Based on first-principle calculations, we show that a family of nonmagnetic materials including TaAs, TaP, NbAs, and NbP are Weyl semimetals (WSM) without inversion centers. We find twelve pairs of ...Weyl points in the whole Brillouin zone (BZ) for each of them. In the absence of spin-orbit coupling (SOC), band inversions in mirror-invariant planes lead to gapless nodal rings in the energy-momentum dispersion. The strong SOC in these materials then opens full gaps in the mirror planes, generating nonzero mirror Chern numbers and Weyl points off the mirror planes. The resulting surface-state Fermi arc structures on both (001) and (100) surfaces are also obtained, and they show interesting shapes, pointing to fascinating playgrounds for future experimental studies.
The existence of topological hinge states is a key signature for a newly proposed class of topological matter, the second-order topological insulators. In the present paper, a universal mechanism to ...generate chiral hinge states in the ferromagnetic axion insulator phase is introduced, which leads to an exotic transport phenomenon, the quantum anomalous Hall effect (QAHE) on some particular surfaces determined by both the crystalline symmetry and the magnetization direction. A realistic material system, Sm-doped Bi2Se3, is then proposed to realize such exotic hinge states by combining first-principles calculations and Green’s function techniques. A physically accessible way to manipulate the surface QAHE is also proposed, which makes it very different from the QAHE in ordinary 2D systems.The second-order topological states—chiral hinge states—are predicted in axion insulators, ferromagnetic insulating materials with quantized electromagnetic response. The authors predict such states to occur in Sm-doped Bi2Se3.
By using first-principles calculations, we propose that WC-type ZrTe is a new type of topological semimetal (TSM). It has six pairs of chiral Weyl nodes in its first Brillouin zone, but it is ...distinguished from other existing TSMs by having an additional two paris of massless fermions with triply degenerate nodal points as proposed in the isostructural compounds TaN and NbN. The mirror symmetry, threefold rotational symmetry, and time-reversal symmetry require all of the Weyl nodes to have the same velocity vectors and locate at the same energy level. The Fermi arcs on different surfaces are shown, which may be measured by future experiments. It demonstrates that the “material universe” can support more intriguing particles simultaneously.
High coulombic efficiency and dendrite suppression in carbonate electrolytes remain challenges to the development of high-energy lithium ion batteries containing lithium metal anodes. Here we ...demonstrate an ultrathin (≤100 nm) lithium-ion ionomer membrane consisting of lithium-exchanged sulfonated polyether ether ketone embedded with polyhedral oligosilsesquioxane as a coating layer on copper or lithium for achieving efficient and stable lithium plating-stripping cycles in a carbonate-based electrolyte. Operando analyses and theoretical simulation reveal the remarkable ability of the ionomer coating to enable electric field homogenization over a considerably large lithium-plating surface. The membrane coating, serving as an artificial solid-electrolyte interphase filter in minimizing parasitic reactions at the electrolyte-electrode interface, enables dendrite-free lithium plating on copper with outstanding coulombic efficiencies at room and elevated (50 °C) temperatures. The membrane coated copper demonstrates itself as a promising current collector for manufacturing high-quality pre-plated lithium thin-film anode.
Metastatic breast cancer remains incurable. Next-generation sequencing (NGS) offers the ability to identify actionable genomic alterations in tumours which may then be matched with targeted ...therapies, but the implementation and utility of this approach is not well defined for patients with metastatic breast cancer.
We recruited patients with advanced breast cancer of any subtype for prospective targeted NGS of their most recent tumour samples, using a panel of 108 breast cancer-specific genes. Genes were classified as actionable or non-actionable using the European Society of Medical Oncology Scale for Clinical Actionability of Molecular Targets (ESCAT) guidelines.
Between February 2014 and May 2019, 322 patients were enrolled onto the study, with 72% (n = 234) of patients successfully sequenced (n = 357 samples). The majority (74%, n = 171) of sequenced patients were found to carry a potentially actionable alteration, the most common being a PIK3CA mutation. Forty-three percent (n = 74) of patients with actionable alterations were referred for a clinical trial or referred for confirmatory germline testing or had a change in therapy outside of clinical trials. We found alterations in AKT1, BRCA2, CHEK2, ESR1, FGFR1, KMT2C, NCOR1, PIK3CA and TSC2 to be significantly enriched in our metastatic population compared with primary breast cancers. Concordance between primary and metastatic samples for key driver genes (TP53, ERBB2 amplification) was > 75%. Additionally, we found that patients with a higher number of mutations had a significantly worse overall survival.
Genomic profiling of patients with metastatic breast cancer can have clinical implications and should be considered in all suitable patients.
Angiogenesis is a hallmark of cancer and plays a critical role in lung cancer progression, which involves interactions between cancer cells, endothelial cells and the surrounding microenvironment. ...However, the gene expression profiles and the changes in the biological phenotype of vascular endothelial cells after interactions with lung cancer cells remain unclear.
An indirect transwell co-culture system was used to survey the interaction between human umbilical vein endothelial cells (HUVECs) and human lung adenocarcinoma CL1-5 cells, as well as to investigate the morphological and molecular changes of HUVECs. The differentially expressed genes (DEGs) in HUVECs after co-culture with cancer cells were identified by microarray. Moreover, a publicly available microarray dataset of 293 non-small-cell lung cancer (NSCLC) patients was employed to evaluate the prognostic power of the gene signatures derived from HUVECs.
The interaction between HUVECs and lung cancer cells changes the morphology of HUVECs, causing them to have a mesenchymal-like morphology and alter their cytoskeleton organization. Furthermore, after co-culture with lung cancer cells, HUVECs showed increased cell motility and microvessel tube formation ability and a decreased apoptotic percentage. Transcriptomic profiling of HUVECs revealed that many survival-, apoptosis- and angiogenesis-related genes were differentially expressed after interactions with lung cancer cells. Further investigations showed that the PI3K/Akt signalling pathway and COX-2 are involved in endothelial tube formation under the stimulation of lung cancer cells. Moreover, Rac-1 activation might promote endothelial cell motility through the increased formation of lamellipodia and filopodia. The inhibitors of PI3K and COX-2 could reverse the increased tube formation and induce the apoptosis of HUVECs. In addition, the gene signatures derived from the DEGs in HUVECs could predict overall survival and disease-free survival in NSCLC patients and serve as an independent prognostic factor.
In this study, we found that cancer cells can promote endothelial cell tube formation and survival, at least in part, through the PI3K/Akt signalling pathway and thus change the microenvironment to benefit tumour growth. The gene signatures from HUVECs are associated with the clinical outcome of NSCLC patients.
Metastatic breast cancer (mBC) is a heterogenous disease with increasing availability of targeted therapies as well as emerging genomic markers of therapeutic resistance, necessitating timely and ...accurate molecular characterization of disease. As a minimally invasive test, analysis of circulating tumour DNA (ctDNA) is well positioned for real-time genomic profiling to guide treatment decisions. Here, we report the results of a prospective testing program established to assess the feasibility of ctDNA analysis to guide clinical management of mBC patients.
Two hundred thirty-four mBC patients (median age 54 years) were enrolled between June 2015 and October 2018 at the Peter MacCallum Cancer Centre, Melbourne, Australia. Median follow-up was 15 months (range 1-46). All patient samples at the time of enrolment were analysed in real time for the presence of somatic mutations. Longitudinal plasma testing during the course of patient management was also undertaken in a subset of patients (n = 67, 28.6%), according to clinician preference, for repeated molecular profiling or disease monitoring. Detection of somatic mutations from patient plasma was performed using a multiplexed droplet digital PCR (ddPCR) approach to identify hotspot mutations in PIK3CA, ESR1, ERBB2, and AKT1. In parallel, subsets of samples were also analysed via next-generation sequencing (targeted panel sequencing and low-coverage whole-genome sequencing LC-WGS). The sensitivity of ddPCR and targeted panel sequencing to identify actionable mutations was compared. Results were discussed at a multidisciplinary breast cancer meeting prior to treatment decisions. ddPCR and targeted panel sequencing identified at least 1 actionable mutation at baseline in 80/234 (34.2%) and 62/159 (39.0%) of patients tested, respectively. Combined, both methods detected an actionable alteration in 104/234 patients (44.4%) through baseline or serial ctDNA testing. LC-WGS was performed on 27 patients from the cohort, uncovering several recurrently amplified regions including 11q13.3 encompassing CCND1. Increasing ctDNA levels were associated with inferior overall survival, whether assessed by ddPCR, targeted sequencing, or LC-WGS. Overall, the ctDNA results changed clinical management in 40 patients including the direct recruitment of 20 patients to clinical trials. Limitations of the study were that it was conducted at a single site and that 31.3% of participants were lost to follow-up.
In this study, we found prospective ctDNA testing to be a practical and feasible approach that can guide clinical trial enrolment and patient management in mBC.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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•C-TiO2 catalyst enhances photocatalytic oxidation of ethylene under visible-light.•Photocatalytic rate increased with increase in concentration of ethylene and oxygen, temperature ...and light intensity.•Water adsorption is in competition with ethylene adsorption on the same C-TiO2 sites.•Experimental data was successfully predicted with the use of L–H kinetic model.•Enthalpy of adsorption: −2.61 (C2H4), −12.2 (H2O), and −3.8 (O2) kcal/mol.
We herein report the visible-light-induced photocatalytic degradation of ethylene by a C-doped TiO2 catalyst synthesized by the sol–gel method. The effects of key parameters such as visible light intensity, temperature, and feed composition (ethylene, oxygen, and water vapor) on the photocatalytic reaction rate were evaluated. Our observations, along with experimental results, indicated that the oxidation rate of ethylene improved significantly with an increase in visible light intensity, temperature, and oxygen and ethylene concentrations. Under all experimental conditions, approximately 96–753ppmv of ethylene, which was adsorbed onto the photocatalyst surfaces (C-doped TiO2) were stoichiometrically oxidized to CO2. High temperature was found to improve the oxidation rate, which could be attributed to an increase in the reactivity of the heterogeneous catalyst and also a hostile adsorption of water on the catalyst. We found that the oxidation rate of ethylene was suppressed considerably with an increase in the water vapor concentration from 547 to 15,000ppmv at two specific temperatures (303 and 318K). This observation can be explained by the law of adsorption, since polar water molecules have higher adsorption affinity on a polar catalyst surface than do nonpolar ethylene molecules. We used a Langmuir–Hinshelwood (L–H) model with explicit temperature dependence for simulating the entire set of experimental rate data. The rate law was expressed as follows to account for the obtained results: r=Iαk′exp-EaRTKe′exp-ΔHe/RTTCe1+Ke′exp-ΔHe/RTTCe+Kw′exp(-ΔHw/RTT)CwKO2′exp-ΔHO2/RTTCO21+KO2′exp-ΔHO2/RTTCO2
Based on the L–H model, we determined the adsorption enthalpies of ethylene, water vapor, and oxygen on the C-doped TiO2 catalyst.
•C dopant improves the transformation of anatase-to-rutile phase.•Carbonate species and coke-like structure cause a absorption in visible -light region.•C-TiO2, prepared with G/T ratio 1 and 400°C, ...shows optimal photocatalytic activity.•The C existed at interstitial positions of TiO2 lattice induced the red shift.•The prepared C-TiO2 enables effectively degrade ethylene under visible -light irradiation.
A C-doped TiO2 photocatalyst has been found to be viable in degrading organic compounds under visible light. However, the characteristics of the C-doped TiO2 in relation to photocatalytic activity remain largely unexplored. In this study, we systematically investigated the effect of carbon content and calcination temperature on the photocatalytic properties of a C-doped TiO2 catalyst prepared by a sol–gel method. The phase, structure, chemical state, optical properties, and surface area/pore distribution of the C-doped TiO2 were characterized using X-ray diffractometer, transmission electron microscope, X-ray photoelectron spectroscopy, UV–visible diffusion reflectance spectroscopy, and specific surface area by the Brunauer–Emmett–Teller method. The results showed that the photocatalytic activity of C-doped TiO2 was greatly enhanced compared to pure TiO2 under visible irradiation. The C dopant retarded the transformation from anatase to rutile. Namely, C doping was shown to stabilize the anatase phase. The results also showed that C atoms were incorporated into the interstitial positions of the TiO2 lattice or formatted coke-like structure on the surface of TiO2. The formation of carbonate species could cause a long-tail absorption in the visible-light region. Ethylene was used to evaluate the photocatalytic activity of C-TiO2 under visible-light irradiation. The results suggested that crystalline structure and smaller particle size enhance the photocatalytic activity of C-doped TiO2. The highest photocatalytic performance was found for a C-doped TiO2 catalyst prepared at glucose to titanium n-butoxide (G/T) molar ratio of 1.0 and calcined at 400°C.
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