2199 research outputs found
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Flexible SERS platform based on PET/ITO/Ag for detection of pesticides
No full texthttps://kent-islandora.s3.us-east-2.amazonaws.com/node/14392/83903-thumbnail.jpgSurface-Enhanced Raman Spectroscopy (SERS) is a sensitive, non-destructive, rapid and powerful detection technique used for wide range of biological systems and chemicals analytes in low concentration and also as a diagnostic tool for environmental and biomedical analysis [1].To enhance the Raman signal the special SERS platform, usually made of silicon, glass or another brittle material, or metallic nanoparticles are required [2].
Due to extensive use of those chemical substances for plant fungicide and insecticide protection the detection and identification of pesticides on the surface of fruits and vegetables is a crucial issue. We show a new type of elastic SERS platform made of poly(ethylene terephthalate) (PET) covered with a layer of indium tin oxide (ITO). This composite is subjected to dielectric barrier discharge (DBD) that develops the active surface of the PET/ITO foil. To enhance the Raman signal, a modified composite was covered with a thin layer of silver using the physical vapor deposition (PVD) technique. The SERS platform was used for measurements popular pesticides, i.e., Thiram and Carbaryl and to quantitative analysis of those pesticides from fruits. The presented SERS platform exhibits excellent enhancement and reproducibility of the Raman signal, which enables the trace analysis of these pesticides in the range up to their maximum residues limit. [3].
REFERENCES
[1] Pilot R, Signorini R, Durante C, Bhamidipati DM, Fabris L., Biosensors (2019); 9, 57
[2] Mosier-Boss PA., Nanomaterials (2017);7,142
[3] Nowicka AB, Czaplicka M, Kowlaska AA, Szymborski T, Kamińska A., Biosensors (2019); 9,</p
High efficiency tunable liquid crystal beam steering device based on FFS Pancharatnam phase
No full texthttps://kent-islandora.s3.us-east-2.amazonaws.com/node/14394/83907-thumbnail.jpgAn increasing demand for fast and efficient random-access pointing has led to more investigation on beam steering approaches. This capability is crucial for LiDAR, remote sensing and many other emerging applications.
Electro-Optical devices have advantages over mechanical approach that include a lower cost, faster steering rates, and a random-access beam pointing capability. We have designed, fabricated, Optimized, and characterized a recently proposed non-mechanical beam steering device based on the Pancharatnam-Berry phase. The architecture of our proposed device employs a linear array of phase control elements (PCEs) which are comprised of a fringe field switching electrode structure, are able to locally control the orientation of the liquid crystal director into a cycloidal pattern to deflect transmitted light. Efficiency data verifies a high beam steering efficiency for the proposed device.</p
The Work of Design Today: New Practices in Research and Creative Activity
No full textThis panel will examine how critical practices in design are changing. Johanna Drucker, John Jennings, Michael Gibson, and Keith Owens will discuss how design educators and researchers can evolve their work, and find new projects and modes of publication.
This was a panel discussion at 12pm (SCI Lobby).</p
Electrically actuated liquid crystal elastomers
No full texthttps://kent-islandora.s3.us-east-2.amazonaws.com/node/14393/83905-thumbnail.jpgA liquid crystal elastomer (LCE) combines a rubber-like elasticity with an orientational order, which makes the material sensitive to external cues such as temperature and light. Recently, Liu et al. [1] demonstrated that LCE coatings change their profile in response to an in-plane AC electric field. The response is attributed to the realignments of the molecular dipoles by the field and the ensuing volumetric expansion of the material [1,2]. We explore experimentally how the temperature, frequency and amplitude of the AC field affect the surface profile of the LCE coatings and demonstrate the existence of two resonance frequencies at which the response is maximized.
References:
[1] Danqing Liu, Nicholas B. Tito, and Dirk J. Broer, Protruding organic surfaces triggered by in-plane electric fields, Nature Communications 8, 1526 (2017).
[2] Guido L. A. Kusters, Inge P. Verheul, Nicholas B. Tito, Paul van der Schoot, and Cornelis Storm, Dynamical Landau–de Gennes theory for electrically-responsive liquid crystal networks, Phys. Rev. E 102, 042703 (2020).</p
Anxiety and stress over COVID-19 pandemic associated with increased eating
No full texthttps://kent-islandora.s3.us-east-2.amazonaws.com/node/17328/87209-thumbnail.jpgObjective Stressful experiences can dramatically affect eating. The relatively sudden, global emergence of the COVID-19 pandemic served as a massive stressor to virtually all people, regardless of infection status. This study hypothesized that actual and perceived stressors from the onset of the COVID-19 pandemic, in the categories of recurring disruptions, environmental threat, and social isolation would be positively associated with increased self-reported eating in the United States. Methods Over 1100 English-fluent adults (52.8% women) living in the United States were recruited for a cross-sectional online survey about eating, COVID-19 consequences, and stress experiences. Linear regressions examined associations between perceived stress on five eating measures, and individual differences in personal/work situations, perceptions, and adverse experiences during the pandemic. Results Anxiety, worry, and stress over, rather than direct consequences of, COVID-19 were most consistently associated with self-reported increased eating. Largely, these fell into the stressor categories of environmental threat and social isolation, not recurring disruptions. Body mass index and current self-reported eating pathology symptoms were also consistently associated with these outcomes. Conclusions These correlational findings suggest specific stressors have pronounced influences on eating behavior of US adults. Remotely deliverable stress mitigation strategies should be explored to attenuate increased eating.</p
The BHMT-betaine methylation pathway epigenetically modulates oligodendrocyte maturation
No full texthttps://kent-islandora.s3.us-east-2.amazonaws.com/node/17238/87039-thumbnail.jpgResearch into the epigenome is of growing importance as a loss of epigenetic control has been implicated in the development of neurodegenerative diseases. Previous studies have implicated aberrant DNA and histone methylation in multiple sclerosis (MS) disease pathogenesis. We have previously reported that the methyl donor betaine is depleted in MS and is linked to changes in histone H3 trimethylation (H3K4me3) in neurons. We have also shown that betaine increases histone methyltransferase activity by activating chromatin bound betaine homocysteine S-methyltransferase (BHMT). Here, we investigated the role of the BHMT-betaine methylation pathway in oligodendrocytes. Immunocytochemistry in the human MO3.13 cell line, primary rat oligodendrocytes, and tissue from MS postmortem brain confirmed the presence of the BHMT enzyme in the nucleus in oligodendrocytes. BHMT expression is increased 2-fold following oxidative insult, and qRT-PCR demonstrated that betaine can promote an increase in expression of oligodendrocyte maturation genes SOX10 and NKX-2.2 under oxidative conditions. Chromatin fractionation provided evidence of a direct interaction of BHMT on chromatin and co-IP analysis indicates an interaction between BHMT and DNMT3a. Our data show that both histone and DNA methyltransferase activity are increased following betaine administration. Betaine effects were shown to be dependent on BHMT expression following siRNA knockdown of BHMT. This is the first report of BHMT expression in oligodendrocytes and suggests that betaine acts through BHMT to modulate histone and DNA methyltransferase activity on chromatin. These data suggest that methyl donor availability can impact epigenetic changes and maturation in oligodendrocytes.</p
Scalable Telehealth Services to Combat Novel Coronavirus (COVID-19) Pandemic
No full textAn ongoing pandemic, the novel coronavirus disease 2019 (COVID-19) is threatening the nations of the world regardless of health infrastructure conditions. In the age of digital electronic information and telecommunication technology, scalable telehealth services are gaining immense importance by helping to maintain social distances while providing necessary healthcare services. This paper aims to review the various types of scalable telehealth services used to support patients infected by COVID-19 and other diseases during this pandemic. Recently published research papers collected from various sources such as Google Scholar, ResearchGate, PubMed, Scopus, and IEEE Xplore databases using the terms "Telehealth", "Coronavirus", "Scalable" and "COVID-19" are reviewed. The input data and relevant reports for the analysis and assessment of the various aspects of telehealth technology in the COVID-19 pandemic are taken from official websites. We described the available telehealth systems based on their communication media such as mobile networks, social media, and software based models throughout the review. A comparative analysis among the reviewed systems along with necessary challenges and possible future directions are also drawn for the proper selection of affordable technologies. The usage of scalable telehealth systems improves the quality of the healthcare system and also reduces the infection rate while keeping both patients and doctors safe during the pandemic.</p
COVID-19 Vaccine Acceptance: We Need to Start Now
No full textIn this perspective, we discuss the importance of developing a vaccine to help curb transmission of severe acute respiratory syndrome coronavirus 2. The question remains: Once a safe and effective vaccine is developed, will the public be willing to get it? We present information from one of the first tracking polls to assess public attitudes and perceptions toward a possible coronavirus disease 2019 vaccine that suggests public hesitancy over a potential vaccine, concern regarding accelerating clinical trials, and unease over the vaccine approval process. Public health experts, government officials, advocates, and others in the scientific community should respect the signals of hesitancy and communicate sensitivity, applying lessons not only to how we message, but also in how we build this urgently needed vaccine if we are to have successful uptake once available.</p
SERS-based sensor for the detection of sexually transmitted pathogens in the male swab specimens: A new approach for gonorrhea diagnosis
No full texthttps://kent-islandora.s3.us-east-2.amazonaws.com/node/14387/83893-thumbnail.jpgSexually transmitted diseases (STDs) refer to infections and syndromes passed through sexual contact and caused by bacteria, viruses, and fungi. It was estimated that each year around 376 million people struggle with bacterial STDs. There are several methods that enable diagnosis of STDs, but each of them has some limitations e.g.: Gram staining is characterized by its low detection rate while microbial culture requires time-consuming incubation and specific conditions for bacterial growth. Even the most recommended tests - nucleic acid amplification tests (NAATs) are very expensive and not every laboratory can afford it. For the above-described reasons, there is still a need to establish rapid, reliable and sensitive method for STDs diagnosis.
More recently, a lot of studies have been done presenting the great potential of the application of SERS (Surface-enhanced Raman Spectroscopy) in diverse fields including medicine and biology. SERS is a kind of fingerprint technique based on the inelastic scattering of incident light by molecules adsorbed on the roughened metal surface (SERS-active substrate). The phenomenon of the SERS technique originates mainly from two main mechanisms: electromagnetic (EM) and chemical.
In this study, we present that SERS-based sensor and chemometric analysis can be performed successfully in direct as well as indirect manner for STD diagnosis. The indirect (confirmatory) approach is based on the identification of unknown pathogenic strain in clinical sample by comparison its spectral image to others spectral image of different bacteria. While the direct one guarantees ultrafast diagnosis (up to 15 min) by classifying SERS spectra of clinical sample to the correct group by means of supervised technique (SIMCA, PLS1-DA). The undoubted advantage of this approach is that it does not involve advance preparation of sample and any chemical reagents while maintaining ultrahigh sensitivity. Hence, both of these methods can compete with many currently used techniques.
This research may have a great impact in biomedical application since, the integration of SERS-based sensor with a small, portable Raman spectrometer could lead to the development of a handheld point-of-care device, which would enable the diagnosis of STD in extremely short time.</p
Dual-action organoplatinum polymeric nanoparticles overcome drug resistance in ovarian cancer
No full texthttps://kent-islandora.s3.us-east-2.amazonaws.com/node/14390/83899-thumbnail.jpgA novel approach of organometallic compounds towards the construction of nanoparticles for cancer therapy to enhance cellular uptake by targeting nucleus and mitochondria was achieved. By mixing the organometallic compound with a biocompatible polymer, PEG50 in a proper ratio coordination driven self- assembly occurs, to yield micelles. Bond formation between Pt and carboxylate ligands confirmed with 1HNMR and 31PNMR studies. Drug loading capacity within micelles found to be 80%. Cytotoxicity studies were carried out with MTT experiments, cellular uptake and cell imaging experiments. Mechanism of action of the micelles was studied with apoptosis, γH2AX, Mitostatus and MitoSOX assays. Results reveal that synthesized nanoparticles show better therapeutic effects on several cancer types including ovarian cancer.</p