Real-time imaging and tracking of microrobots in tissues using ultrasound phase analysis

Ultrasound B-mode imaging has been employed to monitor single agents and collective swarms of microrobots in vitro and ex vivo in controlled experimental conditions. However, low contrast and spatial resolution still limit the effective employment of such a method in a medical microrobotic scenario. Doppler-based ultrasound appears as a promising tool for tracking microrobots in echogenic and dynamic environments as biological tissues. In this Letter, we demonstrate that microrobot displacements can be used as a special signature for their visualization within echogenic media, where B-mode fails. To this aim, we induced vibrations of a magnetic soft microrobot through alternated magnetic fields and used ultrasound phase analysis to derive microrobot features such as size and position over time. By exploiting vibrations, we were able to perform imaging and tracking of a low contrast microrobot both in tissue-mimicking phantom and in chicken breast. The axial resolution was 38 μm, which is four times smaller than the B-mode resolution with the employed equipment. We also performed real-time tracking of the microrobot's positions along linear trajectories with a linear velocity up to 1 mm/s. Overall, the reported results pave the way for the application of the proposed approach for the robust monitoring of medical microrobots in tissue

Non-ergodic site response model based on local recordings for Menta Dam site

The paper describes the development of a non-ergodic site response model for a strategic site in the Aspromonte mountains, in Southern Italy. Fractured metamorphic rocks belonging to Calabrian complex outcrop in this area, located in a region where Southern Apennines crustal faults and subduction of the Calabrian Arc contribute to the seismic hazard. At the site, three accelerometers are installed since 2016 as part of the monitoring system of the Menta Dam, a bituminous-faced rockfill dam constructed for the water supply of the region. Ground motions recorded at the site and elsewhere from regional crustal and subduction earthquakes have been used to evaluate region-specific source and path adjustment to global ground motion models (GMMs). Those regionally adjusted GMMs have, in turn, been used to evaluate the mean bias of site-specific recordings, which is used to estimate non-ergodic site response for the dam site. This analysis highlights that site-specific site response is appreciably larger than the global average prediction of GMMs for periods lower than 0.4s. A non-ergodic GMM is developed that accounts for these effects to be used in subsequent Probabilistic Site Hazard Analysis (PSHA)

Contrast-enhanced ultrasound tracking of helical propellers with acoustic phase analysis and comparison with color Doppler

Medical microrobots (MRs) hold the potential to radically transform several interventional procedures. However, to guarantee therapy success when operating in hard-to-reach body districts, a precise and robust imaging strategy is required for monitoring and controlling MRs in real-time. Ultrasound (US) may represent a powerful technology, but MRs' visibility with US needs to be improved, especially when targeting echogenic tissues. In this context, motions of MRs have been exploited to enhance their contrast, e.g., by Doppler imaging. To exploit a more selective contrast-enhancement mechanism, in this study, we analyze in detail the characteristic motions of one of the most widely adopted MR concepts, i.e., the helical propeller, with a particular focus on its interactions with the backscattered US waves. We combine a kinematic analysis of the propeller 3D motion with an US acoustic phase analysis (APA) performed on the raw radio frequency US data in order to improve imaging and tracking in bio-mimicking environments. We validated our US-APA approach in diverse scenarios, aimed at simulating realistic in vivo conditions, and compared the results to those obtained with standard US Doppler. Overall, our technique provided a precise and stable feedback to visualize and track helical propellers in echogenic tissues (chicken breast), tissue-mimicking phantoms with bifurcated lumina, and in the presence of different motion disturbances (e.g., physiological flows and tissue motions), where standard Doppler showed poor performance. Furthermore, the proposed US-APA technique allowed for real-time estimation of MR velocity, where standard Doppler failed

Three years field trials to assess the effect of kaolin made particles and copper on olive-fruit fly (B.oleae Gmelin) infestations in Sicily

In most countries of Mediterranean Basin, Bactrocera oleae (Gmel), the olive fruit fly, is the key pest insect on olives. In Sicily this pest causes losses of fruits and a poor quality olive oil. Many researchers have recently carried out some field studies which were based on the use of kaolin and copper against the olive-fruit fly. In the last years these products have been effective several times in reducing olive fly infestation. Kaolin had, also, some important effect in reducing heat-stress in fruit crops and olive-trees. The aim of the present study was to assess the effect of kaolin and copper treatment on olive infestations in Sicily and to evaluate chemical and sensory parameters of oils extracted. For this reason, within 2003-2005, the IX Servizio of Assessorato Regionale Agricoltura e Foreste, selected some olive groves where to carry out trials with kaolin and copper and to realize information and divulgation activities

The NorthStar Ambulatory Assessment in Duchenne muscular dystrophy: considerations for the design of clinical trials.

With the emergence of experimental therapies for Duchenne muscular dystrophy (DMD), it is fundamental to understand the natural history of this disorder to properly design clinical trials. The aims of this study were to assess the effects produced on motor function by different DMD genotypes and early initiation of glucocorticoids

SCREENING TOMATO GLUTATHIONE S-TRANSFERASE DIVERSITY FOR ASSOCIATION TO DROUGHT STRESS

Environmental stresses are one of the main challenges in agriculture, as they significantly limit crop productivity. As a result of global warming and climate change, extreme environmental events and abiotic stresses are expected to increase in intensity and frequency. Selecting tolerant plants for more resilient agro-ecosystems is a promising strategy for mitigating the effects of adverse environments. The cultivated tomato (Solanum lycopersicum L.) has a narrow genetic base, and its reduced genetic diversity hampers the progress of breeding. However, the rediscovery and use of local and wild genetic resources allow useful/beneficial alleles to be identified and used in breeding programs. To improve adaptation to harmful conditions, plants have evolved many molecular and genetics mechanisms, including hormone regulation and the activation of specific gene networks. Among others, glutathione S-transferase (GST) genes have been identified in various plant species and found to be involved in different physiological, developmental and stress modulation pathways. The aim of this research is to add insights into the role of tomato GST genes in the plant response to stress by associating allele diversity with drought tolerance. Tomato GST sequences were characterized in silico showing their diffuse clustering pattern across chromosomes with TAU class GSTs duplicated in tandem and mostly aggregated on chromosomes 7 and 9. To characterize the diversity of selected GSTs, a core collection of 75 tomato accessions was selected based on microsatellite screening from a larger collection of worldwide accessions. The core collection was screened for drought tolerance when 50% of plants showed fruit set on the lower flower truss. At this stage, two different water treatments were applied consisting in the complete restitution of the water lost due to evapo-transpiration (Full Water Restitution FWR) and the restitution of 50% of the water lost (Half Water Restitution HWR). After seven days the plants showed visible sign of drought and the leaves were analyzed for gas exchange and colorimetric variations. A gas exchange analyzer (Licor 6400) was used to measure the assimilation rate of foliar CO2 (µmol CO2 m-2 s-1) and transpiration (mmol H2O m-2 s-1). The colorimetric analysis was carried out with a portable Chroma Meters (Minolta). The eco-physiological data showed a continuous variability of the response to drought throughout the collection and allowed to identify eight tomato accessions combining a lower reduction in CO2 assimilation, transpiration and water use efficiency and higher stability in leaf temperatures and colorimetric variations when challenged with HWR. Enriched libraries for GST loci were prepared based on the specific hybridization of short oligonucleotide primers (20-25 bases). Libraries will be sequenced using next/third generation sequencing technology (Illumina or PacBio). Mapped variants and haplotypes in the GST loci will be integrated with drought tolerant traits and used to identify associations with tolerant phenotypes to additional environmental stresses

3D Printing of Small-Scale Soft Robots with Programmable Magnetization

status: publishe

INVESTIGATING THE NUCLEOTIDE DIVERSITY IN THE GLUTATHIONE S-TRANSFERASE GENE FAMILY ACROSS THE TOMATO GENE POOL AND ITS SIGNIFICANCE IN CONTROLLING PLANT RESPONSE TO STRESS

The agricultural sector faces a significant challenge in dealing with environmental stresses, which greatly reduce crop productivity. Due to global warming and climate change, abiotic stresses are predicted to become more frequent. In this scenario, to meet a growing global demand for food, breeding crops for enhanced tolerance to harsh environments is promising. The cultivated tomato (Solanum lycopersicum L.) is one of the most important vegetable crops in the world and the genome of its wild relatives Solanum pimpinellifolium, Solanum lycopersicoides and Solanum pennellii have been sequenced and their effective tolerance to extreme environments well documented. However, knowledge about tomato genetic diversity is limited and its phenotypic significance dramatically unpredictable to make its exploitation proficient. Glutathione S-transferase (GST) genes have been identified in numerous plant species and are involved in various physiological, developmental, and stress modulation pathways. The aim of this study was to provide a comprehensive description of the GST nucleotide diversity in the tomato gene pool and contextual mining of functional significance for plant adaptability to challenging stresses. We identified 83 GST genes in Solanum lycopersicum (ITAG 4.1) and their orthologues within the wild relatives. Sequences were analyzed for their exon-intron structures, conserved protein motifs, putative subcellular locations, phylogenetic relationships and duplication events. Interaction networks, promoter and cis-regulatory elements and gene expression profiles were also identified. Phylogenetic analysis enabled grouping GST genes into ten subclasses. Furthermore, protein–protein interaction networks revealed the central role of GST genes controlling the cell redox state. A reference non redundant core collection of 75 tomato genotypes was selected from a larger collection of worldwide accessions genotyped by SSR markers. The core collection was screened for drought tolerance at the fruit set stage on the first flower truss. The leaves were assayed for gas exchange and colorimetric variations and profiled for H2O2, ascorbic acid and antioxidant capacity. The most tolerant and sensitive tomato accessions were selected. Plants were grown in lysimeters where the water supply was managed to apply two levels of soil water potential that is 10-20 kPa in the control treatment and 100-120 kPa for the drought treatment, respectively. To deepen our understanding of the regulatory mechanisms that control photo-assimilation, photo-assimilate allocation and fruit yield and quality under limited levels of available water, leaves, stems and fruit at different ripening stages were collected for RNA-seq analysis. Further bioinformatics analysis will allow us to validate the role of specific GSTs and other key genes in controlling the response of tomato plants to drought and modulating photo-assimilate allocation in sensitive and tolerant genomic backgrounds