20 research outputs found
Modulation of Sn concentration in ZnO nanorod array: intensification on the conductivity and humidity sensing properties
Tin (Sn)-doped zinc oxide (ZnO) nanorod arrays (TZO) were synthesized onto aluminum-doped ZnO-coated glass substrate via a facile sonicated sol–gel immersion method for humidity sensor applications. These nanorod arrays were grown at different Sn concentrations ranging from 0.6 to 3 at.%. X-ray diffraction patterns showed that the deposited TZO arrays exhibited a wurtzite structure. The stress/strain condition of the ZnO film metamorphosed from tensile strain/compressive stress to compressive strain/tensile stress when the Sn concentrations increased. Results indicated that 1 at.% Sn doping of TZO, which has the lowest tensile stress of 0.14 GPa, generated the highest conductivity of 1.31 S cm− 1. In addition, 1 at.% Sn doping of TZO possessed superior sensitivity to a humidity of 3.36. These results revealed that the optimum performance of a humidity-sensing device can be obtained mainly by controlling the amount of extrinsic element in a ZnO film
Disease-associated glycosylated molecular variants of human C-reactive protein activate complement-mediated hemolysis of erythrocytes in tuberculosis and Indian visceral leishmaniasis
Human C-reactive protein (CRP), as a mediator
of innate immunity, removed damaged cells by activating
the classical complement pathway. Previous studies have
successfully demonstrated that CRPs are differentially induced
as glycosylated molecular variants in certain pathological
conditions. Affinity-purified CRPs from two most
prevalent diseases in India viz. tuberculosis (TB) and
visceral leishmaniasis (VL) have differential glycosylation
in their sugar composition and linkages. As anemia is a
common manifestation in TB and VL, we assessed the
contributory role of glycosylated CRPs to influence hemolysis
via CRP-complement-pathway as compared to
healthy control subjects. Accordingly, the specific binding
of glycosylated CRPs with erythrocytes was established by
flow-cytometry and ELISA. Significantly, deglycosylated
CRPs showed a 7–8-fold reduced binding with erythrocytes
confirming the role of glycosylated moieties. Scatchard
analysis revealed striking differences in the apparent binding constants (104–105M−1) and number of binding
sites (106–107sites/erythrocyte) for CRP on patients’ erythrocytes
as compared to normal. Western blotting along with
immunoprecipitation analysis revealed the presence of
distinct molecular determinants on TB and VL erythrocytes
specific to disease-associated CRP. Increased fragility, hydrophobicity
and decreased rigidity of diseased-erythrocytes
upon binding with glycosylated CRP suggested membrane
damage. Finally, the erythrocyte-CRP binding was shown to
activate the CRP-complement-cascade causing hemolysis,
even at physiological concentration of CRP (10μg/ml).
Thus, it may be postulated that CRP have a protective role
towards the clearance of damaged-erythrocytes in these two
disease