Nanoscale Optical Conductivity Imaging of Double-Moiré Twisted Bilayer Graphene.

A central paradigm of moiré materials relies on the formation of superlattices that yield enlarged effective crystal unit cells. While a critical consequence of this phenomenon is the celebrated flat electronic bands that foster strong interaction effects, the presence of superlattices has further implications. Here we explore the advantages of moiré superlattices in twisted bilayer graphene (TBG) aligned with hexagonal boron nitride (hBN) for passively enhancing optical conductivity in the low-energy regime. To probe the local optical response of TBG/hBN double-moiré lattices, we use infrared (IR) nano-imaging in conjunction with nanocurrent imaging to examine local optical conductivity over a wide range of TBG twist angles. We show that interband transitions associated with the multiple moiré flat and dispersive bands produce tunable transparent IR responses even at finite carrier densities, which is in stark contrast to the previously limited metallic near transparency observed only in undoped pristine graphene.

Associations of physical activity intensity, frequency, duration, and volume with the incidence of sarcopenia in middle-aged and older adults: a 4-year longitudinal study in China.

BACKGROUND: Physical activity (PA) plays an important role in the process of several chronic diseases. It may be also associated with the incidence of sarcopenia. This study aimed to determine the association of PA from different components including frequency, duration, intensity, and volume with the incidence of sarcopenia in middle-aged and older adults. METHODS: This study used data from the China Health and Retirement Longitudinal Study in 2011 and 2015. A total of 3,760 individuals aged ≥ 40 years were involved in this study. Sarcopenia was diagnosed using muscle mass, strength and physical performance according to the Asian Working Group for Sarcopenia. PA information including frequency, duration, intensity, and volume was obtained by a self-reported questionnaire. Logistic regression analysis was employed to examine the association between PA and the incidence of sarcopenia at 4-year follow-up. RESULTS: The incidence of sarcopenia was 5.9% during the 4-year follow-up. Compared to sedentary individuals, those taking 1-2 days or more per week, or a minimum of 10 min each time on vigorous-intensity PA (VPA) had a lower incidence of sarcopenia. Adults spending 3 days or more each week, a minimum of 30 min each time, or 150 min or more per week on moderate-intensity PA (MPA) had a lower presence of sarcopenia than sedentary adults. Adults taking 3 days or more per week, at least 30 min each time, or 150 min or more each week on light-intensity PA (LPA) tended to have a lower incidence of sarcopenia than sedentary individuals. Sensitivity analyses confirmed the robustness of the findings after removing persons with hypertension, dyslipidemia, or diabetes. CONCLUSIONS: These findings suggest that the frequency, duration, and volume of VPA or MPA are negatively associated with the presence of sarcopenia. Participation in LPA tends to have a lower incidence of sarcopenia in middle-aged and older adults.

Probing the Ferromagnetism and Spin Wave Gap in VI3 by Helicity-Resolved Raman Spectroscopy.

Circularly polarized light carries light spin angular momentum, which may lead helicity-resolved Raman scattering to be sensitive to the electronic spin configuration in magnetic materials. Here, we demonstrate that all Raman modes in the 2D ferromagnet VI3 show different scattering intensities to left and right circularly polarized light at low temperatures, which gives direct evidence of the time-reversal symmetry breaking. By measuring the circular polarization of the dominant Raman mode with respect to the temperature and magnetic field, the ferromagnetic (FM) phase transition and hysteresis behavior can be clearly resolved. Besides the lattice excitations, quasielastic scattering is detected in the paramagnetic phase, and it gradually evolves into the acoustic magnon mode at 18.5 cm-1 in the FM state, which gives the spin wave gap that results from large magnetic anisotropy. Our findings demonstrate that helicity-resolved Raman spectroscopy is an effective tool to directly probe the ferromagnetism in 2D magnets.

MicroRNA-148a Inhibits Hepatocellular Carcinoma Cell Growth via Epithelial-to-Mesenchymal Transition and PI3K/AKT Signaling Pathways by Targeting Death Receptor-5.

The purpose of this study was to investigate the role of microRNA-148a (miR-148a) in hepatocellular carcinoma (HCC) metastasis and explore its potential mechanism in HCC cells. Expression levels of miR-148a were measured using qRT-PCR in 120 HCC tissue samples and two HCC cell lines. Migration and invasion assays were used to determine the role of miR-148a in HCC cells. Flow cytometry was used to access the effect of miR-148a on cell cycle of HCC cells. Western blot was performed to analyze the effect of miR-148a on epithelial-to-mesenchymal transition (EMT) and PI3K/AKT signaling pathways in HCC cells. Luciferase reporter assay was conducted to explore the downstream targets and biological function of miR-148a in HCC cells. The results showed that level of miR-148a was significantly downregulated in both HCC tissue and plasma samples in HCC patients. A higher level of miR-148a was positively correlated with better survival time and prognosis of HCC patients. Transfection of miR-148a inhibited the proliferation, migration and invasion of HCC cell lines. Transfection of miR-148a arrested HCC cells at S phase and promoted apoptosis of HCC cells. Death receptor-5 (DR-5) was identified as a direct target of miR-148a in HCC cell lines. Western blot and qRT-PCR analyses showed that miR-148a upregulated EMT and downregulated PI3K/AKT signaling pathways in HCC cell lines. In conclusion, data in the current study indicate that miR-148a inhibits HCC cells growth via downregulation of EMT and PI3K/AKT signaling pathways by targeting death receptor. These data suggest that miR-148a may serve as a therapeutic target for HCC cancer therapy in the future.

Clinical efficacy of weekly cisplatin for treatment of patients with breast cancer.

BACKGROUND: We will investigate the efficacy and safety of weekly cisplatin (WC) for treatment of patients with breast cancer (BC) systematically. METHODS: This study will describe and critically appraise shared decision approaches used in randomized controlled trials of WC for treatment of patients with BC. We will comprehensively search the following databases: PubMed, EMBASE, Web of Science, Cochrane Library, CINAHL, PsycINFO, Allied and Complementary Medicine Database, Wanfang, and Chinese Biomedical Literature Database from inception through July 1, 2019. We will utilize RevMan V.5.3 software (London, UK) for statistical analysis. RESULTS: This study will systematically explore the efficacy and safety of WC for the treatment of patients with BC through evaluating primary outcomes of overall survival, pathological complete response; and secondary outcomes of cancer-specific survival, recurrence-free survival, disease-free survival, quality of life, and toxicities. CONCLUSION: This study will provide latest evidence of WC for the treatment of patients with BC. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019145358.