Search

C18H19N5, triclinic, P1‾ $P\overline{1}$ (no. 2), a = 6.612(4) Å, b = 8.800(5) Å, c = 13.777(8) Å, α = 83.219(7)°, β = 79.329(6)°, γ = 78.744(6)°, V = 769.8(8) Å3, Z = 2, R gt(F) = 0.0394, wR ref(F 2) = 0.0996, T = 100(2) K.

A late-model all-fiber mode-locked laser was introduced in this paper. This pulsed Er-doped fiber laser has a novel Sagnac loop structure and uses the tapered fiber coated with two-dimensional layer ferromagnetic insulator Cr2Si2Te6 as a saturable absorber in order to achieve passive mode locking. When the pump power was 167.6 mW, the laser worked at the fundamental repetition frequency of 19.1 MHz with a signal-to-noise ratio of 62.5 dB. The central wavelength of the spectrum was 1561.0 nm, and the maximum output power was 8.9 mW with a minimum pulse width of 5.2 ps. The mutual interference of beams makes the use of the saturable absorber more efficient. The results reveal that this Er-doped fiber laser has great application potential in nonlinear optics and ultrafast photonics. [ABSTRACT FROM AUTHOR]

To improve the surface quality of natural diamond grinding, the ultrasonic vibration was introduced for composite grinding, and an inelastic collision theory model was established to calculate the amplitude of ultrasonic vibration. The effects of ultrasonic amplitude, grinding speed and grinding grain size on the material removal of natural diamond (100) crystal surface were studied, and the optimal process parameters were sought. The results show that the ultrasonic amplitude ranges from 3.1 to 8.7 µm in the direction of easy grinding of natural diamond (110) crystal surface and 2.9 to 9.1 µm in the direction of easy grinding of natural diamond (100) crystal surface. The optimal process combination parameters of natural diamond (100) crystal surface grinding obtained by orthogonal experiment are ultrasonic amplitude of 6.0 µm, grinding disk speed of 2 800 r/min, diamond grinding grain size code of M3/6. The surface roughness Ra of diamond (100) crystal surface after ultrasonic assisted grinding is 16.21 nm, which is 63.83% lower than that of traditional mechanical grinding. Ultrasonic assisted grinding of natural diamonds can achieve better surface quality than traditional mechanical grinding. [ABSTRACT FROM AUTHOR]

Brazilin possesses anticancer effects, but the mechanisms are poorly understood. This study investigated the mechanisms of brazilin‐induced cell death in the T24 human bladder cancer cell line. Low serum cell culture and the lactate dehydrogenase assay were used to confirm the antitumor effect of brazilin. Annexin V and propidium iodide double staining, transmission electron microscopy, fluo‐3‐AM assay for Ca2+ mobilization and caspase activity assay were performed to identify the type of cell death after brazilin treatment. Mitochondria membrane potentials were measured using JC‐1. Quantitative real‐time polymerase chain reaction and western blot analyses were performed to verify the expression of the necroptosis‐related genes and proteins receptor interacting protein 1 (RIP1), RIP3 and mixed lineage kinase domain‐like (MLKL). The results showed that brazilin induced necrosis in T24 cells and upregulated the mRNA and protein levels of RIP1, RIP3 and MLKL and Ca2+ influx. The necroptosis‐mediated cell death was rescued by the necroptosis inhibitor necrostatin‐1 (Nec‐1), but not by the apoptosis inhibitor z‐VAD‐fmk. Brazilin repressed caspase 8 expression and decreased the mitochondrial membrane potentials; both effects were partially reversed by Nec‐1. Brazilin induced physiological and morphological changes in T24 cells and RIP1/RIP3/MLKL‐mediated necroptosis might be involved. In conclusion, the results confirm the involvement of necroptosis in brazilin‐induced cell death and suggest that brazilin could be explored as an anticancer agent against bladder cancer. [ABSTRACT FROM AUTHOR]