YOD

YOD (Iodum), I, elementi khimiyavii guruhi VII sistemai davrii Mendeleev, raqami at. 53, massai at. 126, 904, mansubi galogenho. S. 1811 khimiki fransavi B. Kurtua kashf kardaast. Dar tabiat dar namudi payvasthoi sobiti 127I vomekhurad. 131I va 133I – izotophoi muhimi radioaktivi sunii Y. meboshand. Miqdori Y. dar qishri Zamin 4 • 10–5% ast. Dar harorati muqarrari Y. kristalli siyohtobi jiloyash metalli ast; t gud. 113,5°S, t jush. 184,35°S, zichiash 4930 kg/m3. Hangomi garm kardan bukhor shuda, bugi zahrnoki bunafsh hosil mekunad. Nomi Y. ham az hamin jo girifta shudaast (yun. iodes – rangi bunafsh). Molekulahoi Y. duatoma meboshand. Y. oksidkunandai zur ast. Dar ob bad, dar halkunandahoi organiki (atseton, khloroform, efir, spirt va mahluli obii yodidi kaliy) nagz hal meshavad. Y. az jihati faoli bad az brom va khlor meistad. Bo oksigen, sulfur, nitrogen bevosita ba reaksiya dokhil nameshavad, bo gidrogen va aksari metallho tanho hangomi garm kardan ba reaksiya medaroyad.
Dar organizmi hayvonot va odam Y. chun mikroelementi zaruri ba mubodilai modda, khususan ba funksiyai gadudi siparshakl, ravandi dissimilyatsiya va g. tasiri kalon dorad. Talaboti shaboruzii odam va hayvonot ba I. 3 mg/kg (dar holati homilagi va khunuk khurdan ziyodtar) ast. Bo sababi norasoii Y. dar khurok va ob ba 1 t namaki oshi 10 – 25 g KI ilova mekunand. Az organizm Y. bo gadudhoi araq, shir, luob, gurda (to 70 – 80%) va kamu besh bo zahra khorij meshavad.
Ba doruhoi Y., ki dar tib istifoda meshavand, mahluli Lyugol, payvasthoi gayriorganikii yod (yodidho, yodidi kaliy va natriy), payvasthoi organikie, ki yodro tajziya mekunand (yodoform, yodinol), payvasthoi organikie, ki dar molekulai onho Y. ustuvor joy giriftaast va g. mansuband.
Doruhoi Y.-i muqarrari tasiri ziddimikrobi dorand. Binobar in onhoro chun doruhoi ziddi ufunat (antiseptiki) kor mefarmoyand. Bo in maqsad payvasthoi organikii on, ki Y.-i muqarrariro tajziya mekunand, istifoda meshavand. Dar vaqti ba pust va luobpardaho molidan doruhoi Y. tasiri angezishovar merasonand. Hangomi istemoli doruhoi Y. onho az rohi medayu ruda ba khun guzashta, miqdori kholesterinro dar tarkibi khun kam mekunad. Y. ba faoliyati gadudi siparshakl tasiri dujoniba merasonad. Hangomi gipoteriaz on dar ravandi hosilshavii tiroksin ishtirok mekunad; dar mavridi ziyod budani faoliyati gadudi siparshakl boshad, voyai kami on metavonad hosilshavii tiroksinro ba takhir andozad (voyai kami Y. – mikroyod hosilshavii gormoni tireotropiro dar hissai peshi gipofiz bozmedorad). Az in ru, doruhoi Y.-i muqarrari va payvasthoi gayriorganikii on (yodidi natriy, yodidi kaliy)-ro bo voyai ziyod baroi peshgiriyu tabobati jogari vogir, bo voyai kam – hangomi giperterioz istifoda mebarand.
Ionhoi Y. ba faoliyati gadudhoi ikhroj taqviyat mebakhshand. Hususan onho kori gadudhoi bronkhhoro tezonda, bo hamin gilzati balgamro kohish medihand. Payvasthoi gayriorganikii Y. (yodidi natriy va yodidi kaliy) chun doruhoi balgamron kor farmuda meshavand. Payvasthoi organikii Y. (mas., bilignost, triombrast, yodamid va g.)-ro ba sifati vasoiti kontrasti rentgeni istifoda mekunand.
Hangomi duru daroz istemol kardani doruhoi Y. va ziyod budani hassosiyat nisbati onho mumkin ast holati yodizm ba vujud oyad (zukom, raftani obi dahon, shoridani ashk, damidani rikhinakho, varami (svinke va g.).
T. Idrisov.