Topological Edge and Corner States in Biphenylene Network

The electronic states and topological properties of the biphenylene network (BPN) are analyzed using a tight-binding model based on the $\pi$-electron network. It is shown that tuning the hopping parameters induces topological phase transitions, leading to the emergence of edge states owing to the nontrivial topological Zak phase of the bulk BPN. Elementary band analysis clearly gives the number of edge states, which are associated with the location of Wannier centers. In addition, we have presented the conditions for the emergence of corner states owing to the higher-order topological nature of BPN.Comment: 11 pages, 10 figure

Laparoscopic liver resection for liver metastasis of leiomyosarcoma of the thigh : a case report

Background Although there is no established treatment strategy for liver metastasis of leiomyosarcoma, liver resection has been reported to be effective in some cases. However, almost all liver resections performed for liver metastasis of primary leiomyosarcoma are reported to be open resections, and there are few reports of liver resection performed by laparoscopy. Here, we report a case of laparoscopic liver resection for liver metastasis of a leiomyosarcoma in the right thigh. Case presentation An 80-year-old man was diagnosed with leiomyosarcoma of the right thigh with liver metastasis. The primary tumor was first resected, and he was discharged on the 25th postoperative day. Four months after primary tumor resection, a laparoscopic right posterior sectionectomy was performed. There were no postoperative complications, and the patient was discharged on the 11th postoperative day with a histopathological diagnosis of liver metastasis of leiomyosarcoma and negative resection margins. Currently, 9 months have passed since the resection of the primary tumor, and 5 months have passed since the laparoscopic liver resection; there is no recurrence. Conclusions The liver metastasis of leiomyosarcoma was successfully removed, with good short-term outcomes after the laparoscopic liver resection. Laparoscopic liver resection seems to be effective for liver metastasis of leiomyosarcoma, which is characterized by a high recurrence rate after surgery. However, more case studies may be necessary to examine the effectiveness and long-term results of laparoscopic liver resection for the treatment of liver metastasis of leiomyosarcoma

Heterogeneous nature of the carbonaceous chondrite breccia Aguas Zarcas – Cosmochemical characterization and origin of new carbonaceous chondrite lithologies

International audienceOn April 23rd, 2019, the Aguas Zarcas meteorite fall occurred in Costa Rica. Because the meteorite was quickly recovered, it contains valuable extraterrestrial materials that have not been contaminated by terrestrial processes. Our X-ray computed tomography (XCT) and scanning electron microscopy (SEM) results on various pre-rain fragments from earlier work (Kerraouch et al., 2020; 2021) revealed several distinct lithologies: Two distinct metal-rich lithologies (Met-1 and Met-2), a CM1/2 lithology, a C1 lithology, and a brecciated CM2 lithology consisting of different petrologic types. Here, we further examined these lithologies in the brecciated Aguas Zarcas meteorite and report new detailed mineralogical, chemical, isotopic, and organic matter characteristics. In addition to petrographic differences, the lithologies also display different chemical and isotopic compositions. The variations in their bulk oxygen isotopic compositions indicate that the various lithologies formed in different environments and/or under diverse conditions (e.g., water/rock ratios). Each lithology experienced a different hydration period during its evolution. Together, this suggests that multiple precursor parent bodies may have been involved in these processes of impact brecciation, mixing, and re-assembly. The Cr and Ti isotopic data for both the CM1/2 and Met-1 lithology are consistent with those of other CM chondrites, even though Met-1 displays a significantly lower ε50Ti isotopic composition that may be attributable to sample heterogeneities on the bulk meteorite scale and may reflect variable abundances of refractory phases in the different lithologies of Aguas Zarcas. Finally, examination of the organic matter of the various lithologies also suggests no strong evidence of thermal events, but a short-term heating cannot completely be excluded. Raman parameters indicate that the peak temperature has been lower than that for Yamato-793321 (CM2, ∼400 °C). Considering the new information presented in this study, we now better understand the origin and formation history of the Aguas Zarcas daughter body