392 research outputs found

    Effect of royal jelly on experimental colitis induced by acetic acid and alteration of mast cell distribution in the colon of rats

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    This study investigated the effects of royal jelly (RJ) on acetic acid-induced colitis in rats. Twenty adult female Wistar albino rats were divided into four treatment groups of 5 animals each, including a control group (Group I); Group II was treated orally with RJ (150 mg kg−1 body weight); Group III had acetic acid-induced colitis; and Group IV had acetic acid-induced colitis treated orally with RJ (150 mg kg−1 body weight) for 4 weeks. Colitis was induced by intracolonic instillation of 4% acetic acid; the control group received physiological saline (10 mL kg−1). Colon samples were obtained under deep anaesthesia from animals in all groups. Tissues were fixed in 10% formalin neutral buffer solution for 24 h and embedded in paraffin. Six-micrometre-thick sections were stained with Mallory’s triple stain and toluidine blue in 1% aqueous solution at pH 1.0 for 5 min (for Mast Cells). RJ was shown to protect the colonic mucosa against the injurious effect of acetic acid. Colitis (colonic damage) was confirmed histomorphometrically as significant increases in the number of mast cells (MC) and colonic erosions in rats with acetic acid-induced colitis. The RJ treatment significantly decreased the number of MC and reduced the area of colonic erosion in the colon of RJ-treated rats compared with rats with untreated colitis. The results suggest that oral treatment with RJ could be used to treat colitis

    Tuning zirconia-supported metal catalysts for selective one-step hydrogenation of levoglucosenone

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    [EN] Levoglucosenone, directly produced from cellulose-containing residual biomass via pyrolysis treatments, is believed to be a promising bio-renewable platform for both fine and commodity chemicals. In this work, the possibilities given by tuneable catalysts based on Pd and Pt supported on metallic oxides to produce the desired product in the one-pot hydrogenation of levoglucosenone are evaluated. Particularly, the excellent catalytic performance of Pd/ZrO2 and Pt/ZrO2 type materials for the synthesis of dihydrolevoglucosenone (or Cyrene) and levoglucosanol, respectively, during the mild hydrogenation of levoglucosenone is demonstrated. In the Cyrene synthesis, the Pd/t-ZrO2 material showed the best catalytic activity compared to other Pd-supported on metallic oxides. This catalyst achieved nearly 95% yields of Cyrene by working under mild reaction conditions, with very low catalyst loadings (¿3 wt%) and using water as the solvent. On the other hand, the one-pot hydrogenation of levoglucosenone to levoglucosanol is reported for the first time with a Pt-based heterogeneous catalyst (Pt/ZrO2-mix, yield ¿90%), by working at low temperatures and mild H2 pressures with water as the solvent. Comparison of the results attained with other Pt-supported metallic oxides let us to conclude that the metal crystal facets (specifically the 100 facet) play an important role in the hydrogenation process to give levoglucosanol selectively. In addition, the stability and re-usability of both catalysts under operational conditions are also evaluated. Finally, catalytic tests including the use of crude bio-liquids obtained from cellulose-rich biomass pyrolysis and containing ¿66 wt% of levoglucosenone are also assayed, thus demonstrating the possibility of scaling-up the process over these metals supported on zirconia catalysts.Financial support by the Spanish Government (CTQ-201567592, SEV-2016-0683 and PGC2018-097277-B-100) is gratefully acknowledged. R.S. thanks the CONICET financial support (CONICET-CSIC, PVCE Program, RD 4183/15). J.M. thanks MICINN (CTQ2015-67592) for the PhD fellowship. Authors also thank the Electron Microscopy Service of Universitat Politecnica de Valencia for their support.Mazarío-Santa-Pau, J.; Parreño-Romero, M.; Concepción Heydorn, P.; Chávez-Sifontes, M.; Spanevello, RA.; Comba, MB.; Suárez, AG.... (2019). Tuning zirconia-supported metal catalysts for selective one-step hydrogenation of levoglucosenone. 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M., Spanevello, R. A., & Suárez, A. G. (2007). An efficient microwave-assisted green transformation of cellulose into levoglucosenone. Advantages of the use of an experimental design approach. Green Chemistry, 9(10), 1137. doi:10.1039/b703690fKudo, S., Zhou, Z., Yamasaki, K., Norinaga, K., & Hayashi, J. (2013). Sulfonate Ionic Liquid as a Stable and Active Catalyst for Levoglucosenone Production from Saccharides via Catalytic Pyrolysis. Catalysts, 3(4), 757-773. doi:10.3390/catal3040757Kudo, S., Goto, N., Sperry, J., Norinaga, K., & Hayashi, J. (2016). Production of Levoglucosenone and Dihydrolevoglucosenone by Catalytic Reforming of Volatiles from Cellulose Pyrolysis Using Supported Ionic Liquid Phase. ACS Sustainable Chemistry & Engineering, 5(1), 1132-1140. doi:10.1021/acssuschemeng.6b02463Kudo, S., Zhou, Z., Norinaga, K., & Hayashi, J. (2011). Efficient levoglucosenone production by catalytic pyrolysis of cellulose mixed with ionic liquid. Green Chemistry, 13(11), 3306. doi:10.1039/c1gc15975eLu, Q., Ye, X., Zhang, Z., Dong, C., & Zhang, Y. (2014). Catalytic fast pyrolysis of cellulose and biomass to produce levoglucosenone using magnetic SO42−/TiO2–Fe3O4. Bioresource Technology, 171, 10-15. doi:10.1016/j.biortech.2014.08.075Wang, Z., Lu, Q., Zhu, X.-F., & Zhang, Y. (2010). Catalytic Fast Pyrolysis of Cellulose to Prepare Levoglucosenone Using Sulfated Zirconia. ChemSusChem, 4(1), 79-84. doi:10.1002/cssc.201000210Corne, V., Botta, M. C., Giordano, E. D. V., Giri, G. F., Llompart, D. F., Biava, H. D., … Spanevello, R. A. (2013). Cellulose recycling as a source of raw chirality. Pure and Applied Chemistry, 85(8), 1683-1692. doi:10.1351/pac-con-12-11-10Tsai, Y., Borini Etichetti, C. M., Di Benedetto, C., Girardini, J. E., Martins, F. T., Spanevello, R. A., … Sarotti, A. M. (2018). Synthesis of Triazole Derivatives of Levoglucosenone As Promising Anticancer Agents: Effective Exploration of the Chemical Space through retro-aza-Michael//aza-Michael Isomerizations. The Journal of Organic Chemistry, 83(7), 3516-3528. doi:10.1021/acs.joc.7b03141Comba, M. B., Tsai, Y., Sarotti, A. M., Mangione, M. I., Suárez, A. G., & Spanevello, R. A. (2017). Levoglucosenone and Its New Applications: Valorization of Cellulose Residues. European Journal of Organic Chemistry, 2018(5), 590-604. doi:10.1002/ejoc.201701227Zanardi, M. M., & Suárez, A. G. (2009). Synthesis of a simple chiral auxiliary derived from levoglucosenone and its application in a Diels–Alder reaction. Tetrahedron Letters, 50(9), 999-1002. doi:10.1016/j.tetlet.2008.12.048Shafizadeh, F., & Chin, P. P. S. (1977). Preparation of 1,6-anhydro-3,4-dideoxy-β-D-glycero-hex-3-enopyranos-2-ulose (levoglucosenone) and some derivatives thereof. Carbohydrate Research, 58(1), 79-87. doi:10.1016/s0008-6215(00)83406-0Krishna, S. H., McClelland, D. J., Rashke, Q. A., Dumesic, J. A., & Huber, G. W. (2017). Hydrogenation of levoglucosenone to renewable chemicals. Green Chemistry, 19(5), 1278-1285. doi:10.1039/c6gc03028aKrishna, S. H., Assary, R. S., Rashke, Q. A., Schmidt, Z. R., Curtiss, L. A., Dumesic, J. A., & Huber, G. W. (2018). Mechanistic Insights into the Hydrogenolysis of Levoglucosanol over Bifunctional Platinum Silica–Alumina Catalysts. ACS Catalysis, 8(5), 3743-3753. doi:10.1021/acscatal.7b03764Sherwood, J., De bruyn Mario, Constantinou, A., Moity, L., McElroy, C. R., Farmer, T. J., … Clark, J. H. (2014). Dihydrolevoglucosenone (Cyrene) as a bio-based alternative for dipolar aprotic solvents. Chem. Commun., 50(68), 9650-9652. doi:10.1039/c4cc04133jZhang, J., White, G. B., Ryan, M. D., Hunt, A. J., & Katz, M. J. (2016). Dihydrolevoglucosenone (Cyrene) As a Green Alternative to N,N-Dimethylformamide (DMF) in MOF Synthesis. ACS Sustainable Chemistry & Engineering, 4(12), 7186-7192. doi:10.1021/acssuschemeng.6b02115Zhang, X., Wang, T., Ma, L., Zhang, Q., Huang, X., & Yu, Y. (2013). Production of cyclohexane from lignin degradation compounds over Ni/ZrO2–SiO2 catalysts. Applied Energy, 112, 533-538. doi:10.1016/j.apenergy.2013.04.077Emeis, C. A. (1993). Determination of Integrated Molar Extinction Coefficients for Infrared Absorption Bands of Pyridine Adsorbed on Solid Acid Catalysts. Journal of Catalysis, 141(2), 347-354. doi:10.1006/jcat.1993.1145Jacob, K.-H., Knözinger, E., & Benier, S. (1993). Adsorption sites on polymorphic zirconia. J. Mater. Chem., 3(6), 651-657. doi:10.1039/jm9930300651Englisch, M., Jentys, A., & Lercher, J. A. (1997). Structure Sensitivity of the Hydrogenation of Crotonaldehyde over Pt/SiO2and Pt/TiO2. Journal of Catalysis, 166(1), 25-35. doi:10.1006/jcat.1997.1494Delbecq, F., & Sautet, P. (1995). Competitive CC and CO Adsorption of α-β-Unsaturated Aldehydes on Pt and Pd Surfaces in Relation with the Selectivity of Hydrogenation Reactions: A Theoretical Approach. Journal of Catalysis, 152(2), 217-236. doi:10.1006/jcat.1995.1077Li, H., Calle-Vallejo, F., Kolb, M. J., Kwon, Y., Li, Y., & Koper, M. T. M. (2013). Why (1 0 0) Terraces Break and Make Bonds: Oxidation of Dimethyl Ether on Platinum Single-Crystal Electrodes. Journal of the American Chemical Society, 135(38), 14329-14338. doi:10.1021/ja406655qYamagishi, S., Fujimoto, T., Inada, Y., & Orita, H. (2005). Studies of CO Adsorption on Pt(100), Pt(410), and Pt(110) Surfaces Using Density Functional Theory. The Journal of Physical Chemistry B, 109(18), 8899-8908. doi:10.1021/jp050722iBertarione, S., Scarano, D., Zecchina, A., Johánek, V., Hoffmann, J., Schauermann, S., … Freund, H.-J. (2004). 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    The Influence of Different Bleaching Protocols on Dentinal Enzymatic Activity: An In Vitro Study

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    This study aimed to investigate matrix metalloproteinase (MMP) activity in human dentin using in-situ and gelatin zymography, after at-home and in-office bleaching, related to their clinical exposure times. Dentin specimens (n = 5) were treated with 35% hydrogen peroxide (50 min per session/4 sessions), 10% carbamide peroxide (180 min/21 sessions), or no treatment. All were subjected to in-situ zymography. Dentin slices were, subsequently, obtained, covered with fluorescein-conjugated gelatin, and examined with confocal laser-scanning microscopy. The fluorescence intensity was quantified and statistically analyzed using one-way ANOVA and Bonferroni tests (α = 0.05). Furthermore, gelatin zymography was performed on protein extracts obtained from dentin powder (N = 8 teeth), treated with hydrogen peroxide or carbamide peroxide, with different exposure times (10/50 min for hydrogen peroxide; 252/1260 min for carbamide peroxide). The results of the in-situ zymography showed no statistical differences between the bleached specimens and the control group, with a medium level of gelatinolytic activity expressed in the dentin tubules. The results of gelatin zymography showed an increased expression of pro-MMP-9 in carbamide peroxide groups. The expression of pro-MMP-2 decreased in all the experimental groups. The bleaching treatments performed on the enamel of sound teeth do not influence dentinal enzymatic activity. However, when unprotected dentin tissue is bleached, matrix metalloproteinases are more expressed, particularly when carbamide peroxide is used, proportional to the exposure time

    Efficient Entropy Estimation for Mutual Information Analysis Using B-Splines

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    International audienceThe Correlation Power Analysis (CPA) is probably the most used side-channel attack because it seems to fit the power model of most standard CMOS devices and is very efficiently computed. However, the Pearson correlation coefficient used in the CPA measures only linear statistical dependences where the Mutual Information (MI) takes into account both linear and nonlinear dependences. Even if there can be simultaneously large correlation coefficients quantified by the correlation coefficient and weak dependences quantified by the MI, we can expect to get a more profound understanding about interactions from an MI Analysis (MIA). We study methods that improve the non-parametric Probability Density Functions (PDF) in the estimation of the entropies and, in particular, the use of B-spline basis functions as pdf estimators. Our results indicate an improvement of two fold in the number of required samples compared to a classic MI estimation. The B-spline smoothing technique can also be applied to the rencently introduced Cramér-von-Mises test

    Origine del Cromo esavalene in Val di Cecina e valutazione integrata degli effetti ambientali e sanitari indotti dalla sua presenza : Seconda fase - Relazione Conclusiva

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    Le analisi dei deceduti e dei ricoverati per le cause studiate nelle prime fasi del progetto hanno mostrato alcuni eccessi statisticamente significativi in alcune sub-aree in studio, i cui risultati sono integralmente riportati e discussi nel primo rapporto (Analisi di mortalit? in Relazione finale - prima fase - febbraio 2009) (Minichilli at al., 2009) e nel rapporto intermedio (Analisi dei ricoverati in Relazione intermedia - seconda fase - febbraio 2011) (Minichilli et al., 2011). Alcune delle patologie evidenziate, sia tumorali che non, sono di particolare interesse in quanto potenzialmente correlate all\u27esposizione della popolazione residente agli inquinanti indice presenti in modo non trascurabile nelle aree in studio (Cromo VI - Cr(VI), Arsenico - As, Mercurio - Hg, Boro - B, Trialometani (THM), Cloruri e Nitrati). Tra i comuni in studio nella prima fase sono stati selezionati quelli con maggiori criticit? per mortalit? o per ospedalizzazione, e per le popolazioni residenti in questi comuni ? stato effettuato un approfondimento mediante un disegno epidemiologico di tipo ecologico basato su dati individuali di mortalit? o di ricovero. I casi appartenenti alle cause selezionate sono stati collocati sul territorio con lo scopo di valutare l\u27omogeneit? della distribuzione di soggetti malati o deceduti (clustering) e di identificare eventuali addensamenti anomali (cluster), e in seconda battuta di valutare la plausibilit? di una relazione con alcune possibili cause (con particolare attenzione a quelle ambientali) che potrebbero aver contribuito agli eccessi evidenziati in microaree sub comunali.Le analisi dei deceduti e dei ricoverati per le cause studiate nelle prime fasi del progetto hanno mostrato alcuni eccessi statisticamente significativi in alcune sub-aree in studio, i cui risultati sono integralmente riportati e discussi nel primo rapporto (Analisi di mortalit? in Relazione finale - prima fase - febbraio 2009) (Minichilli at al., 2009) e nel rapporto intermedio (Analisi dei ricoverati in Relazione intermedia - seconda fase - febbraio 2011) (Minichilli et al., 2011). Alcune delle patologie evidenziate, sia tumorali che non, sono di particolare interesse in quanto potenzialmente correlate all\u27esposizione della popolazione residente agli inquinanti indice presenti in modo non trascurabile nelle aree in studio (Cromo VI - Cr(VI), Arsenico - As, Mercurio - Hg, Boro - B, Trialometani (THM), Cloruri e Nitrati). Tra i comuni in studio nella prima fase sono stati selezionati quelli con maggiori criticit? per mortalit? o per ospedalizzazione, e per le popolazioni residenti in questi comuni ? stato effettuato un approfondimento mediante un disegno epidemiologico di tipo ecologico basato su dati individuali di mortalit? o di ricovero. I casi appartenenti alle cause selezionate sono stati collocati sul territorio con lo scopo di valutare l\u27omogeneit? della distribuzione di soggetti malati o deceduti (clustering) e di identificare eventuali addensamenti anomali (cluster), e in seconda battuta di valutare la plausibilit? di una relazione con alcune possibili cause (con particolare attenzione a quelle ambientali) che potrebbero aver contribuito agli eccessi evidenziati in microaree sub comunali

    SIKE Round 2 Speed Record on ARM Cortex-M4

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    We present the first practical software implementation of Supersingular Isogeny Key Encapsulation (SIKE) round 2, targeting NIST’s 1, 2, and 5 security levels on 32-bit ARM Cortex-M4 microcontrollers. The proposed library introduces a new speed record of SIKE protocol on the target platform. We achieved this record by adopting several state-of-the-art engineering techniques as well as highly-optimized hand-crafted assembly implementation of finite field arithmetic. In particular, we carefully redesign the previous optimized implementations of filed arithmetic on 32-bit ARM Cortex-M4 platform and propose a set of novel techniques which are explicitly suitable for SIKE/SIDH primes. Moreover, the proposed arithmetic implementations are fully scalable to larger bit-length integers and can be adopted over different security levels. The benchmark result on STM32F4 Discovery board equipped with 32-bit ARM Cortex-M4 microcontrollers shows that the entire key encapsulation over p434 takes about 326 million clock cycles (i.e. 1.94 seconds @168MHz). In contrast to the previous optimized implementation of the isogeny-based key exchange on low-power 32-bit ARM Cortex-M4, our performance evaluation shows feasibility of using SIKE mechanism on the target platform. In comparison to the most of the post-quantum candidates, SIKE requires an excessive number of arithmetic operations, resulting in significantly slower timings. However, its small key size makes this scheme as a promising candidate on low-end microcontrollers in the quantum era by ensuring the lower energy consumption for key transmission than other schemes
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