Reducing dioxin formation by adding hydrogen in simulated fly ash

In this study, simulated fly ash containing CuO/CuCl2 was heated at 350 °C in a flow of N2 and also in a nitrogen flow containing 10 vol% H2, to evaluate the influence of hydrogen adding on dioxin formation. The total polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) output derived from the CuO sample under N2 and 10 % H2 was 7.382 and 0.708 ng/g, respectively. As for CuCl2, it was 589 and 46.1 ng/g, respectively. The results show that the hydrogen adding has a good inhibition effect on PCDD/F formation; the inhibition rate was higher than 90 % for PCDD/Fs. HCl and NH3 were detected by Gasmet in the flue gas; the probable inhibition mechanism of hydrogen reaction was proposed, based on our measurements and others' researches.

[Prognosis analysis of primary breast diffuse large B cell lymphoma]

Objective: To investigate the clinical characteristics, therapy modality and prognosis of primary breast diffuse large B-cell lymphoma(PB-DLBCL). Methods: A total of 68 patients with PB-DLBCL treated in Tianjin Medical University Cancer Institute and Hospital were enrolled between January 1, 2004 and January 31, 2017. Clinicopathological data were retrospectively analyzed. 67 patients were female and only one male. The median age was 56 years old. 46 patients had Ann Arbor clinical stageⅠ~Ⅱ disease, and the other 22 were stage Ⅲ~Ⅳ. The patients with and without B symptom were 11 and 57, respectively. Kaplan-Meier method was used for univariate analysis to calculate the 5-year overall survival (OS) rate and 5-year progress-free survival (PFS) rate, compared using the log rank test. Cox regression analysis was used for multivariate analysis. Results: The 1, 3, 5-year OS rate were 84.0%, 78.0% and 73.0%, and 1, 3, 5-year PFS rate were 80.0%, 71.0% and 51.0%, respectively. Univariate analysis indicated that eastern cooperative oncology group (ECOG) score, Ann Arbor clinical stage, international prognostic index (IPI) score, risk stratification, B symptom, β2-microglobulin(β2-MG) level, size of the tumor and cycles of chemotherapy were prognostic factors for OS (all P<0.05), and Ann Arbor clinical stage, IPI score, risk stratification and B symptom were prognostic factors for PFS (all P<0.05). Multivariate analysis indicated that Ann Arbor clinical stage was independent prognostic factor for OS(P=0.029) and B symptom was independent prognostic factor for PFS(P=0.028). Conclusions: Prognosis of PB-DLBCL was relatively good. Ann Arbor clinical stage and B symptom were independent prognostic factors for OS and PFS, respectively.

Effect of Sc spatial distribution on the electronic and ferroelectric properties of AlScN

While aluminum scandium nitride based ferroelectric materials have shown significant promise for non-volatile memory applications, difficulties relating challenges in device performance, such as electrical leakage, to structural characteristics motivate improved understanding of the fundamental structure-property relationship. Spinodal decomposition has been reported in this material system, consistent with our observation of compositional segregation in AlScN films grown by reactive sputter epitaxy. To better understand the effects of spatially non-uniform Sc concentrations, the electronic and ferroelectric (FE) properties of AlScN as a function of Sc distribution are studied using density functional theory (DFT). We explore the impact of Sc-rich atomic planes in wurtzite AlScN with Sc concentration ranging from 0 to 44 at% through a supercell approach. We find that while spontaneous polarization decreases with Sc concentration (∼133 to 102 μC cm-2), periodic Sc-rich planar clusters slow this effect, suggesting that phase segregation counters the effects of increasing Sc composition. Furthermore, the FE switching barrier per formula unit (f.u.) as a function of composition exhibits a local maximum of 0.60 eV f.u.-1 at 25% Sc concentration in the presence of Sc-rich planes but decreases monotonically (0.51 to 0.28 eV f.u.-1) if Sc is uniformly distributed, suggesting that the spatial distribution of Sc plays an important role in the optoelectronic properties of the material by changing the energy landscape. Sc clustering also decreases the bandgap of the material. This study shows that the structural complexity arising from spatial composition modulation provides tunability of ferroelectric properties in AlScN ferroelectrics.

[Development of membrane anatomy theory in gastric cancer surgery]

In the past decade, the concept of membrane anatomy has been gradually applied in gastric cancer surgery. Based on this theory, D2 lymphadenectomy plus complete mesogastric excision (D2+CME) has been proposed, which has been demonstrated to significantly reduce intraoperative bleeding and intraperitoneal free cancer cells during surgery, decrease surgical complications, and improve survival. These results indicate that membrane anatomy is feasible and efficacious in gastric cancer surgery. In this review, we will describe the important contents of membrane anatomy, including "Metastasis V"(2013, 2015), proximal segmentation of dorsal mesogastrium (2015), D2+CME procedure (2016), "cancer leak"(2018), and surgical outcomes of D2+CME (2022).

Chemical potential gradient induced formation of Kirkendall voids at the epitaxial TiN/MgO interface

We report the observation of Kirkendall voids at the epitaxial titanium nitride (TiN)/magnesium oxide(MgO)(001) interface. While epitaxial growth of TiN on MgO has been known for years, many reports show a perfectly sharp epitaxial interface. Because TiN is a prototypical diffusion barrier material, observing the consequence of rapid diffusion at a TiN interface is interesting. Structural characterization of the interface using X-ray diffraction and electron microscopy confirms the diffuse nature of the interface. Rectangular voids that form at the TiN/MgO(001) interface and extend into both TiN and MgO result from a large chemical potential gradient at the interface, which contributes a strong chemical driving force for diffusion. The spatial localization of the observed voids is limited to within ∼10 nm from the interface, consistent with a chemical potential gradient driving force. A composition gradient on the nanometer scale is also observed. Observation of Kirkendall voids at this nitride/oxide interface suggests possibilities for engineering oxygen and nitrogen vacancies at thin film interfaces.

Nanoscale compositional segregation in epitaxial AlScN on Si (111)

We report the growth of epitaxial wurtzite AlScN thin films on Si (111) substrates with a wide range of Sc concentrations using ultra-high vacuum reactive sputtering. Sc alloying in AlN enhances piezoelectricity and induces ferroelectricity, and epitaxial thin films facilitate systematic structure-based investigations of this important and emerging class of materials. Two main effects are observed as a function of increasing Sc concentration. First, increasing crystalline disorder is observed together with a structural transition from wurtzite to rocksalt at ∼30 at% Sc. Second, nanoscale compositional segregation consistent with spinodal decomposition occurs at intermediate compositions, before the wurtzite to rocksalt phase boundary is reached. Lamellar features arising from composition fluctuations are correlated with polarization domains in AlScN, suggesting that composition segregation can influence ferroelectric properties. The present results provide a route to the creation of single crystal AlScN films on Si (111), as well as a means for self-assembled composition modulation.