Graphene oxide shows stress-induced toxicity properties in vivo under different pathophysiological conditions. A dual-path chemical mechanism, involving the overproduction of hydroxyl radicals and the formation of oxidizing cytochrome c intermediates, is responsible for the toxicity properties.

Arrays of ZnO/Zn(x)Cd(1-x)Se (0 ≤ x ≤ 1) core/shell nanocables with shells of tunable compositions have been synthesized on fluorine-doped tin oxide glass substrates via a simple ion-exchange approach. Through the effects of stoichiometry and type II heterojunction, optical absorptions of the nanocable arrays can be controllably tuned to cover almost the entire visible spectrum. Lattice parameters and band gaps of the ternary Zn(x)Cd(1-x)Se shells were found to have respectively linear and quadratic relationships with the Zn content (x). These ZnO/Zn(x)Cd(1-x)Se nanocable arrays are further demonstrated to be promising photoelectrodes for photoelectrochemical solar cells, giving a maximum power conversion efficiency up to 4.74%.

Background: Octupole-deformed nuclei, such as that of 225 Ra, are expected to amplify observable atomic electric dipole moments (EDMs) that arise from time-reversal and parity-violating interactions in the nuclear medium. In 2015, we reported the first "proof-of-principle" measurement of the 225 Ra atomic EDM.Purpose: This work reports on the first of several experimental upgrades to improve the statistical sensitivity of our 225 Ra EDM measurements by orders of magnitude and evaluates systematic effects that contribute to current and future levels of experimental sensitivity. Method: Laser-cooled and trapped225 Ra atoms are held between two high voltage electrodes in an ultra high vacuum chamber at the center of a magnetically shielded environment. We observe Larmor precession in a uniform magnetic field using nuclear-spin-dependent laser light scattering and look for a phase shift proportional to the applied electric field, which indicates the existence of an EDM. The main improvement to our measurement technique is an order of magnitude increase in spin precession time, which is enabled by an improved vacuum system and a reduction in trap-induced heating. Results: We have measured the225 Ra atomic EDM to be less than 1.4 × 10 −23 e cm (95% confidence upper limit), which is a factor of 36 improvement over our previous result. Conclusions:Our evaluation of systematic effects shows that this measurement is completely limited by statistical uncertainty. Combining this measurement technique with planned experimental upgrades we project a statistical sensitivity at the 1 × 10 −28 e cm level and a total systematic uncertainty at the 4 × 10 −29 e cm level.

Zinc blende-structured CdTe nanoribbons (NRs) were synthesized for the first time via a two-step process. The electronic, transport, and photoconductive properties of the CdTe NRs were studied systematically. It was revealed that the CdTe NRs showed p-type conductivity, and presented significant photoresponses to visible-NIR (400-800 nm) irradiation with high responsivity and gain. The contribution of the factors such as surface states of NRs, channel length, light intensity, and working bias voltage to the photoresponse characteristics of CdTe NR photodetectors were discussed. Moreover, single CdTe NR-based visible-NIR photodetectors were also demonstrated to have high stability and reliability.

Probing anisotropic surface properties of layer-type mineral is fundamentally important in understanding its surface charge and wettability for a variety of applications. In this study, the surface properties of the face and the edge surfaces of natural molybdenite (MoS2) were investigated by direct surface force measurements using atomic force microscope (AFM). The interaction forces between the AFM tip (Si3N4) and face or edge surface of molybdenite were measured in 10 mM NaCl solutions at various pHs. The force profiles were well-fitted with classical DLVO (Derjaguin-Landau-Verwey-Overbeek) theory to determine the surface potentials of the face and the edge surfaces of molybdenite. The surface potentials of both the face and edge surfaces become more negative with increasing pH. At neutral and alkaline conditions, the edge surface exhibits more negative surface potential than the face surface, which is possibly due to molybdate and hydromolybdate ions on the edge surface. The point of zero charge (PZC) of the edge surface was determined around pH 3 while PZC of the face surface was not observed in the range of pH 3-11. The interaction forces between octadecyltrichlorosilane-treated AFM tip (OTS-tip) and face or edge surface of molybdenite were also measured at various pHs to study the wettability of molybdenite surfaces. An attractive force between the OTS-tip and the face surface was detected. The force profiles were well-fitted by considering DLVO forces and additional hydrophobic force. Our results suggest the hydrophobic feature of the face surface of molybdenite. In contrast, no attractive force between the OTS-tip and the edge surface was detected. This is the first study in directly measuring surface charge and wettability of the pristine face and edge surfaces of molybdenite through surface force measurements.

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Oocyte quality, which is directly related to reprogramming competence, is a major important limiting factor in animal cloning efficiency. Compared with oocytes matured in vivo, in vitro matured oocytes exhibit lower oocyte quality and reprogramming competence primarily because of their higher levels of reactive oxygen species. In this study, we investigate whether supplementing the oocyte maturation medium with melatonin, a free radical scavenger, could improve oocyte quality and reprogramming competence. We found that 10−9 M melatonin effectively alleviated oxidative stress, markedly decreased early apoptosis levels, recovered the integrity of mitochondria, ameliorated the spindle assembly and chromosome alignment in oocytes, and significantly promoted subsequent cloned embryo development in vitro. We also analyzed the effects of melatonin on epigenetic modifications in bovine oocytes. Melatonin increased the global H3K9 acetylation levels, reduced the H3K9 methylation levels, and minimally affected DNA methylation and hydroxymethylation. Genome‐wide expression analysis of genes in melatonin‐treated and nontreated oocytes was also conducted by high‐throughput RNA sequencing. Our results indicated that melatonin ameliorates oocyte oxidative stress and improves subsequent in vitro development of bovine cloned embryos.

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