330 research outputs found

    A novel single-chip RF-voltage-controlled oscillator for bio-sensing applications

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    A novel interdigiated capacitance (IDC) based affinity biosensor system is presented that detects C-Reactive Protein (CRP), a risk marker for cardiovascular diseases, and transmit the information to a distance location wirelessly. The biosensor system consist of a voltage controlled oscillator (VCO) and an IDC. In the presence of CRP the capacitance of the IDC changes and this directly reflects to the oscillation frequency of the VCO. In the presence of 800 ng/ml antigen the frequency of the system shifts from 1.9438 GHz to 1.94175 GHz and with 64 ug/ml frequency shifts from 1.95975 GHz to 1.94875 GHz with -120 dBc/Hz phase noise

    The morphological investigations on the heart and some vessels of bovine foetus between the 15th and 25th weeks of gestation

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    Background: The aim of this study was to define the morphological and morphometric development of the foetus heart obtained from the domestic cattle in the gestation period of 15–25 weeks. Materials and methods: For this purpose, a total of 30 hearts belonging to cattle foetuses (15 males, 15 females) were used. The ages of foetuses were calculated according to the forehead-to-tail length and examined in three different groups. After dissection; biometric, macroanatomic, morphometric and histological findings were obtained from the foetal hearts according to the groups. In addition, mean values of the morphometric findings were determined. Results: As a result of the study, it was found that with the advancing age the convexity of margo ventricularis dexter increased and margo ventricularis sinister transformed from a convex-concave shape to a flat shape. The heart-to-body weight ratio was determined as 0.08% for Group II female foetuses and 0.09% for all other groups. The heart heights for Groups I, II, and III females were identified as 26.21, 41.00, and 46.27 mm, respectively, and for the males 26.45, 34.89, and 47.15 mm, respectively. In the statistical analysis, it was determined that all the morphometric values measured from the heart correlated significantly with the forehead-to-tail length. Conclusions: The data obtained as a result of the study is thought to help understand the morphological and morphometrical development of the heart, pioneer the attempts to create a foetal cattle heart model, and thus help in the diagnosis of the foetal heart pathologies.acieleck

    Single layers and multilayers of GaN and AlN in square-octagon structure: Stability, electronic properties, and functionalization

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    Further to planar single-layer hexagonal structures, GaN and AlN can also form free-standing, single-layer structures constructed from squares and octagons. We performed an extensive analysis of dynamical and thermal stability of these structures in terms of ab initio finiteerature molecular dynamics and phonon calculations together with the analysis of Raman and infrared active modes. These single-layer square-octagon structures of GaN and AlN display directional mechanical properties and have wide, indirect fundamental band gaps, which are smaller than their hexagonal counterparts. These density functional theory band gaps, however, increase and become wider upon correction. Under uniaxial and biaxial tensile strain, the fundamental band gaps decrease and can be closed. The electronic and magnetic properties of these single-layer structures can be modified by adsorption of various adatoms, or by creating neutral cation-anion vacancies. The single-layer structures attain magnetic moment by selected adatoms and neutral vacancies. In particular, localized gap states are strongly dependent on the type of vacancy. The energetics, binding, and resulting electronic structure of bilayer, trilayer, and three-dimensional (3D) layered structures constructed by stacking the single layers are affected by vertical chemical bonds between adjacent layers. In addition to van der Waals interaction, these weak vertical bonds induce buckling in planar geometry and enhance their binding, leading to the formation of stable 3D layered structures. In this respect, these multilayers are intermediate between van der Waals solids and wurtzite crystals, offering a wide range of tunability. © 2017 American Physical Society

    Spectral characterization and antimicrobial activity of some transition metal complexes of 2-(5-nitro-1H-benzimidazol-2-yl)-4-bromophenol

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    ABSTRACT. MnCl2, FeCl3, Ru(DMSO)4Cl2, CoCl2, NiCl2, PdCl2, CuCl2, AgNO3, CdCl2 and HgCl2 complexes of 2-(5-nitro-1H-benzimidazol-2-yl)-4-bromophenol (HL) were synthesized and characterized. The structures of the complexes were confirmed on the basis of elemental analysis, TGA, molar conductivity and magnetic moment measurements, FT-IR, far-IR, FT-Raman, UV-Visible, NMR and fluorescence spectroscopy. According to the analytical and spectral data, the ligand acted as bidentate, via the imine nitrogen and the phenolate oxygen atoms towards to the metal ions except the Ag(I). The complexes were screened for in vitro antibacterial activities against S. aureus, S. epidermidis, E. coli, K. pneumoniae, P. aeruginosa, P. mirabilis and for antifungal activity against C. albicans. Ciprofloxacin and fluconazole were used as reference for antibacterial and antifungal activities of the complexes, respectively. In most cases, the complexes tested showed considerable activity on S. aureus especially, which is a Gram positive bacterium. In addition, the Hg(II) and Ag(I) complexes were found to have superior activity toward all of the microorganisms whereas the Pd(II) and Cd(II) complexes showed considerably antimicrobial effect on S. aureus and C. albicans selectively.               KEY WORDS: Benzimidazole, Bromophenol, Transition metal complexes, Antibacterial, Antifungal Bull. Chem. Soc. Ethiop. 2019, 33(3), 451-466.   DOI: https://dx.doi.org/10.4314/bcse.v33i3.

    Deep breathing couples CSF and venous flow dynamics

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    Venous system pathologies have increasingly been linked to clinically relevant disorders of CSF circulation whereas the exact coupling mechanisms still remain unknown. In this work, flow dynamics of both systems were studied using real-time phase-contrast flow MRI in 16 healthy subjects during normal and forced breathing. Flow evaluations in the aqueduct, at cervical level C3 and lumbar level L3 for both the CSF and venous fluid systems reveal temporal modulations by forced respiration. During normal breathing cardiac-related flow modulations prevailed, while forced breathing shifted the dominant frequency of both CSF and venous flow spectra towards the respiratory component and prompted a correlation between CSF and venous flow in the large vessels. The average of flow magnitude of CSF was increased during forced breathing at all spinal and intracranial positions. Venous flow in the large vessels of the upper body decreased and in the lower body increased during forced breathing. Deep respiration couples interdependent venous and brain fluid flow—most likely mediated by intrathoracic and intraabdominal pressure changes. Further insights into the driving forces of CSF and venous circulation and their correlation will facilitate our understanding how the venous system links to intracranial pressure regulation and of related forms of hydrocephalus

    Diagnostic value of combined serum biomarkers for the evaluation of liver fibrosis in chronic hepatitis C infection: A multicenter, noninterventional, observational study

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    Background/Aims: The hepatitis C virus (HCV) infection is important cause of chronic hepatitis. Liver biopsy is considered the gold standard for assessment of fibrosis but this procedure is an invasive procedure. We aimed to evaluate the diagnostic efficiency of non-invasive serum biomarkers, separately and in combinations, on liver fibrosis in treatment-naive chronic hepatitis C (CHC) patients. Materials and Methods: Two hundred and sixteen treatment-naive CHC patients were enrolled from 32 locations across Turkey in this open-labelled, non-interventional prospective observational study. FibroTest®, aspartate aminotransferase-to-platelet ratio index(APRI), aspartate aminotransferase and alanine aminotransferase ratio (AAR), fibrosis index based on four factors (FIB-4), Age-platelet(AP) index and Forns index were measured and compared with Metavir scores got from liver biopsies. Results: Data from 182 patients with baseline liver biopsy were suitable for analysis. One hundred and twenty patients (65.9%) had F0-F1 fibrosis and 62 patients (34.1%) had F2-F4 fibrosis. APRI 0.732 area under the curve(AUC) indicated advanced fibrosis with 69% sensitivity and 77% specificity. FIB-4 0.732 AUC and FibroTest 0.715 AUC indicated advanced fibrosis with 69% and 78.4% sensitivity, and 75% and 71.4% specificity, respectively. The combined use of tests also led to an increase in AUC and specificity. Combinations of FibroTest with APRI and/or FIB-4, and FIB-4 with APRI were optimal for the evaluation of liver fibrosis. Conclusion: Fibrotest, FIB-4, APRI, AP index and Forns index exhibit good diagnostic performance for determining liver fibrosis in CHC patients, and the use of at least two tests together will increase their diagnostic value still further. © Copyright 2018 by The Turkish Society of Gastroenterology

    Synthesis, characterization and antimicrobial activity of some transition metal complexes of N-(5-chloro-2-hydroxyphenyl)-3-methoxy-salicylaldimine

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    Cr(III), Fe(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) complexes of N-(5-chloro-2-hydroxyphenyl)-3-methoxy-salicylaldimine (H2L), an ONO type tridentate ligand, were synthesized and characterized by elemental analysis, magnetic moment, molar conductivity, TGA, NMR, IR, UV-vis. and ESI-MS spectral techniques. All of the complexes except [Zn(L)(H2O)2] are paramagnetic. The CoCl2 gives a complex with 1:2 M:L ratio while the others form 1:1 non-ionic complexes with H2L. The ligand coordinated to the metal ions through the both OH oxygen and the azomethine nitrogen atoms acting tridentate behaviour. Octahedral geometry has been proposed for the Fe(II), Cr(III), Co(II), Ni(II) complexes considering the magnetic moment values and the electronic spectral data. The Zn(II) and Fe(III) complexes exhibit five coordination geometries and the Cu(II) complex is four-coordinated having acetato bridged dimeric structure. Antimicrobial activities of the compounds were determined against six bacteria and C. albicans as fungi. The Ni(II) and Co(II) complexes exhibit considerable selective activity on S. epidermidis and C. albicans whereas the ligand has no activity on the microorganisms. In addition, the Cr(III) complex shows antibacterial activity toward S. epidermidis and the Zn(II) complex has antifungal activity on C. albicans

    Expectations of mental illness disclosure outcomes in the work context:A cross-sectional study among Dutch workers

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    Purpose The decision whether to disclose mental illness at work can have important positive and negative consequences for sustainable employment and well-being. The aim of the study is (1) to examine workers’ expectations of outcomes of mental illness disclosure in the workplace and to evaluate their expectations regarding which factors are of influence on these outcomes, (2) to identify distinct subgroups of workers, and (3) to characterize these subgroups in terms of personal, sociodemographic, and work-related characteristics. Methods In this cross-sectional survey study, a sample of 1224 Dutch workers was used. Latent Class Analysis (LCA) was used to identify classes of workers based on expected workplace mental illness outcomes. A three-step approach LCA was chosen to investigate whether the classes differed in characteristics. Results The majority of workers expected predominantly positive outcomes of workplace mental illness disclosure (e.g., being able to be one’s authentic self; 82.4%), even though they simultaneously expected disclosure to lead to advancement-related discrimination (e.g., lower chances of contract renewal; or getting a promotion; 68.4% and 57%, respectively). Six distinct subgroups of workers were identified based on expected workplace mental illness disclosure outcomes: two positive classes (50.1%), two negative classes (33.3%), and two classes who indicated not to know what the outcomes would be (16.7%). Significant differences between the classes were found on personal experience, work-related association with mental illness, gender, educational level, and workplace atmosphere. Conclusion The disclosure process is complex, as most workers were optimistic (i.e., expected generally positive outcomes) whilst simultaneously expecting workplace discrimination. Subgroup differences in expectations regarding workplace mental illness disclosure outcomes were found
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