It is now clear that several of the filamentous bacteria in activated sludge wastewater treatment plants globally, are members of the phylum
Chloroflexi.
They appear to be more commonly found in ...treatment plants designed to remove nitrogen (N) and phosphorus (P), most of which operate at long sludge ages and expose the biomass to anaerobic conditions. The
Chloroflexi
seem to play an important beneficial role in providing the filamentous scaffolding around which flocs are formed, to feed on the debris from lysed bacterial cells, to ferment carbohydrates and to degrade other complex polymeric organic compounds to low molecular weight substrates to support their growth and that of other bacterial populations. A few commonly extend beyond the floc surface, while others can align in bundles, which may facilitate interfloc bridging and hence generate a bulking sludge. Although several recent papers have examined the phylogeny and
in situ
physiology of
Chloroflexi
in activated sludge plants in Denmark, this review takes a wider look at what we now know about these filaments, especially their global distribution in activated sludge plants, and what their functional roles there might be. It also attempts to outline why such information might provide us with clues as to how their population levels may be manipulated, and the main research questions that need addressing to achieve these outcomes.
Selective laser melting (SLM) is an additive manufacturing technique able to produce complex functional parts via successively melting layers of metal powder. This process grants the freedom to ...design highly complex scaffold components to allow bone ingrowth and aid mechanical anchorage.
This paper investigates the compression fatigue behaviour of three different unit cells (octahedron, cellular gyroid and sheet gyroid) of SLM nitinol scaffolds. It was found that triply periodic minimal surfaces display superior static mechanical properties in comparison to conventional octahedron beam lattice structures at identical volume fractions. Fatigue resistance was also found to be highly geometry dependent due to the effects of AM processing techniques on the surface topography and notch sensitivity. Geometries minimising nodal points and the staircase effect displayed the greatest fatigue resistance when normalized to yield strength. Furthermore oxygen analysis showed a large oxygen uptake during SLM processing which must be altered to meet ASTM medical grade standards and may significantly reduce fatigue life. These achieved fatigue properties indicate that NiTi scaffolds produced via SLM can provide sufficient mechanical support over an implants lifetime within stress range values experienced in real life.
The dominant filamentous bacteria associated with bulking incidents in Japanese activated sludge plants with nutrient removal were identified and their quantitative correlations with sludge ...settleability were assessed, with the aim of controlling bulking incidents by specifically suppressing bacterial growth. Fluorescence in situ hybridization (FISH) analyses using existing oligonucleotide FISH probes indicated that the presence of Eikelboom type 1851 filamentous bacteria belonging to the phylum
Chloroflexi
is correlated with biomass settleability in the municipal wastewater treatment plants examined. Real-time quantitative PCR (qPCR) assays developed in this study also showed a linear correlation between type 1851 filament members and sludge settleability, with the exception of some winter samples. The real-time qPCR assays and 16S ribosomal RNA gene amplicon sequencing to reveal the microbial community of activated sludge showed that the abundance of type 1851 at 200 mL g
−1
of sludge volume index was estimated to be about 1.9% of the total microbial cells. The abundance of type 1851 served as a bulking indicator in plants where type 1851 was dominant.
Enhanced bone tissue regeneration and improved osseointegration are among the most important goals in design of multifunctional orthopedic biomaterials. In this study, we used additive manufacturing ...(selective laser melting) to develop multifunctional porous nitinol that combines superelasticity with a rationally designed microarchitecture and biofunctionalized surface. The rational design based on triply periodic minimal surfaces aimed to properly adjust the pore size, increase the surface area (thereby amplifying the effects of surface biofunctionalization), and resemble the curvature characteristics of trabecular bone. The surface of additively manufactured (AM) porous nitinol was biofunctionalized using polydopamine-immobilized rhBMP2 for better control of the release kinetics. The actual morphological properties of porous nitinol measured by microcomputed tomography (e.g., open/close porosity, and surface area) closely matched the design values. The superelasticity originated from the austenite phase formed in the nitinol porous structure at room temperature. Polydopamine and rhBMP2 signature peaks were confirmed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy tests. The release of rhBMP2 continued until 28 days. The early time and long-term release profiles were found to be adjustable independent of each other. In vitro cell culture showed improved cell attachment, cell proliferation, cell morphology (spreading, spindle-like shape), and cell coverage as well as elevated levels of ALP activity and increased calcium content for biofunctionalized surfaces as compared to as-manufactured specimens. The demonstrated functionalities of porous nitinol could be used as a basis for deployable orthopedic implants with rationally designed microarchitectures that maximize bone tissue regeneration performance by release of biomolecules with adjustable and well-controlled release profiles.
IL-1 receptor (IL-1R)/Toll-like receptor (TLR) family and TNF receptor (TNFR) superfamily members are critical for regulating multiple aspects of dendritic cell (DC) biology. Several signaling ...pathways associated with each family utilize the adapter molecule, TRAF6, but its role in DCs is unclear. By examining TRAF6-deficient mice and bone marrow (BM) chimeras reconstituted with TRAF6-deficient fetal liver cells, we show that proper DC maturation requires TRAF6. In response to either microbial components or CD40L, TRAF6-deficient DCs fail to upregulate surface expression of MHCII and B7.2, or produce inflammatory cytokines. Moreover, LPS-treated TRAF6-deficient DCs do not exhibit an enhanced capacity to stimulate naive T cells. Interestingly, a major population of splenic DCs, the CD4
+CD8α
− subset, is nearly absent in both TRAF6-deficient mice and BM chimeras. Together these results indicate that TRAF6 regulates the critical processes required for maturation, activation, and development of DCs, the primary cellular bridge between innate and adaptive immunity.
Neospora caninum is a coccidian intracellular protozoan capable of infecting a wide range of mammals, although severe disease is mostly reported in dogs and cattle. Innate defences triggered by ...monocytes/macrophages are key in the pathogenesis of neosporosis, as these cells are first-line defenders against intracellular infections. The aim of this study was to characterize infection and innate responses in macrophages infected with N. caninum using a well-known cell model to study macrophage functions (human monocyte THP-1 cells). Intracellular invasion of live tachyzoites occurred as fast as 4 h (confirmed with immunofluorescence microscopy using N. caninum-specific antibodies). Macrophages infected by N. caninum had increased expression of pro-inflammatory cytokines (TNFα, IL-1β, IL-8, IFNγ). Interestingly, N. caninum induced expression of host-defence peptides (cathelicidins), a mechanism of defence never reported for N. caninum infection in macrophages. The expression of cytokines and cathelicidins in macrophages invaded by N. caninum was mediated by mitogen-activated protein kinase (MEK 1/2). Secretion of such innate factors from N. caninum-infected macrophages reduced parasite internalization and promoted the secretion of pro-inflammatory cytokines in naïve macrophages. We concluded that rapid invasion of macrophages by N. caninum triggered protective innate defence mechanisms against intracellular pathogens.
We report the first hybrid tandem solar cell with solution processable active layers using colloidal PbS quantum dots (QDs) as the front subcell in combination with a polymer-fullerene rear subcell. ...Al/WO3 is introduced as an interlayer, yielding an open circuit voltage (VOC) equal to about 92% of the sum of the VOC of the subcells. The device exhibits a power conversion efficiency of 1.8%. Optical simulations of various tandem configurations show that combining PbS QDs with small-bandgap polymers is a promising strategy to obtain tandem solar cells with a very broad absorption range and a high short circuit current.
Lead sulfide quantum dots (PbS QDs) show great potential for efficient, low cost photovoltaic applications. Currently, device efficiencies are limited by the high density of trap states caused by ...lattice imperfections on the QD surface. Introducing a thin shell of a wide bandgap semiconductor to the QD surface is a promising method to passivate these trap states. Here we demonstrate solar cells made from PbS–CdS core–shell QDs, yielding a 147 mV increase in V OC compared to core only PbS QDs. We explore the physical reason for this enhancement and demonstrate that it is indeed caused by improved passivation of the PbS surface by the CdS shell, leading to a lower electron trap density.
The article reports qualitative research findings which explored the meanings of kinship and genetic knowledge of fifteen pre-1990 semen donors in the UK. This is presented in the context of public ...and academic debates about the regulation of access to genetic information, genetic information as intellectual property and kinship knowledge, and the multiple ownership of genetic information. Semen donors in the UK traditionally were expected to take no interest in what became of their donations and those who did were considered to be unsuitable as donors. However, the present research reveals that men who donated in the past hold varied attitudes, including curiosity about how donor offspring have fared and what they look like. Whilst some donors would welcome direct contact with donor offspring, there are practical and emotional obstacles to satisfying their curiosity. Donors' views reflect the varied understandings in the UK about the implications of genetic relatedness and the time and energy required to maintain and sustain relationships.
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