Browsing by Subject "extraction"

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  • Kautto, A.; Vehkalahti, M. M.; Ventä, I. (2018)
    The purpose of this study was to assess the age of patients at the time of extraction of third molars. Our data included all routine and surgical extractions of third molars (n = 8199 teeth) performed by general and specialist dentists of the public oral health services of the city of Helsinki over the period 2013-2014. Measurements included patient's age, gender, the identified third molar, the type of anaesthesia, the method of extraction, and the diagnosis at extraction. Patients' ages ranged from 10 to 99 years. We found significant differences between younger and older age groups: third molar extractions occurred more often for women than for men below the age of 30 years (P <0.001) and vice versa for patients older than 30. Extractions were more prevalent for the upper jaw (P <0.001), and surgical extractions were more common than routine extractions (P <0.001) below the age of 40 years, but the corresponding prevalences reversed after the age of 40 years. Diagnoses at extraction differed between younger and older patients. We conclude that the treatment pattern of third molars at public health services varies greatly over a lifetime, and that a greater variety exists than had been reported previously from oral and maxillofacial units.
  • Selin, Markus (Helsingfors universitet, 2012)
    This thesis is constructed as a part of a larger research project aiming to increase understanding of polyketone reductases (PKR) and develop applications from them. PKRs are enzymes in biosynthetic pathways leading to several aromatic secondary metabolites in plants. The previous work in the research group has led to establishment of several callus cultures from plants belonging to the genus Rubus in the family Rosaceae. The aim in the experimental part of this thesis is the identification and semi-quantitation of raspberry ketone (RK) and related aromatics in the cell suspension cultures initiated from the previously established callus cultures. RK is biosynthetically produced by reduction of p-hydroxybenzalacetone (p-OH-BA) by benzalacetone reductase (BAR). As a part of the experimental work, p-OH-BA has to be chemically synthetized and analysed. Special emphasis is placed to experiment, develop and validate an extraction method for phenolic compounds using ASE 200 working station. In the review part of this thesis, the basic procedures of chemical analysis are described, optimization and validation of analytical methods are discussed, and lastly studies related to raspberry ketone (RK) are summarized. The detection limit is 0.73 µg/ml for RK with the established UPLC-UV method, and the quantitation limit (QL) is 2.22 µg/ml. At the QL, the standard deviation of the extraction method is 8.9 % and the results are 6.4 % higher than expected. At the high end of the standard curve the extraction results are 18.7 % higher than expected. Some changes are proposed to optimize the method. Analysis of the cell line extracts with the established UPLC-UV method did not readily reveal any of the studied compounds. Although the interpretation of the results of the MS experiment is still underway, RK was detected from the arctic bramble cell line Ra15. Also, a possible derivative of zingerone was detected from cloudberry cell line extract even without the corresponding standard compound. This shows the power of the MS in metabolite profiling, and gives a course for future studies.
  • Nykänen, Tina (Helsingfors universitet, 2013)
    Rhazya stricta Decne. is a small evergreen shrub belonging to the Apocynaceae family. The plant grows in South Asia and the Middle East, and in these areas it is used in traditional medicine. All parts of the plant are used in different preparations for a variety of purposes such as infections, bowel diseases, itching and diabetes. R. stricta synthesizes about a hundred different alkaloids, of which only a fraction has been studied closer. Some of the analyzed alkaloids have showed some interesting pharmacological properties such as antibacterial and cytotoxic properties. Because it is often both economically and ecologically unsustainable to cultivate or to collect large amounts of medicinal plants from nature, cell cultures have been developed from plants. The properties and synthesized substances of the cell cultures can be analysed and modified in laboratories. In the experimental part of this work, a system was developed for alkaloid extraction, fractionation and isolation from dried cell material from cultured R. stricta hairy root-cells. The goal was to develop a functioning system that eventually enables identification of the alkaloids synthesized by the cultured cells under given conditions. Alkaloids were extracted from 26 g of dried and ground cell mass. The fractionation of the alkaloids was performed with medium pressure liquid chromatography (MPLC) and the fractions were analyzed by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The alkaloids were purified by horizontal TLC and preparative HPLC. Ion-pair chromatography was used for analyzing the extract, fractions and purified alkaloids. Five components from two fractions were eventually isolated. One of the components was tentatively identified as vincanine, but further analyzes have to be performed to identify all components reliably. In total, hairy root-cells seem to synthesize approximately 20 alkaloids with variable polarity.
  • Leppänen, Eveliina (Helsingin yliopisto, 2017)
    Tutkielman tarkoituksena oli selvittää hammaskaarten ahtauden etiologisia tekijöitä, erilaisia arviointimenetelmiä sekä hoitovaihtoehtoja. Tutkielma toteutettiin kirjallisuuskatsauksena. Katsaus pohjautuu pääasiassa tieteellisiin artikkeleihin, jotka on kerätty PubMed- ja Ovid Medline tietokannoista. Alan oppikirjoja on myös käytetty lähteenä. Hammaskaarten ahtaus voidaan määritellä hampaiden ja leukojen koon välisenä epäsuhtana. Pysyvässä hampaistossa A I luokan ahtaustila on kaikkein tavallisin purentavirhe ja eniten ahtautta esiintyy alahammaskaaren etualueella. Kirjallisuudessa on esitetty antropologiaan, genetiikkaan ja ympäristötekijöihin pohjautuvia teorioita ahtauden etiologisiksi tekijöiksi. Ahtauden arviointiin on kehitetty erilaisia menetelmiä käytettäväksi sekä tutkimustyössä että praktiikassa. Ahtauden vaikeusasteesta ja vaihdunta-vaiheesta riippuen ahtautta voidaan hoitaa tilaa säilyttämällä, approksimaalihionnoilla sekä laajentamalla kaaria ja/tai poistamalla pysyviä hampaita. Hoitomenetelmän valintaan vaikuttaa ahtauden määrän lisäksi potilaan inkisiivien asema, huulten jännittyneisyys, profiili ja leukojen kasvurotaation suunta. Ahtaus on varsin yleinen purentavirhe ja sitä esiintyy myös yhdessä muiden purentavirheiden kanssa. Ahtautta on tutkittu laajasti, mutta jatkotutkimuksia tarvitaan hoitojen vaikutusten ja tehokkuuden edelleen arvioimiseksi.
  • Muhonen, Olli (Helsingfors universitet, 2012)
    Forest energy harvesting has increased significantly in recent years. The extraction of forest energy is usually done with conventional forwarders. The productivity of extraction work is, however, quite poor due to a low material density, which results in a small load size. The objective of the study was to increase the productivity of forest energy extraction via solutions that increase the load size. The first method that was studied involved widening the load space hydraulically. The other solution was based on compressing the load with hydraulically tiltable stakes. The study was conducted as a development study. The field studies were carried out in the summer and autumn of 2011 on harvesting sites managed by Metsähallitus and Metsäliitto in the Jyväskylä region. The study material comprises a total of 139 loads. There was a significant difference in raw density between the logging residues and stump pieces for the widening and compressing load space solutions. For this reason, it does not make sense to compare the two load space solutions to each other. The analyses were based on the reported load scale tonnes. Both load space alternatives increased the load size by 20-30 per cent depending on the assortment. For logging residues, the increase in efficient hour productivity for extraction was 13 per cent and for stump pieces it was 30 per cent. With the compressing load space, the efficient hour productivity for full trees increased by 17 per cent. For logging residues, the increase was 5 per cent and for stump pieces it was 12 per cent. Compression was not a successful method for stump pieces and even for logging residues the benefits were mainly based on the increased load space. Compressing the load is mainly beneficial when extracting full trees. The project was carried out together with Osuuskunta Metsäliitto (now Metsä Group), Metsä-Multia Oy and Ponsse Oyj. The modelling work was done by Metsäteho Oy. This study shows results of Metsähallitus project “Maastokuljetuksen kehittäminen”. The project is part of the EffFibre (Value through Intensive and Efficient Fibre Supply) research and development programme coordinated by Forestcluster Ltd.
  • Bertell, Julia (Helsingin yliopisto, 2016)
    Tämän tutkimuksen tarkoituksena oli selvittää, minkälaiset viisaudenhampaat poistetaan suusta ensimmäiseksi ikävuosien 21 ja 24 välillä. Tutkimusaineisto on peräisin Ylioppilaiden terveydenhoitosäätiöllä Helsingissä tehdystä, vuonna 2002 aloitetusta ensimmäisen vuoden opiskelijoiden suun terveyden seurantatutkimuksesta. Lopullinen otoskoko koostui 192 tutkittavasta, joiden keski-ikä ensimmäisen tutkimuskäynnin aikaan oli 20,7 ja toisen käynnin aikaan 23,7 vuotta. Tutkittavista 79 % oli naisia ja 21 % miehiä. Suun terveydentila tutkittiin kliinisesti ensimmäisen ja neljännen opiskeluvuoden lopussa. Kaikista tutkittavista otettiin leukojen panoraamaröntgenkuva ensimmäisen opiskeluvuoden aikana. Viisaudenhampaiden puhkeamisaste rekisteröitiin seuraavasti: puuttuu/poistettu, puhkeamaton, tunnusteltavissa viereisen hampaan distaalipinnalta, osa okklusaalipintaa näkyvissä, koko okklusaalipinta näkyvissä, kruunu osittain näkyvissä ja kruunu kokonaan näkyvissä eli täysin puhjennut. Aineisto analysoitiin Excelillä. Ryhmien väliset erot testattiin Khiin neliö -testillä. Seurannan aikana tutkittavilta poistettiin yhteensä 27 % kaikista suussa olleista viisaudenhampaista, joista 48 % oli yläleuasta ja 52 % alaleuasta. Seurannan aikana naisilta poistettiin enemmän viisaudenhampaita kuin miehiltä (31 % vs. 14 %; P<0.01). Alaleuasta poistettiin enemmän osittain puhjenneita viisaudenhampaita kuin yläleuasta (69 % vs. 41 %; P<0.01). Yläleuasta poistettiin enemmän täysin puhjenneita viisaudenhampaita kuin alaleuasta (35 % vs. 6 %; P<0.01). Johtopäätöksenä todetaan, että osittain puhjenneita alaviisaudenhampaita poistettiin paljon 21 ja 24 ikävuoden välillä, sillä ne aiheuttivat tässä iässä mahdollisesti runsaasti hoidontarvetta ja että naiset hoidattivat aktiivisemmin viisaudenhampaitaan kuin miehet. (200 sanaa)
  • Lehto, Elisa (Helsingin yliopisto, 2020)
    Literature review of the thesis introduces the characteristics of selenium and its importance in human diet. It also gives an overview on different analytical methods used in speciation of selenoamino acids. The aim of this study was to develop a simple and rapid mass spectrometric method which could be used to detect and specify low molecular weight selenoamino acids from different food materials in order to find and quantify probable cancer protective species. Total selenium content was determined by GFAAS from garlic and Brazil nut samples. The selenium concentration in garlic was 0.1 µg/g and 4.4 µg/g in Brazil nuts. Also, the precipitates and supernatants from the sample extractions (hot water, diluted HCl and proteinase K) were analyzed. There were only about 10% of the total selenium in the supernatants (which were further used in analysis). Samples were derivatized by AccQ·Tag reagent (AQC) and analyzed with UHPLC-ESI-MS method. Even though the method was easy and fast to use, it was applicable only for selenoamino acid standards (MeSeCys and SeMet). No results were obtained from the real samples. Therefore, a more sensitive piece of equipment, HPLC-ICP-MS was applied with Hamilton PRP-X100 column and 5 mmol/l ammonium citrate buffer (pH 5.2). Hot water and diluted HCl extracted samples showed no signs of selenium. At last, proteinase K digested Brazil nut sample showed a small peak of SeMet which was identified by retention time matching with the standard and quantified semi quantitatively from standard curve (0,06 µg SeMet /g Brazil nut). This study showed that the sensitivity of the UHPLC-ESI-MS method was not sufficient to detect such low concentrations of selenoamino acids in garlic and Brazil nut samples. However, the AQC derivatization together with UHPLC-ESI-MS offers a fast, linear and repeatable method for future amino acid analysis.
  • Kautto, Arja (Helsingfors universitet, 2017)
    Viisaudenhampaat aiheuttavat monenlaisia ongelmia ja siksi niiden poisto koskettaa lähes jokaista suomalaista. Tutkimuksen tarkoituksena on selvittää viisaudenhampaiden poistoihin johtavien diagnoosien yleisyyttä, poistotapaa, potilaan ikää poistohetkellä ja sukupuolten välisiä eroja. Tutkimuksen aineistona oli Helsingin kaupungin terveyskeskuksen potilastietojärjestelmästä Efficasta aikaväliltä 1.1.2013 - 8.12.2014 viisaudenhampaiden poistoihin liittyvät tiedot: hampaan numero Dd.18, 28, 38, 48, ICD-10 tautiluokituksen mukainen poistodiagnoosi, EBA-alkuinen toimenpidekoodi, potilaan ikä poistohetkellä ja sukupuoli. Tutkimusaineisto koostui 8436 poistetusta viisaudenhampaasta (51 % miesten hampaita, ikähajonta 10-99 vuotta). Aineisto analysoitiin Excelissä. Ryhmien välisten erojen tilastollista merkitsevyyttä testattiin Khi toiseen -testillä. Yleisimmät poistodiagnoosit jakautuivat seuraaviin luokkiin: K05 Hampaiden kiinnityskudosten sairaudet (23 %), K04 Hammasytimen ja hampaan juuren kärkeä ympäröivien kudosten sairaudet (20 %) sekä K02 Hammaskaries (18 %). Leikkaamalla poistettiin vain 27 % kaikista viisaudenhampaista, joista 81 % oli alaleuan hampaita ja joiden yleisimpänä poistodiagnoosina oli pitkäaikainen perikoroniitti (16 %). Yleisin poistoikä oli 20-29 vuotta (34 %). Miehiltä poistettiin viisaudenhampaita keskimäärin 38 vuoden ikäisenä ja naisilta 35,3-vuotiaina. Johtopäätöksenä todetaan, että viisaudenhampaita poistetaan terveyskeskuksessa yleisten biofilmisairauksien takia ja suurin osa tehdään tavanomaisina poistoina.