Addressing preferred orientation in single-particle cryo-EM through AI-generated auxiliary particles

The single-particle cryo-EM field faces the persistent challenge of preferred orientation, lacking general computational solutions. We introduce cryoPROS, an AI-based approach designed to address the above issue. By generating the auxiliary particles with a conditional deep generative model, cryoPROS addresses the intrinsic bias in orientation estimation for the observed particles. We effectively employed cryoPROS in the cryo-EM single particle analysis of the hemagglutinin trimer, showing the ability to restore the near-atomic resolution structure on non-tilt data. Moreover, the enhanced version named cryoPROS-MP significantly improves the resolution of the membrane protein NaX using the no-tilted data that contains the effects of micelles. Compared to the classical approaches, cryoPROS does not need special experimental or image acquisition techniques, providing a purely computational yet effective solution for the preferred orientation problem. Finally, we conduct extensive experiments that establish the low risk of model bias and the high robustness of cryoPROS

Zarrathustra/cryosieve: v1.2.2

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The Preparation of H13 Steel for TBM Cutter and the Performance Test Close to Working Condition

The material of disc cutters is important to full-face tunnel boring machines (TBM). In recent years, disc cutters were optimized and tested by many scholars all around the world. H13(4Cr5MoSiV1) steel is widely used due to its excellent properties, especially in TBM disc cutters. In this paper, H13 steel with optimized composition was prepared and heat treatment. The high temperature compression of H13 steel was conducted at the temperatures ranging from 100 °C to 700 °C, with strain rate at 0.01 s−1. The stress-strain curves, Rockwell hardness and microstructure of H13 steel after compression were obtained and analyzed. The results showed that the compression strength and hardness decreased as the temperature increased; and the compression strength, hardness and ductility decreased rapidly between 600 °C and 700 °C, HR700 (the hardness of H13 steel at 700 °C) only reached 33.23 HRC. It is not recommended for TBM disc cutters to work in an environment over 600 °C

Dietary intake of broiler breeder hens during the laying period affects amino acid and fatty acid profiles in eggs

The objective of this study was to evaluate the effects of maternal dietary intake on the amino acid and fatty acid contents in eggs during the laying period. An experiment with a 2×2 factorial design was conducted with two maternal dietary intake levels (100 and 75% of dietary intake recommended by the Chinese Ministry of Agriculture) and two broiler lines (fat and lean line). A total of 384 hens of fat line and 384 hens of lean line at 23 weeks of age were included in the experiment. Each line was randomly divided into two treatments (n = 192 in each treatment, with 12 replications), and each replication included 16 birds. The treatments were LN (lean line and normal maternal dietary intake, n = 192), LL (lean line and low maternal dietary intake, n = 192), FN (fat line and normal maternal dietary intake, n = 192), and FL (fat line and low maternal dietary intake, n = 192). The amino acid and fatty acid contents in eggs were tested (50 weeks of age). The fat line had higher levels of arginine, aspartic acid, glycine, histidine, leucine, methionine, and threonine in the egg albumen than the lean line. Low maternal dietary intake increased the cystine deposition in egg yolks. There were interactions between maternal dietary intake and line on the deposition of trans-oleic acid, docosanoic acid, and total fatty acid in egg yolks. Low maternal dietary intake increased the deposition of tetradecenoic and linolenic acids and the ratio of total polyunsaturated fatty acids to total saturated fatty acid in egg yolks but decreased the deposition of docosanoic acid. Maternal dietary intake and line affect the amino acid and fatty acid profiles in egg

Interface effect and stress effect on Ge

Ge2Sb2Te5 superlattice-like thin films show great potential for phase-change memory applications. Improvement of the thermal properties of Ge2Sb2Te5 is believed to be related to the Ge2Sb2Te5/Sb interface. The stress effect and interface effect on Ge2Sb2Te5 manifest in structural changes that are observed via X-ray diffraction and Raman spectroscopy experiments. The structure changes from corner-sharing GeTe4-nGen (n = 0) in single-layered Ge2Sb2Te5 to GeTe4-nGen (n = 1, 2, 3) tetrahedra in the superlattice-like thin films that are observed. As a result, Ge2Sb2Te5 prefers the hexagonal structure rather than the face-centred cubic structure during heating

Structural Controlling of Highly-Oriented Polycrystal 3C-SiC Bulks via Halide CVD

Highly-oriented polycrystal 3C-SiC bulks were ultra-fast fabricated via halide chemical vapor deposition (CVD) using tetrachlorosilane (SiCl4) and methane (CH4) as precursors. The effects of deposition temperature (Tdep) and total pressure (Ptot) on the orientation and surficial morphology were investigated. The results showed that the growth orientation of 3C-SiC columnar grains was strongly influenced by Tdep. With increasing Tdep, the columnar grains transformed from <111>- to <110>-oriented. The arrangement of <111>-oriented columnar grains was controlled by Ptot. Lotus-, turtle-, thorn-, and strawberry-like surface morphologies were naturally contributed by different arrangements of <111>-oriented grains, and the deposition mechanism was discussed. The wetting behaviors of CVD-SiC samples by molten aluminum were also examined at 1173 K in a high vacuum atmosphere