Intertwined fractional quantum anomalous Hall states and charge density waves

Motivated by the recent experimental breakthrough on the observation of the fractional quantum anomalous Hall (FQAH) effects in semiconductor and graphene moir\'{e} materials, we explore the rich physics associated with the coexistence of FQAH effect and the charge density wave (CDW) order that spontaneously breaks the translation symmetry. We refer to a state with both properties as "FQAH-crystal". We show that the interplay between FQAH effect and CDW can lead to a rich phase diagram including multiple topological phases and topological quantum phase transitions at the same moir\'e filling. In particular, we demonstrate the possibility of direct quantum phase transitions from a FQAH-crystal with Hall conductivity $\sigma_H = - 2/3$ to a trivial CDW insulator with $\sigma_H = 0$, and more interestingly, to a QAH-crystal with $\sigma_H= -1$.Comment: 9 page

Effect of all-trans retinoic acid on the proliferation and differentiation of brain tumor stem cells

<p>Abstract</p> <p>Objective</p> <p>To investigate the effect of all-trans retinoic acid(ATRA) on the proliferation and differentiation of brain tumor stem cells(BTSCs) <it>in vitro</it>.</p> <p>Methods</p> <p>Limiting dilution and clonogenic assay were used to isolate and screen BTSCs from the fresh specimen of human brain glioblastoma. The obtained BTSCs, which were cultured in serum-free medium, were classified into four groups in accordance with the composition of the different treatments. The proliferation of the BTSCs was evaluated by MTT assay. The BTSCs were induced to differentiate in serum-containing medium, and classified into the ATRA group and control group. On the 10^thday of induction, the expressions of CD133 and glial fibrillary acidic protein (GFAP) in the differentiated BTSCs were detected by immunofluorescence. The differentiated BTSCs were cultured in serum-free medium, the percentage and the time required for formation of brain tumor spheres (BTS) were observed.</p> <p>Results</p> <p><b>BTSCs </b>obtained by limiting dilution were all identified as CD133-positive by immunofluorescence. In serum-free medium, the proliferation of BTSCs in the ATRA group was observed significantly faster than that in the control group, but slower than that in the growth factor group and ATRA/growth factor group, and the size of the BTS in the ATRA group was smaller than that in the latter two groups(<it>P </it>< 0.01). In serum-containing medium, the expression percentages of CD133 and GFAP in the differentiated BTSCs were (2.29% ± 0.27%) and (75.60% ± 4.03%) respectively in the ATRA group, and (7.05% ± 0.49%) and (12.51% ± 0.77%) respectively in the control group. The differentiation rate of BTSCs in the ATRA group was significantly higher than that in the control group (<it>P </it>< 0.05), but there was still CD133 expressed in the ATRA group. The differentiated BTSCs could re-form BTSs in serum-free medium. The percentage of BTS formation in the ATRA group was(4.84% ± 0.32%), significantly lower than that in the control group (17.71% ± 0.78%) (<it>P </it>< 0.05), and the time required for BTS formation in the ATRA group was (10.07 ± 1.03)d, significantly longer than that in the control group (4.08 ± 0.35)d (<it>P </it>< 0.05).</p> <p>Conclusion</p> <p><b>ATRA </b>can promote the proliferation and induce the differentiation of BTSCs, but the differentiation is incomplete, terminal differentiation cannot be achieved and BTSs can be formed again.</p

Vertical Displacement due to Ocean Tidal Loading Around Taiwan Based on GPS Observations

Ocean tidal loading (OTL) is an important factor in GPS positioning, especially along the vertical direction. OTL influences the precision of GPS positioning and produces height variations of up to 12 cm. In this study, daily GPS data obtained from 27 GPS tracking stations around Taiwan were collected, and four OTL models were applied to relative static GPS positions derived from these data. The GPS data were obtained from 8 - 14 August 2006 (summer) and 1 - 30 January 2007 (winter). The software Bernese 5.0 was utilized for data processing

1,4-Bis(2-pyridylmethyl­eneamino­meth­yl)benzene

The asymmetric unit of the centrosymmetric title compound, C20H18N4, contains one half-mol­ecule. The pyridine and benzene rings are oriented at a dihedral angle of 77.21 (7)°

A Smartphone APP for Health and Tourism Promotion

The main purpose of this study is to develop an APP by integrating GPS to provide the digitized information of local cultural spots to guide tourists for tourism promotion and the digitized information of mountaineering trails to monitor energy expenditure (EE) for health promotion. The provided cultural information is also adopted for educational purpose. Extended Technology Acceptance Model (TAM) was used to evaluate the usefulness and behavior intention of the provided information and functions in the developed system. Most users agreed that the system is useful for health promotion, tourism promotion, and folk-culture education. They also showed strong intention and positive attitude toward continuous use of the APP