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To investigate the cell-cell interactions of intergeneric bacterial species, the study detected the survival of Enterococcus faecalis (Ef) under monospecies or coaggregation state with Fusobacterium nucleatum subsp. polymorphum (Fnp) in environmental stress. Ef and Fnp infected the human macrophages with different forms (Ef and Fnp monospecies, Ef-Fnp coaggregates, Ef + Fnp cocultures) for exploring the immunoregulatory effects and the relevant molecular mechanisms. Meanwhile, the transcriptomic profiles of coaggregated Ef and Fnp were analyzed. Ef was shown to coaggregate with Fnp strongly in CAB within 90 min by forming multiplexes clumps. Coaggregation with Fnp reinforced Ef resistance against unfavorable conditions including alkaline, hypertonic, nutrient-starvation, and antibiotic challenges. Compared with monospecies and coculture species, the coaggregation of Ef and Fnp significantly facilitates both species to invade dTHP-1 cells and aid Ef to survive within the cells. Compared with coculture species, dual-species interaction of Ef and Fnp significantly decreased the levels of pro-inflammatory cytokines IL-6, TNF-α, and chemokines MCP-1 secreted by dTHP-1 cells and lessened the phosphorylation of p38, JNK, and p65 signaling pathways. The transcriptome sequencing results showed that 111 genes were differentially expressed or Ef-Fnp coaggregated species compared to Ef monospecies; 651 genes were differentially expressed for Fnp when coaggregation with Ef. The analysis of KEGG pathway showed that Ef differentially expressed genes (DEGs) were enriched in quorum sensing and arginine biosynthesis pathway; Fnp DEGs were differentially concentrated in lipopolysaccharide (LPS) biosynthesis, biofilm formation, and lysine degradation pathway compared to monospecies. Key points: • Coaggregated with Fnp aids Ef's survival in environmental stress, especially in root canals after endodontic treatment. • The coaggregation of Ef and Fnp may weaken the pro-inflammatory response and facilitate Ef to evade killed by macrophages. • The coaggregation between Ef and Fnp altered interspecies transcriptional profiles. [ABSTRACT FROM AUTHOR]

The efficient conversion of low-grade acidic oils to biodiesel is still a great challenge due primarily to the presented free fatty acids (FFAs) and moisture that significantly activate the used catalysts. In this premise, the acidic aluminosilicates (AAS) were employed as catalyst supports for loading of molybdenum and zirconium metals to synthesize the solid acid catalysts of molybdenum and zirconium doped aluminosilicates (ZrMo-AAS). The so-synthesized composite catalysts were characterized by various physicochemical techniques, and their catalytic activities were evaluated for the efficient biodiesel production by using acidic soybean oils as feedstocks. Results revealed that the targeted solid catalysts featured dual Bronsted-Lewis acidic sites and mesoporous structure with the acidity of 719 μmol/g and surface area of 459.7 m2/g, displaying high catalytic performances for the concurrent transesterification of triglycerides and esterification of FFAs with 92.3% of oil conversion and full FFA conversion to biodiesel at a reaction temperature of 130 °C for 12 h with a methanol/oil molar ratio of 30. This solid catalyst had good water and FFA-resistance capacity even with water content to 1% and FFA content of 40%, and moreover could be easily recovered by filtration with a steady reusability with a slight attenuation in the activity after five time reuses, rendering it to have the potential of cost-effective production of biodiesel from the low-grade oils. [ABSTRACT FROM AUTHOR]

The concept of the renormalization group (RG) emerged from the renormalization of quantum field variables, which is typically used to deal with the issue of divergences to infinity in quantum field theory. Meanwhile, in the study of phase transitions and critical phenomena, it was found that the self–similarity of systems near critical points can be described using RG methods. Furthermore, since self–similarity is often a defining feature of a complex system, the RG method is also devoted to characterizing complexity. In addition, the RG approach has also proven to be a useful tool to analyze the asymptotic behavior of solutions in the singular perturbation theory. In this review paper, we discuss the origin, development, and application of the RG method in a variety of fields from the physical, social and life sciences, in singular perturbation theory, and reveal the need to connect the RG and the fractional calculus (FC). The FC is another basic mathematical approach for describing complexity. RG and FC entail a potentially new world view, which we present as a way of thinking that differs from the classical Newtonian view. In this new framework, we discuss the essential properties of complex systems from different points of view, as well as, presenting recommendations for future research based on this new way of thinking. [ABSTRACT FROM AUTHOR]

Bacterial membrane vesicles (MVs) are used as a tool for intercellular communication and seem essential for bacterial survival. However, few data are available on MVs generated by Streptococcus mutans, which is the main aetiological agent of dental caries. The present study presents an integrated proteomics and metabolomics analysis of MVs isolated from S. mutans at initial pH values of 7.5 and 5.5 and explores their function. The results showed that S. mutans releases more MVs with smaller diameters under acidic conditions than under neutral conditions. Proteomic analysis showed 344 common vesicular proteins, including various virulence factors. The expressions of 140 individual proteins and 37 metabolites were altered as a result of culturing S. mutans at different pH values. Co-analyses of proteomic and metabolomics data indicated that ABC transporters underwent significant changes under acid pressure. We concluded that S. mutans produced MVs at different pH values to carry proteins associated with cariogenesis. Moreover, the alterations of S. mutans MVs under acid pressure were associated with ABC transporters. These results increase our knowledge of S. mutans MVs and imply that S. mutans MVs may play a functional role in carious infection. Key points: • S. mutans MVs contained virulence factor-related proteins, even at low pH values. • Integrated proteomics and metabolomics analysis showed that S. mutans MVs alterations under acidic conditions were associated with ABC transporters. [ABSTRACT FROM AUTHOR]

In this paper, a class of switched fractional-order continuous-time systems with order 0 < α < 1 is investigated. First, an interesting property of fractional calculus is revealed, that is, unlike integer-order integral, it does not hold that t 0 D t - α f (t) = t 0 D t 1 - α f (t) + t 1 D t - α f (t) for α > 0 , t 0 < t 1 < t , not to mention fractional derivative. Then, a general formula of solutions for a piecewise-defined differential function with Caputo fractional derivative is introduced. After that, based on the derived equivalent solution of fractional-order piecewise-defined functions, the problem of finite-time stability for a class of switched fractional-order systems is reconsidered. Finally, two illustrative examples are provided to demonstrate the effectiveness of the presented sufficient conditions, respectively. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated the prognostic value of the C-reactive protein/albumin (CRP/Alb) ratio in cancer. However, the role of the CRP/Alb ratio in advanced pancreatic cancer (PC) has not been examined. A retrospective study of 233 patients with advanced PC was conducted. We investigated the relationship between the CRP/Alb ratio, clinicopathological variables, and overall survival (OS). The optimal cutoff point of the CRP/Alb ratio was 0.54. A higher CRP/Alb ratio was significantly associated with an elevated neutrophil-lymphocyte ratio (NLR) ( P < 0.001) and higher modified Glasgow prognostic score (mGPS) ( P < 0.001). Using univariate analyses, we found that the age ( P = 0.009), disease stage ( P < 0.001), NLR ( P < 0.001), mGPS ( P < 0.001), and CRP/Alb ratio ( P < 0.001) were significant predictors of OS. Patients with a higher CRP/Alb ratio had a worse OS than patients with a lower CRP/Alb ratio (hazard ratio (HR) 3.619; 95 % CI 2.681-4.886; P < 0.001). However, the CRP/Alb ratio was identified as the only inflammation-based parameter with an independent prognostic ability in the multivariate analyses ( P < 0.001). The pretreatment CRP/Alb ratio is a superior prognostic and therapeutic predictor of OS in advanced PC. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of paeonol on the proliferation, migration, and inflammation induced by tumor necrosis factor (TNF-α) of rat vascular smooth muscle cells (VSMCs). Primary rat VSMCs were identified by immunofluorescence assay. The inhibition of VSMCs proliferation induced by TNF-α was observed after paeonol treatment in a dose-dependent manner. Treatment with 100 μM paeonol significantly reduced the expression of proliferating cell nuclear antigen (PCNA). On the other hand, transwell assay showed that treatment with paeonol suppressed the invasion of TNF-α-induced VSMCs and the production of inflammation factors stimulated by TNF-α. For apoptosis induced by paeonol, Western blot analysis showed that cleaved caspase-3 and -9 were detected, and pro-apoptotic protein Bax was up-regulated, whereas anti-apoptotic protein Bcl-2 was down-regulated by paeonol in TNF-α-stimulated VSMCs. ELISA analysis data showed that both levels of IL-1β and IL-6 produced by the stimulation of TNF-α were decreased by paeonol in a dose-dependent manner in VSMCs. These results suggest that paeonol can effectively inhibit the proliferation through apoptotic induction through caspase pathway in VSMCs induced by TNF-α. Also, paeonol significantly reduced the invasion and the inflammation stimulated by TNF-α in VSMCs. [ABSTRACT FROM AUTHOR]

Recently, Gandomi and Alavi proposed a robust meta-heuristic optimization algorithm, called Krill Herd (KH), for global optimization. To improve the performance of the KH algorithm, harmony search (HS) is applied to mutate between krill during the process of krill updating instead of physical diffusion used in KH. A novel hybrid meta-heuristic optimization approach HS/KH is proposed to solve global numerical optimization problem. HS/KH combines the exploration of harmony search (HS) with the exploitation of KH effectively, and hence, it can generate the promising candidate solutions. The detailed implementation procedure for this improved meta-heuristic method is also described. Fourteen standard benchmark functions are applied to verify the effects of these improvements, and it is demonstrated that, in most cases, the performance of this hybrid meta-heuristic method (HS/KH) is superior to, or at least highly competitive with, the standard KH and other population-based optimization methods, such as ACO, BBO, DE, ES, GA, HS, KH, PSO, and SGA. The effect of the HS/FA parameters is also analyzed. [ABSTRACT FROM AUTHOR]

It is well established that host-associated microbial communities can interfere with the colonization and establishment of microbes of foreign origins, a phenomenon often referred to as bacterial interference or colonization resistance. However, due to the complexity of the indigenous microbiota, it has been extremely difficult to elucidate the community colonization resistance mechanisms and identify the bacterial species involved. In a recent study, we have established an in vitro mice oral microbial community (O-mix) and demonstrated its colonization resistance against an Escherichia coli strain of mice gut origin. In this study, we further analyzed the community structure of the O-mix by using a dilution/regrowth approach and identified the bacterial species involved in colonization resistance against E. coli. Our results revealed that, within the O-mix there were three different types of bacterial species forming unique social structure. They act as 'Sensor', 'Mediator' and 'Killer', respectively, and have coordinated roles in initiating the antagonistic action and preventing the integration of E. coli. The functional role of each identified bacterial species was further confirmed by E. coli-specific responsiveness of the synthetic communities composed of different combination of the identified players. The study reveals for the first time the sophisticated structural and functional organization of a colonization resistance pathway within a microbial community. Furthermore, our results emphasize the importance of 'Facilitation' or positive interactions in the development of community-level functions, such as colonization resistance. [ABSTRACT FROM AUTHOR]

High-power repetitively-pulsed TEA CO lasers are excited by a glow discharge, and it turns out to be the arc discharge under some conditions. The arc-discharge is a disadvantageous condition and must be avoided. According to the Faraday electromagnetism induction principle, the arc-discharge monitoring system with a magnetic-field probe is designed for high-power repetitively-pulsed TEA CO lasers. The magnetic-field variation induced by the discharge current can be tested, and the discharge state can be distinguished according to the output induction voltage. Experimental results show that the magnetic-field induction voltages generated by a glow discharge and an arc discharge are very different ones. The maximum induction voltage of the glow discharge is 2.0 V, while the minimum induction voltage of the arc discharge is 2.5-4 V. Three alarm levels are set by measuring the arc-discharge intensities. At the first level, automatic filling-exhausting equipment starts to refresh the gas media, at the second level, the laser repetition rate is reduced, and at the third level the laser operation stops immediately. As a result, the working reliability of a high-power repetitively-pulsed TEA CO laser system can be improved significantly by using the arc-discharge monitoring system. [ABSTRACT FROM AUTHOR]

It is a well-recognized fact that the composition of human salivary microbial community is greatly affected by its nutritional environment. However, most studies are currently focused on major carbon or nitrogen sources with limited attention to trace elements like essential mineral ions. In this study, we examined the effect of iron availability on the bacterial profiles of an in vitro human salivary microbial community as iron is an essential trace element for the survival and proliferation of virtually all microorganisms. Analysis via a combination of PCR with denaturing gradient gel electrophoresis demonstrated a drastic change in species composition of an in vitro human salivary microbiota when iron was scavenged from the culture medium by addition of the iron chelator 2,2′-bipyridyl. This shift in community profile was prevented by the presence of excessive ferrous iron (Fe). Most interestingly, under iron deficiency, the in vitro grown salivary microbial community became dominated by several hemolytic bacterial species, including Streptococcus spp., Gemella spp., and Granulicatella spp. all of which have been implicated in infective endocarditis. These data provide evidence that iron availability can modulate host-associated oral microbial communities, resulting in a microbiota with potential clinical impact. [ABSTRACT FROM AUTHOR]

The development of multispecies oral microbial communities involves complex intra- and interspecies interactions at various levels. The ability to adhere to the resident bacteria or the biofilm matrix and overcome community resistance are among the key factors that determine whether a bacterium can integrate into a community. Fusobacterium nucleatum is a prevalent Gram-negative oral bacterial species that is able to adhere to a variety of oral microbes and has been implicated in playing an important role in the establishment of multispecies oral microbial community. However, the majority of experiments thus far has focused on the physical adherence between two species as measured by in vitro co-aggregation assays, while the community-based effects on the integration of F. nucleatum into multispecies microbial community remains to be investigated. In this study, we focus on community integration of F. nucleatum. We demonstrated using an established in vitro mice oral microbiota (O-mix) that the viability of F. nucleatum was significantly reduced upon addition to the O-mix due to cell contact-dependent induction of hydrogen peroxide (HO) production by oral community. Interestingly, this inhibitory effect was significantly alleviated when F. nucleatum was allowed to adhere to its known interacting partner species (such as Streptococcus sanguinis) prior to addition. Furthermore, this aggregate formation-dependent protection was absent in the F. nucleatum mutant strain ΔFn1526 that is unable to bind to a number of Gram-positive species. More importantly, this protective effect was also observed during integration of F. nucleatum into a human salivary microbial community (S-mix). These results suggest that by adhering to other oral microbes, F. nucleatum is able to mask the surface components that are recognized by HO producing oral community members. This evasion strategy prevents detection by antagonistic oral bacteria and allows integration into the developing oral microbial community. [ABSTRACT FROM AUTHOR]

Trastuzumab has been successfully employed for the treatment of Her-2-positive gastric cancer. However, there are problems with both primary and secondary resistance to trastuzumab. In this study, we employed the human gastric carcinoma cell line NCI-N87 with high Her-2 expression to create trastuzumab-resistant NCI-N87/TR cells by stepwise exposure to increasing doses of trastuzumab. Western blotting and Real-time PCR were conducted to detect protein and gene levels. Compared with NCI-N87 cells, the expression of P-IGF-1R and P-AKT proteins was significantly increased in NCI-N87/TR cells (both P = 0.000), while PTEN gene and protein expression showed a significant decrease (both P = 0.000). In addition, mutations of the PTEN gene were detected at exons 5, 7, and 8. The sensitivity of NCI-N87/TR cells to trastuzumab was increased by transfection with the PTEN gene, or by incubation with a PI3K inhibitor (LY294002) or an IGF-IR inhibitor (AG1024), as well as siRNA targeting PI3K p110 or IGF-1R. Taken together, our findings showed that activation of the PI3K-AKT signaling pathway was one of the major mechanisms leading to resistance of NCI-N87/TR gastric cancer cells to trastuzumab, which was probably associated with PTEN gene down-regulation and mutation, as well as with over-activity of the IGF-1R signaling pathway. [ABSTRACT FROM AUTHOR]