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Collagen is a kind of biocompatible protein material, which is widely used in medical tissue engineering, drug delivery, cosmetics, food and other fields. Because of its wide source, low extraction cost and good physical and chemical properties, it has attracted the attention of many researchers in recent years. However, the application of collagen derived from terrestrial organisms is limited due to the existence of diseases, religious beliefs and other problems. Therefore, exploring a wider range of sources of collagen has become one of the main topics for researchers. Marine-derived collagen (MDC) stands out because it comes from a variety of sources and avoids issues such as religion. On the one hand, this paper summarized the sources, extraction methods and characteristics of MDC, and on the other hand, it summarized the application of MDC in the above fields. And on the basis of the review, we found that MDC can not only be extracted from marine organisms, but also from the wastes of some marine organisms, such as fish scales. This makes further use of seafood resources and increases the application prospect of MDC.

Neurogenesis in the developing neocortex begins with the generation of the preplate, which consists of early-born neurons including Cajal-Retzius (CR) cells and subplate neurons. Here, utilizing the Ebf2-EGFP transgenic mouse in which EGFP initially labels the preplate neurons then persists in CR cells, we reveal the dynamic transcriptome profiles of early neurogenesis and CR cell differentiation. Genome-wide RNA-seq and ChIP-seq analyses at multiple early neurogenic stages have revealed the temporal gene expression dynamics of early neurogenesis and distinct histone modification patterns in early differentiating neurons. We have identified a new set of coding genes and lncRNAs involved in early neuronal differentiation and validated with functional assays in vitro and in vivo. In addition, at E15.5 when Ebf2-EGFP+ cells are mostly CR neurons, single-cell sequencing analysis of purified Ebf2-EGFP+ cells uncovers molecular heterogeneities in CR neurons, but without apparent clustering of cells with distinct regional origins. Along a pseudotemporal trajectory these cells are classified into three different developing states, revealing genetic cascades from early generic neuronal differentiation to late fate specification during the establishment of CR neuron identity and function. Our findings shed light on the molecular mechanisms governing the early differentiation steps during cortical development, especially CR neuron differentiation., Author summary Neural stem cells and progenitor cells in the embryonic brain give rise to neurons following a precise temporal order after initial expansion. Early-born neurons including Cajal-Retzius (CR) cells and subplate neurons form the preplate in the developing cerebral cortex, then CR neurons occupy the layer 1, playing an important role in cortical histogenesis. The molecular mechanisms governing the early neuronal differentiation processes remain to be explored. Here, by genome-wide approaches including bulk RNA-seq, single-cell RNA-seq and ChIP-seq, we comprehensively characterized the temporal dynamic gene expression profile and epigenetic status at different stages during early cortical development and uncovered molecularly heterogeneous subpopulations within the CR cells. We revealed CR neuron signatures and cell type-specific histone modification patterns along early neuron specification. Using in vitro and in vivo assays, we identified novel lncRNAs as potential functional regulators in preplate differentiation and CR neuron identity establishment. Our study provides a comprehensive analysis of the genetic and epigenetic programs during neuronal differentiation and would help bring new insights into the early cortical neurogenesis process, particularly the differentiation of CR neurons.

To investigate the surgical treatment methods and evaluate the outcome of gunshot wounds combining with seawater immersion in rabbits' femoral arteries.One hundred healthy New Zealand white rabbits (either sex, 3.14 kg+/-0.61 kg in weight) were randomly divided into a seawater immersion group (n=50) and a simple injury group (n=50). The unilateral femoral arteries of all the rabbits were injured by 0.38 g steel spheres with velocity of 600-800 m/s fired by a 7.62 mm rifle. The rabbits in the seawater immersion group were immersed in seawater (saline content of 2.54%, pH 8.2-8.4, and at 21 degrees C) for 60 minutes but those in the simple injury group were not. After the injured segment (observed by naked eyes) of the femoral artery was excised, the blood flow restoration was reconstructed by direct end-to-end anastomosis, reversed autogenous venous grafting or cryopreserved arterial allografting, according to the length of the arterial defects. At 24 hours, and 7, 14 and 21 days after operation, the blood flow was examined. Operative exploration was performed for the animals with partly or fully obstructed blood flow. The tissues around the anastomosis sites and the grafts were harvested for pathological observation under a light microscope and an electron microscope.In the rabbits with completely transected injury, the unobstructed rates in the first 3 weeks after operation were 80.00% in the seawater immersion group and 86.67% in the single injury group, and no significant difference was found between the two groups (P0.1). In the rabbits with arterial contusion injury, the unobstructed rates in the first 3 weeks after operation were 86.67% in the seawater immersion group and 82.35% in the single injury group, and no significant difference was found between the two groups (P0.1). Most thrombosis occurred in the first operative week. Atypical endothelial cells were detected at the anastomosis sites at the first operative week, and the anastomosis sites were lined with endothelial cells in 3 weeks postoperatively.During the surgical treatment for gunshot wounds combining with seawater immersion, resection of the grossly-injured artery and routine artery reconstruction can obtain satisfactory outcome. Homologous artery is a kind of vascular graft with certain applied value.

To investigate pathological characteristics of gunshot wounds concomitant seawater immersion in rabbits' femoral arteries.Thirty rabbits were divided randomly into 3 groups: simple gunshot-wound group (Group I, n = 10), gunshot wound with seawater immersion for 30 mins (Group II, n = 10), and 60 mins group (Group III, n = 10). Femoral arteries were impacted by 0.38 g steel spheres fired with a 7.62 mm rifle. After being wounded, rabbits in Groups II and III were immersed in seawater for 30 or 60 mins, but those in Group I were not. At 2, 4, 6, 8, 12 hours following injury, a 40 mm segment of the artery on each side of the gunshot point were excised and observed by light and electron microscopy.The patterns of arterial injuries were mainly contusion and transection. Completely transected artery was classified as primary-wound-tract area, contused area and shocked area. Compared with those in Group I, the primary-wound-tract and contused areas in Group II manifested obvious swelling in the arterial wall especially at the outside 2/3 of the media. Vacuolar structures were often seen in smooth muscle cells of the media. Intercellular space among the smooth muscle cells were filled with homogeneous acidophilic substances. Deep rugae among endothelial cells flattened or rugal folds lost their longitudinal orientation, and marked fibrin and platelet deposition were noticed. No significant difference was detected between Group II and III. The pathological changes in the shocked area were similar in 3 groups.For gunshot wounds concomitant seawater immersion in rabbits' femoral arteries, there was a marked swelling of cells and intercellular space in primary-wound-tract area and contusion area. The influence of these pathological changes on surgical reparation deservers further study.