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A novel microfilarial sheath protein (MfP) of the human filarial parasite Wuchereria bancrofti and its proinflammatory activity on host macrophages were identified recently. MfP is a homolog of the nematode bestrophin-9 superfamily that acts as a ligand of macrophage Toll-like receptor 4 (TLR4) to induce inflammation through NF-κB activation. Therefore, the presence and functional implication of this novel protein in adult-stage parasites were open questions to answer. In this study, the bovine filarial parasite Setaria cervi was used to simulate adult W. bancrofti. We detected the presence of MfP in adult-stage S. cervi through clear immunological cross-reactivity and immunolocalization employing an anti-MfP antibody developed in mice. Therefore, our findings put forward S. cervi as a cost-effective source of immunodominant filarial antigen MfP to simulate its future utilization in the immunotherapeutic intervention of lymphatic filariasis.
Efficacious therapeutic strategies against lymphatic filariasis are always sought after. However, natural products are a promising resource for developing effective antifilarial agents. Azadirachtin, a significant tetranortriterpenoid phytocompound found in Azadirachta indica, was evaluated in vitro for antifilarial potential against the filarial parasite Setaria cervi. Dye exclusion and MTT assay confirmed the antifilarial potential of azadirachtin against S. cervi with a median lethal dose (LC50) of 6.28 μg/ml for microfilariae (mf), and 9.55 μg/ml for adult parasites. Morphological aberrations were prominent in the histological sections of the azadirachtin-exposed parasites. Moreover, alterations in the reactive oxygen species (ROS) parameters in treated parasites were evident. Induction of apoptosis in treated parasites was confirmed by DNA laddering, acridine orange (AO)/ethidium bromide (EtBr) double staining and in situ DNA fragmentation. The downregulation of anti-apoptotic CED-9 and upregulation of proapoptotic EGL-1, CED-4 and CED-3 at both the transcription and translation levels confirmed apoptosis execution at the molecular level. Changes in the gene expressions of nuc-1, cps-6 and crn-1 further clarified the molecular cause of DNA degradation. Furthermore, azadirachtin was found to be non-toxic in both in vitro and in vivo toxicity analyses. Therefore, the experimental evidence detailed the pharmacological effectiveness of azadirachtin as a possible therapeutic agent against filariasis.
In this work, effects of heat treatment on the heterojunction between MoOx and ZnO quantum dots (QDs) are analyzed possibly for the first time. Solution-processed and thermal deposition technique is used for the growth of MoOx over the ZnO QDs and compared for the electrical analysis. The absorption and photoluminescence properties of ZnO QDs and MoOx have been analyzed for the optical behavior. Further, the heat-treated heterojunctions are analyzed for built-in potential (0.25 V), carrier density (~2.9 × 1018 cm−3), and responsivity (3.93 mAW−1). The heterojunction of solution-processed MoOx and ZnO QDs shows better stability after heat treatment compared with other devices.
The occurrence of pesticidal pollution in the environment and the resistance in the mosquito species makes an urge for the safer and an effective pesticide. Permethrin, a poorly water-soluble pyrethroid pesticide, was formulated into a hydrodispersible nanopowder through rapid solvent evaporation of pesticide-loaded oil in water microemulsion. Stability studies confirmed that the nanopermethrin dispersion was stable in paddy field water for 5 days with the mean particle sizes of 175.3 ± 0.75 nm and zeta potential of −30.6 ± 0.62 mV. The instability rate of the nanopermethrin particles was greater in alkaline (pH 10) medium when compared with the neutral (pH 7) and acidic (pH 4) dispersion medium. The colloidal dispersion at 45°C was found to be less stable compared with the dispersions at 25 and 5°C. The 12- and 24-h lethal indices (LC50) for nanopermethrin were found to be 0.057 and 0.014 mg l−1, respectively. These results were corroborative with the severity of damages observed in the mosquito larvae manifested in epithelial cells and the evacuation of the midgut contents. Further, the results were substantiated by the decrease in cellular biomolecules and biomarker enzyme activity in nanopermethrin treated larvae when compared to bulk and control treatment.
Does gender matter in people's attitudes and cooperation in community-based natural resource management? If so, how do gender differences in conservation-related attitudes help or hinder sustaining the commons? Since biases ingrained in community norms and expectations often exclude women from decision making in co-management, it is imperative to find plausible answers to these queries in order to understand gender relations and cooperation in co-management. To this end, the authors conducted psychometric surveys and trust experiments on 196 forest-dependent households in West Bengal, India during 2009–2010. The findings suggest that, despite an overall negative perception about women's involvement in co-management, women are more conservation friendly and pro-social than men. It is also noticed that forest biomass and forest incomes as the indicators of sustainability have increased in those forest communities where women's proportional strength as decision makers is greater and people hold an overall positive conservation attitude.
We have recently reported the repair of carious enamel using a full-length amelogenin–chitosan hydrogel through guided stabilization and growth of mineral clusters. The objective of this study was to further evaluate the enamel repair potential of smaller amelogenin peptides like LRAP (leucine-rich amelogenin peptide) and compare their efficiency with their full-length counterpart. The demineralized tooth slices treated with a single application of LRAP–chitosan hydrogel for 3 days showed a dense mineralized layer consisting of highly organized enamel-like apatite crystals. Focus-ion beam technique showed a seamless growth at the interface between the repaired layer and native enamel. There was a marked improvement in the surface hardness after treatment of the demineralized sample with almost 87% recovery of the hardness value to that of sound enamel sections. This current approach can inspire the design of smaller peptide analogues based on naturally occurring amelogenin as a competent, low-cost, and safe strategy for enamel biomimetics to curb the high prevalence of incipient dental caries.
In this work, a systematic study on the factors that influence the lower critical solution temperature (LCST) of poly(N-isopropylacrylamide) (PNIPAM) solutions during remote radiofrequency (RF) heating, using Fe3O4 magnetic nanoparticles (MNPs) is reported. A series of PNIPAM solutions with varying concentrations of Fe3O4 MNPs were prepared and characterized using transmission electron microscopy and Raman spectroscopy. Preliminary studies showed the highest specific absorption rate (SAR) for 15 nm sized Fe3O4 MNPs, which monotonically decreased as the MNP sizes increased to 20-30 nm. In-situ transmission measurements were used to determine the LCST of PNIPAM under various aqueous concentrations with dispersed Fe3O4 MNPs. A systematic decrease in the LCST from 34 °C to 31 °C was observed as the concentration of PNIPAM was increased from 0.3 wt. % to 1.0 wt. %, keeping the concentration of Fe3O4 MNPs constant. On the other hand, varying the concentrations of the MNPs did not drastically affect the LCSTs of PNIPAM solutions. However, varying the ion concentration of the PNIPAM solutions by adding adjusted KOH pellets, showed a pronounced lowering of the LCST by 2-3 °C at all PNIPAM concentrations. The remote triggering of phase transitions in PNIPAM solutions by raising the temperature above the LCST using Fe3O4 MNPs as reported here is important in targeted drug-delivery applications using thermo-responsive polymers.
Filariasis is a mosquito-borne disease that causes lymphedema and the main vector is Culex quinquefasciatus. A simple measure was taken to eradicate the vector using nanoemulsion. Eucalyptus oil nanoemulsion was formulated in various ratios comprising of eucalyptus oil, tween 80 and water by ultrasonication. The stability of nanoemulsion was observed over a period of time and 1:2 ratios of eucalyptus oil (6%) and surfactant (12%) was found to be stable. The formulated eucalyptus oil nanoemulsion was characterized by transmission electron microscopy and dynamic light scattering. The nanoemulsion droplets were found to have a Z-average diameter of 9.4 nm and were spherical in shape. The larvicidal activity of eucalyptus oil nanoemulsion and bulk emulsion was tested and compared. Our nanoemulsion showed higher activity when compared to bulk emulsion. The histopathology of larvae-treated and untreated nanoemulsion was analyzed. Furthermore, biochemical assays were carried out to examine the effect of nanoemulsion on biochemical characteristics of larvae. The treated larval homogenate showed decrease in total protein content and a significant reduction in the levels of acetylcholinesterase. The levels of acid and alkaline phosphatase also showed reduction as compared to control larval homogenate.
The art and science of using biological tissue grafts from animal and human
sources for various ailments is nascent. Various research groups around the
world are actively investigating the potential prostheses of biological
origin. Biological tissue grafts are rendered acellular through various
methods of processing and fabrication before they are used for the specific
purpose. The remainder is a scaffold that offers framework for host cellular
repopulation and revascularization. Different methods of fixation have been
explored over several decades to render the biological grafts suitable for
use with or without extraction of cells. Therefore, methods such as
glutaraldehyde and polyepoxide crosslinking treatments and dye-mediated
photooxidation have been developed to stabilize and deantigenize the tissue
while attempting to maintain its natural mechanical properties. Also,
residual cellular components in a bioprosthetic material have been
associated with undesired effects, such as calcification and immunological
recognition, and thus have been the motivation for various decellularization
processes. The effects of these stabilization and decellularization
treatments on mechanical, biological and chemical properties of treated
tissues have been investigated, specifically with regard to calcification,
immunogenicity, and cytotoxicity concerns. Naturally derived biological
scaffolds offer many mechanical, chemical and biological advantages over
synthetic materials, and thus hold tremendous potential for use in tissue
engineering therapies. Therefore the rationale of using biological grafts in
usable forms is gaining importance in order to avoid unwanted chronic
inflammatory reactions. This review article discusses the need for such
bioprosthetics and the potential role for natural tissues in various
Multilayered foils with 10%Cu/90%Ni and different bi-layer thickness (100-1000 nm) have been fabricated by electrodeposition. TEM and x-ray diffraction analysis indicate discrete layer formation and a (100) textured structure. The maximum tensile strength (590 MPa) is obtained for foils with the smallest layer thickness. Preliminary results on high temperature deformation show a strong dependence of strength and plasticity on layer thickness.
Superplastic testing of the aluminium-lithium alloy 8090 has been performed in the temperature range 485°C to 550°C. Up to 530°C, raising the test temperature has the effect of increasing the m-value and decreasing the flow stress. Changes in superplastic forming characteristics and microstructure have been followed during straining using a variety of techniques. Jump-strain rate testing reveals that in the optimum temperature range (515°C to 525°C).there is a steady decrease in m-value. Cavitation also occurs, but can be suppressed effectively by applying a hydrostatic pressure during testing. Raising the test temperature above this optimum range to 550°C produces a significant decrease in the m-value and a more rapid fall-off with strain. These observations are explained in terms of recrystallisation and grain growth, and the effectiveness of precipitates in pinning grain boundaries at the various temperatures.
PMOD (Photochemical Metal Organic Deposition)-based DTFI (Direct Thin Film Imaging) methodology is a demonstrated means for patterning organic materials on flexible (plastic) substrates. This process is used to pattern 1-micron features at an aspect ratio of 8:1 using contact lithography. Use of oxygen plasma RIE etch to transfer the hard mask pattern to the organic material allows for good sidewall angle control. High etch selectivity between the novolac polymer and PMOD TiOX hard mask (< 800:1) makes the use of very thin hard masks (∼ 200 angstroms) to pattern thick organic films (<10 microns) possible. Selective removal of the PMOD TiOX (TiO2) hard mask makes this process amenable to patterning of functional organic structures fabricated from materials chosen for their desired properties (e.g., glass transition temperature (Tg), etch resisitance, optical properties, mechanical properties, etc.) not their ability to be photopatterned (e.g., photoresist).
Sensorineural hearing loss results from the inability of the inner ear cochlear organ of Corti to transduce mechanical energy incident in the cochlea to electrical signals in auditory nerve fibers. Cochlear implant devices are used to alleviate this condition. Piezoelectric materials offer the unique scope of functioning as cochlear implants, possibly enabling simplification of the process of electrical stimulation and enhancing knowledge of the workings of both the healthy and artificially stimulated inner ear. The requirements imposed on such a device are discussed. It is believed that flexible piezoelectric PVDF and ceramic-polymer composites are best suited for this application. The design of a device which utilizes the bending piezoelectric mode, and results of testing the same in air are presented. Present work is aimed at understanding the fundamental dynamic piezoelectric properties in this mode and is expected to result in a device suitable for in vitro and in vivo testing.
Issues associated with trench etching in low-k OSG (organosilicate glass) films for dual damascene applications and in particular for “via-first” integration scheme were the focus of this study. As a result of designed experiment in dipole ring magnet (DRM) etcher with C4F8/N2/Ar gas mixture the trench process was established with sidewall profile 89° and flat bottom. Selectivity obtained was enough to pursue etch processes using planarizing BARC (bottom antireflective coating) for additional via bottom protection. BARC fill in vias and BARC opening time were tuned to reduce generation of polymers during etch. Effective combination of dry /wet clean recipes was developed for removal of post-RIE (reactive ion etching) residues without significant changes in OSG k-value. Optimized processes were successfully used for creating dual damascene structure complying with integration requirements for 0.13 μm design rules.
A new polymorph of Al2(WO4)3 is observed from in situ high pressure powder X-ray diffraction (ADXRD) measurements at 3.4 GPa. The ADXRD pattern at 3.4 GPa could be explained based on a monoclinic lattice (space group P21) with unit cell parameters: a=9.5884(24), b=12.5204(38), c=7.8463(33) Å, and β=91.98(2)°.