4,663 research outputs found
Preparation, Characterization and Spectroscopic Study of New Tridentate Schiff Base and its Cu(II), Ni(II) and Zn(II) Metal Complexes
A new tridentate ligand has been synthesized derived from phenyl(pyridin-3-yl)methanone. Three coordinated metal complexes were prepared by complexation of the new ligand with Cu(II), Ni(II) and Zn(II) metal salts. The new Schiff base “benzyl -2-[phenyl(pyridin-3-yl)methylidene]hydrazinecarbodithioate” and the new metal complexes were characterized using various physico-chemical and spectroscopic techniques. From the analysis results, the expected structure to the metal complexes are octahedral in geometry for Cu(II) complex, square planner for Ni(II) and tetrahedral for Zn(II) complex. The new compounds are expected to show strong bioactivity against bacteria and cancer cells
Synthesis, Characterization and Bioactivity of New Phosphorous Containing Schiff Bases Prepared from Dithiocarbazate Derivatives and their Transition Metal Complexes
Twelve novel phosphorous containing Schiff bases derived from the four isomeric dithiocarbazates which are methyl hydrazinecrabodithioate (SMDTC), phenyl hydrazinecarbodithioate (SBDTC), 2-methylbenzyl hydrazinecarbodithioate (S2MBDTC) and 4-methylbenzyl hydrazinecarbodithioate (S4MBDTC) with 2-(diphenylphosphino) benzaldehyde (DPPB), (triphenylphosphanylidene) acetaldehyde (TPPA) and (triphenylphosphanylidene)propan-2-one (TPPP). Metal complexes of Cd(II), Co(III), Cu(II), Ni(II) and Zn(II) were synthesized from these twelve Schiff bases to obtain sixty metal complexes. All these novel compounds have been successfully synthesized and characterized by various physico-chemical and spectroscopic techniques. The structures of nine Schiff bases and two transition metal complexes were successfully determined via X-ray crystallographic analysis.
Four novel Schiff bases were coordinated in their metal complexes through nitrogen, sulfur and phosphorous donor atoms (PNS tridentate ligands), while the other eight Schiff bases coordinated through nitrogen and sulfur donor atoms (NS bidentate ligands). The cobalt complexes Co(SMDPB)2 NO3. 3H2O had distorted octahedral geometry, coordinating via the triphenylphosphine phosphorous, azomethine nitrogen and thiolate sulphur atoms of the Schiff bases. The nickel complex has square planar geometry and coordinated via azomethine nitrogen and thiolate sulphur atoms of the Schiff base, while the λ5 phosphorous do not coordinate.
All the seventy two novel compounds have been evaluated for their biological activities against certain pathogenic microbial and two breast cancer cell lines, MCF-7 (human breast carcinoma cells with positive estrogen receptor) and MDA-MB231 (human breast carcinoma cells with negative estrogen receptor). The complexes were mostly antibacterial, but were less active against the fungal strains tested. The Schiff bases in this study show a weak activity except for S2MBDTPA which shows a moderate activity. Complexation of these Schiff bases with the transition metal ions will enhance and increased the activity significantly. It was also found that the complexes contain λ5 P shows more activity than λ3 P. The complexes were generally more active against the MCF-7 cell line as compared to the MDA-MB231 cell line. Most of the metal complexes exhibited higher bioactivity compared to their ligands in the complexes
Synthesis and Characterization of Novel Methyl 2-(1,7,7-Tri methylbicyclo[2.2.1]hept-2-yieldene)hydrazinecarbodithioate Schiff Bases Derived From Methylhydrazine carbodithioate And Their Bi(III) And Ag(II) Complexes
Novel bidentate Schiff bases having nitrogen-sulphur donor sequence was synthesized from condensation of racemate camphor, (R)-camphor and (S)-camphor with Methyl hydrazinecarbodithioate (SMDTC). Its metal complexes were also prepared through the reaction of these ligands with silver and bismuth salts. All complexes were characterized by elemental analyses and various physico-chemical techniques. These Schiff bases behaved as uninegatively charged bidentate ligands and coordinated to the metal ions via ?-nitrogen and thiolate sulphur atoms. The NS Schiff bases formed complexes of general formula, [M(NS)2] or [M(NS)2.H2O] where M is BiIII or AgI, the expected geometry is octahedral for Bi(III) complexes while Ag(I) is expected to oxidized to Ag(II) forming square planner complexes
Predicting the likelihood of heart failure with a multi level risk assessment using decision tree
Heart failure comes in the top causes of death worldwide. The number of deaths from heart failure exceeds the number of deaths resulting from any other causes. Recent studies have focused on the use of machine learning techniques to develop predictive models that are able to predict the incidence of heart failure. The majority of these studies have used a binary output class, in which the prediction would be either the presence or absence of heart failure. In this study, a multi-level risk assessment of developing heart failure has been proposed, in which a five risk levels of heart failure can be predicted using C4.5 decision tree classifier. On the other hand, we are boosting the early prediction of heart failure through involving three main risk factors with the heart failure data set. Our predictive model shows an improvement on existing studies with 86.5% sensitivity, 95.5% specificity, and 86.53% accuracy
Prediction of Flood Severity Level Via Processing IoT Sensor Data Using Data Science Approach
The ‘riverine flooding’ is deemed a catastrophic phenomenon caused by extreme climate changes and other ecological factors (e.g., amount of sunlight), which are difficult to predict and monitor. However, the use of internet of things (IoT), various types of sensing including social sensing, 5G wireless communication and big data analysis have devised advanced tools for early prediction and management of distrust events. To this end, this paper amalgamates machine learning models and data analytics approaches along-with IoT sensor data to investigate attribute importance for the prediction of risk levels in flood. The paper presents three river levels: normal, medium and high-risk river levels for machine learning models. Performance is evaluated with varying configurations and evaluations setup including training and testing of support vector machine and random forest using principal components analysis-based dimension reduced dataset. In addition, we investigated the use of synthetic minority over-sampling technique to balance the class representations within dataset. As expected, the results indicated that a “balanced” representation of data samples achieved high accuracy (nearly 93%) when benchmarked with “imbalanced” data samples using random forest classifier 10-folds cross-validation
Heterogeneity in Phenotype of Usher-Congenital Hyperinsulinism Syndrome:Hearing Loss, Retinitis Pigmentosa, and Hyperinsulinemic Hypoglycemia Ranging from Severe to Mild with Conversion to Diabetes
OBJECTIVE: To evaluate the phenotype of 15 children with congenital hyperinsulinism (CHI) and profound hearing loss, known as Homozygous 11p15-p14 Deletion syndrome (MIM #606528). RESEARCH DESIGN AND METHODS: Prospective clinical follow-up and genetic analysis by direct sequencing, multiplex ligation-dependent probe amplification, and microsatellite markers. RESULTS: Genetic testing identified the previous described homozygous deletion in 11p15, USH1C:c.(90+592)_ABCC8:c.(2694–528)del. Fourteen patients had severe CHI demanding near-total pancreatectomy. In one patient with mild, transient neonatal hypoglycemia and nonautoimmune diabetes at age 11 years, no additional mutations were found in HNF1A, HNF4A, GCK, INS, and INSR. Retinitis pigmentosa was found in two patients aged 9 and 13 years. No patients had enteropathy or renal tubular defects. Neuromotor development ranged from normal to severe delay with epilepsy. CONCLUSIONS: The phenotype of Homozygous 11p15-p14 Deletion syndrome, or Usher-CHI syndrome, includes any severity of neonatal-onset CHI and severe, sensorineural hearing loss. Retinitis pigmentosa and nonautoimmune diabetes may occur in adolescence
Employing hot wire anemometry to directly measure the water balance in a proton exchange membrane fuel cell
Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.Water management in proton exchange membrane fuel cells (PEMFC’s) remains a critical problem for their durability, cost, and performance. Because the anode side of this fuel cell has the tendency to become dehydrated, measuring the water balance can be an important diagnosis tool during fuel cell operation. The water balance indicates how much of the product water leaves at the anode side versus the cathode side. Previous methods of determining the fuel cell water balance often relied on condensing the water in the exhaust gas streams and weighing the accumulated mass which is a time consuming process that has limited accuracy. Currently, our group is developing a novel method to accurately determine the water balance in a PEMFC in real time by employing hot-wire anemometry. The amount of heat transferred from the wire to the anode exhaust stream can be translated into a voltage signal which can be directly converted into the fuel cell water balance. In this work, experimental ex-situ results are presented and the elegance and usefulness of this method is demonstrated.This project has been sponsored by EUDP, J.nr. 64012-
0117 and by PSO under the ForskEL program, Project nr.2013-
1-12041.am201
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