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The stability, geometric structure and electronic properties of a novel body-centered tetragonal carbon allotrope Bct C 8 are systematically investigated. Bct C 8 are formed by sp 3 -bonded carbon atoms and can be regarded as a compressed bundle of carbon nanotubes (CNT). The transition path from CNT to Bct C 8 has been simulated, indicating a possible approach to synthesize Bct C 8 . The X-Ray diffraction, phonon and Raman spectroscopies are presented as reference for experimental studies. Besides, Bct C 8 is a semiconductor with an indirect gap of 1.66 eV and will transform to semimetal when doping with boron and nitride atoms. Furthermore, considering its porous structural character, the lithium storage capability of Bct C 8 are also discussed, a directional fast lithium-ion mobility with a rather low 0.04 eV barrier is revealed. Therefore, the Bct C 8 , once synthesized experimentally, would have fruitful applications in carbon-based electronics and energy storage. [ABSTRACT FROM AUTHOR]

The properties of diamond polytypes under high pressure have been investigated by means of the first-principles calculations. They are unveiled to be thermodynamically and kinetically more stable than hexagonal diamond (h-diamond) even under pressure. The electronic and elastic properties of the diamond polytypes are also explored, revealing very close cohesive energy, band gap and equilibrium density to those of cubic diamond (c-diamond). The Vickers hardness is uncovered to be comparable or even larger than those of the c- and h-diamond. Furthermore, they experience lower energy barriers than the h-diamond during the transforming process from graphite under pressure. Especially, we explored the characterized Raman modes under pressure from 0 to 40 GPa for each allotrope, which can be used to identify the diamond polytypes from the c-diamond T 2 g background mode, and the result may serve as a useful guide for future experimental studies. In addition, the simulated X-ray diffraction spectra under pressure is also presented. [ABSTRACT FROM AUTHOR]

We study a versatile structurally favorable periodic sp2-bonded carbon atomic planar sheet with C4v symmetry by means of the first-principles calculations. This carbon allotrope is composed of carbon octagons and squares with two bond lengths and is thus dubbed as octagraphene. It is a semimetal with the Fermi surface consisting of one hole and one electron pocket, whose low-energy physics can be well described by a tight-binding model of π-electrons. Its Young's modulus, breaking strength, and Poisson's ratio are obtained to be 306 N/m, 34.4 N/m, and 0.13, respectively, which are close to those of graphene. The novel sawtooth and armchair carbon nanotubes as well as unconventional fullerenes can also be constructed from octagraphene. It is found that the Ti-absorbed octagraphene can be allowed for hydrogen storage with capacity around 7.76 wt. %. [ABSTRACT FROM AUTHOR]

Immune checkpoint inhibitors (ICIs) have revolutionized cancer management and have been widely applied; however, they still have some limitations in terms of efficacy and toxicity. There are multiple treatment regimens in Traditional Chinese Medicine (TCM) that play active roles in combination with Western medicine in the field of oncology treatment. TCM with ICIs works by regulating the tumor microenvironment and modulating gut microbiota. Through multiple targets and multiple means, TCM enhances the efficacy of ICIs, reverses resistance, and effectively prevents and treats ICI-related adverse events based on basic and clinical studies. However, there have been few conclusions on this topic. This review summarizes the development of TCM in cancer treatment, the mechanisms underlying the combination of TCM and ICIs, existing studies, ongoing trials, and prospects for future development. [ABSTRACT FROM AUTHOR]

A novel carbon allotrope, T-carbon, is attempted to obtain by using plasma enhanced chemical vapor deposition (PECVD) on the substrates of polycrystalline diamond and single crystalline diamond, respectively. Our measured x-ray diffraction, Raman and infrared spectra of the new form of carbon are in good agreement with the calculated results of T-carbon, and the lattice parameter meets with the results of calculation as well as the high resolution electron microscopy of T-carbon nanowires synthesized by the pulsed laser irradiating modification of carbon multiwall nanotubes, revealing that the phase of T-carbon can be identified in our samples. The experimental preparation of T-carbon by PECVD method indicates that the massive production of T-carbon may be feasible, and extensive investigations with high-throughput experiments on this novel phase are highly expected. Image 1 [ABSTRACT FROM AUTHOR]

Small cell lung cancer (SCLC) is a type of lung cancer characterized by a rapid disease progression and poor prognosis. Its diagnosis is often accompanied by distant metastasis. A literature review revealed that metastases to the stomach from breast, lung and esophageal cancer are frequently reported. While SCLC is a common pathological subtype of lung cancer, literature on SCLC with gastric metastases is sporadic. The present study reviewed the literature using databases, including PubMed, WanFang Data and China National Knowledge Infrastructure, to analyze the clinicopathological features and outcome of patients with gastric metastases from SCLC. A total of 11 case reports and 6 retrospective studies comprising of 19 cases were compared and analyzed. In addition to the aforementioned studies, a case study describing a patient who survived for 10 months following a diagnosis of SCLC with gastric metastases is presented. The aim of the present study was to increase the understanding regarding the diagnosis and treatment of SCLC gastric metastasis. [ABSTRACT FROM AUTHOR]

Abstract: The geometric, electronic, and magnetic properties of twisted zigzag-edged graphene nanoribbons (ZGNRs) and novel graphene Möbius strips (GMS) are systematically investigated with the first-principles calculations based on the density functional theory. All the structures of ZGNRs and GMS are optimized, and their structural stabilities are examined. The molecular energy levels and the spin polarized density of states of ZGNRs are also calculated. It is found that the atomic bonding energies of the twisted ZGNRs decrease quadratically with the increase of the twisted angle, and the gaps between the lowest unoccupied molecular orbital and the highest occupied molecular orbital are varied with the twisted angle. The spin densities of ZGNRs and GMS reveal that the ground states with antiferromagnetic edges persist during the twisting, and the spin flip at some positions of the zigzag edges of GMS can be observed. [Copyright &y& Elsevier]