Molecular beam epitaxy of superconducting FeSex_{x}Te1−x_{1-x} thin films interfaced with magnetic topological insulators

Engineering heterostructures with various types of quantum materials can provide an intriguing playground for studying exotic physics induced by proximity effect. Here, we report the successful synthesis of iron-based superconductor FeSe$_{x}$Te$_{1-x}$ (FST) thin films in the entire composition of $0 \leq x \leq 1$ and its heterostructure with a magnetic topological insulator by using molecular beam epitaxy. Superconductivity is observed in the FST films with an optimal superconducting transition temperature $T_c$ $\sim$ 12 K at around x = 0.1. We found that superconductivity survives in the very Te-rich films ($x \leq 0.05$), showing stark contrast to bulk crystals with suppression of superconductivity due to an appearance of bicollinear antiferromagnetism accompanied by monoclinic structural transition. By examining thickness t dependence on electrical transport properties, we observed strong suppression of the structural transition in films below t $\sim$ 100 nm, suggesting that substrate effects may stabilize superconducting phase near the interface. Furthermore, we fabricated all chalcogenide-based heterointerface between FST and magnetic topological insulator (Cr,Bi,Sb)$_{2}$Te$_{3}$ for the first time, observing both superconductivity and large anomalous Hall conductivity. The anomalous Hall conductivity increases with decreasing temperature, approaching to the quantized value of $e^2/h$ down to the measurable minimum temperature at $T_c$. The result suggests coexistence of magnetic and superconducting gaps at low temperatures opening at the top and bottom surfaces, respectively. Our novel magnetic topological insulator/superconductor heterostructure could be an ideal platform to explore chiral Majorana edge mode

FoundationOne CDx detected an uncovered variant of epidermal growth factor receptor exon 19 deletion by Oncomine Dx target test in a patient with lung adenocarcinoma

A non-smoker woman with advanced lung adenocarcinoma was referred to us. The Oncomine Dx target test (ODxTT), a next-generation sequencing (NGS)-based hot spots panel test, did not detect any driver mutations, so we treated her with chemo-immunotherapy. After second-line chemotherapy, we performed FoundationOne CDx, a NGS-based comprehensive genomic profiling (CGP) test, and identified a rare variant of epidermal growth factor receptor exon 19 deletion that had not been covered by ODxTT. This case highlights the importance of considering the indication of a CGP test for patients who are likely to harbor driver mutations, even when ODxTT fails to detect any

Potential of fluoropyrimidine to be an immunologically optimal partner of immune checkpoint inhibitors through inducing immunogenic cell death for thoracic malignancies

Abstract Background Immune checkpoint inhibitors (ICIs) are a revolutionary paradigm in the treatment of thoracic malignancies and chemoimmunotherapy is a current standard care in this field. Chemotherapeutic agents are known to induce not only direct cytotoxic effects on tumor cells but also immune modulating effects, such as stimulating immunogenic cell death (ICD). Currently, either pemetrexed (PEM) or taxane plus platinum are combined with ICIs for patients with non‐small cell lung cancer (NSCLC); however, it is still unknown whether these agents are immunologically optimal partners for ICIs. Methods To determine the immunologically optimal chemotherapeutic agent, we first evaluated the ability of several chemotherapeutic agents, including platinum, PEM, taxane, and 5‐fluorouracil (5‐FU) to induce ICD using several thoracic tumor cell lines in vitro. ICD was evaluated by the cell surface expression of calreticulin (CRT) and adenosine‐triphosphate (ATP) secretion. We further performed an antitumor vaccination assay in vivo. Results 5‐FU induced cell surface expression of CRT and ATP secretion most efficiently among the several chemotherapeutic agents. This effect was enhanced when it was combined with platinum. In the antitumor vaccination assay in vivo, we found that vaccination with dying‐AB1‐HA (a murine malignant mesothelioma cell line) cells treated with 5‐FU, but neither PEM nor PTX, reduced the tumor growth of living‐AB1‐HA cells inoculated 1 week after vaccination by recruiting CD3+CD8+ T cells into the tumor microenvironment. Conclusion Our findings indicate that fluoropyrimidine can be an immunologically optimal partner of ICIs through the induction of ICD for thoracic malignancies

Transformation of epidermal growth factor receptor mutated lung adenocarcinoma to small-cell carcinoma long after the cessation of tyrosine kinase inhibitor treatment: A case series and literature review

Histological transformation to small-cell lung cancer (SCLC) is a well-known mechanism of acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), and almost all patients receive EGFR-TKIs at the time of transformation. We herein report three cases of EGFR-mutated lung adenocarcinoma that transformed into SCLC long after the cessation of EGFR-TKIs. Rapid tumor progression and elevated SCLC marker levels were observed at the time of transformation. Our case highlights the importance of considering SCLC transformation throughout the clinical course. Careful observation of the tumor behavior and SCLC markers should be performed to avoid diagnostic delays