Comparison of nutrients status in Liaodong Bay and Northern Yellow Sea, China: Controlling factors and nutrient budgets.

Under the dual stress of global warming and human interaction, Liaodong Bay (LDB) and northern Yellow Sea (NYS) are undergoing significant ecological changes. Little is known about the driving nutrients characteristics supporting fishery resource output in these areas. We carried out three field observations in 2019 to investigate nutrient status. Results showed that dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and dissolved silica (DSi) concentrations changed seasonally, with lowest values in spring, and highest values in autumn. High DIN, DIP, and DSi concentrations were detected in LDB and NYS's estuary areas. The Yellow Sea Cold Water Mass plays a role in the distribution and seasonal variation of nutrients. Exchanges across the sediment-water interface, SFGD, atmospheric deposition, and the adjacent sea input dominated DIN dynamics of these areas. DIP primarily came from the adjacent sea input and DSi mainly originated from sediment release and the adjacent sea input. NYS seawater invasion accounted for 13.8% of DIN, 63.4% of DIP, and 35.1% of DSi in LDB. These results provide new insights to better facilitate the formulation of nitrogen and phosphorus reduction and control policies in these marginal seas.

Strategies of Mandibular Revision: A Retrospective Study of Revisional Mandibular Surgery for Unaesthetic Results of Previous Mandibular Reduction.

BACKGROUND: Mandibular reduction has been developed and popularized in Asia for decades. Despite the technical advancement and experience accumulation, complications and unaesthetic results still occur, and some need a revision surgery. This study aims to introduce the experience of revision surgery to reshape the unaesthetic mandibular contour after previous mandibular reduction. METHODS: From May 2011 to September 2017, patients dissatisfied with the result of previous mandibular reduction and who received a secondary mandibular revision were retrospectively reviewed and analyzed. RESULTS: Twenty-five patients were included in this study. Under-correction (88%, 22/25) was the most common aesthetic problem requiring revision, followed by asymmetry (56%, 14/25), broad chin (40%, 10/25), second mandibular angle (32%, 8/25), and over-correction (8%, 2/25). As revision techniques, long-curve mandibular reduction, simple mandibular reduction, and mandibular grinding were performed on 60% (15/25), 36% (9/25), and 4% (1/25) of the patients, respectively. All the patients were satisfied with the results. Cephalometric measurements indicated a significant bone removal after revision. CONCLUSIONS: When performing a revision surgery to reshape the mandibular contour, the surgeon should have a clear surgical plan based on comprehensive evaluation, focus on the balanced harmony of the entire face, use proper technique and instruments, and avoid concomitant injury and complications. The one-staged technique that treats the whole mandible as an entirety is superior than multistaged techniques to improve the aesthetic outcomes to the largest extent. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Development and preparation of a low-immunogenicity porcine dermal scaffold and its biocompatibility assessment.

Acellular dermal matrix (ADM) has been widely used in repair and reconstruction of tissue defect. Therapeutic effect of porcine ADM (PADM) is inferior to that of human ADM (HADM). Relatively high immunogenicity and the resulting strong inflammatory response are major issue in application of PADM. We therefore treated reticular layer PADM (Rl-PADM) with matrix metalloproteinase-7 (MMP-7) and obtained a low-immunogenicity porcine dermal scaffold (LIPDS). Highly immunogenic components, tissue structure, cytocompatibility, and postgrafting histological changes of LIPDS were further investigated. Compared with Rl-PADM, LIPDS showed that the epithelial root sheath, cell debris, laminin, and type IV collagen were almost entirely removed, the structure remained normal, and the interfibrous space was relatively enlarged. Cytocompatibility of LIPDS was similar to that of HADM but superior to Rl-PADM. With regard to the extent of tissue ingrowth in terms of host fibroblasts infiltration and vascularization, LIPDS exhibited clear advantages over Rl-PADM after they had been subcutaneously transplanted in a rat model. In addition, no excessive inflammatory response was observed in LIPDS group up to 28 days postgraft, and the morphosis of collagenous fibers kept essentially normal. However, there were stronger inflammatory response and obvious collagen spallation in Rl-PADM group. The processes of integration and remodeling after the LIPDS grafting were similar to those of a normal wound healing response. The LIPDS graft was vascularized at a relatively high speed. Thus, as an implantable scaffold material, LIPDS is a superior template for guiding tissue regeneration and remodeling.