.

Nickel@Siloxene catalytic nanosheets for high-performance CO2 methanation.

Two-dimensional (2D) materials are of considerable interest for catalyzing the heterogeneous conversion of CO2 to synthetic fuels. In this regard, 2D siloxene nanosheets, have escaped thorough exploration, despite being composed of earth-abundant elements. Herein we demonstrate the remarkable catalytic activity, selectivity, and stability of a nickel@siloxene nanocomposite; it is found that this promising catalytic performance is highly sensitive to the location of the nickel component, being on either the interior or the exterior of adjacent siloxene nanosheets. Control over the location of nickel is achieved by employing the terminal groups of siloxene and varying the solvent used during its nucleation and growth, which ultimately determines the distinct reaction intermediates and pathways for the catalytic CO2 methanation. Significantly, a CO2 methanation rate of 100 mmol gNi-1 h-1 is achieved with over 90% selectivity when nickel resides specifically between the sheets of siloxene.

Ribokinase screened from T7 phage displayed Mycobacterium tuberculosis genomic DNA library had good potential for the serodiagnosis of tuberculosis.

Tuberculosis caused by Mycobacterium tuberculosis (M. tuberculosis) is the leading cause of death among infectious diseases in the worldwide. Lack of more sensitive and effective diagnostic reagents has increased the awareness of rapid diagnosis for tuberculosis. In this study, T7 phage displayed genomic DNA library of M. tuberculosis was constructed to screen the antigens that specially bind with TB-positive serum from the whole genome of M. tuberculosis and to improve the sensitivity and specificity of tuberculosis serological diagnosis. After three rounds of biopanning, results of DNA sequencing and BLAST analysis showed that 19 positive phages displayed four different proteins and the occurrence frequency of the phage which displayed ribokinase was the highest. The results of indirect ELISA and dot immunoblotting indicated that representative phages could specifically bind to tuberculosis-positive serum. The prokaryotic expression vector containing the DNA sequence of ribokinase gene was then constructed and the recombinant protein was expressed and purified to evaluate the serodiagnosis value of ribokinase. The reactivity of the recombinant ribokinase with different clinical serum was detected and the sensitivities and specificities in tuberculosis serodiagnosis were 90% and 86%, respectively by screening serum from tuberculosis patients (n = 90) and uninfected individuals (n = 90) based on ELISA. Therefore, this study demonstrated that ribokinase had good potential for the serodiagnosis of tuberculosis.

Optical Properties of Two-Dimensional Perovskite Films of (C6H5C2H4NH3)2[PbI4] and (C6H5C2H4NH3)2 (CH3NH3)2[Pb3I10].

The temperature dependence of absorption and photoluminescence (PL) spectroscopies were used to study the optical properties of 2D perovskite films, including n = 1 and 3 of (PEA)2(CH3NH3) n-1[Pb nI3 n+1] (PEA = C6H5(CH2)2NH3). In (PEA)2[Pb1I4] (PEPI), excitons coupling to optical phonons with an average energy of ∼30 meV dominate the photophysics of absorption and PL. (PEA)2(CH3NH3)2[Pb3I10] (shortened as PMPI3), nominally prepared as n = 3, actually was a mixture of multiple layered perovskites with various n. In absorption, a PMPI3 film presents respective n materials' excitonic features, coupling to phonons with an average energy of ∼30 meV; in analyzing PL peaked singly at ∼1.6 eV and its width as a function of temperature, we found that PMPI3 behaves like PEPI at around 80 K but like 3D perovskite near room temperature, with three times larger electron-phonon interaction strength compared to that in PEPI.