Study on Photocatalytic Performance of Ag/TiO2 Modified Cement Mortar.

In this paper, Ag-TiO2 photocatalysts with different Ag contents (1 mol%-5 mol%) were prepared and applied to cement mortar. The photocatalytic performance of Ag-TiO2 and photocatalytic cement mortar under UV light and simulated solar light was evaluated. The results showed that Ag loading on the surface of TiO2 could reduce its band gap width and increase its absorbance in the visible region, and 2% Ag-TiO2 had the highest photocatalytic activity under UV light, the degradation rate of methyl orange (MO) was 95.5% at 30 min, and the first-order reaction constant k was 0.0980 min-1, which was 61.7% higher than that of TiO2, and 5% Ag-TiO2 had the highest photocatalytic activity under solar light, the degradation rate of methylene blue (MB) was 69.8% at 40 min, and the first-order reaction constant k was 0.0294 min-1, which was 90.9% higher than that of TiO2. The photocatalytic mortar prepared by the spraying method has high photocatalytic performance, The MO degradation rate of sample S2 under UV light was 87.5% after 120 min, MB degradation rate of sample S5 under solar light was 75.4% after 120 min. The photocatalytic reaction conforms to the zero-order reaction kinetics, which was 1.5 times-3.3 times higher than that of the mixed samples and has no effect on the mechanical properties of mortar.

Comparison between spleen and liver stiffness measurements by sound touch elastography for diagnosing cirrhosis at different aminotransferase levels: a prospective multicenter study.

OBJECTIVES: To compare the performance of spleen stiffness measurement (SSM) and liver stiffness measurement (LSM) by sound touch elastography (STE) for the diagnosis of cirrhosis at different alanine aminotransferase (ALT) levels, and to compare the applicability and repeatability of SSM with LSM performed by STE, a new two-dimensional shear wave elastography technology. METHODS: This prospective multicenter study included 25 centers and recruited chronic hepatitis B (CHB) patients with liver biopsy between May 2018 and November 2019. All patients underwent LSM and SSM by STE. Success and reliability rates were calculated and compared. Intra-observer agreement was assessed using intraclass correlation coefficients (ICCs). Differences between areas under the receiver operating characteristic curves (AUCs) of LSMs and SSMs at different ALT levels were compared using the Delong test. RESULTS: Among 603 CHB patients, the success and reliability rates of SSM were 94.53% (570/603) and 85.74% (517/603), respectively, which were similar to those of LSM (p > 0.05), respectively. The ICC for intra-observer agreements of SSM was 0.964 (p < 0.001). In the total cohort, ALT ≤ 2 × upper limit of normal (ULN) group, and A0-1 group, the AUCs of SSMs were significantly lower than those of LSMs for the diagnosis of cirrhosis (p < 0.001). In the ALT > 2 × ULN group and A2-3 group, the AUC of SSM improved and was not significantly different from that of LSM (p = 0.342, p = 0.510, respectively). CONCLUSIONS: SSM by STE achieved applicability and repeatability equivalent to those of LSM. SSM might be a good substitute to LSM in patients with high ALT levels. KEY POINTS: • Spleen stiffness measurement performed by sound touch elastography was proven to have similar applicability and repeatability to liver stiffness measurement in this prospective multicenter study. • Spleen stiffness measurement demonstrated a poorer diagnostic performance for cirrhosis compared with liver stiffness measurement in the total cohort and low ALT level group, yet it showed a similar diagnostic performance to liver stiffness measurement in patients with high ALT levels.

Usefulness of New Shear Wave Elastography Technique for Noninvasive Assessment of Liver Fibrosis in Patients with Chronic Hepatitis B: A Prospective Multicenter Study.

PURPOSE: To explore the usefulness of liver stiffness measurements (LSMs) by sound touch elastography (STE) and sound touch quantification (STQ) in chronic hepatitis B (CHB) patients for staging fibrosis. METHODS: This prospective multicenter study recruited normal volunteers and CHB patients between May 2018 and October 2019. The volunteers underwent LSM by STE and supersonic shear imaging (SSI) or by STQ and acoustic radiation force impulse imaging (ARFI). CHB patients underwent liver biopsy and LSM by both STE/STQ. The areas under the receiver operating characteristic curves (AUCs) for staging fibrosis were calculated. RESULTS: Overall, 97 volunteers and 524 CHB patients were finally eligible for the study. The successful STE and STQ measurement rates were both 100 % in volunteers and 99.4 % in CHB patients. The intraclass correlation coefficients (ICCs) for the intra-observer stability of STE and STQ (0.94; 0.90) were similar to those of SSI and ARFI (0.95; 0.87), respectively. STE and STQ showed better accuracy than the aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 index (FIB-4) (AUC: 0.87 vs 0.86 vs 0.73 vs 0.77) in staging cirrhosis. However, both STE and STQ were not superior to APRI and FIB-4 in staging significant fibrosis (AUC: 0.76 vs 0.73 vs 0.70 vs 0.71, all P-values > 0.05). CONCLUSION: STE and STQ are convenient techniques with a reliable LSM value. They have a similar diagnostic performance and are superior to serum biomarkers in staging cirrhosis in CHB patients.

Mechanical Properties of Nano SiO2 and Carbon Fiber Reinforced Concrete after Exposure to High Temperatures.

This study presents the key mechanical and residual properties after high-temperature of different Nano SiO2 carbon fiber-reinforced concrete (NSCFRC) mixtures. A total of seven NSCFRC mixtures incorporating 0%-0.35% of carbon fiber by volume of concrete and 0%-2% Nano SiO2 by weight of the binder were studied. The key mechanical properties such as compressive strength, tensile strength, and flexural strength of NSCFRC with 0.25% carbon fiber and 1% NS were 6.8%, 20.3%, and 11.7% higher than PC (0% CFs, 0% NS), respectively. Scanning Electron Microscopy (SEM) shows that Nano SiO2 reduced the internal porosity and increased the compactness of the concrete matrix. Furthermore, the experimental result demonstrates that NSCFRC can improve the mechanical properties of concrete after high-temperature and equations were obtained to describe the evolution of residual properties at elevated temperatures. Results suggested that the effect of carbon fibers on the residual properties of concrete after high-temperature is less than steel fiber and polypropylene fiber. It was also indicated that adding appropriate Nano SiO2 to concrete is an effective means to improve the residual performance after high-temperature.

In situ grown Ni phosphide nanowire array on Ni foam as a high-performance catalyst for hydrazine electrooxidation.

Synthesis of high-performance and cost-effective electrocatalysts towards hydrazine electrooxidation is vital to develop the direct hydrazine fuel cell (DHFC) as a viable energy conversion technology. Herein, we report a combined experimental and theoretical study of nickel phosphides (NixP) as promising catalysts for hydrazine electrooxidation. NixP nanowire array supported on a Ni foam (NF) was synthesized by a one-step phosphorization method using hypophosphite as a P-source. Ni12P5 and Ni2P phases are observed as the products of the direct phosphorization of commercial NF under the applied conditions with Ni2P nanoparticles exclusively distributing on the surface of Ni12P5. The NixP/NF catalyst exhibits a synergetic capabilities of exceptionally high activity, excellent durability and nearly 100% selectivity towards the complete electrooxidation of hydrazine in alkaline condition, which is among the best performance reported on hydrazine electrooxidation catalysts. First-principles calculations have been conducted to gain insight into the catalytic mechanism of Ni phosphides towards hydrazine electrooxidation.

Effect of the position of constriction on water permeation across a single-walled carbon nanotube.

The transportation of water across a cell membrane facilitated by water channel proteins is fundamental to the normal water metabolism in all forms of life. It is understood that the narrow region in a water channel is responsible for gating or selectivity. However, the influence of the position of the narrow region on water transportation is still not thoroughly understood. By choosing a single-walled carbon nanotube (SWNT) as a simplified model and using molecular dynamics simulation, we have found that the water flux through the nanotube would change significantly if the narrow location moves away from the middle region along the tube. Simulation results show that the flux reaches the maximum when the deformation occurs in the middle part of nanotube and decreases as the deformation location moves toward the ends of the nanotube. However, the decrease of water flux is not monotonic and the flux gets the minimum near the ends. These interesting phenomena can be explained in terms of water-water interactions and water-SWNT interactions. It can be concluded that the regulation of water transportation through nanopores depends sensitively on the location of the narrow region, and these findings are helpful in devising high flux nanochannels and nanofiltration as well.

[Study on the flavonoids constituents of Trachelospermum jasminoides].

OBJECTIVE: To study the flavonoids constituents of Trachelospemum jasminoides. METHODS: The compounds were separated and purified by column chromatography with silica gel, and identified by IR, MS, NMR and 2D-NMR. RESULTS: Six flavonoids were identified as apigenin (I), apigenin 7-O-beta-glucoside (II), apigenin 7-O-beta-neospheroside (III), luteoloside (IV), narngin (V) 6,8-di-C-glucopyanosylapigenin (VI), respectively. CONCLUSION: Compounds V and VI are isolated from this plant for the first time.