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The broad electrification scenario of recent photovoltaics roadmaps predicts that by 2050 we will need more than 60 TW of photovoltaics installed and be producing up to 4.5 TW of additional capacity each year if we are to rapidly reduce emissions to ‘net-zero’ and limit global warming to

Machine learning provides a probabilistic framework for metabolic pathway inference from genomic sequence information at different levels of complexity and completion. However, several challenges including pathway features engineering, multiple mapping of enzymatic reactions and emergent or distributed metabolism within populations or communities of cells can limit prediction performance. In this paper, we present triUMPF,triple non-negative matrix factorization (NMF) with community detection formetabolicpathway inference, that combines three stages of NMF to capture myriad relationships between enzymes and pathways within a graph network. This is followed by community detection to extract higher order structure based on the clustering of vertices which share similar statistical properties. We evaluated triUMPF performance using experimental datasets manifesting diverse multi-label properties, including Tier 1 genomes from the BioCyc collection of organismal Pathway/Genome Databases and low complexity microbial communities. Resulting performance metrics equaled or exceeded other prediction methods on organismal genomes with improved precision on multi-organismal datasets.Availability and implementationThe software package, and installation instructions are published ongithub.com/triUMPF

Laser doping is a typical industrial method to introduce a local highly doped region in silicon solar cells to form a selective emitter. Such a process inherently introduces defects that can be a concern to the overall performance of the solar cell. Here, we investigate the effectiveness of laser-induced defect (LasID) passivation on lifetime test structures through different annealing processes, including high-temperature belt-furnace firing, low-temperature belt-furnace annealing, and an advanced hydrogenation process (AHP) for n+ laser-doped selective emitters. We demonstrate clear advantages of post treatment using a rapid 10 s AHP at 300 °C when the lifetime structures are prefired. For the examined laser speeds of 0.5–6 m/s (sheet resistances of 4--70 Ω/□), AHP is the most effective treatment method. For example, for a typical laser doping speed of 4 m/s, starting from the same effective carrier lifetime of 36.9±2.4 μs after laser-doping step for all the passivation treatments, the AHP not only surpasses the conventional approaches by showing the highest recovery of the effective carrier lifetime (∼79% compared with ∼63% and ∼41% for the firing and belt-furnace annealing treatments, respectively) and dark saturation current density reduction in the regions affected by LasIDs but also simultaneously suppresses light-induced degradation (maximum of 4% effective lifetime degradation with respect to the passivated state, as opposed to 14% and 16% degradation for the firing and belt-furnace annealing treatments, respectively) common in Cz grown boron-doped p-type monocrystalline silicon.

Mucin-type O-glycosylation (O-glycosylation) is a common post-translational modification that confers distinct biophysical properties to proteins and plays crucial roles in intercellular signaling. Yet, despite the importance of O-glycans, relatively few tools exist for their analysis and modification. In particular, there is a need for enzymes that can cleave the wide range of O-glycan structures found on protein surfaces, to facilitate glycan profiling and editing. Through functional metagenomic screening of the human gut microbiome, we discovered endo-O-glycan hydrolases from CAZy family GH101 that are capable of slowly cleaving the intact sialyl T-antigen trisaccharide (a ubiquitous O-glycan structure in humans) in addition to their primary activity against the T-antigen disaccharide. We then further explored this sequence space through phylogenetic profiling and analysis of representative enzymes, revealing large differences in the levels of this promiscuous activity between enzymes within the family. Through structural and sequence analysis, we identified active site residues that modulate specificity. Through subsequent rational protein engineering, we improved the activity of an enzyme identified by phylogenetic profiling sufficiently that substantial removal of the intact sialyl T-antigen from proteins could be readily achieved. Our best sialyl T-antigen hydrolase mutant, SpGH101 Q868G, is further shown to function on a number of proteins, tissues, and cells. Access to this enzyme opens up improved methodologies for unraveling the glycan code.

Here we report the results of multiple analytical techniques on sub-mm particulate material derived from Unit 1 of the Fukushima Daiichi Nuclear Power Plant to provide a better understanding of the events that occurred and the environmental legacy. Through combined x-ray fluorescence and absorption contrast micro-focused x-ray tomography, entrapped U particulate are observed to exist around the exterior circumference of the highly porous Si-based particle. Further synchrotron radiation analysis of a number of these entrapped particles shows them to exist as UO2—identical to reactor fuel, with confirmation of their nuclear origin shown via mass spectrometry analysis. While unlikely to represent an environmental or health hazard, such assertions would likely change should break-up of the Si-containing bulk particle occur. However, more important to the long-term decommissioning of the reactors at the FDNPP (and environmental clean-upon), is the knowledge that core integrity of reactor Unit 1 was compromised with nuclear material existing outside of the reactors primary containment., The larger particulates from reactor Unit 1 of the Fukushima Daiichi Nuclear Power Plant have received sparse attention compared to the Unit 2 particulate. Here the authors perform the higher-resolution and 3-dimentional analysis of several high-density micron-scale fragments, from within a larger Unit 1-derived representative ejecta particle.

Microbes transform aqueous mercury (Hg) into methylmercury (MeHg), a potent neurotoxin that accumulates in terrestrial and marine food webs, with potential impacts on human health. This process requires the gene pair hgcAB, which encodes for proteins that actuate Hg methylation, and has been well described for anoxic environments. However, recent studies report potential MeHg formation in suboxic seawater, although the microorganisms involved remain poorly understood. In this study, we conducted large-scale multi-omic analyses to search for putative microbial Hg methylators along defined redox gradients in Saanich Inlet, British Columbia, a model natural ecosystem with previously measured Hg and MeHg concentration profiles. Analysis of gene expression profiles along the redoxcline identified several putative Hg methylating microbial groups, including Calditrichaeota, SAR324 and Marinimicrobia, with the last the most active based on hgc transcription levels. Marinimicrobia hgc genes were identified from multiple publicly available marine metagenomes, consistent with a potential key role in marine Hg methylation. Computational homology modelling predicts that Marinimicrobia HgcAB proteins contain the highly conserved amino acid sites and folding structures required for functional Hg methylation. Furthermore, a number of terminal oxidases from aerobic respiratory chains were associated with several putative novel Hg methylators. Our findings thus reveal potential novel marine Hg-methylating microorganisms with a greater oxygen tolerance and broader habitat range than previously recognized.

To significantly impact climate change, the annual photovoltaic (PV) module production rate must dramatically increase from ∼135 gigawatts (GW) in 2020 to ∼3 terawatts (TW) around 2030. A key knowledge gap is the sustainable manufacturing capacity of existing and future commercial PV cell technologies imposed by scarce metals, and a suitable pathway towards sustainable manufacturing at the multi-TW scale. Assuming an upper material consumption limit as 20% of 2019 global supply, we show that the present industrial implementations of passivated emitter and rear cell (PERC), tunnel oxide passivated contact (TOPCon), and silicon heterojunction (SHJ) cells have sustainable manufacturing capacities of 377 GW (silver-limited), 227 GW (silver-limited) GW and 37 GW (indium-limited), respectively. We propose material consumption targets of 2 mg W−1, 0.38 mg W−1, and 1.8 mg W−1 for silver, indium, and bismuth, respectively, indicating significant material consumption reductions are required to meet the target production rate for sustainable multi-TW scale manufacturing in about ten years from now. The industry needs urgent innovation on screen printing technologies for PERC, TOPCon, and SHJ solar cells to reduce silver consumption beyond expectation in the Industrial Technology Roadmap for PV (ITPRV), or the widespread adoption of existing and proven copper plating technologies. Indium cannot be used in any significant manufacturing capacity for PV production, even for futuristic 30%-efficient tandem devices. The current implementation of low-temperature interconnection schemes using bismuth-based solders will be limited to 330 GW of production. With half the silver-limited sustainable manufacturing capacity as PERC, the limited efficiency gains of SHJ and TOPCon cell technologies do not justify a transition away from industrial PERC, or the introduction of indium- and bismuth limitations for SHJ solar cells. On the other hand, futuristic two-terminal tandems with efficiency potentials over 30% have a unique opportunity to reduce material consumption through substantially reduced series resistance losses.

Age‐related macular degeneration (AMD) is a multifactorial disease, which is characterized by loss of central vision, affecting one in three people by the age of 75. The Y402H polymorphism in the complement factor H (CFH) gene significantly increases the risk of AMD. We show that Y402H‐AMD‐patient‐specific retinal pigment epithelium (RPE) cells are characterized by a significant reduction in the number of melanosomes, an increased number of swollen lysosome‐like‐vesicles with fragile membranes, Cathepsin D leakage into drusen‐like deposits and reduced lysosomal function. The turnover of C3 is increased significantly in high‐risk RPE cells, resulting in higher internalization and deposition of the terminal complement complex C5b‐9 at the lysosomes. Inhibition of C3 processing via the compstatin analogue Cp40 reverses the disease phenotypes by relieving the lysosomes of their overburden and restoring their function. These findings suggest that modulation of the complement system represents a useful therapeutic approach for AMD patients associated with complement dysregulation., Schematic presentation of autophagy‐lysosomal pathway dysfunction in Y402H‐AMD RPE cells and the impact of Cp40 in restoring the lysosomal function.

Antibody–drug conjugates (ADCs) are a class of targeted therapeutics consisting of a monoclonal antibody coupled to a cytotoxic payload. Various bioconjugation methods for producing site-specific A...

avaa käsikirjoitus, kun julkaistu Light-induced degradation (LID) can occur in crystalline silicon (Si) due to increased recombination in the bulk or at the surfaces. As an example, copper (Cu) is a contaminant that reportedly causes LID in the bulk of Si under illumination. In this article, we show that Cu contamination can also increase recombination at the surface under illumination using surface saturation current density (J 0) analysis. More specifically, in the presence of Cu we observed that J 0 increased from 14 fA/cm 2 to 330 fA/cm 2 in SiO 2 passivated Float Zone (FZ) Si, and from 11 fA/cm 2 to 200 fA/cm 2 in corresponding Czochralski (Cz) Si after illumination under an LED lamp (0.6 Suns, 80 °C). In reference samples without Cu contamination, the J 0 was unaffected. These results demonstrate that a significant increase in surface recombination is possible without the presence of hydrogen. Furthermore, hydrogen was not seen to affect the Cu-induced surface degradation as similar experiments made with hydrogenated silicon nitride (SiN x:H) did not show further increase in J 0. However, the timescale of the observed degradation was relatively fast (hours) indicating that Cu-induced surface degradation is a separate phenomenon from the earlier reported surface-related degradation.

We carried out mesocosm experiments using either the anecic earthworm Lumbricus terrestris or the endogeic earthworm Allolobophora chlorotica and loam, silt loam and sandy loam soils to investigate the differing impact of these earthworm of different ecotypes on aggregate formation (percentage water stable aggregates, %WSA) and soil water holding capacity (WHC), two soil properties that underpin many of the ecosystem services provided by soils. Earthworms significantly increased %WSA (by 16–56% and 19–63% relative to earthworm-free controls for L. terrestris and A. chlorotica, respectively). For L. terrestris, this increase was significantly greater in the upper 6.5 cm of the soil where their casts were more obviously present. Allobophora chlorotica treatments significantly increased WHC by 7–16%. L. terrestris only caused a significant increase in WHC (of 11%) in the upper 6.5 cm of the sandy loam soil. Linear regression indicated a consistent relationship between increases in %WSA and WHC for both earthworm species. However, for a given %WSA, WHC was higher for A. chlorotica than L. terrestris likely due to the known differences in their burrow structure. Overall, earthworms increased soil %WSA and WHC but the significant species/ecotype differences need to be considered in discussions of the beneficial impacts of earthworms to soil properties.

In this article, we investigate the extent of lifetime degradation attributed to light- and elevated-temperature-induced degradation (LeTID) in p- type multicrystalline silicon wafers passivated with different configurations of hydrogenated silicon nitride (SiNx:H) and aluminum oxide (AlOx:H). We also demonstrate a significant difference between AlOx:H layers grown by atomic layer deposition (ALD) and plasma-enhanced chemical vapor deposition (PECVD) with respect to the extent of LeTID. When ALD AlOx:H is placed underneath a PECVD SiNx:H layer, as used in a passivated emitter and rear solar cell, a lower extent of LeTID is observed compared with the case when a single PECVD SiNx:H layer is used. On the other hand, the LeTID extent is significantly increased when an ALD AlOx:H is grown on top of the PECVD SiNx:H film. Remarkably, when a PECVD AlOx:H is used underneath the PECVD SiNx:H film, an increase in the LeTID extent is observed. Building on our current understanding of LeTID, we explain these results with the role of ALD AlOx:H in impeding the hydrogen diffusion from the dielectric stack into the c-Si bulk, while PECVD AlOx:H seems to act as an additional hydrogen source. These observations support the hypothesis that hydrogen is playing a key role in LeTID and provide solar cell manufacturers with a new method to reduce LeTID in their solar cells.

Photovoltaic (PV) cells manufactured using p-type Czochralski wafers can degrade significantly in the field due to boron–oxygen (BO) defects. Commercial hydrogenation processes can now passivate such defects; however, this passivation can be destabilized under certain conditions. Module operating temperatures are rarely considered in defect studies, and yet are critical to understanding the degradation and passivation destabilization that may occur in the field. Here we show that the module operating temperatures are highly dependent on location and mounting, and the impact this has on BO defects in the field. The System Advisor Model is fed with typical meteorological year data from four locations around the world (Hamburg, Sydney, Tucson, and Wuhan) to predict module operating temperatures. We investigate three PV system mounting types: building integrated (BIPV), rack-mounted rooftop, and rack mounted on flat ground for a centralized system. BO defect reactions are then simulated, using a three-state model based on experimental values published in the literature and the predicted module operating temperatures. The simulation shows that the BIPV module in Tucson reaches 94 °C and stays above 50 °C for over 1600 h per year. These conditions could destabilize over one-third of passivated BO defects, resulting in a 0.4% absolute efficiency loss for the modules in this work. This absolute efficiency loss could be double for higher efficiency solar cell structures, and modules. On the other hand, passivation of BO defects can occur in the field if hydrogen is present and the module is under the right environmental conditions. It is therefore important to consider the specific installation location and type (or predicted operating temperatures) to determine the best way to treat BO defects. Modules that experience such extreme sustained conditions should be manufactured to ensure incorporation of hydrogen to enable passivation of BO defects in the field, thereby enabling a “self-repairing module.”

Within the British nuclear inventory, waste is classified into three main categories, including Intermediate Level Waste (ILW). ILW mainly consists of fuel casing metallic swarf, where parts of uranium metal are also expected to have been agglomerated. ILW treatment route includes the material storage in stainless steel drums and subsequent grout encapsulation. The solidified matrix is believed to maintain the radioactive waste fully confined and immobile. Recent inspections revealed mechanical distortion around the steel liner in a proportion of the inspected drums. The distortion has been ascribed to the corrosion of the encapsulated metallic parts. The generated corrosion products occupy greater volume than the parent metal, resulting in an internal volume expansion which imposes stress/strain on the encapsulants. This study attempts to correlate the level of internal corrosion with the magnitude of package degradation in ILW drum–simulant systems by favouring the use of powerful synchrotron X-rays.

Marine sinking particles transport carbon from the surface and bury it in deep sea sediments where it can be sequestered on geologic time scales. The combination of the surface ocean food web that produces these particles and the particle-associated microbial community that degrades these particles, creates a complex set of variables that control organic matter cycling. We use targeted metabolomics to characterize a suite of small biomolecules, or metabolites, in sinking particles and compare their metabolite composition to that of the suspended particles in the euphotic zone from which they are likely derived. These samples were collected in the South Atlantic subtropical gyre, as well as in the equatorial Atlantic region and the Amazon River plume. The composition of targeted metabolites in the sinking particles was relatively similar throughout the transect, despite the distinct oceanic regions in which they were generated. Metabolites possibly derived from the degradation of nucleic acids and lipids, such as xanthine and glycine betaine, were an increased mole fraction of the targeted metabolites in the sinking particles relative to surface suspended particles, while algal-derived metabolites like the osmolyte dimethylsulfoniopropionate were a smaller fraction of the observed metabolites on the sinking particles. These compositional changes are shaped both by the removal of metabolites associated with detritus delivered from the surface ocean and by production of metabolites by the sinking particle-associated microbial communities. Further, they provide a basis for examining the types and quantities of metabolites that may be delivered to the deep sea by sinking particles.

Access to efficient enzymes that can convert A and B type red blood cells to 'universal' donor O would greatly increase the supply of blood for transfusions. Here we report the functional metagenomic screening of the human gut microbiome for enzymes that can remove the cognate A and B type sugar antigens. Among the genes encoded in our library of 19,500 expressed fosmids bearing gut bacterial DNA, we identify an enzyme pair from the obligate anaerobe Flavonifractor plautii that work in concert to efficiently convert the A antigen to the H antigen of O type blood, via a galactosamine intermediate. The X-ray structure of the N-acetylgalactosamine deacetylase reveals the active site and mechanism of the founding member of an esterase family. The galactosaminidase expands activities within the CAZy family GH36. Their ability to completely convert A to O of the same rhesus type at very low enzyme concentrations in whole blood will simplify their incorporation into blood transfusion practice, broadening blood supply.

The effects of doping level, illumination intensity and temperature on the regeneration kinetics and dynamics of BO defects in compensated n-Si have been investigated. The regeneration rate, corrected with interstitial oxygen concentration and average injection level, is almost constant in n-type samples with different doping levels under the same regeneration condition. It is proportional to the average injection level during regeneration when the doping level and temperature are fixed. In comparison with previous studies using n-type silicon, the regeneration completeness is significantly improved, especially in samples with net doping levels higher than 1 × 1016 cm−3, due to the higher regeneration temperature and more stable surface passivation films. The remaining incompleteness is mostly dominated by the occupation of the annealed state (as opposed to the activated state). For rapid and complete regeneration, the optimal condition is applying high illumination intensities at around 200°C.

In this work, we investigate the use of advanced hydrogenation and low-temperature diffusion processes (a 3 h 700 °C process after emitter diffusion) for the electrical neutralization of laser-induced defects for laser doped and grooved solar cells. Despite the laser doping and grooving (LDG) process being performed before silicon nitride passivation to avoid thermal expansion mismatch between the silicon and the silicon nitride layer, some crystallographic defects are still formed during the process. The application of a low-temperature diffusion process increases implied open circuit voltages by 14 mV, potentially due to phosphorus diffusion of dislocated regions induced during laser processing. Laser hydrogenation is shown to be capable of passivating the majority of the remaining laser-induced defects. Over 1% absolute improvement in efficiency is achieved on cells with a full area aluminum back surface field. Preliminary results with minimal optimization demonstrate efficiencies of over 19% with a full area Al back contact cell. The potential to achieve much higher voltages when used with a passivated rear is also demonstrated.

The reaction of unirradiated-U with liquid water was investigated under initial vacuum-contained conditions. Ten samples were examined at varying temperatures and reaction times. Post-corrosion examination of the surfaces was conducted using FIB, SIMS and XRD. Measurements of the reacting water pH and degassing of the samples was conducted after the reaction was stopped. From the analyses, it was concluded that bulk-UH 3 formation occurred on the majority of the samples. It is suggested that UH 3 formation was facilitated by a critical ‘threshold’ headspace pressure ∼0.5bar over which pressure deficiency is observed in the free headspace.

Recently, an n -type multi-crystalline silicon (mc-Si) was observed to be susceptible to degradation under illumination at elevated temperatures with similarities to carrier-induced degradation in p -type mc-Si. In this study, we demonstrate degradation and regeneration of the effective lifetime of non-diffused n -type mc-Si wafers using illuminated and dark annealing conditions at moderate temperatures. Under illuminated annealing conditions, the degradation and regeneration rates of the n -type mc-Si are observed to be slower than those of the p -type mc-Si; however, the opposite trend was observed under dark annealing conditions. The carrier-induced degradation kinetics of the n -type wafers can be described by degradation and regeneration that occur simultaneously, and the activation energies have been identified to be 1.23 ± 0.16 eV for the degradation process and 1.34 ± 0.08 eV for the regeneration. Surprisingly, no degradation was observed in n -type mc-Si under dark annealing above 160 °C. Rather, at these conditions, a two-stage improvement in the lifetime was observed. Although degradation occurs after a subsequent laser treatment, the stable lifetime at the end of the degradation is still slightly higher than its initial value.

Polyethylene terephthalate (PET) is an important synthetic polymer accumulating in nature 2 and recent studies have identified microorganisms capable of degrading PET. While the majority of 3 known PET hydrolases originate from the Actinobacteria and Proteobacteria, here we describe the 4 first functional PET-active enzymes from the Bacteroidetes phylum. Using a PETase-specific 5 Hidden-Markov-Model (HMM)-based search algorithm we identified two promiscuous and cold6 active esterases derived from Aequorivita sp. (PET27) and Chryseobacterium jeonii (PET30) acting 7 on PET foil and powder. Notably, one of the enzymes (PET30) was able to hydrolyze PET at 8 temperatures between 4° - 30°C with a similar turnover rate compared to the well-known Ideonella 9 sakaiensis enzyme (IsPETase). 10 PET27 and PET30 homologues were detected in metagenomes encompassing a wide range 11 of different global climate zones. Additional transcript abundance mapping of marine samples imply 12 that these promiscuous enzymes and source organisms may play a role in the long-term 13 degradation of microplastic particles and fibers.

Cleavage of C3 to C3a and C3b plays a central role in the generation of complement-mediated defences. Although the thioester-mediated surface deposition of C3b has been well-studied, fluid phase dimers of C3 fragments remain largely unexplored. Here we show C3 cleavage results in the spontaneous formation of C3b dimers and present the first X-ray crystal structure of a disulphide-linked human C3d dimer. Binding studies reveal these dimers are capable of crosslinking complement receptor 2 and preliminary cell-based analyses suggest they could modulate B cell activation to influence tolerogenic pathways. Altogether, insights into the physiologically-relevant functions of C3d(g) dimers gained from our findings will pave the way to enhancing our understanding surrounding the importance of complement in the fluid phase and could inform the design of novel therapies for immune system disorders in the future.

Polyethylene terephthalate (PET) is an important synthetic polymer accumulating in nature and recent studies have identified microorganisms capable of degrading PET. While the majority of known PET hydrolases originate from the Actinobacteria and Proteobacteria, here we describe the first functional PET-active enzymes from the Bacteroidetes phylum. Using a PETase-specific Hidden-Markov-Model (HMM)-based search algorithm we identified two promiscuous and cold-active esterases derived from Aequorivita sp. (PET27) and Chryseobacterium jeonii (PET30) acting on PET foil and powder. Notably, one of the enzymes (PET30) was able to hydrolyze PET at temperatures between 4° - 30°C with a similar turnover rate compared to the well-known Ideonella sakaiensis enzyme (IsPETase). PET27 and PET30 homologues were detected in metagenomes encompassing a wide range of different global climate zones. Additional transcript abundance mapping of marine samples imply that these enzymes and source organisms play a significant role in the long-term degradation of microplastic particles and fibers.

Recent advances in cell-free protein synthesis have enabled the folding and assembly of full-length antibodies at high titers with extracts from prokaryotic cells. Coupled with the facile engineering of the E. coli translation machinery, E. coli based in vitro protein synthesis reactions have emerged as a leading source of IgG molecules with non-natural amino acids incorporated at specific locations for producing homogeneous antibody drug conjugates. While this has been demonstrated with extract produced in batch fermentation mode, continuous extract fermentation would facilitate supplying material for large-scale manufacturing of protein therapeutics. To accomplish this, the IgG-folding chaperones DsbC and FkpA, and orthogonal tRNA for non-natural amino acid production were integrated onto the chromosome with high strength constitutive promoters. This enabled co-expression of all three factors at a consistently high level in the extract strain for the duration of a five-day continuous fermentation. Cell-free protein synthesis reactions with extract produced from cells grown continuously yielded titers of IgG containing non-natural amino acids above those from extract produced in batch fermentations. In addition, the quality of the synthesized IgGs and the potency of ADC produced with continuously fermented extract were indistinguishable from those produced with batch extract. These experiments demonstrate that continuous fermentation of E. coli to produce extract for cell-free protein synthesis is feasible and helps unlock the potential for cell-free protein synthesis as a platform for biopharmaceutical production.

Efforts are underway to develop countermeasures to prevent the environmental spread of COVID-19 pandemic caused by SARS-CoV-2. Physical decontamination methods like Ultraviolet radiation has shown to be promising. Here, we describe a novel device emitting ultraviolet C radiation (UVC), called NuvaWave, to rapidly and efficiently inactivate SARS-CoV-2. SARS-CoV-2 was dried on a chambered glass slides and introduced in a NuvaWave robotic testing unit. The robot simulated waving NuvaWave over the virus at a pre-determined UVC radiation dose of 1, 2, 4 and 8 seconds. Post-UVC exposure, virus was recovered and titered by plaque assay in Vero E6 cells. We observed that relative control (no UVC exposure), exposure of the virus to UVC for one or two seconds resulted in a >2.9 and 3.8 log10 reduction in viral titers, respectively. Exposure of the virus to UVC for four or eight seconds resulted in a reduction of greater than 4.7-log10 reduction in viral titers. The NuvaWave device inactivates SARS-CoV-2 on surfaces to below the limit of detection within one to four seconds of UVC irradiation. This device can be deployed to rapidly disinfect surfaces from SARS-CoV-2, and to assist in mitigating its spread in a variety of settings.

Adsorbent materials based on titania and phosphate are ideal for treatment of solutions contaminated with heavy metals under acidic conditions, due to their inherent chemical stability and low pKa. Herein, phosphate functionalised titania has been investigated for the first time for removal of heavy metals (Cr, Fe, Cu, Eu, U) under conditions relevant to acid mine drainage (pH 2-5 sulfuric acid). Successful functionalisation was found to depend on the phase of titania used, with anatase preferred according to computational results from density functional theory. The effect of phosphate ligand structure was explored, revealing that the phosphate ethyl ester maximised heavy metal removal. The presence and concentration of counterions (sulfate, nitrate, ammonium) also impacted the speciation and binding of heavy metal cations, demonstrating the importance of adsorbent testing under realistic conditions. Increasing the porosity of the titania framework enhanced heavy metal removal, while maintaining selectivity for the toxic heavy metals over non-toxic cations Na and K. As such, phosphate functionalised titania shows great promise for heavy metal remediation in acidic sulfate environments.

Marine picocyanobacteria of the genus Prochlorococcus are the most abundant photosynthetic organisms in the modern ocean, where they exert a profound influence on elemental cycling and energy flow. The use of transmembrane chlorophyll complexes instead of phycobilisomes as light-harvesting antennae is considered a defining attribute of Prochlorococcus Its ecology and evolution are understood in terms of light, temperature, and nutrients. Here, we report single-cell genomic information on previously uncharacterized phylogenetic lineages of this genus from nutrient-rich anoxic waters of the eastern tropical North and South Pacific Ocean. The most basal lineages exhibit optical and genotypic properties of phycobilisome-containing cyanobacteria, indicating that the characteristic light-harvesting antenna of the group is not an ancestral attribute. Additionally, we found that all the indigenous lineages analyzed encode genes for pigment biosynthesis under oxygen-limited conditions, a trait shared with other freshwater and coastal marine cyanobacteria. Our findings thus suggest that Prochlorococcus diverged from other cyanobacteria under low-oxygen conditions before transitioning from phycobilisomes to transmembrane chlorophyll complexes and may have contributed to the oxidation of the ancient ocean.

Metabolites, or the small organic molecules that are synthesized by cells during metabolism, comprise a complex and dynamic pool of carbon in the ocean. They are an essential form of information, linking genotype to phenotype at the individual, population and community levels of biological organization. Characterizing metabolite distributions inside microbial cells and dissolved in seawater is essential to understanding the controls on their production and fate, as well as their roles in shaping marine microbial food webs. Here, we apply a targeted metabolomics method to quantify particulate and dissolved distributions of a suite of biologically relevant metabolites including vitamins, amino acids, nucleic acids, osmolytes, and intermediates in biosynthetic pathways along a latitudinal transect in the western Atlantic Ocean. We find that, in the euphotic zone, most particulate or intracellular metabolites positively co-vary with the most abundant microbial taxa. In contrast, dissolved metabolites exhibited greater variability with differences in distribution between ocean regions. Although fewer particulate metabolites were detected below the euphotic zone, molecules identified in the deep ocean may be linked to preservation of organic matter or adaptive physiological strategies of deep-sea microbes. Based on the identified metabolite distributions, we propose relationships between certain metabolites and microbial populations, and find that dissolved metabolite distributions are not directly related to their particulate abundances.

Several arenaviruses cause hemorrhagic fevers in humans with high case fatality rates. A vaccine named Candid#1 is available only against Junin virus (JUNV) in Argentina. Specific N-linked glycans on the arenavirus surface glycoprotein (GP) mask important epitopes and help the virus evade antibody responses. However the role of GPC glycans in arenavirus pathogenicity is largely unclear. In a lethal animal model of hemorrhagic fever-causing Machupo virus (MACV) infection, we found that a chimeric MACV with the ectodomain of GPC from Candid#1 vaccine was partially attenuated. Interestingly, mutations resulting in acquisition of N-linked glycans at GPC N83 and N166 frequently occurred in late stages of the infection. These glycosylation sites are conserved in the GPC of wild-type MACV, indicating that this is a phenotypic reversion for the chimeric MACV to gain those glycans crucial for infection in vivo. Further studies indicated that the GPC mutant viruses with additional glycans became more resistant to neutralizing antibodies and more virulent in animals. On the other hand, disruption of these glycosylation sites on wild-type MACV GPC rendered the virus substantially attenuated in vivo and also more susceptible to antibody neutralization, while loss of these glycans did not affect virus growth in cultured cells. We also found that MACV lacking specific GPC glycans elicited higher levels of neutralizing antibodies against wild-type MACV. Our findings revealed the critical role of specific glycans on GPC in arenavirus pathogenicity and have important implications for rational design of vaccines against this group of hemorrhagic fever-causing viruses., Author summary Several arenaviruses cause severe hemorrhagic fevers in humans. The only vaccine against arenavirus infections is Candid#1, a live attenuated vaccine against Argentine hemorrhagic fever. So far, we have successfully attenuated additional one of the arenaviruses, Machupo virus, the causative agent of Bolivian hemorrhagic fever. Unraveling this attenuation mechanism might help the development of live-attenuated vaccines for other arenaviruses. In this study, we revealed that the specific glycans of the viral glycoproteins play an important role in pathogenicity in vivo. The glycans facilitate the virus to evade neutralizing antibodies. This study would contribute to the development of arenavirus vaccine candidates.

Recently, there have been reports of increased series resistance as a consequence of thermal processes applied after the co-firing of screen-printed silicon solar cells. A previous observation of this effect on very heavily diffused emitters concluded that the increased series resistance is the result of a thickening of the glass layer surrounding silver crystallites at the Ag-Si interface. Here, large increases in the front silver contact resistance after particular thermal anneals are reported that have been used to mitigate carrier-induced degradation (CID) in multi-crystalline solar cells that cannot be fully explained by a thickening of the glass layer. Remarkably, under certain conditions the contact resistance immediately after annealing is found to be unstable − decreasing when a forward current is applied to the solar cell, and gradually increasing again once the forward current is removed. It is speculated that the movement of charged particles, most likely hydrogen, could be the cause of this instability.

Monitoring population dynamics in co-culture is necessary in engineering microbial consortia involved in distributed metabolic processes or biosensing applications. However, it remains difficult to measure strain-specific growth dynamics high-throughput formats. This is especially vexing in plate-based functional screens leveraging whole-cell biosensors to detect specific metabolic signals. Here we develop an experimental high-throughput co-culture system to measure and model the relationship between fluorescence and cell abundance, combining chassis-independent recombinase-assisted genome engineering (CRAGE) and whole-cell biosensing with a PemrR-green fluorescent protein (GFP) monoaromatic reporter used in plate-based functional screening. CRAGE was used to construct E. coli EPI300 strains constitutively expressing red fluorescent protein (RFP) and the relationship between RFP expression and optical density (OD600) was determined throughout the EPI300 growth cycle. A linear equation describing the increase of normalized RFP fluorescence during deceleration phase was derived and used to predict biosensor strain dynamics in co-culture. Measured and predicted values were compared using flow cytometric detection methods. Induction of the biosensor lead to increased GFP fluorescence normalized to biosensor cell abundance, as expected, but a significant decrease in relative abundance of the biosensor strain in co-culture and a decrease in bulk GFP fluorescence. Taken together, these results highlight sensitivity of population dynamics to variations in metabolic activity in co-culture and the potential effect of these dynamics on the performance of functional screens in plate-based formats. The engineered strains and model used to evaluate these dynamics provide a framework for optimizing growth of synthetic co-cultures used in screening, testing and pathway engineering applications

Junin virus (JUNV) is a New World arenavirus that is the causative agent of Argentine hemorrhagic fever (AHF). Candid#1 (Can) is a live-attenuated vaccine strain of JUNV that since its introduction has resulted in a marked decrease in AHF incidence within the endemic regions of the Pampas in Argentina. Originally, the viral determinants and mechanisms of Can attenuation were not well understood. Recent work has identified the glycoprotein as the major attenuating factor for Can. The establishment of attenuating strategies based on any of the other viral proteins, however, has not been pursued. Here, we document the role of Can Z resulting in incompatibilities with wild type JUNV that results in decreased growth in vitro. In addition, this incompatibility results in attenuation of the virus in the guinea pig model. Further, we identify a single mutation (V64G) in the Z protein that is able to confer this demonstrated attenuation. By establishing and characterizing a novel attenuation strategy for New World mammarenaviruses, we hope to aid future vaccine development for related emerging pathogens including Machupo virus (MACV), Guanarito virus (GTOV), and Sabia virus (SABV)., Author summary The continual development of safe, effective vaccines against emerging diseases is one of the greatest challenges facing the scientific community. The New World group of mammarenaviruses contains multiple human pathogens, each capable of causing severe hemorrhagic disease. Among these, only Junin virus has a distributed vaccine. By utilizing this vaccine, we are able to determine vaccine development strategies for related New World viruses that represent an emerging threat. Here we demonstrate that manipulation of the viral Z protein is able to produce an incompatibility that ultimately attenuates the virus. This provides yet another tool for future vaccine development to further global public health.

Microbial sulfur metabolism contributes to biogeochemical cycling on global scales. Sulfur metabolizing microbes are infected by phages that can encode auxiliary metabolic genes (AMGs) to alter sulfur metabolism within host cells but remain poorly characterized. Here we identified 191 phages derived from twelve environments that encoded 227 AMGs for oxidation of sulfur and thiosulfate (dsrA, dsrC/tusE, soxC, soxD and soxYZ). Evidence for retention of AMGs during niche-differentiation of diverse phage populations provided evidence that auxiliary metabolism imparts measurable fitness benefits to phages with ramifications for ecosystem biogeochemistry. Gene abundance and expression profiles of AMGs suggested significant contributions by phages to sulfur and thiosulfate oxidation in freshwater lakes and oceans, and a sensitive response to changing sulfur concentrations in hydrothermal environments. Overall, our study provides fundamental insights on the distribution, diversity, and ecology of phage auxiliary metabolism associated with sulfur and reinforces the necessity of incorporating viral contributions into biogeochemical configurations., Some bacteriophage encode auxiliary metabolic genes (AMGs) that impact host metabolism and biogeochemical cycling during infection. Here the authors identify hundreds of AMGs in environmental phage encoding sulfur oxidation genes and use their global distribution to infer phage-mediated biogeochemical impacts.

s: Background: Aseptic loosening of total joint replacements (TJRs) continues to be the main cause of implant failures. The socioeconomic impact of surgical revisions is hugely significant; in the United Kingdom alone, it is estimated that £137 m is spent annually on revision arthroplasties. Enhancing the longevity of titanium implants will help reduce the incidence and overall cost of failed devices. Methods: In realising the development of a superior titanium technology, we exploited the natural affinity of titanium for phosphonic acids and developed a facile means of coating the metal with (3S)1-fluoro-3-hydroxy-4-(oleoyloxy)butyl-1-phosphonate (FHBP), a phosphatase-resistant analogue of lysophosphatidic acid (LPA). Importantly LPA and selected LPA analogues like FHBP synergistically cooperate with calcitriol to promote human osteoblast formation and maturation. Results: Herein, we provide evidence that simply immersing titanium in aqueous solutions of FHBP afforded a surface that was superior to unmodified metal at enhancing osteoblast maturation. Importantly, FHBP-functionalised titanium remained stable to 2 years of ambient storage, resisted ∼35 kGy of gamma irradiation and survived implantation into a bone substitute (Sawbone™) and irrigation. Conclusion: The facile step we have taken to modify titanium and the robustness of the final surface finish are appealing properties that are likely to attract the attention of implant manufacturers in the future. The translational potential of this article: We have generated a functionalised titanium (Ti) surface by simply immersing Ti in aqueous solutions of a bioactive lipid. As a facile procedure it will have greater appeal to implant manufacturers compared to onerous and costly developmental processes.

Conjugated proteins and enzymes are often formed using N-hydroxysuccinimide (NHS) chemistry, which reacts with free primary amines resulting in a loss of charge and a reduction in isoelectric point (pI). Measurement of the extent of reaction of these conjugates is critical for biopharmaceutical developers. Due to this change in protein charge state, denaturing capillary isoelectric focussing (cIEF) offers a potentially straightforward and convenient approach for extent-of-reaction quantification. Here, we demonstrate the potential of this technique with poly(ethylene glycol) (PEG) conjugates of Erwinia chrysanthemil-asparaginase (ErA). Development of an appropriate sample preparation technique is critical to achieving reproducible cIEF electropherograms, particularly for denaturation-resistant proteins such as ErA, and an emphasis was placed on this during development of the PEG-ErA cIEF method. cIEF electropherograms demonstrating a distribution of PEGylation states in a bell-shaped curve were obtained, and assignment of PEGylation states to these peaks was critical to routine use of the method. The method is sensitive enough to resolve non-lysine adducts of PEG (such as those conjugated to histidine residues) and was shown to give reproducible results over a 2 year period. Biopharmaceutical developers should consider cIEF for extent of reaction monitoring and measurement for conjugates of free amine groups.

Microbes transform aqueous mercury (Hg) into methylmercury (MeHg), a potent neurotoxin in terrestrial and marine food webs. This process requires the gene pair hgcAB, which encodes for proteins that actuate Hg methylation, and has been well described for anoxic environments. However, recent studies report potential MeHg formation in suboxic seawater, although the microorganisms involved remain poorly understood. In this study, we conducted large-scale multi-omic analyses to search for putative microbial Hg methylators along defined redox gradients in Saanich Inlet (SI), British Columbia, a model natural ecosystem with previously measured Hg and MeHg concentration profiles. Analysis of gene expression profiles along the redoxcline identified several putative Hg methylating microbial groups, including Calditrichaeota, SAR324 and Marinimicrobia, with the last by far the most active based on hgc transcription levels. Marinimicrobia hgc genes were identified from multiple publicly available marine metagenomes, consistent with a potential key role in marine Hg methylation. Computational homology modelling predicted that Marinimicrobia HgcAB proteins contain the highly conserved structures required for functional Hg methylation. Furthermore, a number of terminal oxidases from aerobic respiratory chains were associated with several SI putative novel Hg methylators. Our findings thus reveal potential novel marine Hg-methylating microorganisms with a greater oxygen tolerance and broader habitat range than previously recognised.

The construction of large, phylogenetically diverse libraries of synthetic genes from a sequence-based family allows rapid evaluation of the substrate specificity encoded within the gene products a...

Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei, GRIFFIN, is a new high-efficiency γ -ray spectrometer designed for use in decay spectroscopy experiments with low-energy radioactive ion beams provided by TRIUMF’s Isotope Separator and Accelerator (ISAC-I) facility. GRIFFIN is composed of sixteen Compton-suppressed large-volume clover-type high-purity germanium (HPGe) γ -ray detectors combined with a suite of ancillary detection systems and coupled to a custom digital data acquisition system. The infrastructure and detectors of the spectrometer as well as the performance characteristics and the analysis techniques applied to the experimental data are described.

This paper presents techniques to tailor and optimize the field-effect passivation of silicon surfaces using the deposition and field-assisted migration of potassium ions. While field-effect passivation of this nature has previously been demonstrated using laboratory scale techniques, in this paper, it is shown how it can be realized using fast and scalable ion deposition and migration methods. Together, the deposition and migration processes are seen to produce excellent improvements to the surface passivation of oxidized 1-Ω·cm n-type float-zone silicon. Effective lifetimes as high as 2.1 ms are observed, in the best case yielding a surface recombination velocity as low as 3.3 cm/s with a corresponding surface dark saturation current density of 8.4 fA/cm2.

Light- and elevated-temperature-induced degradation (LeTID) in p-type multicrystalline silicon has a severe impact on the effective minority carrier lifetime of silicon and remains a crucial challenge for solar cell manufacturers. The precise cause of the degradation is yet to be confirmed; however, several approaches have been presented to reduce the extent of degradation. This paper presents insights on the impact of thermal budgets and cooling rates during post-firing illuminated anneals and their role in changing the lifetime and mitigating LeTID for thermal processes between 350 and 500 °C. We demonstrate that the thermal budget of these processes plays a crucial role in LeTID suppression and that the cooling rate only plays a role during short treatment durations (≤1 min). For the parameter space studied, we show that annealing for an appropriate time and temperature can both enhance the minority carrier lifetime and completely suppress the LeTID, with the injection-dependent Shockley–Read–Hall lifetime analysis indicating that the recombination activity of the LeTID defects in the bulk has been eliminated. Finally, this paper demonstrates a process that results in a stable lifetime after 800 h of conventional light-soaking at 75 °C.

Cleavage of C3 to C3a and C3b plays a central role in the generation of complement-mediated defences. Although the thioester-mediated surface deposition of C3b has been well-studied, fluid-phase dimers of C3 fragments remain largely unexplored. Here we present the first X-ray crystal structures of disulphide-linked human C3d dimers and show they undergo structurally-stabilising N-terminal domain swapping when in complex with the Staphylococcus aureus immunomodulator Sbi. Through binding studies and flow cytometric analyses we uncover the physiologically-relevant roles of these dimers in crosslinking complement receptor 2 and modulating B cell activation to potentially promote anergy. This potential induction of cellular tolerance by C3d dimers could contribute to Sbi-mediated S. aureus immune evasion as well as limit autoreactive immune responses under physiological conditions. Thus, insights gained from our findings could inform the design of novel therapies for autoimmune disorders and enhance our understanding surrounding the importance of complement in the fluid phase.

Motivation Metabolic pathway reconstruction from genomic sequence information is a key step in predicting regulatory and functional potential of cells at the individual, population and community levels of organization. Although the most common methods for metabolic pathway reconstruction are gene-centric e.g. mapping annotated proteins onto known pathways using a reference database, pathway-centric methods based on heuristics or machine learning to infer pathway presence provide a powerful engine for hypothesis generation in biological systems. Such methods rely on rule sets or rich feature information that may not be known or readily accessible. Results Here, we present pathway2vec, a software package consisting of six representational learning modules used to automatically generate features for pathway inference. Specifically, we build a three-layered network composed of compounds, enzymes and pathways, where nodes within a layer manifest inter-interactions and nodes between layers manifest betweenness interactions. This layered architecture captures relevant relationships used to learn a neural embedding-based low-dimensional space of metabolic features. We benchmark pathway2vec performance based on node-clustering, embedding visualization and pathway prediction using MetaCyc as a trusted source. In the pathway prediction task, results indicate that it is possible to leverage embeddings to improve prediction outcomes. Availability and implementation The software package and installation instructions are published on http://github.com/pathway2vec. Supplementary information Supplementary data are available at Bioinformatics online.

Molybdenum ditelluride (MoTe2) is a transition metal dichalcogenide (TMD) which has two phases stable under ambient conditions, a semiconducting (2H) and semimetallic (1T') phase. Despite a host of interesting properties and potential applications, MoTe2 is one of the less-studied TMDs, perhaps due its relatively low abundance in nature or challenges associated with its synthesis, such as the toxicity of most precursors. In this report, we describe the fabrication of thin films of phase-pure IT' MoTe2 using predeposited molybdenum and electrodeposited tellurium layers, at the relatively low temperature of 450 C. This method allows control over film geometry and over the tellurium concentration during the conversion. The MoTe2 films are characterized by Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, atomic force microscopy, and electron microscopies. When applied as a catalyst for the hydrogen evolution reaction, the films display promising initial results. The MoTe2 films have a Tafel slope of below 70 mV dec(-1) and compare favorably with other MoTe2 catalysts reported in the literature, especially considering the inherently scalable fabrication method. The variation in electrocatalytic behavior with thickness and morphology of the films is also investigated.