ALBERT

Description: The direct transfer method, wherein graphene is transferred from its growth metal to a soft substrate, is widely used to fabricate various devices, and the interfacial bonding condition between the substrate and the graphene is vital for transfer success. In this letter, we present a theoretical model to derive the wettability requirements of the soft substrate to sustain the direct transfer of graphene, and verify the theoretical analysis with experiments. We find that the surface energy components of the substrate have a crucial effect upon the graphene transfer, and that substrates possessing a strong polar surface energy are not suitable for transfer. The theoretical model predicts the critical water contact angle of the soft substrate for graphene transfer to be about 50°, and the experiments measure it to be about 60°. These results provide guidelines for choosing proper substrates to transfer graphene during the fabrication of graphene-based flexible devices.

Description: Although metastasis-associated protein 1 (MTA1), a component of the nucleosome remodeling and histone deacetylation complex, is widely up-regulated in human cancers and correlates with tumor metastasis, its regulatory mechanism and related signaling pathways remain unknown. Here, we report a previously unrecognized bidirectional autoregulatory loop between MTA1 and tumor suppressor alternative reading frame (ARF). MTA1 transactivates ARF transcription by recruiting the transcription factor c-Jun onto the ARF promoter in a p53-independent manner. ARF, in turn, negatively regulates MTA1 expression independently of p53 and c-Myc. In this context, ARF interacts with transcription factor specificity protein 1 (SP1) and promotes its proteasomal degradation by enhancing its interaction with proteasome subunit regulatory particle ATPase 6, thereby abrogating the ability of SP1 to stimulate MTA1 transcription. ARF also physically associates with MTA1 and affects its protein stability. Thus, MTA1-mediated activation of ARF and ARF-mediated functional inhibition of MTA1 represent a p53-independent bidirectional autoregulatory mechanism in which these two opposites act in concert to regulate cell homeostasis and oncogenesis, depending on the cellular context and the environment.

Description: Lattice dynamics and phase transition of MgO modified Pb 0.99 (Zr 0.95 Ti 0.05 ) 0.98 Nb 0.02 O 3 (PZTN- x wt. % MgO, x  = 0, 0.1, 0.2, 0.5) ceramics have been investigated by far-infrared (FIR) reflectance in the temperature range of 5.5–300 K and Raman spectra between 77 and 300 K, respectively. With the aid of above complementary methods, the structure of all ceramics was defined as low-temperature ferroelectric rhombohedral phase [ F R ( LT ) ] at room temperature. The FIR dielectric functions were extracted from the multi-Lorentz oscillator dispersion model. The lowest frequency phonon mode, which is related to Pb-BO 3 (B = Zr, Ti, Nb) vibration, mainly dominates the FIR dielectric response. With increasing MgO composition, the dielectric constants ε ( 0 ) at room temperature are estimated to 85.4, 73.4, 73.9, and 41.9, respectively. The decreasing trend can be due to the doubly ionized oxygen vacancies induced by Mg substitution for B-site. The order-disorder phase transition located around 120 K can be clearly clarified from temperature evolution of phonon frequency, damping, and intensity. It decreases slightly with increasing MgO composition, which influence the distortion due to the broken correlation chains and local permanent dipoles creation. Moreover, the transformation from antiferroelectric orthorhombic A O to [ F R ( LT ) ] phase has been observed around 250 K, which is associated with the antiferroelectric displacement of Pb atoms along 〈 110 〉 and coupled rotations of the corner-connected oxygen octahedral. Furthermore, the transition from [ F R ( LT ) ] to [ F R ( HT ) ] (high-temperature ferroelectric rhombohedral phase) was identified around 290 K for MgO-doped PZTN ceramics. It arises from the shift of cation (Pb and Zr/Ti/Nb/Mg ions) along the 〈 111 〉 direction and the transition temperature slightly decreases compared to the pure ceramic.

Description: MicroRNA-532-3p regulates mitochondrial fission through targeting apoptosis repressor with caspase recruitment domain in doxorubicin cardiotoxicity Cell Death and Disease 6, e1677 (March 2015). doi:10.1038/cddis.2015.41 Authors: J-X Wang, X-J Zhang, C Feng, T Sun, K Wang, Y Wang, L-Y Zhou & P-F Li

Description: MicroRNA-185 regulates chemotherapeutic sensitivity in gastric cancer by targeting apoptosis repressor with caspase recruitment domain Cell Death and Disease 5, e1197 (April 2014). doi:10.1038/cddis.2014.148 Authors: Q Li, J-X Wang, Y-Q He, C Feng, X-J Zhang, J-Q Sheng & P-F Li

Description: The multiferroic RMn 2 O 5 family, where R is rare-earth ion or Y, exhibits rich physics of multiferroicity which has not yet well understood. DyMn 2 O 5 is a representative member of this family. The ferroelectric polarization of DyMn 2 O 5 is claimed to be magnetically relevant and have more than one component. Therefore, the polarization reversal upon the sequent magnetic transitions is expected. We investigate the evolution of the ferroelectric polarization upon a partial substitution of Mn 3+ by nonmagnetic Al 3+ in order to tailor the Mn 3+ -Mn 4+ interactions and then to modulate the polarization in DyMn 2− x /2 Al x /2 O 5 . It is revealed that the polarization can be successfully reversed by Al-substitution via substantially suppressing the Mn 3+ -Mn 4+ interactions, while the Dy 3+ -Mn 4+ interactions can sustain against the substitution until a level as high as x  = 0.2. In addition, the independent Dy spin ordering is shifted remarkably down to an extremely low temperature due to the Al 3+ substitution. The present work unveils the possibility of tailoring the Mn 3+ -Mn 4+ and Dy 3+ -Mn 4+ interactions independently, and thus reversing the ferroelectric polarization.

Description: Investigations into the long-term X-ray spectral variability of 10 active galactic nuclei (AGNs) revealed a positive spectral index–flux correlation for each object. An inner advection-dominated accretion flow (ADAF) may connect to a thin disc/corona at a certain transition radius. Both these structures are responsible for the hard X-ray emission in AGNs. The ADAF is hot and its X-ray spectrum is hard, while the corona above the disc is relatively cold and its X-ray spectrum is therefore soft. The radiation efficiency of the ADAF is usually much lower than that of the thin disc. An increase in the transition radius may lead to a decrease in the spectral index (i.e. a hard spectrum) and the X-ray luminosity even if the accretion rate is fixed, and a decrease of transition radius leads to an increase in spectral index. We propose that such X-ray variability is caused by a change in the transition radius. Our model calculations can reproduce the observed index–flux correlations, if the transition radius fluctuates around an equilibrium position and the radiation efficiency of ADAFs is ~5 per cent of that for a thin disc. The average spectral index–Eddington ratio correlation for these ten AGNs sample can also be reproduced by our model calculations, if the equilibrium transition radius increases with decreasing mass accretion rate.

Description: The origin of the solar wind in solar coronal holes has long been unclear. We establish that the solar wind starts flowing out of the corona at heights above the photosphere between 5 megameters and 20 megameters in magnetic funnels. This result is obtained by a correlation of the Doppler-velocity and radiance maps of spectral lines emitted by various ions with the force-free magnetic field as extrapolated from photospheric magnetograms to different altitudes. Specifically, we find that Ne7+ ions mostly radiate around 20 megameters, where they have outflow speeds of about 10 kilometers per second, whereas C3+ ions with no average flow speed mainly radiate around 5 megameters. Based on these results, a model for understanding the solar wind origin is suggested.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tu, Chuan-Yi -- Zhou, Cheng -- Marsch, Eckart -- Xia, Li-Dong -- Zhao, Liang -- Wang, Jing-Xiu -- Wilhelm, Klaus -- New York, N.Y. -- Science. 2005 Apr 22;308(5721):519-23.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Geophysics, Peking University, Beijing 100871, China. cytu@public3.bta.net.cn〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15845846" target="_blank"〉PubMed〈/a〉

Description: Metabolism and ageing are intimately linked. Compared with ad libitum feeding, dietary restriction consistently extends lifespan and delays age-related diseases in evolutionarily diverse organisms. Similar conditions of nutrient limitation and genetic or pharmacological perturbations of nutrient or energy metabolism also have longevity benefits. Recently, several metabolites have been identified that modulate ageing; however, the molecular mechanisms underlying this are largely undefined. Here we show that alpha-ketoglutarate (alpha-KG), a tricarboxylic acid cycle intermediate, extends the lifespan of adult Caenorhabditis elegans. ATP synthase subunit beta is identified as a novel binding protein of alpha-KG using a small-molecule target identification strategy termed drug affinity responsive target stability (DARTS). The ATP synthase, also known as complex V of the mitochondrial electron transport chain, is the main cellular energy-generating machinery and is highly conserved throughout evolution. Although complete loss of mitochondrial function is detrimental, partial suppression of the electron transport chain has been shown to extend C. elegans lifespan. We show that alpha-KG inhibits ATP synthase and, similar to ATP synthase knockdown, inhibition by alpha-KG leads to reduced ATP content, decreased oxygen consumption, and increased autophagy in both C. elegans and mammalian cells. We provide evidence that the lifespan increase by alpha-KG requires ATP synthase subunit beta and is dependent on target of rapamycin (TOR) downstream. Endogenous alpha-KG levels are increased on starvation and alpha-KG does not extend the lifespan of dietary-restricted animals, indicating that alpha-KG is a key metabolite that mediates longevity by dietary restriction. Our analyses uncover new molecular links between a common metabolite, a universal cellular energy generator and dietary restriction in the regulation of organismal lifespan, thus suggesting new strategies for the prevention and treatment of ageing and age-related diseases.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4263271/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4263271/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chin, Randall M -- Fu, Xudong -- Pai, Melody Y -- Vergnes, Laurent -- Hwang, Heejun -- Deng, Gang -- Diep, Simon -- Lomenick, Brett -- Meli, Vijaykumar S -- Monsalve, Gabriela C -- Hu, Eileen -- Whelan, Stephen A -- Wang, Jennifer X -- Jung, Gwanghyun -- Solis, Gregory M -- Fazlollahi, Farbod -- Kaweeteerawat, Chitrada -- Quach, Austin -- Nili, Mahta -- Krall, Abby S -- Godwin, Hilary A -- Chang, Helena R -- Faull, Kym F -- Guo, Feng -- Jiang, Meisheng -- Trauger, Sunia A -- Saghatelian, Alan -- Braas, Daniel -- Christofk, Heather R -- Clarke, Catherine F -- Teitell, Michael A -- Petrascheck, Michael -- Reue, Karen -- Jung, Michael E -- Frand, Alison R -- Huang, Jing -- DP2 OD008398/OD/NIH HHS/ -- P01 HL028481/HL/NHLBI NIH HHS/ -- P40 OD010440/OD/NIH HHS/ -- T32 CA009120/CA/NCI NIH HHS/ -- T32 GM007104/GM/NIGMS NIH HHS/ -- T32 GM007185/GM/NIGMS NIH HHS/ -- T32 GM008496/GM/NIGMS NIH HHS/ -- England -- Nature. 2014 Jun 19;510(7505):397-401. doi: 10.1038/nature13264. Epub 2014 May 14.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California 90095, USA. ; 1] Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA [2]. ; 1] Department of Human Genetics, University of California Los Angeles, Los Angeles, California 90095, USA [2]. ; 1] Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California 90095, USA [2]. ; Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Biological Chemistry, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Surgery, University of California Los Angeles, Los Angeles, California 90095, USA. ; Small Molecule Mass Spectrometry Facility, FAS Division of Science, Harvard University, Cambridge, Massachusetts 02138, USA. ; Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California 92037, USA. ; Pasarow Mass Spectrometry Laboratory, Department of Psychiatry and Biobehavioral Sciences and Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Environmental Health Sciences, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, California 90095, USA. ; Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA. ; 1] Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California 90095, USA [2] UCLA Metabolomics Center, University of California Los Angeles, Los Angeles, California 90095, USA. ; 1] Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA [2] Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, USA. ; 1] Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA [2] Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, California 90095, USA. ; 1] Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA [2] Department of Human Genetics, University of California Los Angeles, Los Angeles, California 90095, USA. ; 1] Molecular Biology Institute, University of California Los Angeles, Los Angeles, California 90095, USA [2] Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California 90095, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24828042" target="_blank"〉PubMed〈/a〉