Cu-Pd bimetallic nanoalloy anchored on a N-rich porous organic polymer for high-performance hydrodeoxygenation of biomass-derived vanillin

The structural composition, particle size on the nanoscale, phase state, and surface property have a significant impact on the performance of nanoalloy catalysts. Here we report a bimetallic Cu3Pd nanoalloy anchored on a N-rich porous organic polymer (BBA-1), Cu3Pd@BBA-1, which shows enhanced catalytic activity for the hydrodeoxygenation of vanillin, a typical compound of lignin-derived bio-oil. The prepared Cu3Pd @BBA-1 bimetallic nanocatalyst exhibits highly efficient catalytic performance in promoting biomass refining compared with its monometallic counterparts, providing 99.3% conversion of vanillin with an exclusive selectivity of 93.6% for the hydrogenolysis product 2-methoxy-4-methylphenol. This catalyst is also found to have superior stability (reproducible conversion values upon several cycles), which represents a significant step forward in promoting biomass refining. The Cu3Pd@BBA-1 and related Cu and Pd based catalysts with varying metallic molar ratios were synthesized by a polyol method using NaBH4 as a strong reducing agent. The specific textural and chemical characteristics of the as-synthesized nanohybrid materials were comprehensively investigated by performing X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, synchrotron powder diffraction, X-ray absorption fine structure spectroscopy, 13C cross polarization magic angle spinning nuclear magnetic resonance, nitrogen physisorption, high resolution transmission electron microscopy, and high angle annular dark field scanning transmission electron microscopy with the corresponding elemental mapping. The catalytic performance of Cu3Pd on other commercial supports such as Al2O3, TiO2 and N-doped carbon is found to be inferior to that on BBA-1, revealing the important role of the nitrogen-rich porous organic polymer matrix. The performance of a 3:1 mixture of the monometallic nanoalloys was substantially lower than that of Cu3Pd@BBA-1. These results and the inputs from the experimental probes used for the characterization indicate that in Cu3Pd@BBA-1, alloying leads to improved surface conditions on the nanoscale and brings about a synergetic electronic effect, thus enabling an enhanced catalytic activity and good recyclability

Prognostic factors in hormone receptor-positive/ human epidermal growth factor receptor 2-negative (Hr+/her2–) advanced breast cancer: A systematic literature review

Purpose: Advanced breast cancer is a heterogeneous disease with several well-defined subtypes, among which, hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2–) is most prevalent. Determination of HR and HER2 status influences prognosis and, thus, disease management. Although literature on these prognostic factors exist, especially in the early breast cancer setting, it remains unclear to what extent these factors can guide clinical decision-making in the advanced disease setting. Therefore, we sought to identify the strength and consistency of evidence for prognostic factors in patients with HR+/HER2– advanced breast cancer. Methods: A systematic literature review (SLR) of the major electronic databases was conducted in November 2018 for primary research studies published since 2010. Endpoints of interest were tumor response, progression-free survival (PFS), overall survival (OS), and breast cancer-specific survival (BCSS). Results: Seventy-nine studies were included wherein all patients were diagnosed with advanced breast cancer and ≥50% of the population were HR+/HER2–. OS was the most commonly assessed endpoint (n=67) followed by PFS (n=33), BCSS (n=5) and tumor response (n=3). The prognostic factors with strongest evidence of association with worse OS were negative progesterone receptor status, higher tumor grade, higher circulating tumor cell (CTC) count and higher Ki67 level, number of metastatic sites (eg multiple vs single) and sites of metastases (eg presence of liver metastases vs absence), shorter time to recurrence or progression to advanced breast cancer, poor performance status, prior therapy attributes in the early or metastatic setting (type of therapy, treatment line, response of prior therapy), and race (black vs white). The prognostic factors that had strongest evidence of association with PFS included CTC count, number and sites of metastases, and absence of prior therapy or higher lines of therapy in the early or metastatic setting. The directionality of association was con-sistent for all prognostic factors except between lymph node and OS, and de novo metastatic breast cancer and PFS. Conclusion: Multiple disease, treatment, and patient-related prognostic factors impact survival, particularly OS, in patients with HR+/HER2– advanced breast cancer. Treatment outcomes can vary considerably due to these factors. Understanding poorer prognostic factors for patients can result in improved clinical decision-making

Optimization of wire-cut electric discharge machining process parameters for hybrid MMC(AA7475/ZrO2/gr) using Taguchi method: an experimental study

AbstractMetal-matrix composites (MMCs) and hybrid metal-matrix composites (HMMCs) are novel materials that possess distinctive mechanical characteristics, making them well-suited for industrial applications. This research implements an experimental study of the mechanical properties of HMMCs, where weight percentages (2, 3, and 4 wt. %) of zirconium dioxide (ZrO2) and graphite powder (Gr) are used as reinforcements and the aluminum alloy 7475 (AA7475) is used as a matrix. In this investigation, the stir casting method was used to prepare the composite by using AA7475 alloy with pre-heated reinforced particles of ZrO2 and graphite with various reinforcement weight percentages. Among these combinations, AA with 4 wt. % ZrO2 and 2 wt.% Gr showed enhanced mechanical properties. The mechanical properties of the ultimate tensile strength, yield strength, and hardness were evaluated. A Scanning Electron Microscope analysis was conducted to study the reinforcement distribution in the matrix. The input parameters for wire-cut electrical discharge machining (WCEDM) are pulse-on time (TON), pulse peak current (IP), and flushing pressure (PF). The material removal rate and surface roughness are the output responses. Determining the ideal set of process parameters in WCEDM for HMMC also involved the use of the Taguchi design technique known as the L9 orthogonal array. The peak current for the MRR and flushing pressure for the SR are the most prominent parameters