Single-cluster anchored on PC6 monolayer as high-performance electrocatalyst for carbon dioxide reduction reaction: First principles study.

Tremendous challenges remain to develop high-efficient catalysts for carbon dioxide reduction reaction (CO2RR) owing to the poor activity and low selectivity. However, the activity of catalyst with single active site is limited by the linear scaling relationship between the adsorption energy of intermediates. Motivated by the idea of multiple activity centers, triple metal clusters (M = Cr, Mn, Fe, Co, Ni, Cu, Pd, and Rh) doped PC6 monolayer (M3@PC6) were constructed in this study to investigate the CO2RR catalytic performance via density functional theory calculations. Results shows Mn3@PC6, Fe3@PC6, and Co3@PC6 exhibit high activity and selectivity for the reduction of CO2 to CH4 with limiting potentials of -0.32, -0.28, and -0.31 V, respectively. Analysis on the high-performance origin shows the more binding sites in M3@PC6 render the triple-atom anchored catalysts (TACs) high ability in regulating the binding strength with intermediates by self-adjusting the charges and conformation, leading to the improved performance of M3@PC6 than dual-atom doped PC6. This work manifests the huge application of PC6 based TACs in CO2RR, which hope to prove valuable guidance for the application of TACs in a broader range of electrochemical reactions.

Density functional theory study of nitrogen-doped black phosphorene doped with monatomic transition metals as high performance electrocatalysts for N2reduction reaction.

Ammonia (NH3) is an essential resource in human production and living activities, and its demand has been rising in recent years. The catalytic synthesis of NH3from N2under mild conditions, inspired by biological nitrogen fixation, has piqued the interest of researchers. In this paper, density functional theory (DFT) calculations were used to investigate the catalytic activity, mechanism, and selectivity of the TM embedded nitrogen-doped phosphorene as high-performance nitrogen reduction reaction (NRR) electrocatalysts in depth. The results show that Nb- and Mo-doped catalysts present excellent catalytic performance, with low limiting potentials of -0.41 and -0.18 V, respectively. The Mo-N3-BP catalyst, for example, not only has an extremely low overpotential (-0.02 V), but also presents superior selectivity to effectively inhibit the HER competition reaction. A deeper look into the catalytic mechanism reveals a volcano relationship between the d-band center and the catalytic activity (Mo and Nb are located near the peak of the volcano-type curve). The d-band center and charge of the metal center can be regarded as effective descriptors for NRR activity on TM embedded nitrogen-doped phosphorene electrocatalysts, which hope to serve as a guiding principle for the design of high performance NRR single-atom catalyst in the future.

First-principles study of pristine and Li-doped borophene as a candidate to detect and scavenge SO2gas.

In this research, the potential application of borophene as gas sensor device is explored. The first-principles theory is employed to investigate the sensing performance of pristine and Li-doped borophene for SO2and five main atmospheric gases (including CH4, CO2, N2, CO and H2). All gases are found to be adsorbed weakly on pristine borophene, which shows weak physical interaction between the pristine borophene and gases. The gas adsorption performance of borophene is improved by the doping of Li atom. The results of adsorption energy suggest that Li-borophene exhibits high selectivity to SO2molecule. Moreover, analyses of the charge transfer, density of states and work function also confirm the introduction of Li adatom on borophene significantly enhances the selectivity and sensitivity to SO2. In addition, desorption time of gas from pristine and Li doped borophene indicates the Li-borophene has good desorption characteristics for SO2molecule at high temperatures. This research would be helpful for understanding the influence of Li doping on borophene and presents the potential application of Li-borophene as a SO2gas sensor or scavenger.

Efficacy and prognostic factors of imatinib plus CALLG2008 protocol in adult patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia.

A CALLG2008 protocol was developed by the Chinese Acute Lymphoblastic Leukemia Cooperative Group for adult acute lymphoblastic leukemia (ALL). We retrospectively analyzed 153 newly diagnosed adult patients with Philadelphia chromosome (Ph)-positive ALL enrolled into imatinib (400 mg/d) plus CALLG2008 regimen between 2009 and 2015. The median age was 40 years (range, 18-68 years), with 81 (52.3%) males. The overall hematologic complete remission (CR) rate was 96.7% after induction. With a median follow-up of 24.2 months, the estimated 3-year overall survival (OS) and event-free survival (EFS) rates were 49.5%(95%confidence interval (CI): 38.5%-59.5%) and 49.2% (95% CI: 38.3%-59.2%), respectively. Fifty-eight (36 with haploidentical donor) patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first CR. Among the patients in CR1 after induction, both the 3-year OS and EFS were significantly better in the allo-HSCT group than in the without allo-HSCT group (73.2%, 95% CI: 58.3%-83.5% vs. 22.2%, 95% CI: 8.7%-39.6% and 66.5%, 95% CI: 50.7%-78.2% vs. 16.1%, 95% CI: 5.1%-32.7%, respectively). Multivariate analysis showed that allo-HSCT and achievement of major molecular response were associated with favorable OS or EFS independently. Interestingly, in the allo-HSCT cohort, the donor type (haploidentical versus matched donors) had no significant impact on EFS or OS. All these results suggested that imatinib plus CALLG2008 was an effective protocol for Ph-positive ALL. Haploidentical donors can also be a reasonable alternative expedient donor pool.

Scutellaria extract decreases the proportion of side population cells in a myeloma cell line by down-regulating the expression of ABCG2 protein.

BACKGROUND AND AIMS: Scutellaria is one of the most popular traditional Chinese herbal remedies against various human diseases, including cancer. In this study, we examined the active effects of Scutellaria extract and its main flavonoid constituents on the proportion of side population cells within human multiple myeloma cell line RPMI8226 in vitro and explored the potential molecular mechanisms involved. MATERIALS AND METHODS: The contents of flavonoids in ethanolic extract of Scutellaria baicalensis Georgi were determined using high performance liquid chromatography. The antiproliferative effect of the ethanolic extract on RPMI-8226 was determined by CCK assay. Apoptosis was measured by annexin combining with propidium iodide in a flow cytometer. Cell cycle analysis was performed by propidium iodide staining in combination with flow cytometry analysis. Hoechst 33342 exclusion assay was used for the identification of side population within RPMI8226 cells. The expression of ABCG2 protein was assessed by Western blotting assay. RESULTS: The content of major flavonoids constitutents of Scutellaria extract was baicalin (10.2%), wogonoside (2.50%), baicalein (2.29%), and wogonin (0.99%), respectively. The crude Scutellaria extract did not show significant anti-proliferative effect, apoptosis induction and cell cycle arrest in RPMI-8226 within the concentrations of 1-75µg/mL. However, the ethanolic extract, baicalein, wogonin and baicalin reduced the side population cells in RPMI-8226, and data showed that baicalein and wogonin had stronger inhibitory effects. Correspondingly, they also exhibited significant effects on decreasing the expression level of ABCG2 protein in RPMI-8226 in vitro. CONCLUSIONS: Our results for the first time demonstrated a novel mechanism of action for Scutellaria extract and its main active flavonoids, namely targeting SP cells by modulating the expression of ABCG2 protein. This study provides an insight for new therapeutic strategies targeting cancer stem cells of multiple myeloma.