Bismacrocycle: Structures and Applications.

In the past half-century, macrocycles with different structures and functions, have played a critical role in supramolecular chemistry. Two macrocyclic moieties can be linked to form bismacrocycle molecules. Compared with monomacrocycle, the unique structures of bismacrocycles led to their specific recognition and assembly properties, also a wide range of applications, including molecular recognition, supramolecular self-assembly, advanced optical material construction, etc. In this review, we focus on the structure of bismacrocycle and their applications. Our goal is to summarize and outline the possible future development directions of bismacrocycle research.

High-order harmonic generation from 2D periodic potentials in circularly and bichromatic circularly polarized laser fields.

We studied the high-order harmonic generation (HHG) from 2D solid materials in circularly and bichromatic circularly polarized laser fields numerically by simulating the dynamics of single-active-electron processes in 2D periodic potentials. Contrary to the absence of HHG in the atomic case, circular HHGs below the bandgap with different helicities are produced from intraband transitions in solids with C 4 symmetry driven by circularly polarized lasers. Harmonics above the bandgap are elliptically polarized due to the interband transitions. High-order elliptically polarized harmonics can be generated efficiently by both co-rotating and counter-rotating bicircular mid-infrared lasers. The cutoff energy, ellipticity, phase, and intensity of the harmonics can be tuned by the control of the relative phase difference between the 1ω and 2ω fields in bicircularly polarized lasers, which can be utilized as an ultrafast optical tool to image the structure of solids.

Nonadiabatic redshifts in high-order harmonic generation from solids.

We studied the multi-plateau high-order harmonic generation (HHG) from solids numerically. It is found that the HHG spectra in the second and higher plateaus are redshifted in short laser pulses due to the nonadiabatic effect. The corresponding FWHMs also increase as a function of the harmonic order, suggesting the step-by-step excitation of higher conduction bands in the HHG process. Although the system is symmetric in the coordinate space, even-order harmonics are present. It is due to the fact that the symmetry of electron motions and the population in the higher conduction bands is broken in the k space and time domain based on the indirect step-by-step excitation model. Our numerical results are in good agreement with recent experimental measurements of Ndabashimiye et al. [Nature 534, 520 (2016)].

[The role and mechanism of costimulatory molecule B7-H3 in the immune reaction of corneal transplantation in mice].

OBJECTIVE: To investigate the role of B7-H3 in the immune reaction of corneal transplantation in mice METHODS: Experimental study. Thirty Corneas of C57BL/6 mice were orthotopically transplanted into the eyes of BALB/c mice, and graft survival was assessed on the basis of Sonoda's standard. When the RI grade was ≥ 2, rejection was acknowledged and brought into the rejected group(R), and the others into the accepted group (A); 8 BALB/c Corneas into their own eyes belonged to isografts (I) ; In addition, 8 normal BALB/c mice were the control group (C) . At last, three eyes in each group (C, I, A, R groups) were used for HE staining and IHC of B7-H3, and there were five eyes in each group for qPCR to detect B7-H3 mRNA expression. Repeated-measures analysis of variance (factorial analysis) followed by LSD test were used for post hoc analysis for expression differences of B7-H3 mRNA between groups. RESULTS: There were 9 accepted grafts and 21 rejected grafts in 30 mice, and transplantation survival rate was 30% in the allograft group, while all grafts were transparent, and transplantation survival rate was 100% in the isografts. IHC results showed that B7-H3 was expressed on the corneal epithelium, endothelium and iris-ciliary body of both normal corneas and Isografts; B7-H3 expression increased in the accepted group and decreased in the rejected group . The results of qPCR conformed to the IHC; Repeated-measures analysis of variance (factorial analysis) followed by LSD test were used for post hoc analysis for differences between groups (F = 429.546) . there was a low B7-H3 mRNA expression in the R group (3.89 ± 0.037) and high expression in the A group (5.04 ± 0.058); and C (4.30 ± 0.023) ,I (4.33 ± 0.031) groups had no significant difference (P = 0.387) ;But there was a significant difference between group R and C (P = 0.003)or group A and C(P = 0.001). CONCLUSION: All above show that B7-H3 may play an important role in the maintenance of ocular immune privilege.

A new rhodamine-based colorimetric chemosensor for naked-eye detection of Cu(2+) in aqueous solution.

A new colorimetric probe 1 based on rhodamine B lactam was developed for naked-eye detection of Cu(2+). The optical feature of 1 for Cu(2+) was investigated by UV-vis absorption spectroscopy. Upon the addition of Cu(2+), the 1 displayed a distinct color change from colorless to pink, which can be directly detected by the naked eye. The stoichiometry of 1 to Cu(2+) complex was found to be 1:1 and the naked-eye detection limit was determined as low as 2 µM. The results suggest that the probe 1 may provide a convenient method for visual detection of Cu(2+) with high sensitivity.

Synthesis and chiral recognition properties of novel fluorescent chemosensors for amino acid.

The charge neutral chiral optical sensors 1a-d containing thiourea and amide groups were synthesized by simple steps in good yields and their structures were characterized by IR, 1H NMR, 13C NMR, MS spectra and elemental analysis. The enantioselective recognition for alpha-phenylglycine and phenylglycinol was examined by fluorescence emission and UV-vis spectra. The fluorescence and UV-vis spectra changes of 1a were obvious when the enantiomers of alpha-phenylglycine anion were added, which exhibited that 1a has good enantioselective recognition ability towards alpha-phenylglycine.