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A TTPP probe was developed to distinguish G-quadruplexes (G4s) from other nucleic acid topologies through longer fluorescence lifetimes and higher quantum yields. In fluorescence lifetime imaging microscopy, TTPP enabled the visualization of cytoplasmic G4s in live cells, and showed the potential to detect cell apoptosis and ferroptosis by tracking cytoplasmic G4s. [ABSTRACT FROM AUTHOR]

In this study, a nano-layered Cu2Se high-performance material is successfully grown using a NaCl-flux method based on the stoichiometric ratios of Cu2Se(NaCl)x (x = 1.5, 2, 2.5, 3, and 3.5). X-ray diffraction results show that samples possess an α-phase structure for 1.5 ≤ x ≤ 2.5, whereas samples consist of a mixture of β- and α-phase structures for x ≥ 3. Electron probe microanalysis results present that almost no Na or Cl atoms were found in all the samples. Meanwhile, the actual composition is close to the nominal composition of Cu2Se when 1.5 ≤ x ≤ 2.5, whereas it deviates from the nominal composition when x ≥ 3. The valence values of Cu and Se atoms are +1 and −2 in the sample, respectively. Transmission electron microscopy results prove that the crystals prepared using the NaCl-flux method have a good quality. The field emission scanning electron microscopy image shows that the samples prepared using the NaCl-flux method have a stacking nano-layered structure with an average thickness of approximately 110 nm. These thin lamellar crystals have several grain boundaries, which can effectively scatter the phonon and thus result in ultra-low lattice thermal conductivity. Cu2Se(NaCl)2.5 exhibits the best thermoelectric performance among all the samples because it has the lowest thermal conductivity. The maximum ZT value reaches 1.42 at 700 K, which is much higher than those prepared using fast melt-quenching (∼0.88 at 700 K), spark plasma sintering (∼0.8 at 700 K) and high-temperature and high-pressure synthesis (∼1.13 at 700 K). [ABSTRACT FROM AUTHOR]

We present here a novel and efficient method for 5mC detection using a DNA strand exchange reaction (SER) strategy. This enzyme-free method needs no pre-treatment of target DNAs and can be adapted to most of the target duplexes under physiological conditions. The high sequence selectivity of this method can distinguish 5mC from normal cytosine in an accurate manner. [ABSTRACT FROM AUTHOR]

A simple and effective one-step method is proposed for the fabrication of hollow periodic mesoporous organosilica spheres (HPMOSs). The obtained HPMOSs possess well-defined spherical morphology, uniform and tunable particle size, adjustable hollow void structure, and radially oriented mesochannels in their shells. [ABSTRACT FROM AUTHOR]

A conveniently amplified DNA AND logic gate platform was designed for the highly sensitive detection of low-abundance DNA fragment inputs based on strand displacement reaction and rolling circle amplification strategy. Compared with others, this system can detect miRNAs in biological samples. The success of this strategy demonstrates the potential of DNA logic gates in disease diagnosis. [ABSTRACT FROM AUTHOR]

Precise quantitative measurement of viscosity at the subcellular level presents great challenges. Two-photon phosphorescence lifetime imaging microscopy (TPPLIM) can reflect micro-environmental changes of a chromophore in a quantitative manner. Phosphorescent iridium complexes are potential TPPLIM probes due to their rich photophysical properties including environment-sensitive long-lifetime emission and high two-photon absorption (TPA) properties. In this work, a series of iridium(iii) complexes containing rotatable groups are developed as mitochondria-targeting anticancer agents and quantitative viscosity probes. Among them, Ir6 ([Ir(ppy-CHO) 2 (dppe)]PF 6 ; ppy-CHO: 4-(2-pyridyl)benzaldehyde; dppe: cis -1,2-bis(diphenylphosphino)ethene) shows satisfactory TPA properties and long lifetimes (up to 1 μs). The emission intensities and lifetimes of Ir6 are viscosity-dependent, which is mainly attributed to the configurational changes in the diphosphine ligand as proved by 1 H NMR spectra. Ir6 displays potent cytotoxicity, and mechanism investigations show that it can accumulate in mitochondria and induce apoptotic cell death. Moreover, Ir6 can induce mitochondrial dysfunction and monitor the changes in mitochondrial viscosity simultaneously in a real-time and quantitative manner via TPPLIM. Upon Ir6 treatment, a time-dependent increase in viscosity and heterogeneity is observed along with the loss of membrane potential in mitochondria. In summary, our work shows that multifunctional phosphorescent metal complexes can induce and precisely detect microenvironmental changes simultaneously at the subcellular level using TPPLIM, which may deepen the understanding of the cell death mechanisms induced by these metallocompounds.

A new bifunctional compound NCC, which undergoes thiol-mediated disulfide cleavage after cell entry, produces a red-shifted fluorescent emission in the cytosol and releases free active DNA alkylating agent CLB into the nucleus, and finally leads to DNA damage and cell death.

Mesoporous MFI zeolites (including M-S-1 and M-ZSM-5) with intracrystal mesopores and self-stacked morphology have been synthesized via a hydrothermal route using cationic polymers as a template.