Benthic carbon mineralization in hadal trenches: Insights from in-situ determination of benthic oxygen consumption

Hadal trenches have been proposed as depocenters of organic material and hot spots for organic matter mineralization. In this study, we for the first time quantified the total benthic O-2 uptake in hadal trenches using in situ chamber incubations. Three trenches in the tropical Pacific were targeted and exhibited relatively high diagenetic activity given the great water depths, that is, the Mariana Trench (2.0x10(2)molO(2)m(-2)d(-1), 10,853m), the Mussau Trench (2.70.1x10(2)molO(2)m(-2)d(-1), 7,011m), and the New Britain Trench (6.00.1x10(2)molO(2)m(-2)d(-1), 8,225m). Combined with the analyses of total organic carbon and C-13 of total organic carbon in the sediments and previously published in situ O-2 microprofiles from hadal settings, we suggest that hadal benthic carbon mineralization partly is governed by the surface production and also is linked to the distance from land. Therefore, we highlight that terrestrial organic matter can be of importance in sustaining benthic communities in some hadal settings. Plain Language Summary Hadal trenches that refer to seafloor areas covered by a water column with depths >6,000m have been proposed as depocenters of organic material and hot spots for organic matter mineralization. We applied in situ benthic chamber incubation techniques within three trenches in the tropical Pacific Ocean (the Mariana Trench, the Mussau Trench, and the New Britain Trench) and thereby reported the first benthic total O-2 uptake rates measured in hadal settings. The benthic carbon mineralization rates generally show a positive correlation with the net primary production in respective provinces and the sedimentary total organic carbon (TOC) level. Analyses of TOC contents and C-13 of TOC indicated a downslope transport of sediment containing a large amount of terrestrial organic matter, possibly via mass-wasting events to the axis of New Britain Trench off the New Britain Island. Therefore, we speculate that both surface production regimes and the distance from land are closely connected with the benthic carbon mineralization rate at the trench axes. The elevated organic carbon turnover rate may in part result from preferential concentration of relatively labile organic matter in the surface sediments of trench axes or efficient utilization of refractory terrestrial material under extreme pressure

Extracellular Proteome Analysis and Flavor Formation During Soy Sauce Fermentation

Aspergillus oryzae is an excellent strain for soy sauce fermentation because of its complicated enzyme system, especially protease. The aim of this study was to investigate the key enzymes and flavors during soy sauce fermentation, and a comparative assessment of extracellular enzymes during various fermentation stages at the proteomic level via iTRAQ analysis is presented. Many important enzymes related to the amino acid and glucose metabolisms participated in the material decomposition under high-salt stress. Dipeptidase, dipeptidyl aminopeptidase, leucine aminopeptidase, aspartic protease pep1, and extracellular metalloproteinase played positive roles during the early stage of soybean mash fermentation, whilst leucine aminopeptidase A and extracellular metalloproteinase NpI were the dominant proteolytic enzymes during the later period of fermentation. At the same time, β-glucosidase and β-xylanase exerted great effects upon glucose metabolism throughout the fermentation process. The results show that protease and amylolytic enzymes are complementary in the formation of flavors such as alcohols, acids, esters, aldehydes, furans, and pyrazines during soy sauce fermentation

The preoperative platelet–lymphocyte ratio neutrophil–lymphocyte ratio: which is better as a prognostic factor in oral squamous cell carcinoma?

Objective: Recent studies have shown that the presence of systemic inflammation and platelet status correlate with poor survival in various cancers. The aim of this study was to evaluate the prognostic value of the preoperative platelet–lymphocyte ratio (PLR) and the neutrophil–lymphocyte ratio (NLR) in patients with oral squamous cell carcinoma (OSCC) undergoing surgery. Methods: In this study, 306 patients with OSCC who had surgery were enrolled. The optimal cutoff value of PLR and NLR was determined by receiver operating characteristic (ROC) curve analysis. The prognostic significance of both markers was determined by uni- and multivariate analysis. Results: The results showed that high NLR and PLR were classified using a cutoff value of 2.7 and 135, respectively, based on ROC curve analysis. Only PLR was associated with decreased disease-free survival [hazard ratio (HR) = 2.237; 95% confidence interval (CI): 1.401–3.571; p = 0.001] and overall survival [HR = 2.022; 95% CI: 1.266–3.228; p = 0.003] by both uni- and multivariate analysis. Conclusion: The preoperative PLR is superior to NLR as an independent indicator in predicting disease-free survival and overall survival in patients who undergo oral cancer resection for OSCC

Efficient sequestration of terrigenous organic carbon in the New Britain Trench

ISSN:0009-2541ISSN:1872-683