81 research outputs found

    Dichlorodioxomolybdenum(VI) complexes bearing oxygen-donor ligands as olefin epoxidation catalysts

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    Treatment of the solvent adduct [MoO2Cl2(THF)2] with either 2 equivalents of N,N-dimethylbenzamide (DMB) or 1 equivalent of N,N'-diethyloxamide (DEO) gave the dioxomolybdenum(vi) complexes [MoO2Cl2(DMB)2] () and [MoO2Cl2(DEO)] (). The molecular structures of and were determined by single-crystal X-ray diffraction. Both complexes present a distorted octahedral geometry and adopt the cis-oxo, trans-Cl, cis-L configuration typical of complexes of the type [MoO2X2(L)n], with either the monodentate DMB or bidentate DEO oxygen-donor ligands occupying the equatorial positions trans to the oxo groups. The complexes were applied as homogeneous catalysts for the epoxidation of olefins, namely cis-cyclooctene (Cy), 1-octene, trans-2-octene, α-pinene and (R)-(+)-limonene, using tert-butylhydroperoxide (TBHP) as oxidant. In the epoxidation of Cy at 55 °C, the desired epoxide was the only product and turnover frequencies in the range of ca. 3150-3200 mol molMo(-1) h(-1) could be reached. The catalytic production of cyclooctene oxide was investigated in detail, varying either the reaction temperature or the cosolvent. Complexes and were also applied in liquid-liquid biphasic catalytic epoxidation reactions by using an ionic liquid of the type [C4mim][X] (C4mim = 1-n-butyl-3-methylimidazolium; X = NTf2, BF4 or PF6] as a solvent to immobilise the metal catalysts. Recycling for multiple catalytic runs was achieved without loss of activity

    Lectin-gated and glycan functionalized mesoporous silica nanocontainers for targeting cancer cells overexpressing Lewis X antigen

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    [EN] Gated mesoporous silica nanoparticles can deliver payload upon the application of a predefined stimulus, and therefore are promising drug delivery systems. Despite their important role, relatively low emphasis has been placed on the design of gating systems that actively target carbohydrate tumor cell membrane receptors. We describe herein a new Lewis X (Le(x)) antigen-targeted delivery system comprising mesoporous silica nanoparticles (MSNs) loaded with ATTO 430LS dye, functionalized with a Le(x) derivative (1) and capped with a fucose-specific carbohydrate-binding protein (Aleuria aurantia lectin (AAL)). This design takes advantage of the affinity of AAL for Le(x) overexpressed receptors in certain cancer cells. In the proximity of the cells, AAL is detached from MSNs to bind Le(x), and selectins in the cells bind Le(x) in the gated MSNs, thereby inducing cargo delivery. Gated MSNs are nontoxic to colon cancer DLD-1 cells, and ATTO 430LS dye delivered correlated with the amount of Le(x) antigen overexpressed at the DLD-1 cell surface. This is one of the few examples of MSNs using biologically relevant glycans for both capping (via interaction with AAL) and targeting (via interaction with overexpressed Le(x) at the cell membrane).The authors thank the Spanish Government (Projects MAT2015-64139-C4-1-R and MAT2013-46101-R (MINECO/ FEDER)), Fondo de Investigacion Sanitaria (PI15/00480) and Generalitat Valenciana (Project PROMETEOII/2014/047 and project GVA/2014/13) for support. R. B. is thankful to Svagata. Eu (Erasmus Mundus Action-II program) for his fellowship. The authors also thank the Electron Microscopy Service at the UPV for support.Bhat, R.; García, I.; Aznar, E.; Arnáiz, B.; Martínez-Bisbal, M.; Liz-Marzán, L.; Penadés, S.... (2018). Lectin-gated and glycan functionalized mesoporous silica nanocontainers for targeting cancer cells overexpressing Lewis X antigen. Nanoscale. 10(1):239-249. https://doi.org/10.1039/c7nr06415bS239249101Argyo, C., Weiss, V., Bräuchle, C., & Bein, T. (2013). Multifunctional Mesoporous Silica Nanoparticles as a Universal Platform for Drug Delivery. Chemistry of Materials, 26(1), 435-451. doi:10.1021/cm402592tAznar, E., Martínez-Máñez, R., & Sancenón, F. (2009). Controlled release using mesoporous materials containing gate-like scaffoldings. Expert Opinion on Drug Delivery, 6(6), 643-655. doi:10.1517/17425240902895980Aznar, E., Oroval, M., Pascual, L., Murguía, J. R., Martínez-Máñez, R., & Sancenón, F. (2016). Gated Materials for On-Command Release of Guest Molecules. Chemical Reviews, 116(2), 561-718. doi:10.1021/acs.chemrev.5b00456Wang, X., Tan, L.-L., Li, X., Song, N., Li, Z., Hu, J.-N., … Yang, Y.-W. (2016). Smart mesoporous silica nanoparticles gated by pillararene-modified gold nanoparticles for on-demand cargo release. Chemical Communications, 52(95), 13775-13778. doi:10.1039/c6cc08241fChen, X., Sun, H., Hu, J., Han, X., Liu, H., & Hu, Y. (2017). Transferrin gated mesoporous silica nanoparticles for redox-responsive and targeted drug delivery. Colloids and Surfaces B: Biointerfaces, 152, 77-84. doi:10.1016/j.colsurfb.2017.01.010Prasad, R., Aiyer, S., Chauhan, D. S., Srivastava, R., & Selvaraj, K. (2016). Bioresponsive carbon nano-gated multifunctional mesoporous silica for cancer theranostics. Nanoscale, 8(8), 4537-4546. doi:10.1039/c5nr06756aAgostini, A., Mondragón, L., Coll, C., Aznar, E., Marcos, M. D., Martínez-Máñez, R., … Amorós, P. (2012). Dual Enzyme-Triggered Controlled Release on Capped Nanometric Silica Mesoporous Supports. ChemistryOpen, 1(1), 17-20. doi:10.1002/open.201200003García-Fernández, A., García-Laínez, G., Ferrándiz, M. L., Aznar, E., Sancenón, F., Alcaraz, M. J., … Orzáez, M. (2017). Targeting inflammasome by the inhibition of caspase-1 activity using capped mesoporous silica nanoparticles. Journal of Controlled Release, 248, 60-70. doi:10.1016/j.jconrel.2017.01.002Ultimo, A., Giménez, C., Bartovsky, P., Aznar, E., Sancenón, F., Marcos, M. D., … Murguía, J. R. (2016). Targeting Innate Immunity with dsRNA-Conjugated Mesoporous Silica Nanoparticles Promotes Antitumor Effects on Breast Cancer Cells. Chemistry - A European Journal, 22(5), 1582-1586. doi:10.1002/chem.201504629Polo, L., Gómez-Cerezo, N., Aznar, E., Vivancos, J.-L., Sancenón, F., Arcos, D., … Martínez-Máñez, R. (2017). Molecular gates in mesoporous bioactive glasses for the treatment of bone tumors and infection. Acta Biomaterialia, 50, 114-126. doi:10.1016/j.actbio.2016.12.025Luo, Z., Ding, X., Hu, Y., Wu, S., Xiang, Y., Zeng, Y., … Zhao, Y. (2013). Engineering a Hollow Nanocontainer Platform with Multifunctional Molecular Machines for Tumor-Targeted Therapy in Vitro and in Vivo. ACS Nano, 7(11), 10271-10284. doi:10.1021/nn404676wZhang, Q., Neoh, K. G., Xu, L., Lu, S., Kang, E. T., Mahendran, R., & Chiong, E. (2014). Functionalized Mesoporous Silica Nanoparticles with Mucoadhesive and Sustained Drug Release Properties for Potential Bladder Cancer Therapy. Langmuir, 30(21), 6151-6161. doi:10.1021/la500746eGuillet-Nicolas, R., Popat, A., Bridot, J.-L., Monteith, G., Qiao, S. Z., & Kleitz, F. (2013). pH-Responsive Nutraceutical-Mesoporous Silica Nanoconjugates with Enhanced Colloidal Stability. Angewandte Chemie International Edition, 52(8), 2318-2322. doi:10.1002/anie.201208840Bringas, E., Köysüren, Ö., Quach, D. V., Mahmoudi, M., Aznar, E., Roehling, J. D., … Stroeve, P. (2012). Triggered release in lipid bilayer-capped mesoporous silica nanoparticles containing SPION using an alternating magnetic field. Chemical Communications, 48(45), 5647. doi:10.1039/c2cc31563gOroval, M., Climent, E., Coll, C., Eritja, R., Aviñó, A., Marcos, M. D., … Amorós, P. (2013). An aptamer-gated silica mesoporous material for thrombin detection. Chemical Communications, 49(48), 5480. doi:10.1039/c3cc42157kHe, D., He, X., Wang, K., Chen, M., Zhao, Y., & Zou, Z. (2013). Intracellular acid-triggered drug delivery system using mesoporous silica nanoparticles capped with T–Hg2+–T base pairs mediated duplex DNA. Journal of Materials Chemistry B, 1(11), 1552. doi:10.1039/c3tb00473bChen, L., Zhou, X., Nie, W., Zhang, Q., Wang, W., Zhang, Y., & He, C. (2016). Multifunctional Redox-Responsive Mesoporous Silica Nanoparticles for Efficient Targeting Drug Delivery and Magnetic Resonance Imaging. ACS Applied Materials & Interfaces, 8(49), 33829-33841. doi:10.1021/acsami.6b11802Croissant, J. G., Zhang, D., Alsaiari, S., Lu, J., Deng, L., Tamanoi, F., … Khashab, N. M. (2016). Protein-gold clusters-capped mesoporous silica nanoparticles for high drug loading, autonomous gemcitabine/doxorubicin co-delivery, and in-vivo tumor imaging. Journal of Controlled Release, 229, 183-191. doi:10.1016/j.jconrel.2016.03.030Oroval, M., Díez, P., Aznar, E., Coll, C., Marcos, M. D., Sancenón, F., … Martínez-Máñez, R. (2016). Self-Regulated Glucose-Sensitive Neoglycoenzyme-Capped Mesoporous Silica Nanoparticles for Insulin Delivery. Chemistry - A European Journal, 23(6), 1353-1360. doi:10.1002/chem.201604104Chen, C., Geng, J., Pu, F., Yang, X., Ren, J., & Qu, X. (2010). Polyvalent Nucleic Acid/Mesoporous Silica Nanoparticle Conjugates: Dual Stimuli-Responsive Vehicles for Intracellular Drug Delivery. Angewandte Chemie International Edition, 50(4), 882-886. doi:10.1002/anie.201005471Yang, X., Liu, X., Liu, Z., Pu, F., Ren, J., & Qu, X. (2012). Near-Infrared Light-Triggered, Targeted Drug Delivery to Cancer Cells by Aptamer Gated Nanovehicles. Advanced Materials, 24(21), 2890-2895. doi:10.1002/adma.201104797Deng, Z., Zhen, Z., Hu, X., Wu, S., Xu, Z., & Chu, P. K. (2011). Hollow chitosan–silica nanospheres as pH-sensitive targeted delivery carriers in breast cancer therapy. Biomaterials, 32(21), 4976-4986. doi:10.1016/j.biomaterials.2011.03.050Palanikumar, L., Choi, E. S., Cheon, J. Y., Joo, S. H., & Ryu, J.-H. (2014). Noncovalent Polymer-Gatekeeper in Mesoporous Silica Nanoparticles as a Targeted Drug Delivery Platform. Advanced Functional Materials, 25(6), 957-965. doi:10.1002/adfm.201402755Li, L.-L., Xie, M., Wang, J., Li, X., Wang, C., Yuan, Q., … Tan, W. (2013). A vitamin-responsive mesoporous nanocarrier with DNA aptamer-mediated cell targeting. Chemical Communications, 49(52), 5823. doi:10.1039/c3cc41072bHäuselmann, I., & Borsig, L. (2014). Altered Tumor-Cell Glycosylation Promotes Metastasis. Frontiers in Oncology, 4. doi:10.3389/fonc.2014.00028Haltiwanger, R. S., & Lowe, J. B. (2004). Role of Glycosylation in Development. Annual Review of Biochemistry, 73(1), 491-537. doi:10.1146/annurev.biochem.73.011303.074043A. Varki , R.Kannagi and B. P.Toole , Glycosylation Changes in Cancer , Cold Spring Harbor Laboratory Press , 2009A. Varki and J. B.Lowe , Biological Roles of Glycans , Cold Spring Harbor Laboratory Press , 2009Gary-Bobo, M., Hocine, O., Brevet, D., Maynadier, M., Raehm, L., Richeter, S., … Durand, J.-O. (2012). Cancer therapy improvement with mesoporous silica nanoparticles combining targeting, drug delivery and PDT. International Journal of Pharmaceutics, 423(2), 509-515. doi:10.1016/j.ijpharm.2011.11.045Brevet, D., Gary-Bobo, M., Raehm, L., Richeter, S., Hocine, O., Amro, K., … Durand, J.-O. (2009). Mannose-targeted mesoporous silica nanoparticles for photodynamic therapy. Chemical Communications, (12), 1475. doi:10.1039/b900427kHocine, O., Gary-Bobo, M., Brevet, D., Maynadier, M., Fontanel, S., Raehm, L., … Frochot, C. (2010). Silicalites and Mesoporous Silica Nanoparticles for photodynamic therapy. International Journal of Pharmaceutics, 402(1-2), 221-230. doi:10.1016/j.ijpharm.2010.10.004Park, I. Y., Kim, I. Y., Yoo, M. K., Choi, Y. J., Cho, M.-H., & Cho, C. S. (2008). Mannosylated polyethylenimine coupled mesoporous silica nanoparticles for receptor-mediated gene delivery. International Journal of Pharmaceutics, 359(1-2), 280-287. doi:10.1016/j.ijpharm.2008.04.010Luo, Z., Cai, K., Hu, Y., Zhao, L., Liu, P., Duan, L., & Yang, W. (2010). Mesoporous Silica Nanoparticles End-Capped with Collagen: Redox-Responsive Nanoreservoirs for Targeted Drug Delivery. Angewandte Chemie International Edition, 50(3), 640-643. doi:10.1002/anie.201005061PENG, J., WANG, K., TAN, W., HE, X., HE, C., WU, P., & LIU, F. (2007). Identification of live liver cancer cells in a mixed cell system using galactose-conjugated fluorescent nanoparticles. Talanta, 71(2), 833-840. doi:10.1016/j.talanta.2006.05.064Yu, M., Jambhrunkar, S., Thorn, P., Chen, J., Gu, W., & Yu, C. (2013). Hyaluronic acid modified mesoporous silica nanoparticles for targeted drug delivery to CD44-overexpressing cancer cells. Nanoscale, 5(1), 178-183. doi:10.1039/c2nr32145aHe, Q., Ma, M., Wei, C., & Shi, J. (2012). Mesoporous carbon@silicon-silica nanotheranostics for synchronous delivery of insoluble drugs and luminescence imaging. Biomaterials, 33(17), 4392-4402. doi:10.1016/j.biomaterials.2012.02.056Wu, S., Huang, X., & Du, X. (2013). Glucose- and pH-Responsive Controlled Release of Cargo from Protein-Gated Carbohydrate-Functionalized Mesoporous Silica Nanocontainers. Angewandte Chemie International Edition, 52(21), 5580-5584. doi:10.1002/anie.201300958Li, J., Qu, X., Payne, G. F., Zhang, C., Zhang, Y., Li, J., … Liu, C. (2015). Biospecific Self-Assembly of a Nanoparticle Coating for Targeted and Stimuli-Responsive Drug Delivery. Advanced Functional Materials, 25(9), 1404-1417. doi:10.1002/adfm.201403636Burchell, J., Poulsom, R., Hanby, A., Whitehouse, C., Cooper, L., Clausen, H., … Taylor-Papadimitriou, J. (1999). An  2,3 sialyltransferase (ST3Gal I) is elevated in primary breast carcinomas. Glycobiology, 9(12), 1307-1311. doi:10.1093/glycob/9.12.1307Pinho, S. S., Reis, C. A., Paredes, J., Magalhaes, A. M., Ferreira, A. C., Figueiredo, J., … Seruca, R. (2009). The role of N-acetylglucosaminyltransferase III and V in the post-transcriptional modifications of E-cadherin. Human Molecular Genetics, 18(14), 2599-2608. doi:10.1093/hmg/ddp194Takahashi, M., Kuroki, Y., Ohtsubo, K., & Taniguchi, N. (2009). Core fucose and bisecting GlcNAc, the direct modifiers of the N-glycan core: their functions and target proteins. Carbohydrate Research, 344(12), 1387-1390. doi:10.1016/j.carres.2009.04.031Li, M., Song, L., & Qin, X. (2010). Glycan changes: cancer metastasis and anti-cancer vaccines. Journal of Biosciences, 35(4), 665-673. doi:10.1007/s12038-010-0073-8Nagao, K., Itoh, Y., Fujita, K., & Fujime, M. (2007). Evaluation of urinary CA19-9 levels in bladder cancer patients classified according to the combinations of Lewis and Secretor blood group genotypes. International Journal of Urology, 14(9), 795-799. doi:10.1111/j.1442-2042.2007.01840.xGao, W., Liang, J., & Liang, Y. (2016). Clinicopathological and prognostic significance of sialyl Lewis X overexpression in patients with cancer: a meta-analysis. OncoTargets and Therapy, 3113. doi:10.2147/ott.s102389Sozzani, P., Arisio, R., Porpiglia, M., & Benedetto, C. (2008). Is Sialyl Lewis x Antigen Expression a Prognostic Factor in Patients With Breast Cancer? International Journal of Surgical Pathology, 16(4), 365-374. doi:10.1177/1066896908324668Yusa, A., Miyazaki, K., Kimura, N., Izawa, M., & Kannagi, R. (2010). Epigenetic Silencing of the Sulfate Transporter Gene DTDST Induces Sialyl Lewisx Expression and Accelerates Proliferation of Colon Cancer Cells. Cancer Research, 70(10), 4064-4073. doi:10.1158/0008-5472.can-09-2383Golijanin, D., Sherman, Y., Shapiro, A., & Pode, D. (1995). Detection of bladder tumors by immunostaininc of the lewis x antigen in cells from voided urine. Urology, 46(2), 173-177. doi:10.1016/s0090-4295(99)80189-7Hittelet, A., Camby, I., Nagy, N., Legendre, H., Bronckart, Y., Decaestecker, C., … Yeaton, P. (2003). Binding Sites for Lewis Antigens Are Expressed by Human Colon Cancer Cells and Negatively Affect Their Migration. Laboratory Investigation, 83(6), 777-787. doi:10.1097/01.lab.0000073129.62433.39De la Torre, C., Casanova, I., Acosta, G., Coll, C., Moreno, M. J., Albericio, F., … Martínez-Máñez, R. (2014). 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    A peculiar class of debris disks from Herschel/DUNES - A steep fall off in the far infrared

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    Aims. We present photometric data of debris disks around HIP 103389 (HD 199260), HIP 107350 (HN Peg, HD206860), and HIP 114948 (HD 219482), obtained in the context of our Herschel Open Time Key Program DUNES (DUst around NEarby Stars). Methods. We used Herschel/PACS to detect the thermal emission of the three debris disks with a 3 sigma sensitivity of a few mJy at 100 um and 160 um. In addition, we obtained Herschel/PACS photometric data at 70 um for HIP 103389. Two different approaches are applied to reduce the Herschel data to investigate the impact of data reduction on the photometry. We fit analytical models to the available spectral energy distribution (SED) data. Results. The SEDs of the three disks potentially exhibit an unusually steep decrease at wavelengths > 70 um. We investigate the significance of the peculiar shape of these SEDs and the impact on models of the disks provided it is real. Our modeling reveals that such a steep decrease of the SEDs in the long wavelength regime is inconsistent with a power-law exponent of the grain size distribution -3.5 expected from a standard equilibrium collisional cascade. In contrast, a very distinct range of grain sizes is implied to dominate the thermal emission of such disks. However, we demonstrate that the understanding of the data of faint sources obtained with Herschel is still incomplete and that the significance of our results depends on the version of the data reduction pipeline used. Conclusions. A new mechanism to produce the dust in the presented debris disks, deviations from the conditions required for a standard equilibrium collisional cascade (grain size exponent of -3.5), and/or significantly different dust properties would be necessary to explain the potentially steep SED shape of the three debris disks presented. (abridged)Comment: 14 pages, 4 figures, accepted by A&

    Evolution of the gulf of Cadiz margin and southwest Portugal contourite depositional system : Tectonic, sedimentary and paleoceanographic implications from IODP expedition 339

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    Acknowledgments This research used samples and data collected through the Integrated Ocean Drilling Program (IODP). The research was partially supported through the CTM 2008-06399-C04/MAR, CTM 2012-39599-C03, CGL2011-26493, CTM2012-38248, SA263U14, IGCP-619, INQUA 1204 and FWF P25831-N29 Projects. Some data were collected with 94-1090-C03-03 (FADO) and MAR-98-0209 (TASYO) Projects. Research was conducted in the framework of the Continental Margins Research Group of the Royal Holloway University of London, People and the Program (Marie Curie Actions) of the European Union's Seventh Framework Program FP7/2007-2013/ under REA Grant Agreement No. 290201 MEDGATE’. We are very grateful to REPSeOL, TGS–NOPEC, and the CSIC-Institut Jaume Almera (http://geodb.ictja.csic.es) for allowing us to use an unpublished seismic data from the Gulf of Cadiz. We thank J. Aguire (UGR, Spain) for comments and suggestions concerning the Pliocene and Quaternary outcrops, B. van den Berg (USAL) for organizing a thought-provoking field-trip to Cadiz, Spain in November, 2014, M. Ángel Caja, L. García Diego, and J. Tritlla (REPSOL) for provenance and diagenetic analysis of early Pliocene sandstones and debrites, and L.J. Lourens (Utrecht University) for providing us the eccentricity and 200-Kys glacio-eustatic sea-level curves included in the Figure 16. Both Prof. D.A.V. Stow (Heriot-Watt Univ., UK) and F.J. Hernández-Molina (RHUL, UK), as the main co-proponents of the IODP Proposal 644 and the co-chiefs of the IODP Exp. 339, thanks to IODP, Exp. IODP 339 Scientists; JR crew and technicians, as well as all people, institutions and companies involved in making IODP a success since 2003. Finally, we also thank the editor, Gert J. De Lange and the reviewers T. Mulder (Bourdeaux Univ.); D. Van Rooij (Ghent Univ) and J. Duarte (Monash Univ.) for their very positive and helpful feedback and discussions in publishing this research.Peer reviewedPublisher PD

    The unusual protoplanetary disk around the T Tauri star ET Cha

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    We present new continuum and line observations, along with modelling, of the faint (6-8) Myr old T Tauri star ET Cha belonging to the eta Chamaeleontis cluster. We have acquired HERSCHEL/PACS photometric fluxes at 70 mic and 160 mic, as well as a detection of the [OI] 63 mic fine-structure line in emission, and derived upper limits for some other far-IR OI, CII, CO and o-H2O lines. The HERSCHEL data is complemented by new ANDICAM B-K photometry, new HST/COS and HST/STIS UV-observations, a non-detection of CO J=3-2 with APEX, re-analysis of a UCLES high-resolution optical spectrum showing forbidden emission lines like [OI] 6300A, [SII] 6731A and 6716A, and [NII] 6583A, and a compilation of existing broad-band photometric data. We used the thermo-chemical disk code ProDiMo and the Monte-Carlo radiative transfer code MCFOST to model the protoplanetary disk around ET Cha. Based on these models we can determine the disk dust mass Mdust = (2.E-8 - 5.E-8) Msun, whereas the total disk gas mass is found to be only little constrained, Mgas = (5.E-5 - 3.E-3) Msun. In the models, the disk extends from 0.022 AU (just outside of the co-rotation radius) to only about 10 AU. Larger disks are found to be inconsistent with the CO J=3-2 non-detection. The low velocity component of the [OI] 6300A emission line is consistent with being emitted from the inner disk. The model can also reproduce the line flux of H2 v=1-0 S(1) at 2.122 mic. An additional high-velocity component of the [OI] 6300A emission line, however, points to the existence of an additional jet/outflow of low velocity (40 - 65) km/s with mass loss rate ~1.E-9 Msun/yr. In relation to our low estimations of the disk mass, such a mass loss rate suggests a disk lifetime of only ~(0.05 - 3) Myr, substantially shorter than the cluster age. The evolutionary state of this unusual protoplanetary disk is discussed.Comment: accepted by Astronomy & Astrophysics (18 pages, 11 figures and 7 tables). Additional 9-page appendix with 6 figures, 3 tables and 37 equation

    A survey of the state-of-the-art techniques for cognitive impairment detection in the elderly

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    With a growing number of elderly people in the UK, more and more of them suffer from various kinds of cognitive impairment. Cognitive impairment can be divided into different stages such as mild cognitive impairment (MCI) and severe cognitive impairment like dementia. Its early detection can be of great importance. However, it is challenging to detect cognitive impairment in the early stage with high accuracy and low cost, when most of the symptoms may not be fully expressed. This survey paper mainly reviews the state of the art techniques for the early detection of cognitive impairment and compares their advantages and weaknesses. In order to build an effective and low-cost automatic system for detecting and monitoring the cognitive impairment for a wide range of elderly people, the applications of computer vision techniques for the early detection of cognitive impairment by monitoring facial expressions, body movements and eye movements are highlighted in this paper. In additional to technique review, the main research challenges for the early detection of cognitive impairment with high accuracy and low cost are analysed in depth. Through carefully comparing and contrasting the currently popular techniques for their advantages and weaknesses, some important research directions are particularly pointed out and highlighted from the viewpoints of the authors alone

    Non-motor symptom burden in patients with Parkinson's disease with impulse control disorders and compulsive behaviours : results from the COPPADIS cohort

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    The study was aimed at analysing the frequency of impulse control disorders (ICDs) and compulsive behaviours (CBs) in patients with Parkinson's disease (PD) and in control subjects (CS) as well as the relationship between ICDs/CBs and motor, nonmotor features and dopaminergic treatment in PD patients. Data came from COPPADIS-2015, an observational, descriptive, nationwide (Spain) study. We used the validated Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale (QUIP-RS) for ICD/CB screening. The association between demographic data and ICDs/CBs was analyzed in both groups. In PD, this relationship was evaluated using clinical features and treatment-related data. As result, 613 PD patients (mean age 62.47 ± 9.09 years, 59.87% men) and 179 CS (mean age 60.84 ± 8.33 years, 47.48% men) were included. ICDs and CBs were more frequent in PD (ICDs 12.7% vs. 1.6%, p < 0.001; CBs 7.18% vs. 1.67%, p = 0.01). PD patients had more frequent previous ICDs history, premorbid impulsive personality and antidepressant treatment (p < 0.05) compared with CS. In PD, patients with ICDs/CBs presented younger age at disease onset, more frequent history of previous ICDs and premorbid personality (p < 0.05), as well as higher comorbidity with nonmotor symptoms, including depression and poor quality of life. Treatment with dopamine agonists increased the risk of ICDs/CBs, being dose dependent (p < 0.05). As conclusions, ICDs and CBs were more frequent in patients with PD than in CS. More nonmotor symptoms were present in patients with PD who had ICDs/CBs compared with those without. Dopamine agonists have a prominent effect on ICDs/CBs, which could be influenced by dose
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