Object: Primary osteoporosis (PO) is the most common bone disease, which is characterized by decreased bone mass, damage of bone tissue microstructure, increased bone fragility, and is prone to fracture. Gut microbiome may be involved in bone metabolism of PO through gut-brain axis regulation of immune system and endocrine system, however, the specific mechanism is still unclear. The purpose of this study was to characterize the gut microbiome of patients with PO and its possible role in the occurrence and development of the disease. Methods: Fecal samples were collected from 48 PO patients and 48 healthy controls (HC). The composition of gut microbiome community was analyzed by 16s rDNA amplification sequencing, and the difference of gut microbiome composition between PO patients and HC individuals was compared. PICRUSt was also used to predict the biological function of gut microbiome in patients with PO, and to explore its possible role in the occurrence and development of this disease. The classification model is constructed by random forest algorithm so as to screen the key biomarkers. Result: The diversity of gut microorganisms in PO patients was significantly higher than that in HC group (p < 0.05) and there was significant difference in microbial composition in PO group. The abundance of Dialister (0.036 vs. 0.004, p < 0.001) and Faecalibacterium (0.331 vs. 0.132, p < 0.001) were significantly enriched which were the key flora related to PO. Although no significant correlation between bone mineral density and the richness of microbial communities are found, PICRUST results show that there are a wide range of potential pathways between gut microbiome and PO patients, including genetic information processing, metabolism, environmental information processing, cellular processes, human diseases, and organic systems. Notably, the discriminant model based on dominant microflora can effectively distinguish PO from HC (AUC = 93.56). Conclusions: The findings show that PO is related to the change of gut microbiome, especially the enriched Dialister and Faecalibacterium genera, which give new clues to understand the disease and provide markers for the diagnosis and new strategies for intervention treatment of the disease.

Dark Matter (DM) theories and mass-tracing-light theories like MOND are by construction nearly degenerate on galactic scales, but not when it comes to the predicted shapes of Roche Lobes of a two-body system (e.g., a globular cluster orbiting a host galaxy). We show that the flattening of the Roche lobe is sensitive to the function µ(g) in modification of the law of gravity. We generalise the analytical results obtained in the deep-MOND limit by , and consider a binary in the framework of a MOND-like gravity modification function µ(g) or a general non-Keplerian gravity g ∝ R −ζ . We give analytical expressions for the inner Lagrange point and Robe lobe axis ratios. The Roche lobe volume is proven to scale linearly with the true mass ratio, which applies to any µ(g), hence mass-tracing light models would overpredict the Roche lobe of a DM-poor globular cluster in a DM-rich host galaxy, and underpredict the size of a DM-richer dwarf satellite. The lobes are squashed with the flattening ∼0.4 in the strong gravity and ∼0.6 in the weak gravity; a precise measurement of the flattening could be used to verify the anisotropic dilation effect which is generic to MOND-like gravity. We generalise these results for extended mass distribution, and compare predicted Roche radii with limiting radii of observed globular clusters and dwarf galaxy satellites.

Vertical and in‐plane heterostructures based on van der Waals (vdW) crystals have drawn rapidly increasing attention owning to the extraordinary properties and significant application potential. However, current heterostructures are mainly limited to vdW crystals with a symmetrical hexagonal lattice, and the heterostructures made by asymmetric vdW crystals are rarely investigated at the moment. In this contribution, it is reported for the first time the synthesis of layered orthorhombic SnS–SnSxSe(1−x) core–shell heterostructures with well‐defined geometry via a two‐step thermal evaporation method. Structural characterization reveals that the heterostructures of SnS–SnSxSe(1−x) are in‐plane interconnected and vertically stacked, constructed by SnSxSe(1−x) shell heteroepitaxially growing on/around the pre‐synthesized SnS flake with an epitaxial relationship of (303)SnS//(033)SnSxSe(1−x), [010]SnS//[100]SnSxSe(1−x). On the basis of detailed morphology, structure and composition characterizations, a growth mechanism involving heteroepitaxial growth, atomic diffusion, as well as thermal thinning is proposed to illustrate the formation process of the heterostructures. In addition, a strong polarization‐dependent photoresponse is found on the device fabricated using the as‐prepared SnS−SnSxSe(1−x) core–shell heterostructure, enabling the potential use of the heterostructures as functional components for optoelectronic devices featured with anisotropy.