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  • 1
    Online Resource
    Online Resource
    IOP Publishing ; 2017
    In:  Journal of Physics D: Applied Physics Vol. 50, No. 3 ( 2017-01-25), p. 035302-
    In: Journal of Physics D: Applied Physics, IOP Publishing, Vol. 50, No. 3 ( 2017-01-25), p. 035302-
    Type of Medium: Online Resource
    ISSN: 0022-3727 , 1361-6463
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2017
    detail.hit.zdb_id: 209221-9
    detail.hit.zdb_id: 1472948-9
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  • 2
    Online Resource
    Online Resource
    Oxford University Press (OUP) ; 2021
    In:  Nephrology Dialysis Transplantation Vol. 36, No. Supplement_1 ( 2021-05-29)
    In: Nephrology Dialysis Transplantation, Oxford University Press (OUP), Vol. 36, No. Supplement_1 ( 2021-05-29)
    Abstract: Despite increasing use of plastic based products and their potential health risks on the humans, very little is known about their possible accumulation in the food chain and their further long-term effect on the human health. Recently, there are increasing reports related to the potential risk of polystyrene microplastics to the human respiratory system and human intestinal epithelia cell line. In this study, we assayed the primary effect of microplastic particles on the human kidney cells. To that aim, we used human podocytes cells and four different types of plastic particles including; polyvinyl chloride (PVC), polypropylene (PP), polyamide (PA) and tyre wear particles to evaluate the effects of microplastics on the viability and morphology of human podocytes in vitro. Method In this study, we applied different biological methods such as, cell viability test and phalloidin staining, to assay the toxicity of particles and their further effects on the actin cytoskeleton organization in human podocytes, respectively. Furthermore, Raman imaging is used to track particle attachment on the cells and to evaluate the possible changes in the cell compartment following the particle treatment. The particle uptake by the cells and changes in cellular biological features were visualized with the use of scanning electron microscopy (SEM). Results As a primary result, the cytotoxicity response of particle treatment was found to be dependent on the polymer type. As an example higher concentration of PP particle as compared to PVC, PA, and tyre wear caused a similar rate of cell mortality. Furthermore, the degree of particle attachment on the cells depended on their adhesion properties, which was higher in PA, PVC and tyre wear in comparison to PP particles. These particles remained attached to the cell surface even after two-three times of washing with PBS. Based on the phalloidin staining results, particle treatment induced cytoskeleton reorganization in podocytes in vitro. With the use of Raman imaging particle attachment was confirmed based on the fingerprint spectra related to each particle. Conclusion This study suggests that exposure duration and particle concentrations are two of the key factors to evaluate the toxicological effect of particles on podocytes as a highly-specialized epithelial cells in the kidney. It is supposed that two mechanisms can be related to the harmful effects of plastic particles on podocytes. First, particle attachment on the cell surface leading to limitation of nutrient uptake by the cells. Second, uptake of smaller size particles into the cells through phagocytosis. More studies are necessary to determine the direct effect of microplastics on human kidney cells.
    Type of Medium: Online Resource
    ISSN: 0931-0509 , 1460-2385
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2021
    detail.hit.zdb_id: 1465709-0
    detail.hit.zdb_id: 90594-X
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  • 3
    Online Resource
    Online Resource
    Ovid Technologies (Wolters Kluwer Health) ; 1983
    In:  Journal of Cardiovascular Pharmacology Vol. 5, No. 5 ( 1983-09), p. 889-897
    In: Journal of Cardiovascular Pharmacology, Ovid Technologies (Wolters Kluwer Health), Vol. 5, No. 5 ( 1983-09), p. 889-897
    Type of Medium: Online Resource
    ISSN: 0160-2446
    Language: English
    Publisher: Ovid Technologies (Wolters Kluwer Health)
    Publication Date: 1983
    detail.hit.zdb_id: 391970-5
    SSG: 15,3
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  • 4
    Online Resource
    Online Resource
    Optica Publishing Group ; 2020
    In:  Optics Express Vol. 28, No. 7 ( 2020-03-30), p. 10239-
    In: Optics Express, Optica Publishing Group, Vol. 28, No. 7 ( 2020-03-30), p. 10239-
    Abstract: Undoubtedly, Raman spectroscopy is one of the most elaborate spectroscopy tools in materials science, chemistry, medicine and optics. However, when it comes to the analysis of nanostructured specimens or individual sub-wavelength-sized systems, the access to Raman spectra resulting from different excitation schemes is usually very limited. For instance, the excitation with an electric field component oriented perpendicularly to the substrate plane is a difficult task. Conventionally, this can only be achieved by mechanically tilting the sample or by sophisticated sample preparation. Here, we propose a novel experimental method based on the utilization of polarization tailored light for Raman spectroscopy of individual nanostructures. As a proof of principle, we create three-dimensional electromagnetic field distributions at the nanoscale using tightly focused cylindrical vector beams impinging normally onto the specimen, hence keeping the traditional beam-path of commercial Raman systems. In order to demonstrate the convenience of this excitation scheme, we use a sub-wavelength diameter gallium-nitride nanostructure as a test platform and show experimentally that its Raman spectra depend sensitively on its location relative to the focal vector field. The observed Raman spectra can be attributed to the interaction with transverse and pure longitudinal electric field components. This novel technique may pave the way towards a characterization of Raman active nanosystems, granting direct access to growth-related parameters such as strain or defects in the material by using the full information of all Raman modes.
    Type of Medium: Online Resource
    ISSN: 1094-4087
    Language: English
    Publisher: Optica Publishing Group
    Publication Date: 2020
    detail.hit.zdb_id: 1491859-6
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  • 5
    In: Nutrients, MDPI AG, Vol. 16, No. 11 ( 2024-05-23), p. 1595-
    Abstract: Recent studies hypothesized that vitamin D supplementation and subsequent higher 25(OH)D serum levels could protect against respiratory infections in children. This cross-sectional study, conducted from May 2022 to December 2023 in Timisoara, Romania, aimed to evaluate the potential influence of vitamin D supplementation on the incidence of respiratory infections among preschool-age children. This study examined 215 children over 18 months who were split into a group of patients with recurrent respiratory infections (n = 141) and another group of patients with only one respiratory tract infection in the past 12 months (n = 74). Patients were evaluated based on their serum vitamin D levels 25(OH)D, demographic characteristics, and health outcomes. The study identified that preschool-age children with recurrent infections had significantly lower mean vitamin D concentrations (24.5 ng/mL) compared to the control group (29.7 ng/mL, p 〈 0.001). Additionally, a higher proportion of vitamin D deficiency was observed among children with recurrent infections in the past 12 months. Notably, vitamin D supplementation above 600 IU/week significantly reduced the likelihood of respiratory infections, evidenced by an odds ratio of 0.523 (p 〈 0.001), indicating that preschool-age children receiving a dose of vitamin D higher than 600 IU/week were about half as likely to experience respiratory infections compared to those who did not. Furthermore, no significant associations were found between sun exposure, daily sunscreen use, and the incidence of respiratory infections. Conclusively, this study underscores the potential role of vitamin D in helping the immune system against respiratory infections in preschool-age children. The observed protective effect of vitamin D supplementation suggests a potential public health strategy to mitigate the incidence of respiratory infections in preschool children on top of the already known benefits.
    Type of Medium: Online Resource
    ISSN: 2072-6643
    Language: English
    Publisher: MDPI AG
    Publication Date: 2024
    detail.hit.zdb_id: 2518386-2
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  • 6
    In: Nanoscale, Royal Society of Chemistry (RSC), Vol. 6, No. 20 ( 2014), p. 11953-11962
    Type of Medium: Online Resource
    ISSN: 2040-3364 , 2040-3372
    Language: English
    Publisher: Royal Society of Chemistry (RSC)
    Publication Date: 2014
    detail.hit.zdb_id: 2515664-0
    detail.hit.zdb_id: 2578181-9
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  • 7
    In: Advanced Optical Materials, Wiley, Vol. 6, No. 8 ( 2018-04)
    Abstract: Metal organic vapor phase epitaxy is used to grow gallium arsenide (GaAs) nanocrystals (NCs) on germanium (Ge) templates on nanoscopic silicon (Si) threads prepared by reactive ion etching. Scanning transmission electron microscopy with energy dispersive X‐ray measurements shows an epitaxial growth of the GaAs on the Ge template that is supported by the Si thread, and that Ge doping is induced to the GaAs by the template. On Ge templates of about 60 nm diameter, as‐grown GaAs NCs show a very regular rhombic‐dodecahedral outer shape that can be explained by a preferential growth along the 〈 110 〉 plane. Photoluminescence measurements of the Ge/GaAs structures reveal radiative emission peaks on top of the GaAs band‐to‐band emission and at sub‐band gap energies. While high energy peaks are originating from Ge acceptor levels in GaAs, sub‐band gap peaks can be explained by radiation from Ge donor and acceptor bands that are amplified by photonic modes hosted in the rhombic‐dodecahedral GaAs NCs. This study shows that a template‐assisted crystal growth at the nanoscale opens up routes for a versatile integration of strongly emitting nanomaterials for a use in on‐chip solid state lighting and photonics.
    Type of Medium: Online Resource
    ISSN: 2195-1071 , 2195-1071
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2018
    detail.hit.zdb_id: 2708158-8
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  • 8
    In: APL Materials, AIP Publishing, Vol. 8, No. 6 ( 2020-06-01)
    Abstract: As a result of its indirect bandgap, emitting photons from silicon in an efficient way remains challenging. Silicon light emitters that can be integrated seamlessly on a CMOS platform have been demonstrated; however, none satisfies an ensemble of key requirements such as a small footprint, room-temperature operation at low voltages, and emission of narrow and polarized lines with a high spectral power density in the near-infrared range. Here, we present an all-silicon electrically driven light emitting diode that consists of an inversely tapered half-ellipsoidal silicon photonic resonator containing a p–n junction used to excite whispering gallery modes (WGMs) inside the resonator. Under low voltage operation at room temperature, such a photonic silicon light-emitting diode exhibits a band-edge emission (900–1300 nm) with a wall-plug efficiency of 10−4. The emitted spectrum is amplified in multiple WGMs and shows peaks that are polarized and have linewidths Δλ as narrow as 0.33 nm and spectral power densities as high as 8 mW cm−2 nm−1. Considering its small footprint of ∼1 µm and remarkable emission characteristics, this silicon light source constitutes a significant step ahead toward fully integrated on-chip silicon photonics.
    Type of Medium: Online Resource
    ISSN: 2166-532X
    Language: English
    Publisher: AIP Publishing
    Publication Date: 2020
    detail.hit.zdb_id: 2722985-3
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  • 9
    In: Advanced Materials Technologies, Wiley, Vol. 6, No. 9 ( 2021-09)
    Abstract: Due to their large contact and loading surfaces as well as high sensitivities to chemical changes, graphene‐based materials (GBMs) are increasingly being employed into novel nanomedicine technologies. Here biomolecule—monolayer graphene—kidney tissue hybrid structures are studied using mapping micro‐Raman and fluorescence spectroscopies. Because in this configuration graphene interacts with molecules on both sides, a double‐sided graphene‐enhanced Raman scattering (GERS) effect up to ≈ 10.1 is found for biomolecules adsorbed on graphene and amino acids in the kidney tissue below graphene. Moreover, graphene causes an efficient autofluorescence quenching (FLQ) up to ≈ 20% emitted by the kidney tissue. Despite the complexity of such layered materials, the intriguing simultaneous occurrence of double‐sided GERS (a new development of GERS) and FLQ phenomena can be well explained by suitable molecular structure and energy level alignment between molecules and graphene. These result in effective charge transfer mediated by non‐covalent interactions as indicated by correlative strain, doping, and defect analyses in graphene based on the Raman data and energy level calculations. Last, the advantages of using graphene over standard photobleaching are demonstrated. This work can be extended to other macromolecular entities toward integrating GBMs in versatile drug delivery, imaging, and sensing devices.
    Type of Medium: Online Resource
    ISSN: 2365-709X , 2365-709X
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2021
    detail.hit.zdb_id: 2850995-X
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  • 10
    Online Resource
    Online Resource
    Oxford University Press (OUP) ; 2023
    In:  Annals of Work Exposures and Health Vol. 67, No. Supplement_1 ( 2023-05-10), p. i59-i59
    In: Annals of Work Exposures and Health, Oxford University Press (OUP), Vol. 67, No. Supplement_1 ( 2023-05-10), p. i59-i59
    Abstract: Microplastic research has been increasing due to the uncertainty of potential effects on the environment and human health. However, microplastic references are currently missing. Not only is there a lack of references there is also a lack of diversity in polymer type for references, especially in toxicological studies. In specific, inhalation studies must rely on microplastics that are respirable and/or inhalable ( & lt; 10 µm) to result in toxicological outcomes.  Therefore, in this project, we focus on using solvent precipitation to produce microplastic references from TPU, PA-6, PET, and LDPE for microplastic inhalation toxicity studies. Particle size distribution of the dispersion is used to verify that the desired size range is achieved. To demonstrate that the produced microplastic references are representative from its original material, molecular and particle descriptors are characterized. Chemical composition, molecular weight, crystallinity, solidity, density, are among the descriptors tested for both the produced microplastic references and its corresponding commercial counterpart. Preliminary results have shown that quantities needed for in-vitro testing and particle size range desired is achieved with successful production of sub-100 nm constituent particle counts and all-respirable mass-based diameters. SEM images confirm the size distribution and show distribution of particle shapes. Chemical composition via spontaneous Raman Scattering illustrates clear polymer spectra signals from the microplastic dispersions. These microplastic reference materials are complemented by toxicology controls. In addition, the in-vitro screening uses both submersed and air-liquid interface cultures to expose cells. This study will thus provide information on microplastic material descriptors relevant for inhalation toxicity.
    Type of Medium: Online Resource
    ISSN: 2398-7308 , 2398-7316
    Language: English
    Publisher: Oxford University Press (OUP)
    Publication Date: 2023
    detail.hit.zdb_id: 2885096-8
    detail.hit.zdb_id: 2885099-3
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