205 research outputs found
Spectral characterization and antimicrobial activity of some transition metal complexes of 2-(5-nitro-1H-benzimidazol-2-yl)-4-bromophenol
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.
Left ventricular volume: an optimal parameter to detect systolic dysfunction on prospectively triggered 64-multidetector row computed tomography: another step towards reducing radiation exposure
In this study, we define the correlation between LV volumes (both LV end-diastolic volume [LVEDV] and LV end-systolic volume [LVESV]) and ejection fraction (EF) on 64 slice multi-detector computed tomography (MDCT). We also determine the accuracy of all the LV volume (LVV) parameters to detect LV systolic dysfunction (LVSD) and investigate the feasibility of using LVV as a surrogate of LVSD on prospectively gated imaging to prevent the radiation exposure of retrospective imaging. 568 patients undergoing 64-detector MDCT were divided into 2 groups: Group 1—subjects without any heart disease and LVEF ≥ 50%; and Group 2—patients with coronary artery disease and LVEF < 50% (defined as LVSD). The LVV (LV cavity only) and Total LV volume (cavity + LV mass) at end-systole and end-diastole (LVESV, Total LVESV, LVEDV and Total LVEDV) were measured. The upper limit values (mean + 2 SD) of all LVV parameters in Group 1 were used as the reference criterion to diagnose LVSD in Group 2. An exponential correlation was found between LVEF and all the LVV parameters. The specificity to detect LVSD in Group 2 was >90% and the sensitivity was 88.9, 83.3, 61.3 and 74.9% by using LVESV, Total LVESV, LVEDV and Total LVEDV, respectively. Systolic and diastolic LV volumes had a high correlation with LVEF and a high accuracy to detect LVSD. Thus, on prospectively triggered imaging, ventricular volumes can predict patients with reduced LVEF, and appropriate referrals can be made
Protective effect of leptin against ischemia-reperfusion injury in the rat small intestine
BACKGROUND: The small intestine is extremely sensitive to ischemia-reperfusion (I/R) injury and a range of microcirculatory disturbances which contribute to tissue damage. Previous studies have shown that leptin plays an important physiological role in the microvasculature. The aim of this study was to evaluate the protective effects of leptin in I/R – induced mucosal injury in the small intestine. METHODS: Forty rats were divided into 5 groups (n = 8). Group I was subjected to a sham operation. Following mesenteric ischemia in group II (control); physiologic saline 1 cm(3), in group III; leptin 100 μg/kg, and physiologic saline 1 cm(3), in group IV; N(G)-L-arginine methyl ester (L-NAME) 20 mg/kg, and physiologic saline 1 cm(3), in group V; leptin 100 μg/kg, L-NAME 20 mg/kg, and physiologic saline 1 cm(3 )were given intra-peritoneally. In these groups, an I/R procedure was performed by occlusion of the superior mesenteric artery for 45 min followed by 120 min reperfusion. After reperfusion, the small intestines were resected for malondialdehyde (MDA) and nitric oxide (NO) concentration and histopathologic properties. Mucosal lesions were scored between 0 and 5. Tissue MDA and NO concentration and histopathologic grades were compared statistically. RESULTS: Tissue MDA level significantly increased (P < 0.05), tissue NO level significantly decreased in group V animals, compared to group III animals respectively (P < 0.001). Histopathologically, intestinal injury significantly decreased in the leptin treated ischemic group. CONCLUSION: Leptin can be used safely in mesenteric occlusive diseases, since it induces NO formation and release in mesenteric vessels
Non-contrast cardiac computed tomography can accurately detect chronic myocardial infarction: Validation study
BackgroundThis study evaluates whether non-contrast cardiac computed tomography (CCT) can detect chronic myocardial infarction (MI) in patients with irreversible perfusion defects on nuclear myocardial perfusion imaging (MPI).MethodsOne hundred twenty-two symptomatic patients with irreversible perfusion defect (N = 62) or normal MPI (N = 60) underwent coronary artery calcium (CAC) scanning. MI on these non-contrast CCTs was visually detected based on the hypo-attenuation areas (dark) in the myocardium and corresponding Hounsfield units (HU) were measured.ResultsNon-contrast CCT accurately detected MI in 57 patients with irreversible perfusion defect on MPI, yielding a sensitivity of 92%, specificity of 72%, negative predictive value (NPV) of 90%, and a positive predictive value (PPV) of 77%. On a per myocardial region analysis, non-contrast CT showed a sensitivity of 70%, specificity of 85%, NPV of 91%, and a PPV of 57%. The ROC curve showed that the optimal cutoff value of LV myocardium HU to predict MI on non-contrast CCT was 21.7 with a sensitivity of 97.4% and specificity of 99.7%.ConclusionNon-contrast CCT has an excellent agreement with MPI in detecting chronic MI. This study highlights a novel clinical utility of non-contrast CCT in addition to assessment of overall burden of atherosclerosis measured by CAC
Hammerstein model performance of three axes gimbal system on Unmanned Aerial Vehicle (UAV) for route tracking [Rota takibinde insansiz hava araci üzerinde bulunan üç eksenli yalpa sisteminin hammerstein model başarimi]
Aselsan;et al.;Huawei;IEEE Signal Processing Society;IEEE Turkey Section;Netas26th IEEE Signal Processing and Communications Applications Conference, SIU 2018 -- 2 May 2018 through 5 May 2018 -- -- 137780In this study, focuses on the non-linear Hammerstein model under external disturbance with white Gaussian noise based on the experimental input (motor velocities) and output (end effector position) data of the three axes gimbal system on the Unmanned Aerial Vehicle (UAV), which is autonomously moving for route tracking. The performance of UAV in reaching the target point on a planned route in sinusoidal form in avoiding obstacles, depends on the route tracking performance of the three axes gimbal system on the UAV. In intelligence activities such as exploration and surveillance, Hammerstein and Nonlinear AutoRegressive and Moving Average (NARMA) models of the gimbal system with great importance for UAV that real time image transmission and in the tasks of leaving payloads to targets with unknown coordinates with the least mistake are obtained. The parameters of the obtained models are estimated by Recursive Least Squares (RLS) algorithm and the model performances are compared. © 2018 IEEE
The controller of the camera used in target tracking for unmanned vehicle with model predictive controller [Insansiz araçlarda hedef takibinde kullanilan kamera sisteminin model öngörülü denetleyici ile denetimi]
2014 22nd Signal Processing and Communications Applications Conference, SIU 2014 -- 23 April 2014 through 25 April 2014 -- Trabzon -- 106053In this study, unmanned vehicles used for target tracking camera RRP (revolute revolute prismatic) joint structure with a three-jointed robot arm with the position, velocity and acceleration control is made. In order to be able to follow the specified trajectory, the system used in the control of the robot arm with joint structure RRP target tracking model based on changing according to the structure proposed by the MPC is implemented. Also the PID (Proportional Integral Dervative) is provided with control comparison was made. MATLAB/Simulink simulations performed unmanned vehicles used for target tracking in robotic camera control with the system were investigated in the MPC. © 2014 IEEE
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