618 research outputs found

    Augmenter of liver regeneration enhances the success rate of fetal pancreas transplantation in rodents

    Get PDF
    Background. Treatment of fetal pancreas (FP) isografts with insulin- like growth factor-I greatly improves the rate of conversion to euglycemia in diabetic rats. Complete knowledge of other factors that may facilitate the engraftment and function of FP in vivo is still embryonic. Augmenter of liver regeneration (ALR) is a newly described polypeptide growth factor found in weanling rat livers. ALR has trophic effects on regenerating liver. We studied the effects of in situ administration of this agent on FP isografts in rats. Methods. Streptozotocin-diabetic Lewis rats (blood glucose >300 mg/dl) received 16 FP isografts transplanted intramuscularly. ALR was delivered from day 1 through day 14, in doses of 40 or 400 ng/kg/d. Animals were followed for 3 months with serial weights and blood glucose monitoring. These animals were compared with those treated with vehicle alone. Results. Of the group treated with ALR at 40 ng/kg/day for 14 days, 89% (eight of nine) were euglycemic (P=0.0003). Of the group treated with ALR at 400 ng/kg/day for 14 days, 88% (seven of eight) were euglycemic (P=0.0007). Of the group treated with vehicle alone, none of the six were euglycemic. Euglycemia is defined here as glucose<200 mg/dl for 3 days. Pathology of the intramuscular transplant site showed patches of islet tissue embedded in fat. These patches demonstrated insulin immunoreactivity. Conclusions. Diabetes was reversed in a significantly greater proportion of FP + ALR-treated recipients than those animals treated with vehicle alone. Local delivery of growth factors my be used as an adjunct to FP transplantation to improve the rate of success. This in situ model may be useful to further evaluate other soluble factors

    Evaluating Evidence-Based Content, Features of Exercise Instruction, and Expert Involvement in Physical Activity Apps for Pregnant Women: Systematic Search and Content Analysis

    Get PDF
    Background: Guidelines for physical activity and exercise during pregnancy recommend that all women without contraindications engage in regular physical activity to improve both their own health and the health of their baby. Many women are uncertain how to safely engage in physical activity and exercise during this life stage and are increasingly using mobile apps to access health-relatedinformation. However, the extent to which apps that provide physical activity and exercise advice align with current evidence-based pregnancy recommendations is unclear. Objective: This study aims to conduct a systematic search and content analysis of apps that promote physical activity and exercise in pregnancy to examine the alignment of the content with current evidence-based recommendations; delivery, format, and features of physical activity and exercise instruction; and credentials of the app developers. Methods: Systematic searches were conducted in the Australian App Store and Google Play Store in October 2020. Apps were identified using combinations of search terms relevant to pregnancy and exercise or physical activity and screened for inclusion (with a primary focus on physical activity and exercise during pregnancy, free to download or did not require immediate paid subscription, and an average user rating of ≥4 out of 5). Apps were then independently reviewed using an author-designed extraction tool. Results: Overall, 27 apps were included in this review (Google Play Store: 16/27, 59%, and App Store: 11/27, 41%). Two-thirds of the apps provided some information relating to the frequency, intensity, time, and type principles of exercise; only 11% (3/27) provided this information in line with current evidence-based guidelines. Approximately one-third of the apps provided information about contraindications to exercise during pregnancy and referenced the supporting evidence. None of the apps actively engaged in screening for potential contraindications. Only 15% (4/27) of the apps collected information about the user\u27s current exercise behaviors, 11% (3/27) allowed users to personalize features relating to their exercise preferences, and a little more than one-third provided information about developer credentials. Conclusions: Few exercise apps designed for pregnancy aligned with current evidence-based physical activity guidelines. None of the apps screened users for contraindications to physical activity and exercise during pregnancy, and most lacked appropriate personalization features to account for an individual\u27s characteristics. Few involved qualified experts during the development of the app. There is a need to improve the quality of apps that promote exercise in pregnancy to ensure that women are appropriately supported to engage in exercise and the potential risk of injury, complications, and adverse pregnancy outcomes for both mother and child is minimized. This could be done by providing expert guidance that aligns with current recommendations, introducing screening measures and features that enable personalization and tailoring to individual users, or by developing a recognized system for regulating apps

    2D Semiconductor Nonlinear Plasmonic Modulators

    Get PDF
    A plasmonic modulator is a device that controls the amplitude or phase of propagating plasmons. In a pure plasmonic modulator, the presence or absence of a pump plasmonic wave controls the amplitude of a probe plasmonic wave through a channel. This control has to be mediated by an interaction between disparate plasmonic waves, typically requiring the integration of a nonlinear material. In this work, we demonstrate the first 2D semiconductor nonlinear plasmonic modulator based on a WSe2 monolayer integrated on top of a lithographically defined metallic waveguide. We utilize the strong coupling between the surface plasmon polaritons, SPPs, and excitons in the WSe2 to give a 73 percent change in transmission through the device. We demonstrate control of the propagating SPPs using both optical and SPP pumps, realizing the first demonstration of a 2D semiconductor nonlinear plasmonic modulator, with a modulation depth of 4.1 percent, and an ultralow switching energy estimated to be 40 aJ

    Alternatives to the use of synthetic organic coagulant aids in drinking water treatment: improvements in the application of the crude extract of Moringa oleifera seed

    Full text link
    [EN] Drinking water treatment is a process based on multiple stages that has a main objective to provide water safe enough to be consumed by humans. Coagulation–flocculation is used to remove colloidal and suspended solids. This process improves the performance of subsequent stages (as sedimentation or filtration) as well as the water quality with a desired end-use. For many years, inorganic and organic synthetic polyelectrolytes have been used in coagulation–flocculation processes. However, its use has been deeply studied recently to determine the potential impact of residual concentration of these substances on human health and the environment. Strict regulations limit the concentration of free residual monomer after the addition of polyacrylamide (PAM) in drinking water treatment and study the effect of interaction of the residues with disinfection products. Therefore, in the last years there has been a resurgence of interest to use natural materials with the same performance that synthetic, but with lower hazard for the environment and humans. This work studies the use of the flocculant extracted from Moringa oleifera seed, in combination with polyaluminum chloride (PAC). The performance is compared with the combination PAC–PAM in terms of coagulant activity and physical–chemical quality of the water treated. Jar test was carried out using two types of natural water (with presence of bentonites) and different combinations of coagulant and flocculants. Results show that coagulant activity of PAC–Moringa combination is comparable with the results obtained with PAC–PAM, reducing initial turbidity up to 90% in all the tests. With regard to physical–chemical quality of the treated water, PAC–Moringa produces values under the drinking water quality standards for all the parameters analyzed. It is remarkable that the decrease of 50% in the trihalomethanes formation potential rate shown for PAC–Moringa combination, observed when treating natural water with presence of bentonites. Therefore, the results obtain in this work encourage the use of Moringa oleifera extract as a natural, low cost, effective, and low-toxicity alternative to the use of synthetic organic polyelectrolytes as polyacrylamide for drinking water treatment.This research has been done in the framework of the project “Study of synthetic and natural coagulants susceptible of being used in the water treatment plant of “Ribarroja del Turia” (Valencia) as substitutes for polyacrylamide”. The authors wish to thank the staff of the laboratory of the Department of Water Quality of the company “Aguas de Valencia” located in La Presa (Manises) for its collaboration in the water tests of this work.García Fayos, B.; Arnal Arnal, JM.; Monforte Monleon, L.; Sancho Fernández, MP. (2015). Alternatives to the use of synthetic organic coagulant aids in drinking water treatment: improvements in the application of the crude extract of Moringa oleifera seed. Desalination and Water Treatment. 55(13):3635-3645. doi:10.1080/19443994.2014.939487S363536455513Van Benschoten, J. E., & Edzwald, J. K. (1990). Chemical aspects of coagulation using aluminum salts—I. Hydrolytic reactions of alum and polyaluminum chloride. Water Research, 24(12), 1519-1526. doi:10.1016/0043-1354(90)90086-lBOLTO, B. (1995). Soluble polymers in water purification. Progress in Polymer Science, 20(6), 987-1041. doi:10.1016/0079-6700(95)00010-dCrapper, D. R., Krishnan, S. S., & Dalton, A. J. (1973). Brain Aluminum Distribution in Alzheimer’s Disease and Experimental Neurofibrillary Degeneration. Science, 180(4085), 511-513. doi:10.1126/science.180.4085.511Davison, A. M., Oli, H., Walker, G. S., & Lewins, A. M. (1982). WATER SUPPLY ALUMINIUM CONCENTRATION, DIALYSIS DEMENTIA, AND EFFECT OF REVERSE-OSMOSIS WATER TREATMENT. The Lancet, 320(8302), 785-787. doi:10.1016/s0140-6736(82)92678-2Rondeau, V., Commenges, D., Jacqmin-Gadda, H., & Dartigues, J.-F. (2000). Relation between Aluminum Concentrations in Drinking Water and Alzheimer’s Disease: An 8-year Follow-up Study. American Journal of Epidemiology, 152(1), 59-66. doi:10.1093/aje/152.1.59Rondeau, V. (2001). RE: ALUMINUM IN DRINKING WATER AND COGNITIVE DECLINE IN ELDERLY SUBJECTS: THE PAQUID COHORT. American Journal of Epidemiology, 154(3), 288-a-290. doi:10.1093/aje/154.3.288-aGauthier, E., Fortier, I., Courchesne, F., Pepin, P., Mortimer, J., & Gauvreau, D. (2000). Aluminum Forms in Drinking Water and Risk of Alzheimer’s Disease. Environmental Research, 84(3), 234-246. doi:10.1006/enrs.2000.4101Kawamura, S. (1976). Considerations on Improving Flocculation. Journal - American Water Works Association, 68(6), 328-336. doi:10.1002/j.1551-8833.1976.tb02421.xA.D. Faust, O.M. Aly, Chemistry of Water Treatment, Butterworths, Boston, MA, 1983, pp. 326–328.Martenson, C. H., Sheetz, M. P., & Graham, D. G. (1995). In Vitro Acrylamide Exposure Alters Growth Cone Morphology. Toxicology and Applied Pharmacology, 131(1), 119-129. doi:10.1006/taap.1995.1053Kaggwa, R. C., Mulalelo, C. I., Denny, P., & Okurut, T. O. (2001). The impact of alum discharges on a natural tropical wetland in uganda. Water Research, 35(3), 795-807. doi:10.1016/s0043-1354(00)00301-8Dearfield, K. L., Abernathy, C. O., Ottley, M. S., Brantner, J. H., & Hayes, P. F. (1988). Acrylamide: its metabolism, developmental and reproductive effects, genotoxicity, and carcinogenicity. Mutation Research/Reviews in Genetic Toxicology, 195(1), 45-77. doi:10.1016/0165-1110(88)90015-2McCollister, D. D., Oyen, F., & Rowe, V. K. (1964). Toxicology of acrylamide. Toxicology and Applied Pharmacology, 6(2), 172-181. doi:10.1016/0041-008x(64)90103-6BOLTO, B., & GREGORY, J. (2007). Organic polyelectrolytes in water treatment. Water Research, 41(11), 2301-2324. doi:10.1016/j.watres.2007.03.012World Health Organization, Guidelines for drinking-water quality: Incorporating first and second addenda, in: World Health Organization (Ed.) Recommendations, third ed., vol. 1, World Health Organization, Geneva, 2008, pp. 188–194.Hamilton, M. A. (1994). A Statistician’s View of the U.S. Primary Drinking Water Regulation on Coliform Contamination. Environmental Science & Technology, 28(11), 1808-1811. doi:10.1021/es00060a009J. Criddle, A review of the mammalian and aquatic toxicity of polyelectrolites, NR 2545 Medmenhan, Foundation for Water Research 1990.Hebert, A., Forestier, D., Lenes, D., Benanou, D., Jacob, S., Arfi, C., … Levi, Y. (2010). Innovative method for prioritizing emerging disinfection by-products (DBPs) in drinking water on the basis of their potential impact on public health. Water Research, 44(10), 3147-3165. doi:10.1016/j.watres.2010.02.004Gerecke, A. C., & Sedlak, D. L. (2003). Precursors ofN-Nitrosodimethylamine in Natural Waters. Environmental Science & Technology, 37(7), 1331-1336. doi:10.1021/es026070iCharrois, J. W. A., Arend, M. W., Froese, K. L., & Hrudey, S. E. (2004). DetectingN-Nitrosamines in Drinking Water at Nanogram per Liter Levels Using Ammonia Positive Chemical Ionization. Environmental Science & Technology, 38(18), 4835-4841. doi:10.1021/es049846jS.A.A. Jahn, Proper use of African natural coagulants for rural water supplies- Research in the Sudan and a guide for new projects, Deutsche Gesellschaft für Technische Zusammenarheit (GTZ), Eschborn, 1986.Dorea, C. C. (2006). Use of Moringa spp. seeds for coagulation: a review of a sustainable option. Water Science and Technology: Water Supply, 6(1), 219-227. doi:10.2166/ws.2006.027Kawamura, S. (1991). Effectiveness of Natural Polyelectrolytes in Water Treatment. Journal - American Water Works Association, 83(10), 88-91. doi:10.1002/j.1551-8833.1991.tb07236.xLee, S. H., Lee, S. O., Jang, K. L., & Lee, T. H. (1995). Microbial flocculant from Arcuadendron sp. TS-49. Biotechnology Letters, 17(1), 95-100. doi:10.1007/bf00134203Effect of synthetic and natural coagulant on lignin removal from pulp and paper wastewater. (1997). Water Science and Technology, 35(2-3). doi:10.1016/s0273-1223(96)00943-2Broekaert, W. F., Cammue, B. P. A., De Bolle, M. F. C., Thevissen, K., De Samblanx, G. W., Osborn, R. W., & Nielson, K. (1997). Antimicrobial Peptides from Plants. Critical Reviews in Plant Sciences, 16(3), 297-323. doi:10.1080/07352689709701952Jahn, S. A. A. (1988). Using Moringa Seeds as Coagulants in Developing Countries. Journal - American Water Works Association, 80(6), 43-50. doi:10.1002/j.1551-8833.1988.tb03052.xMuyibi, S. A., & Okuofu, C. A. (1995). Coagulation of low turbidity surface waters withMoringa oleiferaseeds. International Journal of Environmental Studies, 48(3-4), 263-273. doi:10.1080/00207239508710996Ndabigengesere, A., Narasiah, K. S., & Talbot, B. G. (1995). Active agents and mechanism of coagulation of turbid waters using Moringa oleifera. Water Research, 29(2), 703-710. doi:10.1016/0043-1354(94)00161-yOkuda, T., Baes, A. U., Nishijima, W., & Okada, M. (2001). Isolation and characterization of coagulant extracted from moringa oleifera seed by salt solution. Water Research, 35(2), 405-410. doi:10.1016/s0043-1354(00)00290-6Ghebremichael, K. A., Gunaratna, K. R., Henriksson, H., Brumer, H., & Dalhammar, G. (2005). A simple purification and activity assay of the coagulant protein from Moringa oleifera seed. Water Research, 39(11), 2338-2344. doi:10.1016/j.watres.2005.04.012Sánchez-Martín, J., Ghebremichael, K., & Beltrán-Heredia, J. (2010). Comparison of single-step and two-step purified coagulants from Moringa oleifera seed for turbidity and DOC removal. Bioresource Technology, 101(15), 6259-6261. doi:10.1016/j.biortech.2010.02.07

    The writing on the wall: the concealed communities of the East Yorkshire horselads

    Get PDF
    This paper examines the graffiti found within late nineteenth and early-twentieth century farm buildings in the Wolds of East Yorkshire. It suggests that the graffiti were created by a group of young men at the bottom of the social hierarchy - the horselads – and was one of the ways in which they constructed a distinctive sense of communal identity, at a particular stage in their lives. Whilst it tells us much about changing agricultural regimes and social structures, it also informs us about experiences and attitudes often hidden from official histories and biographies. In this way, the graffiti are argued to inform our understanding, not only of a concealed community, but also about their hidden histor

    Patient participation in undergraduate medical education: development of an informative patient resource

    Get PDF

    Adsorption of mono- and multivalent cat- and anions on DNA molecules

    Get PDF
    Adsorption of monovalent and multivalent cat- and anions on a deoxyribose nucleic acid (DNA) molecule from a salt solution is investigated by computer simulation. The ions are modelled as charged hard spheres, the DNA molecule as a point charge pattern following the double-helical phosphate strands. The geometrical shape of the DNA molecules is modelled on different levels ranging from a simple cylindrical shape to structured models which include the major and minor grooves between the phosphate strands. The densities of the ions adsorbed on the phosphate strands, in the major and in the minor grooves are calculated. First, we find that the adsorption pattern on the DNA surface depends strongly on its geometrical shape: counterions adsorb preferentially along the phosphate strands for a cylindrical model shape, but in the minor groove for a geometrically structured model. Second, we find that an addition of monovalent salt ions results in an increase of the charge density in the minor groove while the total charge density of ions adsorbed in the major groove stays unchanged. The adsorbed ion densities are highly structured along the minor groove while they are almost smeared along the major groove. Furthermore, for a fixed amount of added salt, the major groove cationic charge is independent on the counterion valency. For increasing salt concentration the major groove is neutralized while the total charge adsorbed in the minor groove is constant. DNA overcharging is detected for multivalent salt. Simulations for a larger ion radii, which mimic the effect of the ion hydration, indicate an increased adsorbtion of cations in the major groove.Comment: 34 pages with 14 figure
    • …
    corecore