Nuclear-targeted carbon quantum dot mediated CRISPR/Cas9 delivery for fluorescence visualization and efficient editing.

Nuclear targeted delivery has great potential in improving the efficiency of non-viral carrier mediated genome editing. However, direct and efficient delivery of CRISPR/Cas9 plasmid into the nucleus remains a challenge. In this study, a nuclear targeted gene delivery platform based on fluorescent carbon quantum dots (CQDs) was developed. Polyethylenimine (PEI) and polyethylene glycol (PEG) synergistically passivated the surface of CQDs, providing an excitation-independent green-emitting fluorescent CQDs-PEI-PEG conjugate (CQDs-PP) with an ultra-small size and positive surface charge. Here we show that CQDs-PP could bind CRISPR/Cas9 plasmid to form a nano-complex by electrostatic attraction, which can bypass lysosomes and enter the nucleus by passive diffusion, and thereby improve the transfection efficiency. Also, CQDs-PP could deliver CRISPR/Cas9 plasmid into HeLa cells, resulting in the insertion/deletion mutation of the target EFHD1 gene. More importantly, CQDs-PP exhibited a considerably higher gene editing efficiency as well as comparable or lower cytotoxicity relative to Lipo2000 and PEI-passivated CQDs-PEI (CQDs-P). Thus, the nuclear-targeted CQDs-PP is expected to constitute an efficient CRISPR/Cas9 delivery carrier in vitro with imaging-trackable ability.

Channel Coupling Dynamics of Deep-Lying Orbitals in Molecular High-Harmonic Generation.

Investigation on structures in the high-harmonic spectrum has provided profuse information of molecular structure and dynamics in intense laser fields, based on which techniques of molecular ultrafast dynamics imaging have been developed. Combining ab initio calculations and experimental measurements on the high-harmonic spectrum of the CO_{2} molecule, we find a novel dip structure in the low-energy region of the harmonic spectrum which is identified as fingerprints of participation of deeper-lying molecular orbitals in the process and decodes the underlying attosecond multichannel coupling dynamics. Our work sheds new light on the ultrafast dynamics of molecules in intense laser fields.

[Correlation between cervical vertigo and vestibular function evaluated by vestibular evoked myogenic potentials].

OBJECTIVE: To analyze the relationship between cervical vertigo and vestibular function evaluated by vestibular evoked myogenic potentials(VEMPs) and analyze the correlations between cervical vertigo and vestibular dysfunction, discuss the related factors of cervical vertigo and guide the clinical treatment of patients with cervical vertigo. METHODS: A total of 75 patients with cervical vertigo as the main complaint in the outpatient clinic of the Second Hospital of Shanxi Medical University from August 2019 to July 2020 were set as the diseased group, and 60 patients without cervical and vestibular related diseases in the hospital were selected to set as non-diseased group. The age of diseased group was 12 to 70 years with an average of (46.40±10.91) years, including 25 males and 50 females;and the age of non-diseased group was 22 to 60 years with an average of(43.78±7.75) years, including 19 males and 51 females. VEMPs were performed in the two groups. The data of VEMPs were collected and the results were compared and analyzed. The patients with abnormal cervical myogenic vestibular evoked myogenic potential (cVEMP) were divided into light, moderate and severe groups. The correlation between VEMPs and cervical vertigo and its severity were analyzed by statistical method. RESULTS: (1)The severity of cervical vertigo in diseased group:33 cases of mild, 34 cases of moderate, 8 cases of severe; cVEMP examination:62 cases were positive and 13 cases were negative, including 13 cases of mild, 33 cases of moderate, 16 cases of severe. The cVEMP of non-diseased group:4 cases were positive and 56 cases were negative.(2) The level of cVEMP in diseased group was higher than that in non-diseased group (P<0.001). It can be considered that there was a correlation between cervical vertigo and vestibular function.(3)The correlation between the level of cVEMP and the level of cervical vertigo in diseased group was analyzed. The Spearman rank sum test was used, and the correlation coefficient was 0.687, which was statistically significant (P<0.05). And it can be considered that the two indicators have a high degree of correlation. CONCLUSION: It is feasible to evaluate the relationship between cervical vertigo and vestibular function by VEMPs. For patients with cervical vertigo, the higher the severity, the greater the positive rate of VEMPs, which indicates that it has a greater impact on vestibular function. The treatment of patients with cervical vertigo should be the combination of cervical rehabilitation and vestibular function.

MicroRNA-21 facilitates osteoblast activity.

MicroRNAs are emerging as critical post-transcriptional modulators in bone remodeling, regulating the functions of osteoblasts and osteoclasts. Intercellular crosstalk between osteoblasts and osteoclasts is mediated by miR-21 that controls the bone homeostasis response, providing potential targets for the maintenance of osteoblast function. The aim of this study was to investigate the effects of miR-21 on osteoblast function, and to explore the underlying mechanism. Increased alkaline phosphatase (ALP) activity and accelerated matrix mineralization was observed in mouse pre-osteoblast MC3T3-E1 cells compared with the non-induction (control) group. MiR-21 positively regulates osteogenic differentiation and mineralization by facilitating the expression of key osteogenic factors (ALP, Runx2, Osteopontin (OPN), Osterix (OSX) and Mef2c) in MC3T3-E1 cells. Furthermore, a deficiency of miR-21 suppresses the expression of those factors at both the mRNA and protein levels, indicating that miR-21 is a positive regulator of osteoblastic differentiation. H-E staining, Azan staining, Masson's Trichrome staining and Toluidine blue staining were performed in jaw and femur tissues of miR-21 knockout (miR-21KO) and wild-type (WT) mice. Immunohistochemical staining revealed substantially lower levels of ALP, Runx2 and OSX expression in jaw and femur tissues of miR-21KO mice. A similar trend was observed in femur tissues using quantitative real-time (RT) PCR. A total of 17 osteogenesis-related mRNAs were found to be differentially expressed in miR-21KO femur tissues using Mouse Gene Expression Microarray analysis. GeneSpring and Ingenuity Pathway Analysis revealed several potential target genes that are involved in bone remodeling, such as IL-1ß and HIF-1α. Several important pathways were determined to be facilitators of miR-21, which provides a reliable reference for future studies to elucidate the biological mechanisms of osteoblast function. Taken together, these results lead us to hypothesize a potential role for miR-21 in regulating osteoblast function, thus representing a potential biomarker of osteogenesis.

Photoinduced charge transfer rate of Cy3/C60 blend material.

The rates of charge separation and charge recombination of the cyanine dye/C60 heterojunction solar cell in an external electric field were provided using the Marcus and Marcus-Levich-Jortner formalisms. The vibrational mode as another influencing factor was also introduced into the rate expression for the planar heterojunction solar cell. Detailed theoretical analysis of the excited-state of the Cy3/C60 blend was achieved using density functional theory and time-dependent density functional theory. The Gibbs free energy was regulated by an external electric field, while the reorganisation energy presented the opposite conclusion. Frequency analysis was utilised to demonstrate the energy stability of the obtained structures. The rate calculated using the Marcus formalism was greater than that obtained by the Marcus-Levich-Jortner formalism. Consideration of the calculated rates in all vibration modes and at different external electric field strengths indicated that vibrational mode and external electric field played important roles in determining the rates of charge separate and charge recombination, which could provide a more accurate theoretical rate for organic photovoltaic devices.

Attosecond nonlinear Fourier transformation spectroscopy of CO2 in extreme ultraviolet wavelength region.

The interferometric autocorrelation functions of attosecond pulse trains in the time domain were measured by detecting CO(2) (2+) as well as the atomic and molecular fragment ions generated via two-photon absorption of intense vacuum ultraviolet-extreme ultraviolet light by CO(2). It was demonstrated that the Fourier transformation of the interferometric autocorrelation functions of the respective fragment ions appearing in a time-of-flight mass spectrum exhibit spectroscopic information in the frequency domain corresponding to the two-photon photofragment excitation spectra of CO(2) and the double ionization excitation spectrum to form CO(2) (2+).

Dynamic alignment of C2H4 investigated by using two linearly polarized femtosecond laser pulses.

We have studied multielectron ionization and Coulomb explosion of C2H4 irradiated by 110 fs, 800 nm laser pulses at an intensity of approximately 10(15) W/cm2. Strong anisotropic angular distributions were observed for the atomic ions Cn+(n = 1-3). Based on the results of two crossed linearly polarized laser pulses, we conclude that such anisotropic angular distributions result from dynamic alignment, in which the rising edge of the laser pulses aligns the neutral C2H4 molecules along the laser polarization direction. The angular distribution of the exploding fragments, therefore, reflects the degree of the alignment of molecules before ionization. Using the same femtosecond laser with intensity below the ionization threshold, the alignment of C2H4 molecules was also observed.