{"id":5959,"date":"2026-10-19T09:48:14","date_gmt":"2026-10-19T09:48:14","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-lyfjafraedi-xiaxia-di\/"},"modified":"2026-10-19T09:48:14","modified_gmt":"2026-10-19T09:48:14","slug":"doktorsvorn-i-lyfjafraedi-xiaxia-di","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-lyfjafraedi-xiaxia-di\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed lyfjafr\u00e6\u00f0i &#8211; Xiaxia Di"},"content":{"rendered":"<div class=\"field-items\">\n<div class=\"field-item even\" property=\"content:encoded\">\n<p>M\u00e1nudaginn 7. jan\u00faar ver Xiaxia Di doktorsritger\u00f0 s\u00edna \u00ed lyfjav\u00edsindum vi\u00f0 Lyfjafr\u00e6\u00f0ideild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0: <strong>Leit a\u00f0 efnum me\u00f0 \u00f3n\u00e6misb\u00e6landi \u00e1hrif \u00far \u00edslenskum sj\u00e1varhryggleysingjum. <\/strong><strong>Searching for immunomodulatory compounds from Icelandic marine invertebrates.<\/strong><strong>\u00a0<\/strong><\/p>\n<p>Andm\u00e6lendur eru dr. Valeria Costantino, pr\u00f3fessor vi\u00f0 lyfjafr\u00e6\u00f0ideild University of Naples Federico II, \u00cdtal\u00edu, og dr. Gu\u00f0mundur G. Haraldsson, pr\u00f3fessor vi\u00f0 Raunv\u00edsindadeild H\u00e1sk\u00f3la \u00cdslands.<\/p>\n<p>Lei\u00f0beinendur voru dr. Sesselja \u00d3marsd\u00f3ttir, pr\u00f3fessor vi\u00f0 Lyfjafr\u00e6\u00f0ideild, dr. J\u00f3na Freysd\u00f3ttir, pr\u00f3fessor vi\u00f0 L\u00e6knadeild, og dr. Ingibj\u00f6rg Har\u00f0ard\u00f3ttir, pr\u00f3fessor vi\u00f0 L\u00e6knadeild. Auk \u00feeirra s\u00e1tu \u00ed doktorsnefndinni dr. Margr\u00e9t \u00deorsteinsd\u00f3ttir og dr. El\u00edn Soff\u00eda \u00d3lafsd\u00f3ttir, pr\u00f3fessorar vi\u00f0 Lyfjafr\u00e6\u00f0ideild.\u00a0<\/p>\n<p>Dr. El\u00edn Soff\u00eda \u00d3lafsd\u00f3ttir, pr\u00f3fessor og forseti Lyfjafr\u00e6\u00f0ideildar, stj\u00f3rnar ath\u00f6fninni sem fer fram \u00ed \u00d6skju, stofu 132, og hefst kl. 14:00.<\/p>\n<p><strong>\u00c1grip af ranns\u00f3kn <\/strong><\/p>\n<p>Markmi\u00f0 verkefnisins var a\u00f0 einangra og skilgreina efnabyggingar n\u00fdrra og \u00feekktra efna me\u00f0 \u00f3n\u00e6misb\u00e6landi \u00e1hrif \u00far sj\u00e1varhryggleysingjum \u00far sj\u00f3num \u00ed kringum \u00cdsland. \u00cd fyrsta og \u00f6\u00f0rum hluta ranns\u00f3knarinnar var notu\u00f0 l\u00edfvirknileidd einangrun til a\u00f0 einangra \u00far sj\u00e1varsv\u00f6mpum hreinar fj\u00f6l\u00f3metta\u00f0ar fitus\u00fdrur og fitus\u00e6kna efna\u00fe\u00e6tti me\u00f0 \u00f3n\u00e6misb\u00e6landi \u00e1hrif. \u00cd s\u00ed\u00f0ari hlutum ranns\u00f3knarinnar var efnainnihald \u00fardr\u00e1tta \u00far sj\u00e1varsvampinum Geodia barretti og mosad\u00fdrinu Flustra foliacea skima\u00f0 og greint me\u00f0 UPLC-qTOF-MS sem leiddi \u00ed lj\u00f3s n\u00edtj\u00e1n n\u00fdja og sext\u00e1n \u00feekkta alkal\u00f3\u00ed\u00f0a, \u00fear me\u00f0 talin d\u00edket\u00f3p\u00edperas\u00edn (DKP) hringlaga tv\u00edpept\u00ed\u00f0, br\u00f3mu\u00f0 k\u00ednol\u00edn\u00f3n, oxind\u00f3l, pyrr\u00f3l\u00f3[2,3-b]ind\u00f3l, ind\u00f3l og imidaz\u00f3l aflei\u00f0ur. Skima\u00f0 var eftir \u00f3n\u00e6misb\u00e6landi \u00e1hrifum einangra\u00f0ra efna \u00ed angafrumul\u00edkani og h\u00f6f\u00f0u sum \u00feeirra \u00e1hrif \u00e1 seytun angafrumnanna \u00e1 frumubo\u00f0efnunum IL-12p40 og IL-10 og getu \u00feeirra til a\u00f0 s\u00e9rh\u00e6fa T frumur \u00ed Th1 frumur. Ni\u00f0urst\u00f6\u00f0ur \u00feessarar ranns\u00f3knar benda til a\u00f0 hafsv\u00e6\u00f0i\u00f0 umhverfis \u00cdsland geti veri\u00f0 g\u00f3\u00f0 uppspretta l\u00edfvirkra efna sem h\u00e6gt er a\u00f0 rannsaka frekar og e.t.v. \u00fer\u00f3a sem lyfjasprota til a\u00f0 me\u00f0h\u00f6ndla sj\u00fakd\u00f3ma \u00fear sem b\u00f3lga kemur vi\u00f0 s\u00f6gu.<\/p>\n<p><strong>Abstract <\/strong><\/p>\n<p>The aim of the study was to isolate and identify new and known compounds with immunomodulatory activity from marine invertebrates collected in Icelandic waters. In the first and second parts of the study, a bioassay-guided isolation method was successfully exploited to identify pure polyunsaturated fatty acids and lipophilic fractions from marine sponges, which had immunomodulatory effects. In the later parts of this study, crude extracts from the marine sponge Geodia barretti and the bryozoan Flustra foliacea were chemically profiled by UPLC-qTOF-MS and the chemical investigation resulted in identification of nineteen new and sixteen previously known alkaloids, including diketopiperazine (DKP) cyclic dipeptides, brominated quinolinones, oxindoles, pyrrolo[2,3-b]indoles, indoles and imidazoles derivatives. All the isolated compounds were screened for immunomodulatory activity using dendritic cell (DC) model and some affected DC secretion of the cytokines IL-12p40 and IL-10 as well as the ability of the DCs to direct differentiation of co-cultured T cells to a Th1 phenotype. These studies indicate that the marine environment around Iceland may be a rich source of biological compounds, which could be investigated further with regard to their potential of becoming a drug lead for treatment of inflammatory related diseases.<\/p>\n<p><strong>Um doktorsefni\u00f0<\/strong><\/p>\n<p>Xiaxia Di er f\u00e6dd \u00e1ri\u00f0 1987 \u00ed K\u00edna en flutti til \u00cdslands \u00e1ri\u00f0 2014. H\u00fan lauk BS pr\u00f3fi \u00ed lyfjafr\u00e6\u00f0i fr\u00e1 Hebei-h\u00e1sk\u00f3la \u00e1ri\u00f0 2010 og MS pr\u00f3fi \u00ed efnafr\u00e6\u00f0i n\u00e1tt\u00faruefna fr\u00e1 Shandong-h\u00e1sk\u00f3la \u00e1ri\u00f0 2013. \u00c1rin 2013-2014 starfa\u00f0i h\u00fan sem v\u00edsindama\u00f0ur hj\u00e1 CSPC Pharma \u00ed Shijiazhuang \u00ed K\u00edna. Xiaxia er d\u00f3ttir Zhenlun Di, kaups\u00fdslumanns og Xueyun Bai, verslunarkonu.<\/p>\n<\/div><\/div>\n","protected":false},"featured_media":1106,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2019-01-07T14:00:00+00:00","_phd_date_end":"2019-01-07T17:00:00+00:00","_phd_location":"Askja Stofa 132","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Leit a\u00f0 efnum me\u00f0 \u00f3n\u00e6misb\u00e6landi \u00e1hrif \u00far \u00edslenskum sj\u00e1varhryggleysingjum. 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