Label-Free, High Content Screening Using Raman Microspectroscopy: The Toxicological Response of Different Cell Lines to Amine-Modified Polystyrene Nanoparticles

Nanotoxicology has become an established area of science due to growing concerns over the production and potential use of nanomaterials in a wide-range of areas from pharmaceutics to nanomedicine. Although different cytotoxicity assays have been developed and are widely used to determine the toxicity of nanomaterials, the production of multi-parametric information in a rapid and non-invasive way is still challenging, when the amount and diversity of physicochemical properties of nanomaterials are considered. High content screening can provide such analysis, but is often prohibitive in terms of capital and recurrent costs in academic environments. As a label-free technique, the applicability of Raman microspectroscopy for the analysis of cells, tissues and bodily fluids has been extensively demonstrated. The multi-parametric information in the fingerprint region has also been used for the determination of nanoparticle localisation and toxicity. In this study, the applicability of Raman microspectroscopy as a \u27high content nanotoxicological screening technique\u27 is demonstrated, with the aid of multivariate analysis, on non-cancerous (immortalized human bronchial epithelium) and cancerous cell-lines (human lung carcinoma and human lung epidermoid cells). Aminated polystyrene nanoparticles are chosen as model nanoparticles due to their well-established toxic properties and cells were exposed to the nanoparticles for periods from 24-72 hours. Spectral markers of cellular responses such as oxidative stress, cytoplasmic RNA aberrations and liposomal rupture are identified and cell-line dependent systematic variations in these spectral markers, as a function of the exposure time, are observed using Raman microspectroscopy, and are correlated with cellular assays and imaging techniques

Anharmonicity in GaTe layered crystals

The temperature dependencies (10-300 K) of seven Raman-active mode frequencies in layered semiconductor gallium telluride have been measured in the frequency range from 25 to 300 cm -1. Softening and broadening of the optical phonon lines are observed with increasing temperature. Comparison between the experimental data and theories of the shift of the phonon lines during heating of the crystal showed that the experimental dependencies can be explained by contributions from thermal expansion and lattice anharmonicity. Lattice anharmonicity is determined to be due to three-phonon processes

Graphene Nanoflake Uptake Mediated by Scavenger Receptors

The biological interactions of graphene have been extensively investigated over the last 10 years. However, very little is known about graphene interactions with the cell surface and how the graphene internalization process is driven and mediated by specific recognition sites at the interface with the cell. In this work, we propose a methodology to investigate direct molecular correlations between the biomolecular corona of graphene and specific cell receptors, showing that key protein recognition motifs, presented on the nanomaterial surface, can engage selectively with specific cell receptors. We consider the case of apolipoprotein A-I, found to be very abundant in the graphene protein corona, and observe that the uptake of graphene nanoflakes is somewhat increased in cells with greatly elevated expression of scavenger receptors B1, suggesting a possible mechanism of endogenous interaction. The uptake results, obtained by flow cytometry, have been confirmed using Raman microspectroscopic mapping, exploiting the strong Raman signature of graphene

The influence of TiC dispersion and density on the microstructural features and microhardness fused by TIG arc process

Surface hardening is a technique to modify a thin layer on the substrate serving the purpose to resist annihilation from the wear and corrosion conditions. In this work titanium carbide (TiC) particulates was incorporated on the surface of the AISI 4340 low alloy steel at different content and heat inputs using the tungsten inert gas (TIG) melting process. The examined melt sizes, microstructures, defects and microhardness were reported. It was found that all tracks were free from crack defects with each track possessing sound metallurgical bonding to the substrate. The containment of majority undissolved TiC followed by the reprecipitated ones were densed when melting was conducted at 2160 J/mm between 1mg/mm2 to 2 mg/mm2 powder. The reprecipitated mostly the globular and flower type microstructures were seen dispersed and surrounded by overwhelmingly more of the Fe matrix fused at 1008 J/mm between 0.4 mg/mm2 to 0.5 mg/mm2. The arc was constricted to allow extensive dissolution when higher 1 mg/mm2 to 2 mg/mm2 powder were used and so dissolution and reprecipitation was poor. The populated undissolved TiC above 1 mg/mm2 deemed for the demarcation hardness trends which were evident by sudden dropped from above 1400 HV to ~ 900 HV and rised back to 1050 HV. Dissolution of substrate and particulates were enhanced with higher heat input associated with lower powder content

Hybrid EEFIT mission to february 2023 Kahramanmaraş earthquake sequence

The southwestern part of Türkiye was hit on 6 February 2023 by an Mw 7.8 (epicentre:Pazarcık) and then an Mw 7.5 earthquake (epicentre: Elbistan). The event was followed by tensof thousands of aftershocks including the Mw 6.3 event on 20 February (epicentre: Uzunbağ).This paper reports on the preliminary findings of the mission organised by the UK’s EarthquakeEngineering Field Investigation Team (EEFIT) to the Kahramanmaraş Earthquake sequence ofFebruary 2023. This mission followed a hybrid model, combining field and remote investigationtechniques, to investigate the characteristics of the earthquake sequence, its impact on buildingsand infrastructure, as well as the efficacy of relief, response and recovery operations. The keymessages include that the building stock is hard to categorise which brings along difficulties withdamage assessment, that the recovery and reconstruction require multi-sectoral engagement ofkey stakeholders, and that the auditing and quality control mechanisms within the constructionindustry need revisiting in the way forward for better disaster resilience in Türkiye

The Türki̇ye earthquake sequence of February 2023: A longitudinal study report by EEFIT

On 6 February 2023 at 4:17 am local time, a large area in southeastern Türkiye and northern Syria was hit by an Mw 7.8 earthquake, which was followed by an Mw 7.5 earthquake at 1:24 pm local time, causing the loss of more than 50,000 lives, some 100,000 injuries and significant damage to buildings and infrastructure, estimated to be in the range of 84.1 billion USD for Türkiye alone. The largest earthquake in Türkiye since the deadly 1939 Erzincan earthquake with however much larger losses, the sequence immediately attracted the attention of the global post-disaster reconnaissance/engineering communities. This included the Earthquake Engineering Field Investigation Team (EEFIT), who, within one week of the event, gathered a team with 30 people from academia and industry in the UK (19), Türkiye (5), New Zealand (1), Hungary (1), Bulgaria (1), Greece (1) and USA (1) with two support members from the UK and the Netherlands, to study the events and their impacts, and also to develop suggestions to reduce the existing vulnerabilities in the future. The team was organised in the form of 6 working groups as shown below, which were (1) strong ground motions and seismotectonics, (2) geotechnics, (3) structures, (4) infrastructure, (5) remote sensing and (6) relief response and recovery

2023 Türki̇ye deprem sekansi deprem mühendi̇sli̇ği̇ saha çalişmalari eki̇bi̇ (EEFIT) Misyonu: Türkçe geni̇şleti̇lmi̇ş özet

Türkiye'nin güneydoğusunda ve kuzey Suriye'de geniş bir alan, 6 Şubat 2023 tarihinde yerel saatle sabaha karşı 04:17'de gerçekleşen 7.8 büyüklüğünde yıkıcı bir depremle sarsıldı, aynı gün içerisinde 13:24’te meydana gelen 7.5 büyüklüğündeki deprem ile yıkımın boyutu ve etki alanı büyük ölçüde arttı. Bu depremler, yalnızca Türkiye'de 84.1 milyar $’ı (≈2.5 trilyon ₺) aşan ekonomik kayba, bina ve altyapı stokunda ciddi hasara, 100,000'den fazla yaralı ve 50,000'den fazla can kaybına neden oldu

Papillon-Lefevre syndrome - Analysis of peripheral blood lymphocyte subsets

We have studied the peripheral blood lymphocyte populations in our 6 patients (2 female and 4 male) with a mean age of 11.19 with Papillon-Lefevre Syndrome (PLS) using adequate monoclonal antibodies and double coloured flow cytometry. Total B, T, CD4, CD8, CD29, CD45RA, NK, HLA-DR cells were studied. Total B, T, CD4 and CD8 lymphocytes were within normal limits. We have observed an increase in the CD29 lymphocytes and NK cells and a decrease in CD45RA lymphocytes. We think that these findings are important in explaining B lymphocyte activation and in the pathogenesis of the PLS

Papillon-Lefevre syndrome. Analysis of neutrophil chemotaxis

PAPILLON-LEFEVRE SYNDROME (PLS) IS DESCRIBED as the association of palmar-plantar hyperkeratosis with precocious periodontal disease which results in exfoliation of primary and permanent dentitions. This study was planned to assess the chemotaxis of peripheral blood neutrophils in 7 patients (3 females and 4 males) with Papillon-Lefevre syndrome. The neutrophil chemotaxis was analyzed using the zymosan activated serum (ZAS) assay. Chemotaxis and spontaneous migration measurements were compared to those of the healthy control subjects. The peripheral blood neutrophil chemotaxis and spontaneous migration were depressed in all patients with Papillon-Lefevre syndrome. The decreased chemotaxis of peripheral blood neutrophils strongly suggests that the neutrophils may act as one of the important key determinants in the pathogenesis of severe periodontal destruction in patients with PLS

Clinical and immunological findings in 2 siblings with Papillon-Lefevre syndrome

RAPID AND SEVERE DESTRUCTION Of periodontal tissues in early childhood has been reported both in systemically healthy children and in children with systemic disorders. In this study, the clinical and immunological findings of two siblings in a family with Papillon-Lefevre syndrome are presented. The peripheral blood lymphocytes were analyzed using a double colored flow cytometry and adequate monoclonal antibodies to CD2, CD3, CD4, CD5, CD8, CD11b, CD16, CD19, and HLA-DR receptors. CD11b expression was found to be higher in both siblings (35% and 37%). The elevated CD11b expression may be related to a defect in neutrophils. The expression of natural killer cells was found to be higher in one patient but the results were in normal range. The CD2+, CD3+, CD4+, CD5+, CD8+, and CD19+ lymphocytes were in normal range in both patients. We think that the depressed chemotaxis of peripheral neutrophils, and higher expression of HLA-DR and CD11b molecules in peripheral leukocytes were useful in explaining the pathogenesis of the Papillon-Lefevre syndrome