CPX has a strong synergistic antileukemia effect with dexamethasone (DEX) in GC-resistant T-ALL cells.

<p>(A) to (C) When combined with DEX (1 <i>μ</i>M), CPX demonstrated a potent growth inhibition of the three GC-resistant cells even at a concentration as low as 1 <i>μ</i>M, especially after 72 h exposure. (D) Flow cytometric analysis showed that CPX (1 <i>μ</i>M) had a synergistic effect on inducing apotosis after 48 h treatment with DEX (1 <i>μ</i>M) in CEM-C1 cells. D+C; DEX+CPX.</p

Percentage of apoptosis in the presence of 10 <i>μ</i>M CPX ().

<p>Percentage of apoptosis in the presence of 10 <i>μ</i>M CPX ().</p

Percentage of viable cells in the presence of 10 <i>μ</i>M CPX ().

<p>Percentage of viable cells in the presence of 10 <i>μ</i>M CPX ().</p

CPX induced apoptosis in T-ALL cells.

<p>(A) and (B) Flow cytometric analysis showed an increased rate of early stage of apoptosis (Annexin V-FITC+/PI-, H4) after 12 h treatment of CPX (10 <i>μ</i>M) and both rates of the early and late phase of apoptotic cell death (Annexin V-FITC+/PI+, H2) were increased after 24 h treatment in GC resistant cells of CEM-C1 and Jurkat, as well as GC-sensitive CEM-C7 cells.</p

CPX induced apoptosis in T-ALL cells by downregulation of anti-apoptosis proteins.

<p>(A) and (B) Western blot analysis indicated that DEX induced the expression of pro-apoptosis proteins of Bim and Bax only in GC-sensitive cells of CEM-C7 and no obvious inhibition of anti-apoptosis proteins in both GC-sensitive and -resistant cells. (C) and (D) However, CPX at the concentration of 10 <i>μ</i>M inhibited the expressions of anti-apoptosis proteins, Bcl-2, Mcl-1, and Bcl-xL instead of inducing the expressions of pro-apoptotic proteins of Bim and Bax in both GC-sensitive CEM-C7 cells as well as in GC-resistant CEM-C1 cells. (E) CPX, at the concentration ranging from 1 to 20 <i>μ</i>M, activated Caspase-3 by induction of its two processed forms in CEM-C1 cells.</p

A marked synergistic inhibition on the expressions of both c-Myc and β-catenin was induced by CPX when used in combination with DEX.

<p>(A) DEX (1 <i>μ</i>M) inhibited c-Myc expression only in GC-sensitive CEM-C7 cells. (B) 10 <i>μ</i>M CPX inhibited c-Myc and β-catenin expressions in both GC-sensitive CEM-C7 cells and GC-resistant CEM-C1 cells. (C) 1 <i>μ</i>M CPX had no obvious inhibition on the expressions of c-Myc and β-catenin, but when it was used with DEX (1 <i>μ</i>M), there was a marked synergistic inhibition on the expressions of both c-Myc and β-catenin. (D) Pre-treatment of the tumor cells with Fe³⁺ blocked the inhibitory effect of CPX on the expressions of β-catenin and c-Myc.</p

Stable Ferroelectric Perovskite Structure with Giant Axial Ratio and Polarization in Epitaxial BiFe_0.6Ga_0.4O₃ Thin Films

Ferroelectric perovskites with strongly elongated unit cells (<i>c</i>/<i>a</i> > 1.2) are of particular interest for realizing giant polarization induced by significant ionic off-center displacements. Here we show that epitaxial BiFe_0.6Ga_0.4O₃ (BFGO) thin films exhibit a stable super-tetragonal-like structure with twinning domains regardless of film thickness and substrate induced strain, evidenced with high resolution X-ray diffractometry (HR-XRD), transmission electron microscopy (TEM) and piezoresponse force microscopy (PFM). The origin of the structural stability of BFGO is investigated by the first-principles calculation. The ferroelectric properties of BFGO are studied by PFM, first-principles calculation and macroscopic polarization–electric field (<i>P</i>–<i>E</i>) hysteresis measurement. A giant ferroelectric polarization of ∼150 μC/cm² is revealed by the first-principles calculations and confirmed by experiments. Our studies provide an alternative pathway of employing Ga-substitution other than the extensively studied strain engineering to stabilize the supertetragonal structure in BiFeO₃-based epitaxial thin films

Enhanced Shubnikov–De Haas Oscillation in Nitrogen-Doped Graphene

N-doped graphene displays many interesting properties compared with pristine graphene, which makes it a potential candidate in many applications. Here, we report that the Shubnikov–de Haas (SdH) oscillation effect in graphene can be enhanced by N-doping. We show that the amplitude of the SdH oscillation increases with N-doping and reaches around 5k Ω under a field of 14 T at 10 K for highly N-doped graphene, which is over 1 order of magnitude larger than the value found for pristine graphene devices with the same geometry. Moreover, in contrast to the well-established standard Lifshitz–Kosevich theory, the amplitude of the SdH oscillation decreases linearly with increasing temperature and persists up to a temperature of 150 K. Our results also show that the magnetoresistance (MR) in N-doped graphene increases with increasing temperature. Our results may be useful for the application of N-doped graphene in magnetic devices

Quantitative Observation of Threshold Defect Behavior in Memristive Devices with <i>Operando</i> X‑ray Microscopy

Memristive devices are an emerging technology that enables both rich interdisciplinary science and novel device functionalities, such as nonvolatile memories and nanoionics-based synaptic electronics. Recent work has shown that the reproducibility and variability of the devices depend sensitively on the defect structures created during electroforming as well as their continued evolution under dynamic electric fields. However, a fundamental principle guiding the material design of defect structures is still lacking due to the difficulty in understanding dynamic defect behavior under different resistance states. Here, we unravel the existence of threshold behavior by studying model, single-crystal devices: resistive switching requires that the pristine oxygen vacancy concentration reside near a critical value. Theoretical calculations show that the threshold oxygen vacancy concentration lies at the boundary for both electronic and atomic phase transitions. Through <i>operando</i>, multimodal X-ray imaging, we show that field tuning of the local oxygen vacancy concentration below or above the threshold value is responsible for switching between different electrical states. These results provide a general strategy for designing functional defect structures around threshold concentrations to create dynamic, field-controlled phases for memristive devices