Search results

The mining activity in open-pit coal sites exerts a high pressure over the surrounding environment and on the health of people working and living nearby. Using data form a total of six field campaigns, this study aimed to capture the level of exploitation activities in the residential area close to the coal open-mine in terms of mass concentrations and total carbon fractions (TC) of ambient PM10, PM2.5 samples. Sampling campaigns were performed between spring of 2018 and spring of 2020, covered both working (full time, part-time) and non-working days at the coal exploitation, and captured also the seasonal variations of different fractions of PM and of their carbonaceous fraction. Fine fraction was also analyzed based on the aerosol Angstrom exponent, determined from measurements of the aerosol scattering coefficient
at 450 nm, 550 nm and 700 nm by a nephelometer. The mass concentrations of PM and TC showed significant variations from full time working days to non-working days. The air quality (AQ) level is determined by the air quality index (AQI) specific for PM10. In situ measurements clearly indicated that AQIlocal gives better image on the level of air pollution than the AQIestim from AQ monitoring stations in the region, closest to the Matasari site. Insights into the morphology and composition of particles were obtained by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX/EDS) and Fourier transform infrared spectroscopy (FTIR) analyses. Major elements that were identified C, O, Si, Ca, K, S, Cu, Ni, Fe, Mg, Ti have both crustal and anthropogenic origin, in various proportions.

NBD-chloride was used as a chromogenic and fluorogenic label to obtain three new derivatives, starting from 1,8-diamino-3,6-dioxaoctane, 4-aminobenzo-15-crown-5-ether and 4-aminobenzo-18-crown-6-ether (compounds D-F, respectively). These compounds were compared with the corresponding derivatives obtained in a similar way, from NBD-chloride and 1-aza-18-crown-6-ether and 4,13-diaza-18-crown-6-ether (compounds A-C, respectively). UV-Vis, IR, NMR, fluorescence and MS spectra are discussed.

Background: Head and neck cancers, and particularly, oral cancers have a complex pathogenesis that includes genetic
mutations and epigenetic alterations which interfere with cellular signaling and can trigger tumor development. The purpose of
this study was to reveal whether low-frequency hotspot mutations may be detected in a study lot with histopathological evidence
of squamous cell carcinoma (SCC) of the oral mucosa and skin of the head and neck. Methods: Tumor biopsies from treatment
naïve patients were tested for BRAF V600, NRAS G12/G13, NRAS Q61, KRAS Q61 mutations, and EGFR exon 19 deletions (Ex19Del)
using droplet digital PCR (ddPCR). The tumors were also analyzed for EGFR T790M mutations by RT-PCR, using a CE-IVD validated
kit, with a limit of detection of 0.05%. Results: None of the examined cases exhibited NRAS G12/G13, NRAS Q61, KRAS Q61, BRAF
V600, or EGFR T790M mutations, indicating that these alterations are rare events in SCC pathogenesis. Interestingly, among the
12 specimens tested by ddPCR for EGFR Ex19Del, an HPV-negative cSCC tumor occurring in the parotid region tested positive for
this drug-sensitizing mutation, offering unexplored therapeutic perspectives to the patient from whom it was collected.
Conclusions: Our study highlights the important clinical implications of detecting low-frequency hotspot mutations in tumor
biopsies by ddPCR. We believe that the ddPCR-assisted analysis of these mutations in larger SCC cohorts may provide us with
mechanistic insights regarding their role in SCC pathogenesis and guide the development of novel therapeutic strategies for this
problematic disease.

The paper has a structure with four parts and presents the climatic risk aspects that happened in Romania during the winter of the year 2019, concentrating on Bucharest, where a very rare and dangerous phenomenon occurred, `freezing rain`. The first part contains the theoretical analysis of the subject under discussion (the notion of risk and freezing rain), in the second part we analyzed the synoptic context (the causes that led to the phenomena) and the datacollected, the third part presents the results of the research (the duration of phenomena and the case study in the city), and the last part deals with proposed measures in order to reduce the risk of freezing rain, measures that can apply to any dangerous weather phenomena with freezing deposits. Therefore, the study aims to analyze this risk starting from the theoretical explanation of the synoptic context that generated its production to the quantitative analysis of the phenomena. To achieve this objective, the periods ECMWF models and the synoptic databases were accessed, with the help of which the representation and evolution of the phenomena was managed.

Introduction: The gastrointestinal stromal tumors (GIST) are dominated by KIT and PDGFRA mutation. The immunohistochemical detection of CD117, a protein express by KIT gene, is essential for the diagnosis and those that are negative always represented a diagnostic challenge Case reports: In this article we present a series of 4 cases of CD117 negative GIST tumors, diagnosed and surgically resected in Fundeni Clinical Institute and an overview of the histogenesis, diagnostic problems and management of c-kit negative GIST. All patients were males and the tumors were located in the stomach and small bowel. Conclusion: It is important for the pathologists to beware of the fact that a CD117 negative in the context of a typical morphological appearance does not exclude a GIST tumor and also the oncologist must be aware not to exclude the therapy with imatinib based on the negativity of CD117.

Homogeneous and isotropic thick spheres loaded with constant internal and/or external pressures can not be economically designed because the maximum equivalent stress is a local value. It was analytically demonstrated that, by neglecting the body loads, a functionally graded material (FGM) may be characterized in linear static analyses by two material constants: Young's modulus E(r) and Poisson's ratio ν(r). If these two functions are both known, the solution of the problem, displacement and stress distributions may be relatively easy obtained. For the inverse problem, in which a desired stress combination distribution is imposed, finding of E(r) and ν(r) is more difficult, if such a solution exists. More than that, if the solution exists, it is not unique, because two unknown functions are involved. For ν(r) = const., analytical solutions are available for E(r), but only for two particular stress conditions. In this paper, the inverse problem is solved iteratively using a finite element model and an algorithm of stress uniformization developed by the authors of this paper is proposed. In this original approach, the existing solutions were reproduced as a verification and afterwards new solutions were obtained for the remaining classical theories of resistance. The new obtained solutions were also verified by using the analytical solutions of the direct problem.

2,2-Diphenyl-1-picrylhydrazyl (DPPH) is an intensely coloured organic stable free radical with paramagnetic and redox properties. In this work we present three new derivatives of DPPH, in which an amino substituent was designed for one of the p-phenyl position. The synthetic details and the structural characterizations of the compounds are shown.

The multilayer (10 layers) Al doped ZnO (AZO) thin films were deposited on glass substrate by sol-gel & dipping method. X-Ray diffraction measurements showed that the AZO films were polycrystalline with a hexagonal wurtzite structure. The morphological properties of the films were analyzed by atomic force microscopy showing continuous and homogeneous film, completely covering the substrates. The thickness, optical constants, optical band gap (Eg) and transmittance (T) of AZO films were assessed by spectroscopic ellipsometry on UV-vis-NIR spectral range. The AZO film has high transmittance above 80% in the visible region and the optical band-gap energy around 3.7 eV. The electrical characteristics regarding conductivity, mobility and carrier concentrations, were measured by Hall Effect measurements (van der Pauw method). The bulk carrier concentration of the AZO film with 10 layers was found to be 1.16x1019 cm-3. The vibrational bands were obtained by Raman analysis. Defects due to oxygen vacancies in the prepared AZO films were evidenced by photoluminescence spectroscopy (PL). The optical and electrical properties of the AZO thin films proved the possibility to be used in optoelectronic applications.