Microbiota: A potential orchestrator of antidiabetic therapy

The gut microbiota, as a ‘new organ’ of humans, has been identified to affect many biological processes, including immunity, inflammatory response, gut-brain neural circuits, and energy metabolism. Profound dysbiosis of the gut microbiome could change the metabolic pattern, aggravate systemic inflammation and insulin resistance, and exacerbate metabolic disturbance and the progression of type 2 diabetes (T2D). The aim of this review is to focus on the potential roles and functional mechanisms of gut microbiota in the antidiabetic therapy. In general, antidiabetic drugs (α-glucosidase inhibitor, biguanides, incretin-based agents, and traditional Chinese medicine) induce the alteration of microbial diversity and composition, and the levels of bacterial component and derived metabolites, such as lipopolysaccharide (LPS), short chain fatty acids (SCFAs), bile acids and indoles. The altered microbial metabolites are involved in the regulation of gut barrier, inflammation response, insulin resistance and glucose homeostasis. Furthermore, we summarize the new strategies for antidiabetic treatment based on microbial regulation, such as pro/prebiotics administration and fecal microbiota transplantation, and discuss the need for more basic and clinical researches to evaluate the feasibility and efficacy of the new therapies for diabetes

Research on Protection Scheme of DC Microgrid Integrated with Fault Current Limiting Control Technology

[Introduction] With the development of new loads, such as distributed power sources and electric vehicles, DC(Direct Current) microgrids have the advantages of fewer commutation links and lower system losses than AC(Alternating Current) microgrids, and have become the current research hotspot. Due to the small coverage of the DC microgrid and access to a large amount of distributed power sources, the fault current rises quickly with a large amplitude when inter-pole short-circuit fault occurs, making it difficult to achieve differential coordination with traditional overcurrent protection used in AC distribution networks and posing a great challenge to fault localization. [Method] Therefore, in response to the characteristics of fault current in DC microgrids, the method for designing overcurrent protection setting value based on the precise control value of fault current through the integration of current limiting and protection was proposed. Combined with the reasonable capacity design of each branch, it can easily achieve differential coordination and accurately locate faults. [Result] A corresponding DC microgrid model is built on the PSCAD/EMTDC simulation platform. The proposed protection scheme is simulated and verified, and the result shows that the scheme can correctly locate the fault point and quickly remove the fault. [Conclusion] The proposed protection scheme can ensure the selectivity of overcurrent, which verifies the rationality of the scheme

Distribution and conservation of the Indo-Pacific humpback dolphin in China

National Natural Science Foundation of China [30830016]; Program for New Century Excellent Talents in University [NCET-07-0445]; Ministry of Education of China; Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP) [20060319002];The Indo- Pacific humpback dolphin (Sousa chinensis Osbeck, 1765) is a threatened species inhabiting the waters of China. Despite being of conservation concern, the distribution and abundance of this species has not been comprehensively evaluated. From 1994 to 2008 we performed over 14 000 km of line-transect surveys and administered over 700 questionnaires to collect basic information on the geographic range and likely abundance of Indo Pacific humpback dolphins along the southern and eastern coasts of China. Through our study we were able to establish a reporting network of stranding and incidental catches for this species. Our quantitative data suggests that only 76 animals remain around Xiamen, 39 in the Hepu Nature Reserve and 114 in the estuary of the Dafengjiang River. Qualitative data from local fishing people and government officials suggests that dolphins may exist year-round in waters off Ningde and Shantou. We found that wild populations of Sousa chinensis in this important region are clearly being affected by human disturbance and habitat deterioration, including underwater blasting, vessel collision, fishing, aquaculture and water pollution. Although some protected areas have been established and this species is protected under Chinese law, there remains virtually no protection for this animal

Abundance, distribution and conservation of Chinese White Dolphins (Sousa chinensis) in Xiamen, China

In recent years, human activities appear to present the greatest threat to the Chinese white dolphin (Sousa chinensis). Increasing death records of this species in Xiamen have already become a focus of attention among the local government, the public, and the media. A comprehensive understanding about the status of Xiamen population is important not only to evaluate the conservation measures taken previously, but to design adaptive measures appropriate to this population. In this study, a survey using line-transect methodology was carried out to cover an area of about 700 km 2 in Xiamen waters. A total of 102 separate sightings were made on 6157 km of transect line. The abundance estimate ranged from 67 (CV = 41.6%) to 93 (CV = 26.34%), with an average of 86 (CV = 20.16%). Overall, Xigang (West harbor) and Jiyu represented the major area of distribution in Xiamen. Significant seasonal changes in distribution were found. In spring, significant numbers of dolphins occurred in Xigang and few in other areas, while in other seasons, the sighting rate in Xigang decreased relatively with sightings in Jiyu, Dapan, and Dadeng increasing obviously, suggesting an outward movement pattern of Chinese white dolphins from the inside harbor to outside waters after spring. Some suggestions for redesigning the Xiamen Nature Reserve and other management measures are put forward. (c) 2007 Published by Elsevier GmbH on behalf of Deutsche Gesellschaft fur Saugetierkunde

Enhancement of Synthetic <i>Trichoderma</i>-Based Enzyme Mixtures for Biomass Conversion with an Alternative Family 5 Glycosyl Hydrolase from <i>Sporotrichum thermophile</i>

<div><p>Enzymatic conversion of lignocellulosic materials to fermentable sugars is a limiting step in the production of biofuels from biomass. We show here that combining enzymes from different microbial sources is one way to identify superior enzymes. Extracts of the thermophilic fungus <i>Sporotrichum thermophile</i> (synonym <i>Myceliophthora thermophila</i>) gave synergistic release of glucose (Glc) and xylose (Xyl) from pretreated corn stover when combined with an 8-component synthetic cocktail of enzymes from <i>Trichoderma reesei</i>. The <i>S. thermophile</i> extracts were fractionated and an enhancing factor identified as endo-β1,4- glucanase (StCel5A or EG2) of subfamily 5 of Glycosyl Hydrolase family 5 (GH5_5). In multi-component optimization experiments using a standard set of enzymes and either StCel5A or the ortholog from <i>T. reesei</i> (TrCel5A), reactions containing StCel5A yielded more Glc and Xyl. In a five-component optimization experiment (i.e., varying four core enzymes and the source of Cel5A), the optimal proportions for TrCel5A vs. StCel5A were similar for Glc yields, but markedly different for Xyl yields. Both enzymes were active on lichenan, glucomannan, and oat β-glucan; however, StCel5A but not TrCel5A was also active on β1,4-mannan, two types of galactomannan, and β1,4-xylan. Phylogenetically, fungal enzymes in GH5_5 sorted into two clades, with StCel5A and TrCel5A belonging to different clades. Structural differences with the potential to account for the differences in performance were deduced based on the known structure of TrCel5A and a homology-based model of StCel5A, including a loop near the active site of TrCel5A and the presence of four additional Trp residues in the active cleft of StCel5A. The results indicate that superior biomass-degrading enzymes can be identified by exploring taxonomic diversity combined with assays in the context of realistic enzyme combinations and realistic substrates. Substrate range may be a key factor contributing to superior performance within GH5_5.</p></div

Activities of pure TrCel5A and StCel5A on defined substrates.

<p>Sigmacell is crystalline cellulose; PASC is phosphoric-acid swollen cellulose; lichenan and β-glucan are two types of mixed-linkage β1,3-β1,4 glucan, one from Iceland moss and the other from oats; xyloglucan is β1,4-linked glucan with α1,6-linked Xyl side chains from tamarind; mannan is insoluble β1,4-mannan; locust bean gum and guar gum are two types of β1,4-linked mannan with side chains of α1,6-linked galactose; xylan is β1,4-linked xylan; arabinoxylan is β1,4-linked xylan with α1,6-linked arabinose side chains; laminarin is predominantly β1,3-linked glucan. Shaded bars, StCel5A; open bars, TrCel5A. TrCel5A had no detectable activity against mannan, either galactomannan, xylan, or arabinoxylan. Neither enzyme had detectable activity against xyloglucan.</p

Third fractionation (hydrophobic interaction) of fraction 5 from the separation shown in Figure 2.

<p><b>(A)</b> OD₂₈₀. <b>(B)</b> Activity with (black solid line) or without (red dashed line) 8-CSM, as described in the legend to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109885#pone-0109885-g001" target="_blank">Fig. 1</a>. Glc released by 8-CSM alone was 0.26±0.01 g/L. <b>(C)</b> Degree of synergy calculated from (B).</p

Alignment of the catalytic domains of fungal proteins in subfamily 5 of GH5 (GH5_5) showing its further division into two subclades, GH5_5_1 and GH5_5_2.

<p>All of the sequences have N-terminal CBM's except TaCel5A. StCel5A and TrCel5A are show in green. Sequences from Basidiomycota are shown in red; all other sequences are from Ascomycota. Species abbreviations and taxonomic affiliations are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109885#pone.0109885.s006" target="_blank">Table S6</a>.</p

Surface views of StCel5A and TrCel5A showing Trp residues (blue) that are conserved in all members of GH5_5_1 (e.g., TrCel5A) or GH5_5_2 (e.g., StCel5A).

<p>The active-site Glu residues are shown in red. For orientation, the loop at the top of TrCel5A is the loop 2 shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109885#pone-0109885-g010" target="_blank">Fig. 10</a>.</p