356 research outputs found

    Performance Analysis of Multi-User MIMO Schemes under Realistic 3GPP 3-D Channel Model for 5G mmWave Cellular Networks

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    Novel techniques such as mmWave transmission and massive MIMO have proven to present many attractive features able to support high data demand for 5G NR technologies. Towards the standardization of 5G networks, channel modeling has become an important step in order to test the reliability of theoretical studies. In this paper, we study the performance of a 5G network at mmWave range for the downlink. We consider a single trisectorized base station equipped with planar arrays, and we model users as a spatial Poisson process in a hexagonal grid. We adopt the latest 3GPP channel model described in TR 38.901 and we provide a thorough description and step-by-step tutorial of it along with our customizations and MATLAB scripts for channel generation in the presented scenario. Moreover, we evaluate the performance of Multi-User Multi-Layer MIMO techniques, such as Signal-to-Leakage-plus-Noise Ratio (SLNR) precoding and MMSE combined with different system configurations by means of achievable per-user rate

    A Mendelian polymorphism underlying quantitative variations of goat αs1-casein

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    Using SDS-polyacrylamide gel electrophoresis and rocket immunoelectrophoresis, 3 new alleles, designated αs1-CnB-,αs1-CnF and αs1-Cno, were identified at the goat αs1-Cn locus, in addition to alleles αs1-CnA, αs1-CnB and αs1-CnC previously reported by BOULANGER al. (1984). Alleles αs1-CnA, αs1-CnB and αs1-CnC are associated with a high content of αs1-casein (approximate mean contribution of each allele being 3.6 g/I) compared to αs1-CnF with a low content (0.6 g/I) and αs1-CnB- with an intermediate content (1.6 g/1) ; αs1-Cno appears to be a true null allele. In a sample of 213 Alpine females from 49 flocks in West Central France, the frequencies of the 6 alleles were : αs1-CnA = 0.14 ; αs1-CnB = 0.05 ; αs1-CnC = 0.01 ; αs1-CnB- = 0.34 ; αs1-CnF = 0.41 ; and αs1-Cno = 0.05. In a sample of 159 Saanen females from 52 flocks of the same region, the frequencies were : αs1-CnA = 0.07 ; αs1-CnB = 0.06 ; αs1-CnC = 0 ; αs1-CnB- = 0.41 ; αs1-CnF = 0.43 ; αs1-Cno = 0.03. Additional data confirm that loci αs1-Cn and αs2-Cn are closely linked. Preliminary investigations indicated a significant superiority in casein content of milks from goats possessing the allele αs1-CnA, as compared to that of milks from goats of genotypes αs1-CnF / αs1-CnF and αs1-CnB- /αs1-CnF and, in a large herd (N = 251), a strong correlation was observed between the αs1-casein content and the rennet-casein content of milk (r = 0.68 ; b = 0.64).A l’aide d’électrophorèses en gel de polyacrylamide SDS et d’immuno-électrophorèses « rocket », 3 allèles, appelés αs1-CnB-, αs1-CnF et αs1-Cno ont été identifiées au locus αs1-Cn de la chèvre, en plus des allèles αs1-CnA, αs1-CnB et αs1-CnC déjà détectés par BOULANGER et al. (1984). Les allèles αs1-CnA, αs1-CnB et αs1-CnC sont associés à un taux élevé de caséine αs1 (contribution approximative de chaque allèle : 3,6 g/I), l’allèle αs1-CnF a un taux faible (0,6 g/I) et l’allèle αs1-CnB a un taux intermédiaire (1,6 g/1). Dans un échantillon de 213 femelles Alpine provenant de 49 troupeaux du centre-ouest de la France, les fréquences des 6 allèles actuellement identifiés étaient les suivantes : αs1-CnA = 0,14 ; αs1-CnB = 0,05 ; αs1-CnC = 0,01; αs1-CnB- = 0,34 ; αs1-CnF = 0,41 et αs1-Cno = 0,05. Dans un échantillon de 159 femelles Saanen provenant de 52 troupeaux de la même région, les fréquences étaient : αs1-CnA = 0,07 ; αs1-CnB = 0,06 ; αs1-CnC = 0; αs1-CnB- = 0,41 ; αs1-CnF = 0,43 ; αs1-Cno = 0,03. Des données supplémentaires confirment que les loci αs1-Cn et αs2-Cn sont étroitement liés. Des investigations préliminaires révèlent que le taux de caséine des laits des chèvres possédant l’allèle αs1-CnA est significativement supérieur à celui des laits des chèvres de génotype αs1-CnF / αs1-CnF ou αs1-CnB- /αs1-CnF; parailleurs, dans un grand troupeau (N = 251), une forte corrélation a été observée entre le taux de caséine αs1 et le taux de matières azotées coagulables (r = 0,68 ; b = 0,64)

    High-Definition Ultrasound Characterization of Squamous Carcinoma of the Tongue: A Descriptive Observational Study

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    High-definition ultrasonography is a diagnostic tool that uses sound echoes to produce images of tissues and organs. In the head and neck region, ultrasounds have been used to diagnose different types of lesions. The intraoral approach was shown to be a real-time, non-invasive way to characterize oral lesions. The tongue is the most often examined region because of its accessibility. This observational study aimed to describe the qualitative characteristics of tongue squamous cell carcinoma images obtained with high-definition intraoral ultrasound by comparing them with the corresponding histopathological sample. Twenty patients were enrolled in this study. The scans of the lesions were carried out with an 18 MHz linear ultrasound probe following the long axis of the lesion. For each lesion, five frames were selected, on which descriptive analysis was performed. A histological sample was taken and then compared to the ultrasonographic acquisition. The so-nographic appearance of the tissue layers has a good correlation between ultrasound and histolog-ical morphology, and it was easy to distinguish the tumor from the homogenous composition of the tongue tissues. Furthermore, a correlation between the structure by section and pattern of tumor margin features by ultrasound was obtained. Intraoral ultrasonography appears to be a promising technique in the non-invasive characterization of tongue squamous cell carcinoma. Further studies will be needed to improve the technique in terms of ergonomics and repeatability

    Evolution of CsPbBr3 nanocrystals upon post-synthesis annealing under an inert atmosphere

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    Annealing a film of CsPbBr3 nanocrystals (NCs) leads to the removal of surface ligands and ripening of the NCs below 200 °C

    Respiratory inhibition of isolated mammalian mitochondria by salivary antifungal peptide histatin-5

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    Histatin-5 is a peptide secreted in the human saliva, which possesses powerful antifungal activity. Previous studies have shown that this peptide exerts its candidacidal activity, through the inhibition of both mitochondrial respiration and the formation of reactive oxygen species. The purpose of the present study was to investigate the biological consequences of histatin-5 action on mammalian mitochondria to verify if the toxic mechanism exerted on mitochondria from Candida albicans is an exclusive for fungal cells. Moreover, hypothesising that the damage exerted on mitochondria may induce programmed cellular death pathways, we evaluated two main markers of apoptosis: the mitochondrial membrane potential (DeltaPsi) and the release of cytochrome c. The results obtained show that exposure of isolated mammalian mitochondria to histatin-5 determines: (i) a large inhibition of the respiratory chain at the level of complex 1, (ii) a slight decrease in the mitochondrial membrane potential, and (iii) no release of cytochrome c. (C) 2003 Elsevier Inc. All rights reserved

    Neurological sequelae in patients with covid-19: A histopathological perspective

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    Background: Neuroinvasive properties of SARS-CoV-2 have allowed the hypothesis of several pathogenic mechanisms related to acute and chronic neurological sequelae. However, neu-ropathological correlates have been poorly systematically investigated, being retrieved from reports of single case or limited case series still. Methods: A PubMed search was carried out to review all publications on autopsy in subjects with “COronaVIrus Disease-19” (COVID-19). Among them, we focused on histological findings of the brain, which were compared with those from the authors’ autoptic studies performed in some COVID-19 patients. Results: Only seven studies reported histological evidence of brain pathology in patients deceased for COVID-19, including three with reverse transcription–quantitative polymerase chain reaction evidence of viral infection. All these studies, in line with our experience, showed vascular-related and infection-related secondary inflammatory tissue damage due to an abnormal immune response. It is still unclear, however, whether these findings are the effect of a direct viral pathology or rather reflect a non-specific consequence of cardiovascular and pulmonary disease on the brain. Conclusions: Notwithstanding the limited evidence available and the heterogeneity of the studies, we provide a preliminary description of the relationship between SARS-CoV-2 and brain sequelae. Systematic autoptic investigations are needed for accurate detection and adequate management of these patients

    Topical application of chlorhexidine gel with brush-on technique in the tailored treatment of plaque induced gingivitis

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    Aim: This study aimed to assess the action of a chlorhexidine-based brush-on gel application in the treatment of plaque-related gingivitis. Methods: The enrollment involved consecutive patients diagnosed with plaque-induced gingivitis. Each participant's full mouth plaque score and gingival index were recorded at the first appointment (t0) and at follow ups after 1 week (t1), 2 weeks (t2) and 3 weeks (t4). All patients were randomly sorted into two groups: A study group, who was given instruction to brush their gums daily with a chlorhexidine gel, and a control group who received a placebo gel. The two groups' data at baseline were compared using a chi-square test, while the t-Student and Mann-Whitney tests were employed to analyze the index's trends, both separately and compared. Results: In total, 30 patients were enrolled, 15 referring to the study group and 15 to the control group. The study group had an 87% decrease in their plaque score and an 84% decrease in their gingival index (p < 0.05). The control group displayed a reduction in plaque score and gingival index of 74% and 84%, respectively (p < 0.05). The plaque score decreased statistically more significantly in the study group than in the control group. Conclusion: Topical employment of a chlorhexidine-containing brush-on gel appears to be a useful home tool in the treatment of plaque-induced gingivitis, associated with professional debridement
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