Detection of 12426 SB2 candidates in the LAMOST-MRS, using a binary spectral model

We use an updated method for the detection of double-lined spectroscopic binaries (SB2) using $v \sin{i}$ values from spectral fits. The method is applied to all spectra from LAMOST-MRS. Using this method, we detect 12426 SB2 candidates, where 4321 are already known and 8105 are new discoveries. We check their spectra manually to minimise possible false positives. We also detect several cases of contamination of the spectra by solar light. Additionally, for candidates with multiple observations we compute mass ratios with systemic velocities and determine Keplerian orbits. We present an updated catalogue of all SB2 candidates together with additional information for some of them in separate data tables.Comment: accepted in MNRAS 2023-10-16. arXiv admin note: substantial text overlap with arXiv:2207.0699

The site conditions of the Guo Shou Jing Telescope

The weather at Xinglong Observing Station, where the Guo Shou Jing Telescope (GSJT) is located, is strongly affected by the monsoon climate in north-east China. The LAMOST survey strategy is constrained by these weather patterns. In this paper, we present a statistics on observing hours from 2004 to 2007, and the sky brightness, seeing, and sky transparency from 1995 to 2011 at the site. We investigate effects of the site conditions on the survey plan. Operable hours each month shows strong correlation with season: on average there are 8 operable hours per night available in December, but only 1-2 hours in July and August. The seeing and the sky transparency also vary with seasons. Although the seeing is worse in windy winters, and the atmospheric extinction is worse in the spring and summer, the site is adequate for the proposed scientific program of LAMOST survey. With a Monte Carlo simulation using historical data on the site condition, we find that the available observation hours constrain the survey footprint from 22h to 16h in right ascension; the sky brightness allows LAMOST to obtain the limit magnitude of V = 19.5mag with S/N = 10.Comment: 10 pages, 8 figures, accepted for publication in RA

Retrosynthetic planning with experience-guided Monte Carlo tree search

Abstract In retrosynthetic planning, the huge number of possible routes to synthesize a complex molecule using simple building blocks leads to a combinatorial explosion of possibilities. Even experienced chemists often have difficulty to select the most promising transformations. The current approaches rely on human-defined or machine-trained score functions which have limited chemical knowledge or use expensive estimation methods for guiding. Here we propose an experience-guided Monte Carlo tree search (EG-MCTS) to deal with this problem. Instead of rollout, we build an experience guidance network to learn knowledge from synthetic experiences during the search. Experiments on benchmark USPTO datasets show that, EG-MCTS gains significant improvement over state-of-the-art approaches both in efficiency and effectiveness. In a comparative experiment with the literature, our computer-generated routes mostly matched the reported routes. Routes designed for real drug compounds exhibit the effectiveness of EG-MCTS on assisting chemists performing retrosynthetic analysis

Research progress in ceramic slurries and rheology via photopolymerization-based 3D printing

Ceramic 3D printing based on stereolithography has attracted wide attention because it can fabricate complex ceramic components with high dimensional accuracy, good surface finish, uniform microstructure, and excellent mechanical properties. It is one of the important technical means to achieve high-performance parts by additive manufacturing. The core of the technology is to prepare ceramic slurries with high solid loading and good printability, and its composition has a vital influence on the curing effect and printing process. In this review, two main additive manufacturing methods, stereolithography (SL) and digital light processing (DLP), commonly used in ceramic 3D printing were introduced, and advantages and disadvantages of the two methods were compared. Based on the research work in the field of ceramic slurries in recent years, the effects of monomer/oligomer and diluent, dispersant, physical properties of ceramic particles and solid loading on viscosity, shear thinning/thickening behavior, viscoelasticity, yield stress were discussed. Finally, the main development trends and challenges of ceramic slurries via stereolithography were put forward in, and a general guiding principle for the construction of ceramic slurries with high solid loading was provided

Interleukin-10 inhibits interleukin-1β production and inflammasome activation of microglia in epileptic seizures

Abstract Background Microglia are important for secreting chemical mediators of inflammatory responses in the central nervous system. Interleukin (IL)-10 and IL-1β secreted by glial cells support neuronal functions, but the related mechanisms remain vague. Our goal was to demonstrate the efficacy of IL-10 in suppressing IL-1β and in inflammasome activation in mice with epileptic seizure based on an epileptic-seizure mouse model. Methods In this study, mice in which epileptic seizures were induced by administering picrotoxin (PTX) were used as a case group, and mice injected with saline were employed as the control group. The expression of nucleic acids, cytokines, or signaling pathways was detected by reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), flow cytometry, and Western blotting. Results Our results demonstrated that IL-10 inhibits IL-1β production through two distinct mechanisms: (1) Treatment with lipopolysaccharides (LPS) results in IL-10 overexpression in microglia and reduced NLRP3 inflammasome activity, thus inhibiting caspase-1-related IL-1β maturation; (2) next, autocrine IL-10 was found to subsequently promote signal transducer and activator of transcription-3 (STAT-3), reducing amounts of pro-IL-1β. Conclusions Our results indicate that IL-10 is potentially effective in the treatment of inflammation encephalopathy, and suggest the potential usefulness of IL-10 for treating autoimmune or inflammatory ailments

Study on grid inefficiency for mesh-type Frisch-grid ionization chambers

In this study, the grid inefficiency $$\sigma$$ for a mesh-type Frisch-grid ionization chamber (FGIC) was investigated using the finite element method and Monte Carlo method. A grid inefficiency $$\sigma$$ evaluation model was developed, which can determine the relationship between the physical parameters of the detector and the grid inefficiency with reasonable accuracy. An artificial neural network (ANN) was applied in the investigation of the grid inefficiency factor $$\sigma$$. The trained ANN was able to describe and predict the grid inefficiency factor $$\sigma$$ with different physical parameters for the mesh-type FGIC. Thus, it can serve as a reference for the development of mesh-type FGICs and correct grid inefficiency $$\sigma$$ measurements

AIDA: ab initio domain assembly for automated multi-domain protein structure prediction and domain–domain interaction prediction

Motivation: Most proteins consist of multiple domains, independent structural and evolutionary units that are often reshuffled in genomic rearrangements to form new protein architectures. Template-based modeling methods can often detect homologous templates for individual domains, but templates that could be used to model the entire query protein are often not available. Results: We have developed a fast docking algorithm ab initio domain assembly (AIDA) for assembling multi-domain protein structures, guided by the ab initio folding potential. This approach can be extended to discontinuous domains (i.e. domains with ‘inserted’ domains). When tested on experimentally solved structures of multi-domain proteins, the relative domain positions were accurately found among top 5000 models in 86% of cases. AIDA server can use domain assignments provided by the user or predict them from the provided sequence. The latter approach is particularly useful for automated protein structure prediction servers. The blind test consisting of 95 CASP10 targets shows that domain boundaries could be successfully determined for 97% of targets. Availability and implementation: The AIDA package as well as the benchmark sets used here are available for download at http://ffas.burnham.org/AIDA/. Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics online