Tip enhanced laser ablation sample transfer for mass spectrometry

© 2015 Materials Research Society. Mass spectrometry is one of the primary analysis techniques for biological analysis but there are technological barriers in sampling scale that must be overcome for it to be used to its full potential on the size scale of single cells. Current mass spectrometry imaging methods are limited in spatial resolution when analyzing large biomolecules. The goal of this project is to use atomic force microscope (AFM) tip enhanced laser ablation to remove material from cells and tissue and capture it for subsequent mass spectrometry analysis. The laser ablation sample transfer system uses an AFM stage to hold the metal-coated tip at a distance of approximately 10 nm from a sample surface. The metal tip acts as an antenna for the electromagnetic radiation and enables the ablation of the sample with a spot size much smaller than a laser focused with a conventional lens system. A pulsed nanosecond UV or visible wavelength laser is focused onto the gold-coated silicon tip at an angle nearly parallel with the surface, which results in the removal of material from a spot between 500 nm and 1 um in diameter and 200 and 500 nm deep. This corresponds to a few picograms of ablated material, which can be captured on a metal surface for MALDI analysis. We have used this approach to transfer small peptides and proteins from a thin film for analysis by mass spectrometry as a first step toward high spatial resolution imaging

Long-term effects of fertilizer and manure application on soil quality and sustainability of jute-rice-wheat production system in Indo-Gangetic plain

A long-term fertilizer experiment was initiated in 1971 in sandy loam soil (Eutrochrept) of Barrackpore, West Bengal to study the effects of applying organic and inorganic sources of nutrients on yield of jute-rice-wheat system and soil health. The unfertilized soil supported yields of 0.8 t ha-1 of jute fibre, 1.5 t ha-1 of rice grain and 0.7 t ha-1 of wheat grain (average yield of 42 years). Application of 150% recommended NPK through chemical fertilizers produced maximum yields of jute (2.1 t ha-1), rice (3.8 t ha-1) and wheat (2.8 t ha-1). The yields obtained with 150% NPK fertilizers were 5%, 2.7% and 12% higher than that with 100% NPK fertilizers +FYM. Combined application of 100% NPK fertilizers and FYM, however, increased soil organic carbon, available nitrogen, phosphorus and potassium from 5.60 to 8.90 g kg-1, 270 to 316 kg ha-1, 40.7 to 120 kg ha-1 and 139 to 236 kg ha-1 respectively. Maximum DTPA-extractable micronutrients in soil were also observed with 100%NPK fertilizers+FYM. Applying FYM together with NPK fertilizers increased microbial biomass from 221 to 435 mg kg-1 and microbial quotient from 3.95 to 4.89 with concomitant increase in dehydrogenase, phosphatase and fluorescein-diacetate-hydrolyzing activities in the soil. The acid phosphatase activity (139 to 275 ?g PNPg-1 h-1) was much lower than alkaline phosphatase activity  (479 to 616 ?g PNPg-1 h-1). The enzymes assayed showed significant correlation with microbial-C and organic C. Beneficial effects of integrated nutrient management (NPK+FYM) on soil health were reflected on the yields of all the crops

Development of Fluxed Iron Oxide Pellets for Steel Making Utilizing Waste Materials

Lump lime is conventionally used as a flux material in steel making. However, use of burnt lump lime often creates problem in operation due to its high melting point, poor dissolution property, fine generation tendency and hygroscopic nature. Lime in combination with iron oxide may form a low melting oxidizing slag and makes the refining process faster. In this context, NML has developed a novel process of making fluxed pellet utilizing waste materials from steel plant without using any binder and without firing. The developed pellet shows very good cold crushing strength (30Kg/pellet), drop impact strength (150) and tumbler index (98%). The high temperature properties of the pellets like thermal shock resistance, melting point (1180oC) and dissolution time (30-60 sec) in molten bath are also found to be excellent. Performance of pellets has been assessed in a simulated oxygen bottom blown process in laboratory scale. Very fast decarburization and dephosphorization, improved metallic yield and decrease in oxygen consumption with controlled foaming are observed. Overall, in the present study the lime-fluxed iron ore pellets, developed in a binder-less room temperature process utilizing waste materials of steel plant are found to possess good cold handling and thermal properties, and favorable melting and refining characteristics, to warrant their application as a partial/complete substitute of the traditional scrap-lime combination in basic oxygen steel making or faster refining in steel making process

Influence of surface engineering on 3D printed Ti lattice structure towards enhanced tissue integration: An in vitro and in vivo study

Reconstruction of segmental defects are popularly approached with surface engineered additively manufactured scaffolds owing to its enhanced post-surgery tissue integration properties. The present work is aimed at fabrication of Ti lattice structures using 3D printing, with a novel approach of silane chemistry-based surface modification of those Ti-surfaces with osteogenic peptides (OGP). The lattice structures with 0.6 mm strut-diameter having 0.5 mm inter-strut distance were chosen for fabrication using an extrusion-based 3D printing. Based on the evidence, it could be concluded that extrusion-based 3D printing is an optimal alternative as compared to those high cost incurring additive manufacturing processes. Therefore, OGP were grafted on the pristine Ti-surfaces using a silane chemistry based novel vapour deposition process. In vitro assessments of the surface modified scaffolds using human amniotic derived mesenchymal stem cells showed evidence of enhanced cell adhesion and viability. In vivo subcutaneous study in rat models of the surface modified Ti-scaffolds also showed enhanced tissue integration in terms of Collagen I deposition around the boundary of the tissue-integrated struts as compared to those of pristine scaffolds. The study has established that the novel surface modification technique is capable to engineer the Ti-surfaces towards enhanced tissue integration in vivo

Novel magnetite nanoparticles coated with waste sourced bio- based substances as sustainable and renewable adsorbing materials

This study examines the possibility of using bio-based product isolated from urban solid wastes as a material for environmental technological applications. To this end, Fe3O4 nanoparticles coated with different amounts of soluble bio-based products (SBO) were synthesized as low-cost nanoadsorbent for the removal of pollutants in wastewater. Particles of 10 nm diameter with Fe3O4 core and SBO shell were obtained. The concentration of SBO employed in the synthesis had no effect on the size and structure of the NPs, but ruled the pHPZC and aggregation of the nanoparticles in water. The cationic dye crystal violet (CV) was used as a model pollutant to test the adsorption capacity of the nanoparticles. The results indicated that both the medium pH and NP dosage were significant parameters to enhance the removal of CV. The results contribute to the studies which show how wastes can become a source of revenue through the industrial exploitation of their chemical value.Fil: Magnacca, Giuliana. Università di Torino; ItaliaFil: Allera, Alex. Università di Torino; ItaliaFil: Montoneri, Enzo. Università di Torino; ItaliaFil: Celi, Luisella. Università di Torino; ItaliaFil: Benito, Damián Ezequiel. Universidad Nacional de La Plata. Laboratorio de Investigación y Desarrollo de Métodos Analíticos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Gagliardi, Leonardo Gabriel. Universidad Nacional de La Plata. Laboratorio de Investigación y Desarrollo de Métodos Analíticos; ArgentinaFil: Martire, Daniel Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Gonzalez, Monica Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Carlos, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

Numerical study of nano-biofilm stagnation flow from a nonlinear stretching/shrinking surface with variable nanofluid and bioconvection transport properties

A mathematical model is developed for stagnation point flow toward a stretching or shrinking sheet of liquid nano-biofilm containing spherical nano-particles and bioconvecting gyrotactic micro-organisms. Variable transport properties of the liquid (viscosity, thermal conductivity, nano-particle species diffusivity) and micro-organisms (species diffusivity) are considered. Buongiorno’s two-component nanoscale model is deployed and spherical nanoparticles in a dilute nanofluid considered. Using a similarity transformation, the nonlinear systems of partial differential equations is converted into nonlinear ordinary differential equations. These resulting equations are solved numerically using a central space finite difference method in the CodeBlocks Fortran platform. Graphical plots for the distribution of reduced skin friction coefficient, reduced Nusselt number, reduced Sherwood number and the reduced local density of the motile microorganisms as well as the velocity, temperature, nanoparticle volume fraction and the density of motile microorganisms are presented for the influence of wall velocity power-law index (m), viscosity parameter (c2), thermal conductivity parameter (c4), nano-particle mass diffusivity (c6), micro-organism species diffusivity (c8), thermophoresis parameter (Nt), Brownian motion parameter (Nb), Lewis number (Le), bioconvection Schmidt number (Sc), bioconvection constant (σ) and bioconvection Péclet number (Pe). Validation of the solutions via comparison related to previous simpler models is included. Further verification of the general model is conducted with the Adomian decomposition method (ADM). Extensive interpretation of the physics is included. Skin friction is elevated with viscosity parameter (c2) whereas it is suppressed with greater Lewis number and thermophoresis parameter. Temperatures are elevated with increasing thermal conductivity parameter (c4) whereas Nusselt numbers are reduced. Nano-particle volume fraction (concentration) is enhanced with increasing nano-particle mass diffusivity parameter (c6) whereas it is markedly reduced with greater Lewis number (Le) and Brownian motion parameter (Nb). With increasing stretching/shrinking velocity power-law exponent (m), skin friction is decreased whereas Nusselt number and Sherwood number are both elevated. Motile microorganism density is boosted strongly with increasing micro-organism diffusivity parameter (c8) and Brownian motion parameter (Nb) but reduced considerably with greater bioconvection Schmidt number (Sc) and bioconvection Péclet number (Pe). The simulations find applications in deposition processes in nano-bio-coating manufacturing processes

Condensed-phase biogenic–anthropogenic interactions with implications for cold cloud formation

Anthropogenic and biogenic gas emissions contribute to the formation of secondary organic aerosol (SOA). When present, soot particles from fossil fuel combustion can acquire a coating of SOA. We investigate SOA-soot biogenic-anthropogenic interactions and their impact on ice nucleation in relation to the particles' organic phase state. SOA particles were generated from the OH oxidation of naphthalene, α-pinene, longifolene, or isoprene, with or without the presence of sulfate or soot particles. Corresponding particle glass transition (Tg) and full deliquescence relative humidity (FDRH) were estimated using a numerical diffusion model. Longifolene SOA particles are solid-like and all biogenic SOA sulfate mixtures exhibit a core-shell configuration (i.e. a sulfate-rich core coated with SOA). Biogenic SOA with or without sulfate formed ice at conditions expected for homogeneous ice nucleation, in agreement with respective Tg and FDRH. α-pinene SOA coated soot particles nucleated ice above the homogeneous freezing temperature with soot acting as ice nuclei (IN). At lower temperatures the α-pinene SOA coating can be semisolid, inducing ice nucleation. Naphthalene SOA coated soot particles acted as ice nuclei above and below the homogeneous freezing limit, which can be explained by the presence of a highly viscous SOA phase. Our results suggest that biogenic SOA does not play a significant role in mixed-phase cloud formation and the presence of sulfate renders this even less likely. However, anthropogenic SOA may have an enhancing effect on cloud glaciation under mixed-phase and cirrus cloud conditions compared to biogenic SOA that dominate during pre-industrial times or in pristine areas