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Red algae Pterocladiella capillacea off the coast of China were investigated for genetic diversity. With 176 samples categorized into six populations based on concatenated rbcL and cox1 sequences, the results rang warning bells for the genetic diversity of Pterocladiella capillacea along the Chinese coastline: (1) a good diversity of haplotype (Hd > 0.5) in Naozhou and Hui’an populations situated along the southern coast of China, but highest in the former; (2) less nucleotide diversity in each of the six populations (Pi < 0.005); (3) genetic differentiation occurred between the north population in Changdao and the two southern grown populations in Nan’ao, and Naozhou. To identify molecular markers, an MP phylogenetic tree was used to illustrate genetic profiles in detail, with 161 concatenated sequences clustered into four branches: Changdao (north), Nan’ao (south), Naozhou (south), and the remaining regions (middle). The Fst value for each of Changdao, Nan’ao, and Naozhou was greater than 0.5, which denotes that these three populations are genetically different to those growing in the middle coast. Moreover, a 30-haplotype-based median-joining network corroborated this genetic differentiation, though variations between all the investigated populations were not very high due to the relatively smaller values of genetic distance between the six (Dxy < 0.01). Overall, red algae P. capillacea in Chinese coastal seawater showed a higher haplotype diversity and lower nucleotide diversity. Such a genetic profile indicates that both natural random genetic drift and interference from human activities have possibly affected the distribution of gene frequencies in red algae P. capillacea along the Chinese coastline.

Abstract In this paper, we consider differential delay systems of the form x′(t)=−∑s=12k−1(−1)s+1∇F(x(t−s)), $$x'(t)=-\sum_{s=1}^{2k-1}(-1)^{s+1} \nabla F \bigl(x(t-s) \bigr), $$ in which the coefficients of the nonlinear terms with different hysteresis have different signs. Such systems have not been studied before. The multiplicity of the periodic orbits is related to the eigenvalues of the limit matrix. The results provide a theoretical basis for the study of differential delay systems.

Abstract We investigate a singular fractional differential equation with an infinite-point fractional boundary condition, where the nonlinearity f(t,x) $f(t,x)$ may be singular at x=0 $x = 0$, and g(t) $g(t)$ may also have singularities at t=0 $t= 0$ or t=1 $t=1$. We establish the existence of positive solutions using the fixed point index theory in cones.

The whole chloroplast genome (cp DNA) sequence of Caulerpa lentillifera J. Agardh has been characterized from Illumina pair-end sequencing. The circular cpDNA was 119,402 bp in length, containing 122 genes, which included 91 protein-coding genes, 28 tRNA genes, and 3 ribosomal RNA genes (four rRNA species). The overall AT content of C. lentillifera cpDNA is 67.4%. The 48 genes phylogenetic analysis suggested that C. lentillifera formed a monophyletic clade with congeneric C. racemosa.

Many studies classifying Gracilaria species for the exploitation of agarophytes and the development of the agar industry were conducted before the prevalence of molecular tools, resulting in the description of many species based solely on their morphology. Gracilaria firma and G. changii are among the commercially important agarophytes from the western Pacific; both feature branches with basal constrictions that taper toward acute apices. In this study, we contrasted the morpho-anatomical circumscriptions of the two traditionally described species with molecular data from samples that included representatives of G. changii collected from its type locality. Concerted molecular analyses using the rbcL and cox1 gene sequences, coupled with morphological observations of the collections from the western Pacific, revealed no inherent differences to support the treatment of the two entities as distinct taxa. We propose merging G. changii (a later synonym) into G. firma and recognize G. firma based on thallus branches with abrupt basal constrictions that gradually taper toward acute (or sometimes broken) apices, cystocarps consisting of small gonimoblast cells and inconspicuous multinucleate tubular nutritive cells issuing from gonimoblasts extending into the inner pericarp at the cystocarp floor, as well as deep spermatangial conceptacles of the verrucosa-type. The validation of specimens under different names as a single genetic species is useful to allow communication and knowledge transfer among groups from different fields. This study also revealed considerably low number of haplotypes and nucleotide diversity with apparent phylogeographic patterns for G. firma in the region. Populations from the Philippines and Taiwan were divergent from each other as well as from the populations from Malaysia, Thailand, Singapore and Vietnam. Establishment of baseline data on the genetic diversity of this commercially important agarophyte is relevant in the context of cultivation, as limited genetic diversity may jeopardize the potential for its genetic improvement over time.

Pleural fibrosis can dramatically lower the quality of life. Numerous studies have reported that epithelial-mesenchymal transition (EMT) regulated by transforming growth factor-β (TGF-β) is involved in fibrosis. However, the molecular mechanism is inadequately understood. Fibroblast-specific protein-1 (S100A4) is a target of TGF-β signaling. In our previous study, we have reported that S100A4 is highly expressed in pleural fibrosis. Thus, we suggest that S100A4 took part in the TGF-β-induced EMT in pleural fibrosis. In this study, we determined the expression of S100A4 and EMT-related markers in Met-5A cells (pleural mesothelial cells) treated with TGF-β or TGF-β inhibitor by real-time PCR and western blot. In order to explore the role of S100A4, we used siRNA to knock down the expression of S100A4 in cell model. We found that the expression of epithelial cell marker was decreased and the mesenchymal cell marker increased with S100A4 upregulation after treatment with TGF-β. Moreover, the changes of EMT-related event were restricted when the expression of S100A4 was knocked down. Conversely, S100A4 can partially rescue the EMT-related expression changes induced by TGF-β inhibitor. These findings suggest that S100A4 expression is induced by the TGF-β pathway, and silencing S100A4 expression can inhibit the process of TGF-β-induced EMT. [ABSTRACT FROM AUTHOR]

Background: Emodin is the main active component of rhubarb, which has demonstrated many beneficial effects against inflammation. Nanosilver is an effective antimicrobial agent. The present study was designed to observe the effects of Emodin combined with silver nanoparticles (E/S) on sepsis protection and related mechanism. Methods: E/S was prepared by loading different concentrations of Emodin on nanosilver and cytotoxicity of E/S were determined by suphorhodamine B assays. Anti-microbial activities of E/S were assayed by direct interaction with various common pathogens and anti-adhesive activites of E/S on leukocytes with endothelial cells were assayed by biochemical analysis. Next, inflammatory cell enumeration, inflammatory mediators in bronchoalveolar lavage fluid (BALF) and endothelial cell function were analyzed on a clinically relevant model of sepsis induced by cecal ligation and puncture (CLP) after E/S administration. The effects of E/S on NF-kB and p38 were also examined by western blot. Results: E/S exhibited little cytotoxicity action on endothelial cells and significant inhibitory activities against all tested common microorganisms and adherence between leukocyte and endothelial cells. E/S induced anti-sepsis protection mainly mediated by inhibition of inflammatory cells infiltration, down-regulation of TNF-alpha, IL-8 and lactic dehydrogenase (LDH), and inhibition of NF-kB and p38 pathways in mice 24 h post-CLP. Conclusion: Our data suggest that E/S has strong anti-sepsis effects, which was related with anti-inflammatory protection and thereby promote survival following sepsis challenge. [ABSTRACT FROM AUTHOR]

A carbon nanotube/Nafion composite film modified electrode is described for the sensitive and convenient determination of Pb2+. In the presence of 1% Nafion, multi-walled carbon nanotubes (MWNT) were successfully dispersed into ethanol by ultrasonication. After evaporating the ethanol, a MWNT/Nafion composite film-modified electrode was achieved. The resulting MWNT/Nafion film modified electrode possesses high cation exchange capacity, large surface area, strong adsorption ability and catalytic activity. Compared with the unmodified electrode and Nafion film-modified electrode, the MWNT/Nafion film-modified electrode remarkably increases the stripping peak current of Pb2+. Furthermore, the influences of supporting electrolyte, volume of MWNT/Nafion suspension, accumulation potential and accumulation time were investigated. The striping peak current of Pb2+ is proportional to its concentration over the range 8.0 × 10−8 to 6.0 × 10−6 mol L−1. The limit of detection (S/N = 3) is as low as 5.0 × 10−9 mol L−1. Finally, this newly developed method was used to determine Pb2+ in water samples. [ABSTRACT FROM AUTHOR]