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It is widely appreciated that the β relaxation peak in loss modulus curve, upon an oscillatory excitation, is generally merged with α relaxation. The consensus on physical origin of β relaxation dynamics is still absent due to its subtle feature. Here we confine the metallic glass film between two substrates to enhance β relaxation using molecular dynamics simulations. Prominent humps occur at intermediate times in intermediate scattering function along confined direction, which features β relaxation. Layering phenomenon originating from confinement excludes the arbitrary hopping distance. Both particle collision with substrates and layering phenomenon increase β relaxation time window and delay α relaxation, facilitating observation of β relaxation.We provide an effective pathway to promote β relaxation and reveal the dominant mechanism from the atomic movement and structure characteristics.

The emerging K2NiF4-type oxyhydrides with unique hydride ions (H−) and O2- coexisting in the anion sublattice offer superior functionalities for numerous applications. However, the exploration and innovations of the oxyhydrides are challenged by their rarity as a limited number of compounds reported in experiments, owing to the stringent laboratory conditions. Herein, we employed a suite of computations involving ab initio methods, informatics and machine learning to investigate the stability relationship of the K2NiF4-type oxyhydrides. The comprehensive stability map of the oxyhydrides chemical space was constructed to identify 76 new compounds with good thermodynamic stabilities using the high-throughput computations. Based on the established database, we reveal geometric constraints and electronegativities of cationic elements as significant factors governing the oxyhydrides stabilities via informatics tools. Besides fixed stoichiometry compounds, mixed-cation oxyhydrides can provide promising properties due to the enhancement of compositional tunability. However, the exploration of the mixed compounds is hindered by their huge quantity and the rarity of stable oxyhydrides. Therefore, we propose a two-step machine learning workflow consisting of a simple transfer learning to discover 114 formable oxyhydrides from thousands of unknown mixed compositions. The predicted high H− conductivities of the representative oxyhydrides indicate their suitability as energy conversion materials. Our study provides an insight into the oxyhydrides chemistry which is applicable to other mixed-anion systems, and demonstrates an efficient computational paradigm for other materials design applications, which are challenged by the unavailable and highly unbalanced materials database.

Highly conducting molecular wires are extremely desirable in molecular-scale circuitry, but restricted by their role as tunnel barriers due to their steep conductance recession with the length. This work innovatively reveals that in equilibrium, the conductance of the newly designed porphyrin-graphene nanoribbons (GNRs) molecular wires would increase with the length, presenting appealing “even” conducting superiority, different with pure-GNRs molecular wires. Such anomalous transport behavior is not related with edge states of GNRs but the contribution of the porphyrin part in the transport. More interestingly, this “even” conducting advantage would be more prominent with slightly larger voltage, originated from narrower HOMO-LUMO gap of “even” assembled molecular wires. Besides, one of these hybrid molecular wires shows exceedingly strong transmission. This work suggests valuable applications of these new-assembled molecular wires in nano-electronics. Keywords: Newly designed molecular wires, Unconventional conducting behavior, Electron transport mechanisms, First principles

Studies in the yeast Saccharomyces cerevisiae have shown that the inheritance of endoplasmic reticulum (ER), mitochondria, and vacuoles involves the capture of a tubular structure at the bud tip. Ptc1p, a serine/threonine phosphatase, has previously been shown to regulate mitochondrial inheritance by an unknown mechanism. Ptc1p regulates the high osmolarity glycerol mitogen-activated protein kinase (MAPK) pathway and has also been implicated in the cell wall integrity (CWI) MAPK pathway. Here we show that the loss of Ptc1p or the Ptc1p binding protein, Nbp2p, causes a prominent delay in the delivery of ER tubules to the periphery of daughter cells and results in a dramatic increase in the level of phosphorylated Slt2p, the MAPK in the CWI pathway. Either loss of Slt2p or inhibition of the CWI pathway by addition of sorbitol, suppresses the ER inheritance defect in the ptc1Δ and nbp2Δ mutants. Our findings indicate that Ptc1p and Nbp2p regulate ER inheritance through the CWI MAPK pathway by modulating the MAPK, Slt2p. [ABSTRACT FROM AUTHOR]

In Saccharomyces cerevisiae, the endoplasmic reticulum (ER) is found along the cell periphery (cortical ER) and nucleus (perinuclear ER). In this study, we characterize a novel ER protein called Ice2p that localizes to the cortical and perinuclear ER. Ice2p is predicted to be a type-HI transmembrane protein. Cells carrying a genomic disruption of ICE2 display defects in the distribution of cortical ER in mother and daughter cells. Furthermore, fluorescence imaging of ice2Δ cells reveals an abnormal cortical ER tubular network morphology in both the mother cell and the developing bud. Subcellular fractionation analysis using sucrose gradients corroborate the data from the fluorescence studies. Our findings indicate that Ice2p plays a role in forming and/or maintaining the cortical ER network in budding yeast. [ABSTRACT FROM AUTHOR]

The endoplasmic reticulum (ER) consists of a polygonal array of interconnected tubules and sheets that spreads throughout the eukaryotic cell and is contiguous with the nuclear envelope. This elaborate structure is created and maintained by a constant remodeling process that involves the formation of new tubules, their cytoskeletal transport and homotypic fusion. Since the ER is a large, single-copy organelle, it must be actively segregated into daughter cells during cell division. Recent analysis in budding yeast indicates that ER inheritance involves the polarized transport of cytoplasmic ER tubules into newly formed buds along actin cables by a type V myosin. The tubules then become anchored to a site at the bud tip and this requires the Sec3p subunit of the exocyst complex. The ER is then propagated along the cortex of the bud to yield a cortical ER structure similar to that of the mother cell. In animal cells, the ER moves predominantly along microtubules, whereas actin fibers serve a complementary role. It is not yet clear to what extent the other components controlling ER distribution in yeast might be conserved in animal cells. [ABSTRACT FROM AUTHOR]

Molecular dynamics (MD) simulation has been employed to study the wetting transitions of liquid gallium droplet on the graphene surfaces, which are decorated with three types of carbon nanopillars, and to explore the effect of the surface roughness and morphology on the wettability of liquid Ga. The simulation results showed that, at the beginning, the Ga film looks like an upside-down dish on the rough surface, different from that on the smooth graphene surface, and its size is crucial to the final state of liquid. Ga droplets exhibit a Cassie–Baxter (CB) state, a Wenzel state, a Mixed Wetting state, and a dewetting state on the patterned surfaces by changing distribution and the morphology of nanopillars. Top morphology of nanopillars has a direct impact on the wetting transition of liquid Ga. There are three transition states for the two types of carbon nanotube (CNT) substrates and two for the carbon nanocone (CNC) one. Furthermore, we have found that the substrates show high or low adhesion to the Ga droplet with the variation of their roughness and top morphology. With the roughness decreasing, the adhesion energy of the substrate decreases. With the same roughness, the CNC/graphene surface has the lowest adhesion energy, followed by CNT/graphene and capped CNT/graphene surfaces. Our findings provide not only valid support to previous works but also reveal new theories on the wetting model of the metal droplet on the rough substrates.