Complete Atlas for Mechanically Constrained Double 3R Chains

In this paper, a new methodology is applied to a mechanically constrain planar parallel robot formed by double 3R chains. This will transform the considered system to 8-bar mechanism. Graphical technique is introduced to enumerate all possible graphs. Then a new structural code is used to detect isomorphism and locked chains. Finally, reverse transformation is applied to construct 8-bar linkages from their corresponding graphs. As a result, a new complete atlas for 8-bar linkages is introduced for the first time, which consists of 39 linkages for independent link connections and 30 linkages for dependent link connections. Two, three and four fixed pivots are included in the proposed atlas. All enumerated linkages are compared with their corresponding kinematic chains introduced by Tsa

Seroprevalence of Toxoplasma gondii among a group of Egyptian patients with type I diabetes mellitus

Abstract Background Toxoplasmosis is probably one of the most common parasitic infections of humans. While infection of healthy adults is usually relatively mild, serious disease can result in utero or when the host is immuno-compromised. Toxoplasmosis in diabetic patients may occur due to recently acquired acute infection or they may suffer from dissemination of reactivated latent infection. In the present study, the antinuclear antibody prevalence was tested to determine the possible relationship with Toxoplasma seroprevalence and clinical findings in type I diabetic patients. Methods Toxoplasma gondii antibodies were tested serologically in 60 patients of type I diabetes mellitus and 60 controls using ELISA technique. Results The seropositivity for anti-Toxoplasma IgG antibodies in the study groups was 45% in type I diabetes mellitus patients (group 1) and 23.3% in the control (group 2) with p value = 0.012 showing a statistically significant difference between groups, while only three patients of diabetes type1 group were positive for anti-Toxoplasma IgM with p value = 0.244 showing no statistically significant differences between the two groups. Results showed that only one patient of diabetes type 1 (group1) had positive ANA and one control (group2) had positive ANA. Thus, no correlation could be detected from such results. Conclusion The study results showed a statistically significantly higher proportion (45%) of seropositivity anti-Toxoplasma IgG antibodies among type I diabetes mellitus patients compared to 23.3% among the control group, while there was no association could be detected between the studied groups regarding the ANA

Ab Initio Study of the Vibrational Signatures for the Covalent Functionalization of Graphene

The present work reports a theoretical study of the infrared (IR) and Raman spectra of chemical structures that are useful for the description of the surface chemistry of carbon materials. There has been a recent demand in materials science and surface functionalization to couple organic entities with sp² carbon nanostructures. A slab model of single-layer graphene with its edges terminated by hydrogen atoms containing 82 atoms per unit cell was used in our study. The organic coupling agent, perfluorophenylazide (PFPA), was used according to a recent experiment [Liu, L.-H.; et al. Nano Lett. <b>2010</b>, <i>10</i>, 3754]. Two <i>ab initio</i> DFT functionals, B3LYP and ωB97XD, were adopted to calculate the IR and Raman spectra. The computational approach was tested by comparing the calculated IR spectra to those obtained experimentally for various reference compounds. The vibrational features were probed before and after the reaction, and the changes, arising in both PFPA and graphene spectra as a result of the coupling, were identified. B3LYP gave better agreement with the experimental results than ωB97XD for frequency calculations. The stretch modes of the azide group, as well as the fingerprint feature of the CF₂ axial stretching vibrations, were used to probe the reaction, and the results were in good agreement with the experimental observations. Special attention was paid to the elucidation of the origins of the G-, D-, and D′-bands in the Raman spectra of graphene. Finally, the predicted assignments were employed to interpret the IR and Raman spectra obtained experimentally for functionalized graphenes

Additional file 1 of High incidence of fosfomycin-resistant uropathogenic E. coli among children

Supplementary Material

Synthesis, characterization, computational studies and biological activities of Co(II), Ni(II) and Cu(II) complexes of 2-Amino-1,3,4-thiadiazole derivatives

<p>Co(II), Ni(II), and Cu(II) complexes of 2-Amino-5-ethyl-1,3,4-thiadiazole (AET) and 2-Amino-5-(ethylthio)-1,3,4-thiadiazole (AEST) have been synthesized and characterized based on elemental analysis, magnetic susceptibility, infrared (4000–400 cm⁻¹), mass spectrometry (ESI and MALDI), UV–Vis (200–1100 nm) and thermal analysis (TGA/DTA). Molar conductance measurements proved that [<i>M</i>(L)₂(H₂O)₂]Cl₂·H₂O are electrolytic complexes where <i>M</i> represents Co, Ni, and Cu divalent metal ions. The geometrical isomerism of [<i>M</i>(L)₂(H₂O)₂]²⁺ ions were investigated by DFT-B3LYP calculations incorporated in Gaussian09 package; it favored the <i>all trans</i> isomers due to having the lowest energy points on the potential energy surface. The outcome of DFT-B3LYP quantum mechanical calculations using 6-31G(d) basis set favor six-coordinate sites <i>via</i> a bidentate ligand through <i>exo</i> amino and adjacent <i>endo</i> thiadiazole nitrogen (N₃) donors. These results were consistent with magnetic measurements combined with infrared and UV–Vis spectral interpretations. The predicted metal–ligand binding energies from B3LYP/6-31G(d) calculations follow the trend Cu²⁺>Ni²⁺>Co²⁺, in agreement with the Irving–Williams series. Both AET and AEST ligands and the synthesized complexes were screened for their antibacterial activity and the outcome was high antimicrobial activity of the complexes compared to the free ligands against one or more microbial species and in some cases (copper complexes) higher activity than standard drugs.</p> <p></p