Effect of basic oxygen furnace slag particle size on sequestration of carbon dioxide from landfill gas.

The mineral carbon sequestration capacity of basic oxygen furnace (BOF) slag offers great potential to absorb carbon dioxide (CO2) from landfill emissions. The BOF slag is highly alkaline and rich in calcium (Ca) containing minerals that can react with the CO2 to form stable carbonates. This property of BOF slag makes it appealing for use in CO2 sequestration from landfill gas. In a previous study, CO2 and CH4 removal from the landfill gas was investigated by performing batch and column experiments with BOF slag under different moisture and synthetic landfill gas exposure conditions. The study showed two stage CO2 removal mechanism: (1) initial rapid CO2 removal, which was attributed to the carbonation of free lime (CaO) and portlandite [(Ca(OH)2)], and (2) long-term relatively slower CO2 removal, which was attributed to be the gradual leaching of Ca2+ from minerals (calcium-silicates) present in the BOF slag. Realising that the particle size could be an important factor affecting total CO2 sequestration capacity, this study investigates the effect of gradation on the CO2 sequestration capacity of the BOF slag under simulated landfill gas conditions. Batch and column experiments were performed with BOF slag using three gradations: (1) coarse (D50 = 3.05 mm), (2) original (D50 = 0.47 mm), and (3) fine (D50 = 0.094 mm). The respective CO2 sequestration potentials attained were 255 mg g-1, 155 mg g-1, and 66 mg g-1. The highest CO2 sequestration capacity of fine BOF slag was attributed to the availability of calcium containing minerals on the slag particle surface owing to the highest surface area and shortest leaching path for the Ca2+ from the inner core of the slag particles.

Biological evaluation of ultrananocrystalline and nanocrystalline diamond coatings.

Nanostructured biomaterials have been investigated for achieving desirable tissue-material interactions in medical implants. Ultrananocrystalline diamond (UNCD) and nanocrystalline diamond (NCD) coatings are the two most studied classes of synthetic diamond coatings; these materials are grown using chemical vapor deposition and are classified based on their nanostructure, grain size, and sp3 content. UNCD and NCD are mechanically robust, chemically inert, biocompatible, and wear resistant, making them ideal implant coatings. UNCD and NCD have been recently investigated for ophthalmic, cardiovascular, dental, and orthopaedic device applications. The aim of this study was (a) to evaluate the in vitro biocompatibility of UNCD and NCD coatings and (b) to determine if variations in surface topography and sp3 content affect cellular response. Diamond coatings with various nanoscale topographies (grain sizes 5-400 nm) were deposited on silicon substrates using microwave plasma chemical vapor deposition. Scanning electron microscopy and atomic force microscopy revealed uniform coatings with different scales of surface topography; Raman spectroscopy confirmed the presence of carbon bonding typical of diamond coatings. Cell viability, proliferation, and morphology responses of human bone marrow-derived mesenchymal stem cells (hBMSCs) to UNCD and NCD surfaces were evaluated. The hBMSCs on UNCD and NCD coatings exhibited similar cell viability, proliferation, and morphology as those on the control material, tissue culture polystyrene. No significant differences in cellular response were observed on UNCD and NCD coatings with different nanoscale topographies. Our data shows that both UNCD and NCD coatings demonstrate in vitro biocompatibility irrespective of surface topography.

Pulse laser deposited nanostructured ZnO thin films: a review.

This review summarizes the work principles of pulse laser deposition (PLD) apparatus, physical processes like ablation, and plasma plume formation accompanying the deposition of un-doped ZnO from target to substrate material. Various modes of deposition and factors influencing the properties of thin films such as substrate temperature, background gas pressure, laser energy density (laser fluence), target to substrate distance, repetition rate, oxygen partial pressure in deposition chamber, deposition time and post growth annealing which control deposition parameters such as adsorption, desorption, surface diffusion, nucleation, and crystallization/re-crystallization are also discussed in this review. Moreover, various film properties such as morphology, roughness of the film surface, film thickness, grain size, optical transmittance, sensitivity, electrical conductivity, uniformity and electrical resistivity of the deposited ZnO thin films have also been enumerated in the present review.

Three new species of the genus Odontomutilla Ashmead, 1899 (Hymenoptera: Mutillidae) from India.

Three new species of velvet ant, Odontomutilla jaferpaloti sp. nov. (India: Karnataka), O. vishwanathi sp. nov. (India: Karnataka), and O. himalayensis sp. nov. (India: Uttarakhand), are described and illustrated. Diagnostic features of these new species, to separate them from similar species are provided. The updated key to the species of India is given.

Differential migration and proliferation of geometrical ensembles of cell clusters.

Differential cell migration and growth drives the organization of specific tissue forms and plays a critical role in embryonic development, tissue morphogenesis, and tumor invasion. Localized gradients of soluble factors and extracellular matrix have been shown to modulate cell migration and proliferation. Here we show that in addition to these factors, initial tissue geometry can feedback to generate differential proliferation, cell polarity, and migration patterns. We apply layer by layer polyelectrolyte assembly to confine multicellular organization and subsequently release cells to demonstrate the spatial patterns of cell migration and growth. The cell shapes, spreading areas, and cell-cell contacts are influenced strongly by the confining geometry. Cells within geometric ensembles are morphologically polarized. Symmetry breaking was observed for cells on the circular pattern and cells migrate toward the corners and in the direction parallel to the longest dimension of the geometric shapes. This migration pattern is disrupted when actomyosin based tension was inhibited. Cells near the edge or corner of geometric shapes proliferate while cells within do not. Regions of higher rate of cell migration corresponded to regions of concentrated growth. These findings demonstrate that multicellular organization can result in spatial patterns of migration and proliferation.

A Revolutionary Blueprint for Mitigation of Hypertension via Nanoemulsion.

Hypertension is one of the most important causes of mortality, affecting the health status of the patient. At the same time, hypertension causes a huge health and economic burden on the whole world. The incidence and prevalence of hypertension are rising even among young people in both urban as well as rural communities. Although various conventional therapeutic moieties are available for the management of hypertension, they have serious flaws such as hepatic metabolism, reduced dose frequency, poor aqueous solubility, reduced bioavailability, and increased adverse effects, making the drug therapy ineffective. Therefore, it is required to design a novel drug delivery system having the capability to solve the constraints associated with conventional treatment of hypertension. Nanotechnology is a new way of using and manipulating the matter at the molecular level, whose functional organization is measured in nanometers. The applications of nanotechnology in the field of medicine provide an alternative and novel direction for the treatment of cardiovascular diseases and show excellent performance in the field of targeted drug therapy. Various nanotechnologies based drug delivery systems, such as solid lipid nanoparticles, nanosuspension, nanoemulsion, liposome, self-emulsifying systems, and polymeric nanoparticles, are available. Among them, nanoemulsion has provided a niche to supplement currently available therapeutic choices due to numerous benefits like stability, ease of preparation, enhanced drug absorption, reduced hepatic metabolism, increased dose frequency, enhanced bioavailability, and encapsulation of hydrophilic as well as hydrophobic drugs. This present review provides an in-depth idea about progression in treatment of hypertension, constraints for antihypertensive drug therapy, need of nanoemulsions to overcome these constraints, comparative analysis of nanoemulsions over other nanostructure drug delivery systems, pharmacodynamics studies of nanoemulsions for treatment of hypertension, recent patents for drug-loaded nanoemulsions meant for hypertension, and marketed formulations of nanoemulsions for hypertension.

Review of the genus Odontomutilla Ashmead, 1899 (Hymenoptera: Mutillidae) of the Indian subcontinent, with description of two new species.

Review of the 12 species and one subspecies of the genus Odontomutilla of the Indian subcontinent is provided. Two new species, O. sairandhriensis Terine, Girish Kumar Lelej, sp. nov., ♀ (Kerala part of Southern Western Ghats) and O. fletcheri Lelej, Terine Girish Kumar, sp. nov. ♀, ♂ (Sri Lanka), and the hitherto unknown male of O. trichocondyla (André, 1894) are described and illustrated. Mutilla indiga Bingham, 1908, ♂ (India: Uttar Pradesh) is transferred from the genus Odontomutilla to Smicromyrme Thomson, 1870 (comb. nov.). Odontomutilla speciosa (Smith, 1855), ♀ is excluded from the Indian subcontinent fauna as misidentified O. spectra (Bingham, 1908). Keys to the 12 species and one subspecies (males and females) of the genus are given.

Effect of basic oxygen furnace slag type on carbon dioxide sequestration from landfill gas emissions.

This study investigates the carbon dioxide (CO2) sequestration potential of three different basic oxygen furnace (BOF) slags (IHE-3/15, IHE-9/17, and Riverdale) subjected to simulated landfill gas (LFG) conditions (50% CH4 and 50% CO2 v/v) in a series of batch and column experiments. Batch experiments were performed at different moisture contents (0%, 10%, 15% and 20% moisture by weight) and temperatures (7 °C, 23 °C and 54 °C) to examine the effect of moisture and temperature on the CO2 sequestration potential of the BOF slags. The column experiments were conducted under continuous humid gas flow conditions. The results from the batch experiments show that the CO2 sequestration was significantly higher in a moist state (10%, 15%, 20% moisture (w/w)) versus the dry state (0% moisture). The optimum moisture content (w/w) for CO2 sequestration was different for each BOF slag; IHE-3/15 (10%), IHE-9/17 (20%) and Riverdale (20%). The variation in ambient temperature did not show any significant effect on the CO2 sequestration capacity of the BOF slags. The CO2 sequestration capacity of IHE-3/15, IHE-9/17 and Riverdale BOF slags determined by long-term batch experiments were 105 mg/g, 80 mg/g and 67 mg/g, respectively. The IHE-3/15 slag demonstrated the highest carbonation potential and was attributed to its finer particle size and higher free lime, portlandite and larnite content. The IHE-9/17 and Riverdale slags showed significantly lower CO2 sequestration capacity in comparison to the IHE-3/15 slag. The amount of free lime, portlandite and larnite, which are considered to be the most reactive minerals during carbonation, was nearly 1.3 times less than that of the IHE-3/15 slag in the IHE-9/17 and Riverdale slags. Also, the Riverdale slag showed relatively lower CO2 sequestration in column experiment in comparison to the batch experiments, perhaps due to a high in-situ density which limited CO2 diffusion and hence the CO2 uptake. Overall, this study provides a means to analyze the suitability of the use of BOF slags in landfill covers for mitigating fugitive CO2 emissions from landfills.

Formation of capillary tube-like structures on micropatterned biomaterials.

The survival of three-dimensional tissue requires a vascular network to provide transport of oxygen and metabolic byproduct. Here, we report a new approach to create capillary blood vessels in vitro on biomaterials suitable for use as scaffolds in engineering tissues. Endothelial cells were cultured on chemical and topographical patterns of micro-sized grooves on gelatin. Selective attachment and spreading of cells within the grooves was ensured by microcontact printing the plateau regions with cell resistant PEG/PLA (polyethyleneglycol-L-polylacticacid). Human microvascular endothelial cells plated on these patterned biomaterials attached and spread exclusively within the grooves. These topographical features promote endothelial cells to form capillary tube-like structures. The results demonstrated that capillary structures formed on biomaterials are useful for engineering vascularized tissues.

Biological responses to immobilized microscale and nanoscale surface topographies.

Cellular responses are highly influenced by biochemical and biomechanical interactions with the extracellular matrix (ECM). Due to the impact of ECM architecture on cellular responses, significant research has been dedicated towards developing biomaterials that mimic the physiological environment for design of improved medical devices and tissue engineering scaffolds. Surface topographies with microscale and nanoscale features have demonstrated an effect on numerous cellular responses, including cell adhesion, migration, proliferation, gene expression, protein production, and differentiation; however, relationships between biological responses and surface topographies are difficult to establish due to differences in cell types and biomaterial surface properties. Therefore, it is important to optimize implant surface feature characteristics to elicit desirable biological responses for specific applications. The goal of this work was to review studies investigating the effects of microstructured and nanostructured biomaterials on in vitro biological responses through fabrication of microscale and nanoscale surface topographies, physico-chemical characterization of material surface properties, investigation of protein adsorption dynamics, and evaluation of cellular responses in specific biomedical applications.

Nanoporous Aluminum Oxide Membranes Coated with Atomic Layer Deposition-Grown Titanium Dioxide for Biomedical Applications: An In Vitro Evaluation.

The surface topographies of nanoporous anodic aluminum oxide (AAO) and titanium dioxide (TiO2) membranes have been shown to modulate cell response in orthopedic and skin wound repair applications. In this study, we: (1) demonstrate an improved atomic layer deposition (ALD) method for coating the porous structures of 20, 100, and 200 nm pore diameter AAO with nanometer-thick layers of TiO2 and (2) evaluate the effects of uncoated AAO and TiO2-coated AAO on cellular responses. The TiO2 coatings were deposited on the AAO membranes without compromising the openings of the nanoscale pores. The 20 nm TiO2-coated membranes showed the highest amount of initial protein adsorption via the micro bicinchoninic acid (micro-BCA) assay; all of the TiO2-coated membranes showed slightly higher protein adsorption than the uncoated control materials. Cell viability, proliferation, and inflammatory responses on the TiO2-coated AAO membranes showed no adverse outcomes. For all of the tested surfaces, normal increases in proliferation (DNA content) of L929 fibroblasts were observed over from 4 hours to 72 hours. No increases in TNF-alpha production were seen in RAW 264.7 macrophages grown on TiO2-coated AAO membranes compared to uncoated AAO membranes and tissue culture polystyrene (TCPS) surfaces. Both uncoated AAO membranes and TiO2-coated AAO membranes showed no significant effects on cell growth and inflammatory responses. The results suggest that TiO2-coated AAO may serve as a reasonable prototype material for the development of nanostructured wound repair devices and orthopedic implants.

Laser 3D printing with sub-microscale resolution of porous elastomeric scaffolds for supporting human bone stem cells.

A reproducible method is needed to fabricate 3D scaffold constructs that results in periodic and uniform structures with precise control at sub-micrometer and micrometer length scales. In this study, fabrication of scaffolds by two-photon polymerization (2PP) of a biodegradable urethane and acrylate-based photoelastomer is demonstrated. This material supports 2PP processing with sub-micrometer spatial resolution. The high photoreactivity of the biophotoelastomer permits 2PP processing at a scanning speed of 1000 mm s(-1), facilitating rapid fabrication of relatively large structures (>5 mm(3)). These structures are custom printed for in vitro assay screening in 96-well plates and are sufficiently flexible to enable facile handling and transplantation. These results indicate that stable scaffolds with porosities of greater than 60% can be produced using 2PP. Human bone marrow stromal cells grown on 3D scaffolds exhibit increased growth and proliferation compared to smooth 2D scaffold controls. 3D scaffolds adsorb larger amounts of protein than smooth 2D scaffolds due to their larger surface area; the scaffolds also allow cells to attach in multiple planes and to completely infiltrate the porous scaffolds. The flexible photoelastomer material is biocompatible in vitro and is associated with facile handling, making it a viable candidate for further study of complex 3D-printed scaffolds.

Ontology analysis of global gene expression differences of human bone marrow stromal cells cultured on 3D scaffolds or 2D films.

Differences in gene expression of human bone marrow stromal cells (hBMSCs) during culture in three-dimensional (3D) nanofiber scaffolds or on two-dimensional (2D) films were investigated via pathway analysis of microarray mRNA expression profiles. Previous work has shown that hBMSC culture in nanofiber scaffolds can induce osteogenic differentiation in the absence of osteogenic supplements (OS). Analysis using ontology databases revealed that nanofibers and OS regulated similar pathways and that both were enriched for TGF-ß and cell-adhesion/ECM-receptor pathways. The most notable difference between the two was that nanofibers had stronger enrichment for cell-adhesion/ECM-receptor pathways. Comparison of nanofibers scaffolds with flat films yielded stronger differences in gene expression than comparison of nanofibers made from different polymers, suggesting that substrate structure had stronger effects on cell function than substrate polymer composition. These results demonstrate that physical (nanofibers) and biochemical (OS) signals regulate similar ontological pathways, suggesting that these cues use similar molecular mechanisms to control hBMSC differentiation.

Two-photon polymerization of 3-D zirconium oxide hybrid scaffolds for long-term stem cell growth.

Two-photon polymerization is a technique that involves simultaneous absorption of two photons from a femtosecond laser for selective polymerization of a photosensitive material. In this study, two-photon polymerization was used for layer-by-layer fabrication of 3-D scaffolds composed of an inorganic-organic zirconium oxide hybrid material. Four types of scaffold microarchitectures were created, which exhibit layers of parallel line features at various orientations as well as pores between the line features. Long-term cell culture studies involving human bone marrow stromal cells were conducted using these 3-D scaffolds. Cellular adhesion and proliferation were demonstrated on all of the scaffold types; tissuelike structure was shown to span the pores. This study indicates that two-photon polymerization may be used to create microstructured scaffolds out of an inorganic-organic zirconium oxide hybrid material for use in 3-D tissue culture systems.

Geometric control of cell migration.

Morphological polarization involving changes in cell shape and redistribution of cellular signaling machinery, initiate the migration of mammalian cells. Golgi complex typically localizes in front of the nucleus, and this frontwards polarization has been proposed to be involved in directional migration. However, the sequence of events remains unresolved. Does Golgi polarization precede directional migration or vice-versa? We address this question by constraining cells to specific areas and shapes then tracking their motile behavior and the spatio-temporal distribution of Golgi apparatus upon release. Results show that while the position of the Golgi complex depends on the cell geometry, the subcellular localization of the Golgi complex does not define the cell's leading edge. Cells constrained within elongated geometries exhibit polarized extension of lamellipodia and upon release, migrate preferentially along the long axis of the cell. Minimally constrained cells released from larger areas however, exhibit retarded migration regardless of lamellipodia protrusion activity.

Micropatterning different cell types with microarray amplification of natural directional persistence.

In vivo, different cell types assemble in specific patterns to form functional tissues. Reproducing this process in vitro by designing scaffold materials to direct cells precisely to the right locations at the right time is important for the next generation of biomaterials. Here, using microarray amplification of natural directional persistence (MANDIP), simultaneous assembly of fibroblasts and endothelial cells is demonstrated by directing their long-range migration. Amplification of the directional persistence occurs through morphology-induced polarity and the asymmetric positioning of individual microsized adhesive islands that restrict lamellipodia attachment, and thus migration, to one preset direction. Quantitative analysis of cell migration on different MANDIP designs yields insight to the relative importance of the asymmetric island shapes and their arrangement. The approach enables spatial patterning of different cell types with micrometer-scale precision over large areas for investigation of cell-cell interactions within complex tissue architectures.

Liquid supported denture-management of flabby ridges.

The ideal properties of a denture are adequate rigidity on polished surface to bear masticatory forces and at the same time, flexibility and softness on the tissue surface for proper and even distribution of masticatory forces. The problem with conventional denture is rigidity of tissue surface; leads to uneven distribution of load. This drawback even worsens in the case of flabby, atrophic and unemployed ridges with excessive bone resorption. The liquid supported denture allows continued adaptation and eliminates the disadvantages of denture designs based on the application of temporary tissue conditioners or soft liners.