Accurate Structure Prediction and Conformational Analysis of Cyclic Peptides with Residue-Specific Force Fields

Cyclic peptides (CPs) are promising candidates for drugs, chemical biology tools, and self-assembling nanomaterials. However, the development of reliable and accurate computational methods for their structure prediction has been challenging. Here, 20 all-trans CPs of 5–12 residues selected from Cambridge Structure Database have been simulated using replica-exchange molecular dynamics with four different force fields. Our recently developed residue-specific force fields RSFF1 and RSFF2 can correctly identify the crystal-like conformations of more than half CPs as the most populated conformation. The RSFF2 performs the best, which consistently predicts the crystal structures of 17 out of 20 CPs with rmsd < 1.1 Å. We also compared the backbone (ϕ, ψ) sampling of residues in CPs with those in short linear peptides and in globular proteins. In general, unlike linear peptides, CPs have local conformational free energies and entropies quite similar to globular proteins

47, XYY mosaic karyotype and congenital absence of bilateral vas deferens Case report

We report a rare case of infertility presenting with a 47, XYY mosaicism and congenital bilateral absence of vas deferens. With our patient's informed written consent, we performed a complete set of genetic tests for male infertility

Conjugated Polymers/DNA Hybrid Materials for Protein Inactivation

Chromophore-assisted light inactivation (CALI) is a powerful tool for analyzing protein functions due to the high degree of spatial and temporal resolution. In this work, we demonstrate a CALI approach based on conjugated polymers (CPs)/DNA hybrid material for protein inactivation. The target protein is conjugated with single-stranded DNA in advance. Single-stranded DNA can form CPs/DNA hybrid material with cationic CPs via electrostatic and hydrophobic interactions. Through the formation of CPs/DNA hybrid material, the target protein that is conjugated with DNA is brought into close proximity to CPs. Under irradiation, CPs harvest light and generate reactive oxygen species (ROS), resulting in the inactivation of the adjacent target protein. This approach can efficiently inactivate any target protein which is conjugated with DNA and has good specificity and universality, providing a new strategy for studies of protein function and adjustment of protein activity

47, XYY mosaic karyotype and congenital absence of bilateral vas deferens

We report a rare case of infertility presenting with a 47, XYY mosaicism and congenital bilateral absence of vas deferens. With our patient's informed written consent, we performed a complete set of genetic tests for male infertility

Cyclotron quantization and mirror-time transition on nonreciprocal lattices

Unidirectional transport and localized cyclotron motion are two opposite physical phenomena. Here, we study the interplay effects between them on nonreciprocal lattices subject to a magnetic field. We show that, in the long-wavelength limit, the trajectories of the wave packets always form closed orbits in four-dimensional (4D) complex space. Therefore, the semiclassical quantization rules persist despite the nonreciprocity, which preserves real Landau levels. We predict a different type of non-Hermitian spectral transition induced by the spontaneous breaking of the combined mirror-time reversal ($\mathcal{MT}$) symmetry, which generally exists in such systems. An order parameter is proposed to describe the $\mathcal{MT}$ phase transition, not only to determine the $\mathcal{MT}$ phase boundary but also to quantify the degree of $\mathcal{MT}$-symmetry breaking. Such an order parameter can be generally applied to all types of non-Hermitian phase transitions

The Maize Landcover in 2019 in Northern China

The landcover of maize with a resolution of 30 m in 2019 in the Northern part of China

The Maize Landcover in 2016 in Northern China

The landcover of maize with a resolution of 30 m in 2016 in the Northern part of China

The Maize Landcover in 2018 in Northern China

The landcover of maize with a resolution of 30 m in 2018 in the Northern part of China

The Maize Landcover in 2014 in Northern China

The landcover of maize with a resolution of 30 m in 2014 in the Northern part of China

The Maize Landcover in 2017 in Northern China

The landcover of maize with a resolution of 30 m in 2017 in the Northern part of China