Fibrinogen as a potential diagnostic marker for prediction and evaluation of postpartum hemorrhage: a retrospective study

To investigate whether prenatal fibrinogen (FIB) or other related factors could be utilized to evaluate the risk of postpartum hemorrhage (PPH). A retrospective study was conducted in a database from January 2015 to December 2019. A total of 128 patients were enrolled and evaluated with FIB, in which 55 patients were assigned to low FIB and 73 in normal FIB. According to the volume of blood loss, the mean of the low FIB group ( Prenatal FIB was significantly related to thrombin time (TT), which may be an independent factor to predict the coagulation state of prenatal pregnancy.</p

Unique Domain Structure of Two-Dimensional α‑Mo₂C Superconducting Crystals

The properties of two-dimensional (2D) materials such as graphene and monolayer transition metal dichalcogenides are strongly influenced by domain boundaries. Ultrathin transition metal carbides are a class of newly emerging 2D materials that are superconducting and have many potential applications such as in electrochemical energy storage, catalysis, and thermoelectric energy conversion. However, little is known about their domain structure and the influence of domain boundaries on their properties. Here we use atomic-resolution scanning transmission electron microscopy combined with large-scale diffraction-filtered imaging to study the microstructure of chemical vapor deposited high-quality 2D α-Mo₂C superconducting crystals of different regular shapes including triangles, rectangles, hexagons, octagons, nonagons, and dodecagons. The Mo atom sublattice in all these crystals has a uniform hexagonal closely packed arrangement without any boundaries. However, except for rectangular and octagonal crystals, the C atom sublattices are composed of three or six domains with rotational-symmetry and well-defined line-shaped domain boundaries because of the presence of three equivalent off-center directions of interstitial carbon atoms in Mo octahedra. We found that there is very small lattice shear strain across the domain boundary. In contrast to the single sharp transition observed in single-domain crystals, transport studies across domain boundaries show a broad resistive superconducting transition with two distinct transition processes due to the formation of localized phase slip events within the boundaries, indicating a significant influence of the boundary on 2D superconductivity. These findings provide new understandings on not only the microstructure of 2D transition metal carbides but also the intrinsic influence of domain boundaries on 2D superconductivity