Extended applications of electric cell-substrate impedance sensing for assessment of the structure-function of α2β1 integrin

Electric cell-substrate impedance sensing (ECIS) was applied to assess the structure-function of α2β1 integrin, receptor for collagen and laminin. On collagen-coated gold electrodes, expression of this integrin on human rhabdomyosarcoma (RD) cells (RDX2C2) yielded a five-fold increase in resistance when compared with mock transfected RD (RDpF) cells (34.5±5.2 versus 6.5±0.8 Ω/cell). An intermediate level of 16±2 Ω/cell was measured upon expression of an α2β1 mutant that lacked the α2 cytoplasmic domain (RDX2CO). On laminin, the resistance measured for RDX2C2 cells was also higher but only twice that of RDpF cells at 71±4 and 37±4 Ω/cell, respectively. In comparison, RDX2CO cells (38±4 Ω/cell), exhibiting no enhanced adhesive function, yielded a similar result to that of RDpF cells. On fibronectin, RDX2C2 and RDpF cells, exhibiting comparable levels of adhesion, were similar in resistance measurements at 85±5and 89±7 Ω/cell, respectively. It has been shown that deletion of α2 cytoplasmic domain results in dysregulated recruitment of the α2β1 mutant to focal adhesion complexes that mediate binding of fibronectin. RDX2CO cells on fibronectin, exhibiting reduced adhesive function, was associated with noticeably lower resistance (60±4 Ω/cell). Monitoring electroporation of the RD plasma membrane also indirectly validated cell attachment as reflected by the resistance measured. Results from this study demonstrated the potential of ECIS for study of the structure-function of βl integrin adhesion receptors.     

Base Catalysed Condensation of Acetone with Uracil Derivatives: One Step Synthesis of Pyranopyrimidines

Condensation of uracil derivatives (1,3,4) with acetone in the presence of triethylamine gave pyranopyrimidines (2,5,6).     

Studies on 1,10-Phenanthroline Complexes of Some Hydroxyaryltellurium Trihalides

The synthesis and structural features of some newly synthesized 1,10-phenanthroline complexes of p-hydroxyphenyl-and 3-methyl-4-hydroxyphenyltellurium trihalides (chlorides, bromides, and iodides) are reported. The resulting complexes have been subjected to elemental analyses, conductance and cryoscopic measurements, infra-red and proton magnetic resonance spectral studies. Solution studies reveal the weak to 1:1 electrolyte type behavior of these complexes in solution. Spectral studies indicate the linkage of phenanthroline to the tellurium atom through the nitrogen atoms. Central tellurium atom in these complexes is hexa-coordinated in an octahedral way.     

rmpM Genosensor for Detection of Human Brain Bacterial Meningitis in Cerebrospinal Fluid

Human brain bacterial meningitis is a life-threatening disease caused mainly by Neisseria meningitidis, lead to damage of the outer membrane covering (meninges) of brain or even death. The usual methods of diagnosis are either time-consuming or have some limitations. The specific rmpM (reduction-modifiable protein M) virulent gene based genosensor is more sensitive, specific, and can detect N. meningitidis directly from the patient cerebrospinal fluid in 30 min including 1-min response time. 5′-Thiol-labeled single-stranded DNA (ssDNA) probe was immobilized onto screen-printed gold electrode (SPGE) and hybridized with denatured (95 °C) single-stranded genomic DNA (ssG-DNA) for 10 min at 25 °C. The electrochemical response was measured by cyclic voltammetry, differential pulse voltammetry (DPV) and electrochemical impedance using redox indicators. The sensitivity of the genosensor was 9.5087?(μA/cm²)/ng with DPV and limit of detection was 3 ng/6 μL ssG-DNA. The immobilization of the ssDNA probe and hybridization with ssG-DNA from N. meningitidis was characterized by atomic force microscopy and Fourier transform infrared spectroscopy. The rmpM genosensor was stable for 6 months at 4 °C with 10 % loss in initial DPV current. The advantage of rmpM genosensor is to detect bacterial meningitis simultaneously in multiple patients using SPGE array during an outbreak of the disease.     

Spatial dependency of the groundwater uranium in the alluvial soil region of Gunnaur,India

Journal of Radioanalytical and Nuclear Chemistry - GIS based groundwater uranium and other physico-chemical parameters pH, electrical conductivity, oxidation reduction potential, temperature,...     

Dialkylzinc-assisted alkynylation of nitrones

[reaction: see text]. Reaction of nitrones with terminal alkynes takes place readily in the presence of a substoichiometric amount of diethylzinc in toluene, affording N-propargyl-hydroxylamines in excellent yields and purity.