pH dependent isotropic to nematic phase transitions in graphene oxide dispersions reveal droplet liquid crystalline phases

Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Royal Society of Chemistry for personal use, not for redistribution. The definitive version was published in Chemical Communications 50 (2014): 6668-6671, doi:10.1039/C4CC00970C.Size fractionation, amplified by the surface charge density of graphene oxide (GO) sheets, broadens the pH dependent isotropic (I) to nematic (N) phase transition in aqueous dispersions of graphene oxide (GO). In this biphasic region, a highly organized droplet nematic phase of uniform size (20 ± 2.8 μm diameter) with an isotropic interior is observed.Supports from the Australian Research Council (LP110100612 to MM), National Institute of Biomedical Imaging and Bioengineering (R01EB002045 to RO) and HFSP fellowship (to SM) are acknowledged.2015-05-0

The Feeling of Numbers: emotions in everyday engagements with data and their visualisation

This paper highlights the role that emotions play in engagements with data and their visualisation. To date, the relationship between data and emotions has rarely been noted, in part because data studies have not attended to everyday engagements with data. We draw on an empirical study to show a wide range of emotional engagements with diverse aspects of data and their visualisation, and so demonstrate the importance of emotions as vital components of making sense of data. We nuance the argument that regimes of datafication, in which numbers, metrics and statistics dominate, are characterised by a renewed faith in objectivity and rationality, arguing that in datafied times, it is not only numbers but also the feeling of numbers that is important. We build on the sociology of a) emotions and b) the everyday to do this, and in so doing, we contribute to the development of a sociology of data

Biochemical evidence for an alternate pathway in N-linked glycoprotein biosynthesis

Asparagine-linked glycosylation is a complex protein modification conserved among all three domains of life. Herein we report the in vitro analysis of N-linked glycosylation from the methanogenic archaeon Methanococcus voltae. Using a suite of synthetic and semisynthetic substrates, we show that AglK initiates N-linked glycosylation in M. voltae through the formation of α-linked dolichyl monophosphate N-acetylglucosamine, which contrasts with the polyprenyl diphosphate intermediates that feature in both eukaryotes and bacteria. Notably, AglK has high sequence homology to dolichyl phosphate β-glucosyltransferases, including Alg5 in eukaryotes, suggesting a common evolutionary origin. The combined action of the first two enzymes, AglK and AglC, afforded an α-linked dolichyl monophosphate glycan that serves as a competent substrate for the archaeal oligosaccharyl transferase AglB. These studies provide what is to our knowledge the first biochemical evidence revealing that, despite the apparent similarity of the overall pathways, there are actually two general strategies to achieve N-linked glycoproteins across the domains of life.National Institutes of Health (U.S.) (Grant GM039334

Synthesis, Structure, and Electric Conductivity of Higher Hydrides of Ytterbium at High Pressure

While most of the rare earth metals readily form trihydrides, due to increased stability of the filled 4f electronic shell for Yb(II), only YbH$_{2.67}$, formally corresponding to Yb$^{\rm II}$(Yb$^{\rm III}$H$_4$)$_2$ or Yb$_3$H$_8$, remains the highest hydride of ytterbium. Utilizing diamond anvil cell methodology and synchrotron powder x-ray diffraction we have attempted to push this limit further via hydrogenation of metallic Yb (at room temperature and heated in situ) and of Yb$_3$H$_8$. Compression of the latter has also been investigated in a neutral pressure transmitting medium, PTM. While the in situ heating of Yb facilitates the formation of YbH$_2$ plus x hydride, we have not observed the clear qualitative differences between the systems compressed in H$_2$ and He or Ne PTM. In all these cases a sequence of phase transitions from the unit cells of P-31m symmetry to the I4/m and I4/mmm systems occurred within ca. 13 to 18 GPa and around 27 GPa, respectively. At the same time, the molecular volume of the systems compressed in H$_2$ PTM is ca. 1.5% larger than of those compressed in inert gases, suggesting a small hydrogen uptake. Nevertheless, hydrogenation towards YbH$_3$ is incomplete, and polyhydrides do not form up to the highest pressure studied here of ca. 75 GPa. As pointed out by our electronic transport measurements under compression in NaCl PTM, the mixed-valence Yb$_3$H$_8$ retains its semiconducting character up to at least 50 GPa, although the very low remnant activation energy of conduction, smaller than 5 meV, suggests that the metallization under further compression should be achievable. Finally, we provide a theoretical description of a hypothetical stoichiometric YbH$_3$

Optical characteristics of a-Si: H layers deposited by PACVD at various temperatures

Amorphous a-Si:H layers fabricated by plasma assisted chemical vapour deposition are studied. The layers were grown on monocrystalline silicon at various temperatures, ranging from the room temperature to 400 °C. Structure and chemical composition (hydrogen content) of the layers were characterized by use of fourier transform infrared spectroscopy (FTIR). A main attention in the studies was focused on optical properties of the layers. The respective measurements were made by variable angle spectroscopic ellipsometry within 170–1900 nm spectral range, at room temperature and during post-annealing the sample up to 400 °C. The Kramers–Krönig optical model was matched to the ellipsometric angle spectra, Ψ(λ) and Δ(λ), and hence the layers’ thicknesses and optical indices were calculated. The band gap of the studied materials was calculated from the Tauc expression for the extinction index near the band edge. The results show that the layers deposited at 150 °C have similar properties. Their growth rate is higher than 0.1 nm/s and hydrogen content does not exceed 10 at.%. All they have relatively high refractive index within visible light range. The highest refractive index is for the layer deposited at 400 °C and reaches almost 4.0 at 460 nm. The band gap of all layers deposited at 150 °C and above exceeds 2 eV but is not higher than 2.4 eV. The band gap of the layers deposited below 150 °C is less than 2 eV. Post-annealing of the layers for 40 min at 400 °C does not change their optical indices but clearly reduces the depolarization

Large-Area Graphene-Based Nanofiltration Membranes by Shear Alignment of Discotic Nematic Liquid Crystals of Graphene Oxide

Graphene-based membranes demonstrating ultrafast water transport, precise molecular sieving of gas and solvated molecules shows great promise as novel separation platforms; however, scale-up of these membranes to large-areas remains an unresolved problem. Here we demonstrate that the discotic nematic phase of graphene oxide (GO) can be shear aligned to form highly ordered, continuous, thin films of multi-layered GO on a support membrane by an industrially adaptable method to produce large-area membranes (13 × 14 cm2) in \u3c 5 s. Pressure driven transport data demonstrate high retention (\u3e 90%) for charged and uncharged organic probe molecules with a hydrated radius above 5 Å as well as modest (30–40%) retention of monovalent and divalent salts. The highly ordered graphene sheets in the plane of the membrane make organized channels and enhance the permeability (71±5 l m−2 hr−1 bar−1 for 150±15 nm thick membranes)

Poor competitiveness of Bradyrhizobium in pigeon pea root colonisation in Indian soils

Background Pigeon pea, a legume crop native to India, is the primary source of protein for more than a billion people in developing countries. The plant can form symbioses with N2-fixing bacteria, however reports of poor crop nodulation in agricultural soils abound. We report here study of the microbiota associated with pigeon pea, with a special focus on the symbiont population in different soils and vegetative and non-vegetative plant growth. Results Location with respect to the plant roots was determined to be the main factor controlling the microbiota followed by developmental stage and soil type. Plant genotype plays only a minor role. Pigeon pea roots have a reduced microbial diversity compared to the surrounding soil and select for Proteobacteria and especially for Rhizobium spp. during vegetative growth. While Bradyrhizobium, a native symbiont of pigeon pea, can be found associating with roots, its presence is dependent on plant variety and soil conditions. A combination of metagenomic survey, strain isolation and co-inoculation with nodule forming Bradyrhizobium spp. and non-N2 fixing Rhizobium spp. demonstrated that the latter is a much more successful coloniser of pigeon pea roots. Conclusions Poor nodulation of pigeon pea in Indian soils may be caused by a poor Bradyrhizobium competitiveness against non-nodulating root colonisers such as Rhizobium. Hence, inoculant strain selection of symbionts for pigeon pea should not only be based on their nitrogen fixation potential but more importantly on their competitiveness in agricultural soils

Exacerbations and Real-World Outcomes After Single-Inhaler Triple Therapy of Budesonide/Glycopyrrolate/Formoterol Fumarate, Among Patients with COPD: Results from the EROS (US) Study [Corrigendum]

Strange C, Tkacz J, Schinkel J, et al. Int J Chron Obstruct Pulmon Dis. 2023;18:2245–2256. The authors have advised that there are errors in the 95% CI interval values on page 2248. Results, Baseline and Follow-Up Exacerbation Rates, sentence 3, the text “Relative rates of total exacerbations for prompt were 0.76, 95% CI: (0.72 – 0.79) and 0.66, 95% CI: (0.63 – 0.69) versus delayed and very delayed” should read “Relative rates of total exacerbations for prompt were 0.76, 95% CI: (0.69 – 0.83) and 0.66, 95% CI: (0.60 – 0.72) versus delayed and very delayed”. Results, Baseline and Follow-Up Exacerbation Rates, sentence 5, the text “Relative rates of severe exacerbations for prompt were 0.75 (95% CI: 0.67-0.90) and 0.38 (95% CI: 0.29-0.47) versus delayed and very delayed” should read “Relative rates of severe exacerbations for prompt were 0.75 (95% CI: 0.45-1.15) and 0.38 (95% CI: 0.22-0.55) versus delayed and very delayed”. The authors apologize for these errors and confirm that the overarching interpretation of the results and conclusions of the study remain consistent with the originally published article and no other text or figures are affected