Microelectrode Array With Transparent ALD TiN Electrodes

Low noise platinum black or sputtered titanium nitride (TiN) microelectrodes are typically used for recording electrical activity of neuronal or cardiac cell cultures. Opaque electrodes and tracks, however, hinder the visibility of the cells when imaged with inverted microscope, which is the standard method of imaging cells plated on microelectrode array (MEA). Even though transparent indium tin oxide (ITO) electrodes exist, they cannot compete in impedance and noise performance with above-mentioned opaque counterparts. In this work, we propose atomic layer deposition (ALD) as the method to deposit TiN electrodes and tracks which are thin enough (25–65 nm) to be transparent (transmission ∼18–45%), but still benefit from the columnar structure of TiN, which is the key element to decrease noise and impedance of the electrodes. For ALD TiN electrodes (diameter 30 μm) impedances from 510 to 590 kΩ were measured at 1 kHz, which is less than the impedance of bare ITO electrodes. Human induced pluripotent stem cell (hiPSC)-derived cortical neurons were cultured on the ALD TiN MEAs for 14 days without observing any biocompatibility issues, and spontaneous electrical activity of the neurons was recorded successfully. The results show that transparent ALD TiN film is a suitable electrode material for producing functional MEAs

Fine mapping of the linkage group 2 drought tolerance QTL in pearl millet [Pennisetum glaucum (L.) R. Br.]

Pearl millet is an important cereal crop capable of growing in semi-arid, arid and marginal regions of the world. Drought is a major abiotic constraint affecting pearl millet production globally. Previously identified and validated major linkage group 2 (LG2) drought tolerance (DT) QTL contributing to hybrid grain and stover yield potential to terminal drought stress is being fine mapped. The fine mapping population was generated by crossing two near-isogenic lines (NILs) differing for the LG2 DT QTL. A modified double digest restriction site associated DNA (ddRAD) technique using SphI and MluCI enzyme combination was employed. A total of 290 out of 6,067 F2 mapping population of the cross (H77/833-2-P10 × ICMR 01029-P10), and parents were genotyped on Illumina HiSeq2500. Out of 52,028 SNPs that were identified from a total of 888.85 million reads at a read depth of 10 in the mapping population, a total of 6,821 SNPs were used for mapping. The genotypic data of these SNPs were used in combination with that of seven SSRs that had known linkage relationship with LG2 DT QTL interval. Linkage map was constructed using QTL IciMapping 4.1 software at a LOD threshold of 3.0. A total of 189 SNPs anchored to seven SSRs were mapped to the LG2 DT QTL. The length of linkage group (LG) was 639.72 cM (Haldane units) with an average inter-marker distance of 6.73 cM. In order to refine the fine mapping process, ddRAD technique is being further employed for genotyping rest of the fine mapping population

Characterisation of Innate Fungal Recognition in the Lung

The innate recognition of fungi by leukocytes is mediated by pattern recognition receptors (PRR), such as Dectin-1, and is thought to occur at the cell surface triggering intracellular signalling cascades which lead to the induction of protective host responses. In the lung, this recognition is aided by surfactant which also serves to maintain the balance between inflammation and pulmonary function, although the underlying mechanisms are unknown. Here we have explored pulmonary innate recognition of a variety of fungal particles, including zymosan, Candida albicans and Aspergillus fumigatus, and demonstrate that opsonisation with surfactant components can limit inflammation by reducing host-cell fungal interactions. However, we found that this opsonisation does not contribute directly to innate fungal recognition and that this process is mediated through non-opsonic PRRs, including Dectin-1. Moreover, we found that pulmonary inflammatory responses to resting Aspergillus conidia were initiated by these PRRs in acidified phagolysosomes, following the uptake of fungal particles by leukocytes. Our data therefore provides crucial new insights into the mechanisms by which surfactant can maintain pulmonary function in the face of microbial challenge, and defines the phagolysosome as a novel intracellular compartment involved in the innate sensing of extracellular pathogens in the lung

A tomato strigolactone-impaired mutant displays aberrant shoot morphology and plant interactions

Strigolactones are considered a new group of plant hormones. Their role as modulators of plant growth and signalling molecules for plant interactions first became evident in Arabidopsis, pea, and rice mutants that were flawed in strigolactone production, release, or perception. The first evidence in tomato (Solanum lycopersicon) of strigolactone deficiency is presented here. Sl-ORT1, previously identified as resistant to the parasitic plant Orobanche, had lower levels of arbuscular mycorrhizal fungus (Glomus intraradices) colonization, possibly as a result of its reduced ability to induce mycorrhizal hyphal branching. Biochemical analysis of mutant root extracts suggested that it produces only minute amounts of two of the tomato strigolactones: solanacol and didehydro-orobanchol. Accordingly, the transcription level of a key enzyme (CCD7) putatively involved in strigolactone synthesis in tomato was reduced in Sl-ORT1 compared with the wild type (WT). Sl-ORT1 shoots exhibited increased lateral shoot branching, whereas exogenous application of the synthetic strigolactone GR24 to the mutant restored the WT phenotype by reducing the number of lateral branches. Reduced lateral shoot branching was also evident in grafted plants which included a WT interstock, which was grafted between the mutant rootstock and the scion. In roots of these grafted plants, the CCD7 transcription level was not significantly induced, nor was mycorrhizal sensitivity restored. Hence, WT-interstock grafting, which restores mutant shoot morphology to WT, does not restore mutant root properties to WT. Characterization of the first tomato strigolactone-deficient mutant supports the putative general role of strigolactones as messengers of suppression of lateral shoot branching in a diversity of plant species

Proceedings of Abstracts, School of Physics, Engineering and Computer Science Research Conference 2022

© 2022 The Author(s). This is an open-access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. For further details please see https://creativecommons.org/licenses/by/4.0/. Plenary by Prof. Timothy Foat, ‘Indoor dispersion at Dstl and its recent application to COVID-19 transmission’ is © Crown copyright (2022), Dstl. This material is licensed under the terms of the Open Government Licence except where otherwise stated. To view this licence, visit http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: [email protected] present proceedings record the abstracts submitted and accepted for presentation at SPECS 2022, the second edition of the School of Physics, Engineering and Computer Science Research Conference that took place online, the 12th April 2022

Inductively coupled passive resonance sensor for monitoring biodegradable polymers in vitro

Capacitive sensors can be used to monitor changes in materials by monitoring complex permittivity. Inductively coupled passive resonance sensors provide means to make short range wireless permittivity measurements if the sensors are embedded in the tested material. In this study, inductively coupled sensors were embedded in biodegradable polymers, which are important materials in regenerative medicine. However, it is challenging to observe their decay especially in vivo. After preparing the samples by compression moulding, the encapsulated sensors and a reference series were immersed in buffer solution. The signals from the passive resonance sensors were measured for eight weeks. In addition, mechanical and chemical testing was periodically carried out to monitor the state of the reference series. The wirelessly measured signals are compared with water absorption, flexural modulus, glass transition temperature and viscosity.publishedVersionPeer reviewe

Coupling of Rotational Motion with Shape Fluctuations of Core-Shell Microgels Having Tunable Softness

Bolisetty S, Hoffmann M, Lekkala S, Hellweg T, Ballauff M, Harnau L. Coupling of Rotational Motion with Shape Fluctuations of Core-Shell Microgels Having Tunable Softness. Macromolecules. 2009;42(4):1264-1269.The influence of shape fluctuations on deformable thermosensitive microgels in aqueous solution is investigated by dynamic light scattering (DLS) and depolarized dynamic light scattering (DDLS). The systems under study consist of a solid core of polystyrene and a thermosensitive shell of cross-linked poly(N-isopropylacrylamide) (PNIPA) without and with embedded palladium nanoparticles. PNIPA is soluble in water but has a lower critical solution temperature at (LCST). Below the LCST the PNIPA shell is swollen. Here we find that besides translational and rotational diffusion, the particles exhibit additional dynamics resulting from shape fluctuations. This leads to a pronounced apparent increase of the rotational diffusion coefficient. Above the transition temperature the shell collapses and provides a rather tight envelope of the core. In this state the dynamics of the shell is frozen, and the core-shell particles behave like hard spheres. A simple physical model is presented to capture and explain the essentials of the coupling of rotational motion and shape fluctuations

Bioresorbable Conductive Wire with Minimal Metal Content

The emergence of transient electronics has created the need for bioresorbable conductive wires for signal and energy transfer. We present a fully bioresorbable wire design where the conductivity is provided by only a few micrometers thick electron-beam evaporated magnesium layer on the surface of a polymer fiber. The structure is electrically insulated with an extrusion coated polymer sheath, which simultaneously serves as a water barrier for the dissolvable magnesium conductor. The resistance of the wires was approximately 1 Ω cm–1 and their functional lifetime in buffer solution was more than 1 week. These properties could be modified by using different conductor materials and film thicknesses. Furthermore, the flexibility of the wires enabled the fabrication of planar radio frequency (RF) coils, which were wirelessly measured. Such coils have the potential to be used as wireless sensors. The wire design provides a basis for bioresorbable wires in applications where only a minimal amount of metal is desired, for example, to avoid toxicity

Day-to-day repeatability of the results of the finger-toe-plot analysis

Non-invasive arterial pulse wave (PW) measurement provides valuable information on the vascular health. The aim of the study is to characterize the between-visit or day-to-day repeatability of combined finger and toe photoplethysmographic (PPG) signal analysis method called finger-toe plot (FT-plot) and compare it with the repeatability of other methods proposed for vascular characterization. Ten 22–36-year-old subjects were examined on 3 different days in order to find out the day-to-day repeatability of the results. The repeatability of the extracted parameters was analyzed by means of intra-class correlation coefficients (ICC) and free-marginal multirater κ agreement. ICCs varied widely from below 0.2 to almost 0.9, but κ coefficients higher than 0.7 were achieved for most of the results. Based on the presented results, the FT-plot analysis has at least sufficient day-to-day repeatability. However, further studies with real patients and different stages of cardiovascular diseases are required for confirming the findings.acceptedVersionPeer reviewe

Itemset trees for targeted association querying

Association mining techniques search for groups of frequently co-occurring items in a market-basket type of data and turn these groups into business-oriented rules. Previous research has focused predominantly on how to obtain exhaustive lists of such associations. However, users often prefer a quick response to targeted queries. For instance, they may want to learn about the buying habits of customers that frequently purchase cereals and fruits. To expedite the processing of such queries, we propose an approach that converts the market-basket database into an itemset tree. Experiments indicate that the targeted queries are answered in a time that is roughly linear in the number of market baskets, N. Also, the construction of the itemset tree has O(N) space and time requirements. Some useful theoretical properties are proven