A review of localization systems for robotic endoscopic capsules

Obscure gastrointestinal (GI) bleeding, Crohn disease, Celiac disease, small bower tumors, and other disorders that occur in the GI tract have always been challenging to be diagnosed and treated due to the inevitable difficulty in accessing such a complex environment within the human body. With the invention of wireless capsule endoscope, the next generation of the traditional cabled endoscope, not only a dream has come true for the patients who have experienced a great discomfort and unpleasantness caused by the conventional endoscopic method, but also a new research field has been opened to develop a complete miniature robotic device that is swallowable and has full functions of diagnosis and treatment of the GI diseases. However, such an ideal device needs to be equipped with a highly accurate localization system to be able to exactly determine the location of lesions in the GI tract and provide essential feedback to an actuation mechanism controlling the device's movement. This paper presents a comprehensive overview of the localization systems for robotic endoscopic capsules, for which the motivation, challenges, and possible solutions of the proposed localization methods are also discussed.     

Effects of fuel ethanol content and volatility on regulated and unregulated exhaust emissions for the latest technology gasoline vehicles

Oxygenate content and fuel volatility (distillation) variables are important parameters affecting vehicle exhaust emissions, and data on their effects on the latest technology vehicles are quite limited. For this study, 12 California-certified LEV to SULEV vehicles were tested on a matrix of 12 fuels with varying levels of ethanol concentration (0, 5.7, and 10 vol %), T50 (195, 215, and 235 degrees F), and T90 (295, 330, and 355 degrees F). There were statistically significant interactions between ethanol and T90 for NMHC, ethanol, and T50 for CO and ethanol and T50 for NO(x). NMHC emissions increased with increasing ethanol content at the midpoint and high level of T90 but were unaffected at the low T90 level. CO emissions decreased as the ethanol content increased from the low to the midpoint level for all levels of T50, but between the 5.7 and 10% ethanol levels, CO showed only an increase for the high level of T50. NO(x) emissions increased with ethanol content for some conditions. Non-methane organic gases (NMOG) and toxic emissions were examined for only a subset of fuels with the highest T90 level, with NMOG, acetaldehyde, benzene, and 1-,3-butadiene all found to increase with increasing ethanol content.     

Nucleation mechanism for the direct graphite-to-diamond phase transition

Graphite and diamond have comparable free energies, yet forming diamond from graphite in the absence of a catalyst requires pressures that are significantly higher than those at equilibrium coexistence. At lower temperatures, the formation of the metastable hexagonal polymorph of diamond is favoured instead of the more stable cubic diamond. These phenomena cannot be explained by the concerted mechanism suggested in previous theoretical studies. Using an ab initio quality neural-network potential, we carried out a large-scale study of the graphite-to-diamond transition assuming that it occurs through nucleation. The nucleation mechanism accounts for the observed phenomenology and reveals its microscopic origins. We demonstrate that the large lattice distortions that accompany the formation of diamond nuclei inhibit the phase transition at low pressure, and direct it towards the hexagonal diamond phase at higher pressure. The proposed nucleation mechanism should improve our understanding of structural transformations in a wide range of carbon-based materials.     

Model selection for modified gravity

In this article, we review model selection predictions for modified gravity scenarios as an explanation for the observed acceleration of the expansion history of the Universe. We present analytical procedures for calculating expected Bayesian evidence values in two cases: (i) that modified gravity is a simple parametrized extension of general relativity (GR; two nested models), such that a Bayes' factor can be calculated, and (ii) that we have a class of non-nested models where a rank-ordering of evidence values is required. We show that, in the case of a minimal modified gravity parametrization, we can expect large area photometric and spectroscopic surveys, using three-dimensional cosmic shear and baryonic acoustic oscillations, to 'decisively' distinguish modified gravity models over GR (or vice versa), with odds of ?1:100. It is apparent that the potential discovery space for modified gravity models is large, even in a simple extension to gravity models, where Newton's constant G is allowed to vary as a function of time and length scale. On the time and length scales where dark energy dominates, it is only through large-scale cosmological experiments that we can hope to understand the nature of gravity.     

Nanostructuring polymeric materials by templating strategies

This contribution summarizes efforts in designing, assembling/synthesizing, and structurally and functionally characterizing nanostructured materials using anodized aluminum oxide (AAO) as a thin-film template. Optical waveguide spectroscopy, using a nanoporous template as the guiding structure, is a particularly powerful analytical tool. The layer-by-layer approach for the fabrication of multilayer assemblies is shown to allow the fabrication of nanotube arrays. In addition to using dendrimers as building blocks, semiconducting nanomaterial (e.g., quantum dot) hybrid architectures with very interesting photophysical properties can be assembled. These can be employed, for example, in biosensing applications. Other strategies for using the AAO layers as templates include the growth of polymeric nanorod arrays from different functional monomers, which, after the dissolution of the template, are still able to guide light. This opens up novel concepts for integrated optics platforms with nanostructured materials.     

Conditioned medium increases the polyploid cell composition of bovine somatic cell nuclear-transferred blastocysts

The effects of bovine cumulus cell-conditioned medium on cloned bovine embryonic development and subsequent chromosome complement were examined using an air-dry procedure. Conditioned media were prepared using CR1aa supplemented with either fetal bovine serum (FBS) or bovine serum albumin (BSA). Nuclear-transferred embryos were reconstructed with nuclei from cumulus cells. Similar cleavage, morula, and blastocyst development was observed in conditioned media groups compared with the co-culture group. No differences (P > 0.05) were observed in the composition of blastocyst chromosomes after co-culture in different media, either with or without starvation of donor cells. The overall diploid blastocyst rate ranged from 75% to 84%. Chromosomal complement of blastocysts, however, was very different between conditioned medium and co-culture treatments. Overall incidence of chromosomal anomalies was 40% in conditioned medium, which was significantly higher (P < 0.001) than the co-culture group (20%). Moreover, a higher incidence (P < 0.05) of chromosomally abnormal blastocysts (41.5%) was observed after culture with FBS-containing conditioned medium than those cultured in BSA-containing conditioned medium (31.4%). No diploid improvement was observed after exchange of the culture system from conditioned medium to co-culture, or from co-culture to conditioned medium after the first 72 h of culture. The results of this study also indicated that the overall cell number was much lower (P < 0.01) in blastocysts with chromosomal abnormalities than those with a normal diploid state. We have concluded that medium conditioned with bovine cumulus cells increases the incidence of chromosomal anomalies in nuclear reconstructed embryos.     

Fas and Fas ligand protein and mRNA in normal and atretic mouse ovarian follicles

Apoptosis is the underlying mechanism of follicular atresia in the mammalian ovary. However, the apoptotic pathways governing this ovarian process are not completely elucidated. In the present study, expression of Fas and Fas ligand, the proximal members of the death receptor pathway, was evaluated in mouse ovarian follicles using immunofluorescence and in situ hybridization. Normal or atretic follicles were obtained from immature female Swiss mice after administration of 10 iu equine chorionic gonadotrophin for 48 or 72 h, respectively. Expression of both Fas and Fas ligand mRNA and protein was observed in granulosa cells of normal and atretic follicles. Although the oocytes of normal follicles failed to show any staining, those of atretic follicles stained intensely for Fas, indicating that the presence of Fas in the oocyte determines the fate of the follicle.     

Effectiveness of potassium lactate and sodium diacetate in combination with irradiation to control Listeria monocytogenes on frankfurters

ABSTRACT:  The use of antimicrobial ingredients in combination with irradiation is an effective antilisterial intervention strategy for ready-to-eat meat products. Microbial safety was evaluated for frankfurters formulated with 0% or 3% added potassium lactate/sodium diacetate solution and inoculated with Listeria monocytogenes before or after treatment with irradiation (0, 1.8, or 2.6 kGy). Frankfurters were stored aerobically or vacuum packaged and L. mo nocytogenes counts and APCs were determined while refrigerated. The incorporation of lactate/diacetate with or without irradiation had a strong listeriostatic effect for aerobically stored frankfurters. Outgrowth was suppressed and counts were not different from initial counts (5.2 log CFU/frank compared with 5.0 log CFU/frank); however, those without the additive increased steadily (5.4 to 9.3 log CFU/frank). Irradiation treatments alone had higher L. monocytogenes counts after 3 wk. For vacuum-packaged frankfurters, both the addition of lactate/diacetate and irradiation were effective at controlling growth after 8 wk. Large and incremental reductions in total counts were seen for irradiation treatments. Initial counts were reduced by 3 log CFU with the application of 1.8 kGy while 2.6 kGy decreased counts over 5 log CFU. These reductions were maintained throughout storage for lactate/diacetate-treated frankfurters. By 8 wk, L. monocytogenes counts on 1.8 and 2.6 kGy irradiated frankfurters without lactate/diacetate increased to 7.43 and 6.13 log CFU, respectively. Overall, lactate/diacetate retarded the outgrowth of L. monocytogenes on frankfurters throughout aerobic storage and the combination of irradiation and 3% lactate/diacetate reduced and retarded growth of L. monocytogenes , especially during the last 2 wk of vacuum-packaged storage.     

The 2-oxoglutarate-dependent oxygenase JMJD6 catalyses oxidation of lysine residues to give 5S-hydroxylysine residues

Amino acid analyses reveal that JMJD6-catalysed hydroxylation of RNA-splicing regulatory protein fragments occurs to give hydroxylysine products with 5S stereochemistry. This contrasts with collagen lysyl hydroxylases, which give 5R-hydroxylated products. The work suggests that more than one subfamily of lysyl hydroxylases has evolved and illustrates the importance of stereochemical assignments in proteomic analyses.     

A general procedure to synthesize highly crystalline metal oxide and mixed oxide nanocrystals in aqueous medium and photocatalytic activity of metal/oxide nanohybrids

A conventional and general route has been exploited to the high yield synthesis of many kinds of highly crystalline metal oxide and mixed oxide nanocrystals with different morphologies including belt, rod, truncated-octahedron, cubic, sphere, sheet via the hydrothermal reaction of inorganic precursors in aqueous solution in the presence of bifunctional 6-aminohexanoic acid (AHA) molecules as a capping agent. This method is a simple, reproducible and general route for the preparation of a variety of high-crystalline inorganic nanocrystals in scale-up. The shape of inorganic nanocrystals such as CoWO(4), La(2)(MoO(4))(3) can be controlled by simply adjusting the synthesis conditions including pH solution and reaction temperature. Further, by tuning precursor monomer concentration, the mesocrystal hierarchical aggregated microspheres (e.g., MnWO(4), La(2)(MoO(4))(3)) can be achieved, due to the spontaneous assembly of individual AHA-capped nanoparticles. These obtained AHA-capped nanocrystals are excellent supports for the synthesis of a variety of hybrid metal/oxide nanocrystals in which noble metal particles are uniformly deposited on the surface of each individual nanosupport. The photocatalytic activity of Ag/TiO(2) nanobelts as a typical hybrid photocatalyst sample for Methylene Blue degradation was also studied.