Centre for Advanced Microscopy

Electron-pinned defect dipoles, in the form of highly stable triangle-diamond and/or triangle-linear dopant defect clusters with well defined relative positions for Ti reduction, are present in rutile In + Ta co-doped TiO₂ for the colossal permittivity and low loss.

Antigen-presenting cells survey their environment and present captured antigens bound to major histocompatibility complex (MHC) molecules. Formation of MHC-antigen complexes occurs in specialized compartments where multiple protein trafficking routes, still incompletely understood, converge. Autophagy is a route that enables the presentation of cytosolic antigen by MHC class II molecules. Some reports also implicate autophagy in the presentation of extracellular, endocytosed antigen by MHC class I molecules, a pathway termed "cross-presentation." The role of autophagy in cross-presentation is controversial. This may be due to studies using different types of antigen presenting cells for which the use of autophagy is not well defined. Here we report that active use of autophagy is evident only in DC subtypes specialized in cross-presentation. However, the contribution of autophagy to cross-presentation varied depending on the form of antigen: it was negligible in the case of cell-associated antigen or antigen delivered via receptor-mediated endocytosis, but more prominent when the antigen was a soluble protein. These findings highlight the differential use of autophagy and its machinery by primary cells equipped with specific immune function, and prompt careful reassessment of the participation of this endocytic pathway in antigen cross-presentation.

Semiconductor nanowires have proven a versatile platform for the realization of novel structures unachievable by traditional planar epitaxy techniques. Among these, the periodic arrangement of twin planes to form twinning superlattice structures has generated particular interest. Here we demonstrate twinning superlattice formation in GaAs nanowires and investigate the diameter dependence of both morphology and twin plane spacing. An approximately linear relationship is found between plane spacing and nanowire diameter, which contrasts with previous results reported for both InP and GaP. Through modeling, we relate this to both the higher twin plane surface energy of GaAs coupled with the lower supersaturation relevant to Au seeded GaAs nanowire growth. Understanding and modeling the mechanism of twinning superlattice formation in III-V nanowires not only provides fundamental insight into the growth process, but also opens the door to the possibility of tailoring twin spacing for various electronic and mechanical applications.

A deep investigation of amorphous V2O5-P2O5 powders for magnesium batteries communicates the vital properties to achieving the superior electrochemical performance at a 75 : 25 V2O5 : P2O5 molar ratio. The manipulation of the inter-layer spacing and amorphization of V2O5 can enhance Mg(2+) diffusion and afford a cathode with high-voltage reversibility.

While III-V binary nanowires are now well controlled and their growth mechanisms reasonably well understood, growing ternary nanowires, including controlling their morphology, composition and crystal structure remains a challenge. However, understanding and control of ternary alloys is of fundamental interest and critical to enable a new class of nanowire devices. Here, we report on the progress in understanding the complex growth behaviour of gold-seeded GaAs1-xSbx nanowires grown by metalorganic vapour phase epitaxy. The competition between As and Sb atoms for incorporation into the growing crystal leads to a tunability of the Sb content over a broad range (x varies from 0.09 to 0.6), solely by changing the AsH3 flow. In contrast, changing TMSb flow is more effective in affecting the morphology and crystal structure of the nanowires. Inclined faults are found in some of these nanowires and directly related to the kinking of the nanowires and controlled by TMSb flow. Combined with the observed sharp increase of wetting angle between the Au seed and nanowire, the formation of inclined faults are attributed to the Au seed being dislodged from the growth front to wet the sidewalls of the nanowires, and are related to the surfactant role of Sb. The insights provided by this study should benefit future device applications relying on taper- and twin-free ternary antimonide III-V nanowire alloys and their heterostructures.

The introduction of <graphic xmlns:xlink="http://www.w3.org/1999/xlink" id="ugt1" xlink:href="http://pubs.rsc.org/MH/2019/c9mh00516a/c9mh00516a-t1..gif"/> defect-pairs into centrosymmetric rutile TiO₂ produces a new form of collective nonlinear electrical polarization.

The metal-resistant -Proteobacterium Cupriavidus metallidurans drives gold (Au) biomineralisation 2 and the (trans)formation of Au nuggets largely via unknown biochemical processes, ultimately 3 leading to the reductive precipitation of mobile, toxic Au(I/III)-complexes. In this study proteomic 4 responses of C. metallidurans CH34 to mobile, toxic Au(III)-chloride are investigated. Cells were 5 grown in the presence of 10 and 50 M Au(III)-chloride, 50 M Cu(II)-chloride and without 6 additional metals. Differentially expressed proteins were detected by difference gel electrophoresis 7 and identified by liquid chromatography coupled mass spectrometry. Proteins that were more 8 abundant in the presence of Au(III)-chloride are involved in a range of important cellular functions, 9 e.g., metabolic activities, transcriptional regulation, efflux and metal transport. To identify Au-10 binding proteins, protein extracts were separated by native 2D gel electrophoresis and Au in protein 11 spots was detected by laser absorption inductively coupled plasma mass spectrometry. A chaperon 12 protein commonly understood to bind copper (Cu), CupC, was identified and shown to bind Au. 13 This indicates that it forms part of a multi-metal detoxification system and suggests that 14 similar/shared detoxification pathways for Au and Cu exist. Overall, this means that 15 C. metallidurans CH34 is able to mollify the toxic effects of cytoplasmic Au(III) by sequestering this 16 Au-species. This effect may in the future be used to develop CupC-based biosensing capabilities 17 for the in-field detection of Au in exploration samples. 18 Significance to Metallomics 19 The bacterium Cupriavidus metallidurans CH34 is known to survive on the surface of and 20 (trans)form natural gold grains. It reacts to the toxicity induced by mobile gold-complexes using a 21 range of proteomic responses. Specifically, C. metallidurans overexpresses the chaperone protein 22 CupC, which binds cytoplasmic gold, forms part of a multi-metal detoxification system to export 23

The evolution of epidermal scales was a major innovation in lepidosaurs, providing a barrier to dehydration and physical stress, while functioning as a sensitive interface for detecting mechanical stimuli in the environment. In snakes, mechanoreception involves tiny scale organs (sensilla) that are concentrated on the surface of the head. The fully marine sea snakes (Hydrophiinae) are closely related to terrestrial hydrophiine snakes but have substantially more protruding (dome-shaped) scale organs that often cover a larger portion of the scale surface. Various divergent selection pressures in the marine environment could account for this morphological variation relating to detection of mechanical stimuli from direct contact with stimuli and/or indirect contact via water motion (i.e. ‘hydrodynamic reception’), or co-option for alternate sensory or non-sensory functions. We addressed these hypotheses using immunohistochemistry, and light and electron microscopy, to describe the cells and nerve connections underlying scale organs in two sea snakes, Aipysurus laevis and Hydrophis stokesii . Our results show ultrastructural features in the cephalic scale organs of both marine species that closely resemble the mechanosensitive Meissner-like corpuscles that underlie terrestrial snake scale organs. We conclude that the scale organs of marine hydrophiines have retained a mechanosensory function, but future studies are needed to examine whether they are sensitive to hydrodynamic stimuli.

:H, with a radius of 5.5 nm. Complementary infrared spectroscopy measurements exhibit a damage cross-section comparable to the core dimensions. The morphology of the density variations results from freezing in the local viscous flow arising from the non-uniform temperature profile in the radial direction of the ion path. The concomitant drop in viscosity mediated by the thermal conductivity appears to be the main driving force rather than the presence of a density anomaly.

High-brightness, high-current electron guns for energy recovery linac light sources and high repetition rate X-ray free-electron lasers require an exit beam energy of ≥500 keV to reduce space-charge induced emittance growth in the drift space from the gun exit to the following superconducting accelerator entrance. At the Japan Atomic Energy Agency, we have developed a DC photoemission gun employing a segmented insulator to mitigate the field emission problem, which is a major obstacle for operation of DC guns at ≥500 kV. The first demonstration of generating a 500-keV electron beam with currents up to 1.8 mA is presented.

A defect-engineering strategy is reported to enhance the photovoltaic performance of BiNbO₄. Synergetic effects: enhanced light absorption, ferroelectric-like depolarization and interfacial polarization on BiNbO₄ homojunction lead to an increase in the photovoltaic effects.

In this study, the probiotic Lactobacillus casei was microencapsulated using the method of spray-drying combined with polyelectrolyte complexation of alginate, fructooligosaccharide and chitosan, and cross-linking with calcium chloride, followed by freeze-drying. Survival rate and physicochemical properties of the prepared microparticles were evaluated. In addition, viability of Lactobacillus casei in simulated gastric and intestinal juices was investigated. Positively charged microparticles with average size of 11.08±1.1 μm and high cell viability of 10.98±0.11 log cfu/g were prepared. The synbiotic microparticles were stable during exposure to simulated gastric and intestinal juices, while release of viable cells above the therapeutic value (8.31±0.14 log cfu/g) in the simulated colonic pH was observed.The presented method for microencapsulation of synbiotics shows potential for effective protection of viable probiotic cells during exposure to harsh environmental conditions.

A polycrystalline, Ca0.88Al0.91Si1.09N2.85O0.15, was synthesized by a solid state reaction in the ternary system Ca3N2, AlN, and Si3N4, which was accompanied by a two-step heat treatment, 1600°C for 2 h and then 1800°C for 2 h under the nitrogen pressure of 0.92MPa. The space group of the polycrystalline was confirmed as orthorhombic Cmc21 (36) by means of a convergent-beam electron diffraction (CBED). The lattice parameters were refined using the Rietveld method to be a = 980.005(8), b = 564.928(4), and c = 506.241(3) pm with the corresponding weighted profile residual, Rwp = 0.092. Ca0.88Al0.91Si1.09N2.85O0.15 was formed due to the creation of cation vacancies at Ca2+ site in CaAlSiN3, which has the isomorphic structure with LiSi2N3 and NaSi2N3, by partial replacement of N3- by O2-.

CO2 geological storage may be part of the solution to reduce carbon emissions to the atmosphere. An understanding of the geochemical processes occurring during CO2 storage is needed to reduce risk. Drill cores from a low salinity reservoir site proposed for CO2 storage, and the overlying and underlying formations were characterised for minerals by QEMSCAN, total metals and porosity. Elements including Li, Ba, Sr, K, Mg, V, Zn, REE, Fe, Pb, P, and S were relatively elevated in the Moolayember Formation underlying the reservoir. Synchrotron XFM showed the main host of Mn was siderite, with Rb in K-feldspar, Zn and Cu in sphalerite and chalcopyrite, and As in pyrite in coal pores associated with coal laminations. Drill cores are reacted at reservoir conditions with synthetic formation water and an impure CO2 stream composition of CO2-SOx-NOx-O2 expected to be injected at the site. Elements released were dependant on mineral content with quartz rich reservoir, lower Precipice Sandstone, core reactions resulted in dissolution of trace carbonates, alteration of sulphides and monazite, and variable elevated dissolved Pb, and U. Dissolved Co, Ni, Ca, Zn, Li, Rb, and U were released at relatively elevated concentrations from the mudstone. For carbonate cemented upper Precipice Sandstone or Moolayember Formation core strong dissolution of calcite and ankerite, with corrosion of siderite, Fe-rich chlorite, and sulphides or monazite were observed after reaction. Dissolved elements including Ca, Mg, Mn, Sr, and Ba increased in experiments from reaction of calcite, siderite and ankerite. Generally dissolved Fe, Pb, Cr, Cu, Co etc. increased from dissolution, and subsequently decreased in concentration with adsorption and precipitation. The fast mobilisation of elements including Fe and Pb are consistent with release of metals from carbonate dissolution and desorption. The presence of O2 and NOX in the gas stream results in Fe-(oxyhydr)oxide precipitation especially where Fe has been rapidly mobilised from dissolution of siderite and Fe-chlorite. This acts as a sink for Fe and provides new adsorption sites for sequestering a proportion of the trace metals. These processes are applicable to other CO2 storage sites and potential leakage indicators in overlying drinking water aquifers. The findings are also more broadly applicable to subsurface energy storage such as compressed air renewable energy storage, CO2 enhanced recovery, geothermal, natural gas or hydrogen storage.

BACKGROUND: Mucocutaneous depositions of various metals such as silver, lead, gold, arsenic, mercury, iron, and bismuth have been previously published. Heavy metal deposition typically occurs in the setting of either prolonged topical application to intact skin, topical application to eroded or ulcerated skin, as a result of either parenteral administration, or due to penetrating traumatic exposure. METHOD: We report a unique case of mucocutaneous pigmentation occurring in a snow skier after topical application of a zinc-containing sunblock. Formalin-fixed paraffin-embedded tissue was utilized for electron microscopy. RESULT: Backscatter electron imaging and energy dispersive spectroscopy revealed that the dominant metal present was zinc. CONCLUSIONS: Mucocutaneous deposition of metals is enhanced by damage to the surface epithelium. Metal-containing topical agents, although commonly used, may rarely result in a permanent pigmentary alteration. We believe similar cases of mucocutaneous deposition of zinc exist; however, as these may be currently misdiagnosed as amalgam tattoos, the true incidence of this disorder is presently undefined.

Jamborite was originally described with the formula (Ni2þ,Ni3þ,Fe)(OH)2(OH,S,H2O) from Ca’ de’ Ladri and&#13;\nMonteacuto Ragazza near Bologna, and Castelluccio di Moscheda near Modena, Italy. Re-examination of the mineral from&#13;\nthe type localities and Rio Vesale, Sestola, Val Panaro (Emilia-Romagna, Italy), led to the discovery of a crystal suitable for&#13;\nstudy by single-crystal and powder X-ray diffraction, SEM-EDS, and Raman spectroscopy. Jamborite crystallizes in the&#13;\nspace group R3m, with the unit-cell parameters a 3.068(4) A ̊ , c 23.298(11) A ̊ , and Z 1⁄4 3. The structure refinement (R1 1⁄4&#13;\n0.0818) showed that jamborite contains brucite-like sheets of edge-sharing octahedra (Ni2þ,M3þ)(O,OH)6 with a distinctive&#13;\ndouble layer of partially occupied H2O molecules between them. Raman data indicate that the sulfur is present as sulfate&#13;\nrather than sulfide. The new analytical data were recalculated on the basis of 1 (NiþCaþCoþFe) to give the formula&#13;\n[(Ni2þ&#13;\n0.902Ca2þ&#13;\n0.002)(Co3þ&#13;\n0.072Fe3þ&#13;\n0.024)]R1.000(OH)1.884Cl0.012(H2O)0.004(SO4)0.1000.900H2O. The sulfur occupancy was too&#13;\nlow to be located in the refinement, but the ’1:1 ratio of M3þ:S from the chemical analysis implies that SO4&#13;\n2– replaces OH–&#13;\nin the brucite sheet rather than sitting in the interlayer space. The splitting of the H2O layer allows avoidance of short&#13;\nSO4&#13;\n2–H2O distances. Thus, jamborite is not a member of the hydrotalcite supergroup. Jamborite is redefined as&#13;\nM2þ&#13;\n1–xM3þ&#13;\nx(OH)2–x(SO4)xnH2O, where M2þ is dominantly Ni, M3þ is dominantly Co, x 1/3 and probably 1/7 (x 1⁄40.10&#13;\nfor the neotype sample), and n , (1–x). The low M3þ/M2þ ratio relative to honessite and hydrohonessite and high Co content&#13;\nmay explain the rarity of jamborite as an early alteration product of millerite. The redefinition of jamborite and designation&#13;\nof the neotype specimen from Rio Vesale have been approved by the Commission on New Minerals, Nomenclature and&#13;\nClassification (CNMNC), voting proposal 14-E.

Intensive bulk photovoltaic effects are produced in narrow-bandgap centrosymmetric materials by a new strategy based on polar nano-regions.

Abstract We report the single-crystal average structure of cyanotrichite, Cu 4 Al 2 [SO 4 ](OH) 12 (H 2 O) 2 , from the Maid of Sunshine mine, Arizona, USA. Cyanotrichite crystallizes in space group C 2/ m , with the unit-cell parameters a = 12.625(3), b = 2.8950(6), c = 10.153(2) Å and β = 92.17(3)o. All non-hydrogen atoms were located and refined to R 1 = 0.0394 for all 584 observed reflections [ F o &gt; 4σ F o ] and 0.0424 for all 622 unique reflections. The cyanotrichite structure consists of a principal building unit of a three-wide [Cu 2 Al(OH) 6 ] ribbon of edge-sharing Cu and Al polyhedra || b, similar to that found for camerolaite. The ribbons lie in layers || (001) and between these layers, while SO 4 tetrahedra and H 2 O molecules form rods running || b. A hydrogen-bonding scheme is also proposed. A sample of cyanotrichite from the Cap Garonne mine, Le Pradet, France, showed a 4 b superstructure with the following unit cell: space group P 2/ m , a = 12.611(2) Å, b = 11.584(16) = 4 × 2.896(4) Å, c = 10.190(1) Å and β = 92.29(6)o. The supercell could not be refined in detail, but nevertheless imposes constraints on the local structure in that while the space-group symmetry prevents full order of SO 4 and H 2 O in the 4 b supercell, it requires that the sequence of species along any given rod is [-SO 4 -SO 4 -(H 2 O) 2 -(H 2 O) 2 -] rather than [-SO 4 -(H 2 O) 2 -SO 4 -(H 2 O) 2 -].

Gene transcription is an essential process in cell biology, and allows cells to interpret and respond to internal and external cues. Traditional bulk population methods (Northern blot, PCR, and RNAseq) that measure mRNA levels lack the ability to provide information on cell-to-cell variation in responses. Precise single cell and allelic visualization and quantification is possible via single molecule RNA fluorescence in situ hybridization (smFISH). RNA-FISH is performed by hybridizing target RNAs with labeled oligonucleotide probes. These can be imaged in medium/high throughput modalities, and, through image analysis pipelines, provide quantitative data on both mature and nascent RNAs, all at the single cell level. The fixation, permeabilization, hybridization and imaging steps have been optimized in the lab over many years using the model system described herein, which results in successful and robust single cell analysis of smFISH labeling. The main goal with sample preparation and processing is to produce high quality images characterized by a high signal-to-noise ratio to reduce false positives and provide data that are more accurate. Here, we present a protocol describing the pipeline from sample preparation to data analysis in conjunction with suggestions and optimization steps to tailor to specific samples.

Abstract YAP/TAZ signaling is crucial for sprouting angiogenesis and vascular homeostasis through the regulation of endothelial remodeling. Thus far the underlying molecular mechanisms that explain how YAP/TAZ control the vasculature remain unclear. We here identify Deleted-in-Liver-Cancer-1 (DLC1) as a direct transcriptional target of the activated YAP/TAZ-TEAD complex in the endothelium. Substrate stiffening and VEGF stimuli promote the endothelial expression of DLC1. DLC1 expression is dependent on the presence of YAP and TAZ, and constitutive activation of YAP efficiently promotes expression of DLC1. We show that DLC1 limits F-actin fiber formation, integrin-based focal adhesion lifetime and integrin-mediated traction forces. Depletion of endothelial DLC1 strongly perturbs cell polarization in directed collective migration and inhibits the formation of angiogenic sprouts. Importantly, the inability of YAP-depleted endothelial cells to collectively migrate and form angiogenic sprouts can be rescued by ectopic expression of DLC1. Together, these findings reveal that DLC1 fills a hitherto missing link between YAP/TAZ signaling and endothelial dynamics during angiogenesis.