Browsing by Subject "REDUCTION"

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  • Lagerspets, Emi; Valbonetti, Evelyn; Eronen, Aleksi; Repo, Timo (2021)
    We report here novel Cu(I) thiophene carbaldimine catalysts for the selective aerobic oxidation of primary alcohols to their corresponding aldehydes and various diols to lactones or lactols. In the presence of the in situ generated Cu(I) species, a persistent radical (2,2,6,6-tetramethylpiperdine-N-oxyl (TEMPO)) and N-methylimidazole (NMI) as an auxiliary ligand, the reaction proceeds under aerobic conditions and at ambient temperature. Especially the catalytic system of 1-(thiophen-2-yl)-N-(4-(trifluoromethoxy)phenyl)methanimine (ligand L2) with copper(I)-iodide showed high reactivity for all kind of alcohols (benzylic, allylic and aliphatic). In the case of benzyl alcohol even 2.5 mol% of copper loading gave quantitative yield. Beside high activity under aerobic conditions, the catalysts ability to oxidize 1,5-pentadiol to the corresponding lactol (86% in 4 h) and Nphenyldiethanolamine to the corresponding morpholine derivate lactol (86% in 24 h) is particularly noteworthy.
  • Kormi, Eeva; Snall, Johanna; Tornwall, Jyrki; Thoren, Hanna (2016)
    Purpose: The aim of the study was to clarify the use of perioperative glucocorticoids (GCs) in association with oral and maxillofacial surgical procedures. Materials and Methods: We conducted a survey of consultant oral and maxillofacial surgeons (OMSs) working in tertiary and secondary referral hospitals in Finland. Results: The administration of GCs is common among OMSs (85.2% of respondents), especially in association with orthognathic surgery (100% of respondents) and facial fractures (43.5%). All OMSs who administered GCs reported that they reduce swelling. The next most common reasons for administering GCs were established practice (43.5%) and pain reduction (39.1%). The regimens differed widely from a 5-mg single dose to a 116-mg total dose of dexamethasone equivalent. Conclusions: GCs are widely administered by OMSs, especially in major surgery. The literature shows some benefits of their use in dental and orthognathic operations, and their use seems rather safe. Proof of efficacy remains to be determined for other major maxillofacial surgical procedures; thus further studies are needed. (C) 2016 American Association of Oral and Maxillofacial Surgeons
  • Välkki, Kirsi Johanna; Thomson, Katariina Hanne; Grönthal, Thomas Sven Christer; Junnila, Jouni Juho Tapio; Rantala, Merja Hilma Johanna; Laitinen-Vapaavuori, Outi Maria; Mölsä, Sari Helena (2020)
    Background Surgical site infections (SSI) are associated with increased morbidity and mortality. To lower the incidence of SSI, antimicrobial prophylaxis is given 30-60 min before certain types of surgeries in both human and veterinary patients. However, due to the increasing concern of antimicrobial resistance, the benefit of antimicrobial prophylaxis in clean orthopaedic and neurosurgeries warrants investigation. The aims of this retrospective cross-sectional study were to review the rate of SSI and evaluate the compliance with antimicrobial guidelines in dogs at a veterinary teaching hospital in 2012-2016. In addition, possible risk factors for SSI were assessed. Results Nearly all dogs (377/406; 92.9%) received antimicrobial prophylaxis. Twenty-nine dogs (7.1%) did not receive any antimicrobials and only four (1.1%) received postoperative antimicrobials. The compliance with in-house and national protocols was excellent regarding the choice of prophylactic antimicrobial (cefazolin), but there was room for improvement in the timing of prophylaxis administration. Follow-up data was available for 89.4% (363/406) of the dogs. Mean follow-up time was 464 days (range: 3-2600 days). The overall SSI rate was 6.3%: in orthopaedic surgeries it was 6.7%, and in neurosurgeries it was 4.2%. The lowest SSI rates (0%) were seen in extracapsular repair of cranial cruciate ligament rupture, ulnar ostectomy, femoral head and neck excision, arthrotomy and coxofemoral luxation repair. The highest SSI rate (25.0%) was seen in arthrodesis. Omission of antimicrobials did not increase the risk for SSI (P = 0.56; OR 1.7; CI(95%)0.4-5.0). Several risk factors for SSI were identified, including methicillin-resistantStaphylococcus pseudintermediuscarriage (P = 0.02; OR 9.0; CI(95%)1.4-57.9) and higher body temperature (P = 0.03; OR 1.69; CI(95%)1.0-2.7; mean difference + 0.4 degrees C compared to dogs without SSI). Conclusions Antimicrobial prophylaxis without postoperative antimicrobials is sufficient to maintain the overall rate of SSI at a level similar to published data in canine clean orthopedic and neurosurgeries.
  • Uudekll, Peep; Kozlova, Jekaterina; Mandar, Hugo; Link, Joosep; Sihtmae, Mariliis; Kaosaar, Sandra; Blinova, Irina; Kasemets, Kaja; Kahru, Anne; Stern, Raivo; Tatte, Tanel; Kukli, Kaupo; Tamm, Aile (2017)
    Spherical nickel particles with size in the range of 100-400 nm were synthesized by non-aqueous liquid phase benzyl alcohol method. Being developed for magnetically guided biomedical applications, the particles were coated by conformal and antimicrobial thin titanium oxide films by atomic layer deposition. The particles retained their size and crystal structure after the deposition of oxide films. The sensitivity of the coated particles to external magnetic fields was increased compared to that of the uncoated powder. Preliminary toxicological investigations on microbial cells and small aquatic crustaceans revealed non-toxic nature of the synthesized particles.
  • Isenberg, Stefan; Weller, Stefan; Kargin, Denis; Valic, Srecko; Schwederski, Brigitte; Kelemen, Zsolt; Bruhn, Clemens; Krekic, Kristijan; Maurer, Martin; Feil, Christoph M.; Nieger, Martin; Gudat, Dietrich; Nyulaszi, Laszlo; Pietschnig, Rudolf (2019)
    Invited for this month's cover picture are the groups of Professors Rudolf Pietschnig at the University of Kassel, Professor Dietrich Gudat at the University of Stuttgart and Professor Laszlo Nyulaszi at the Budapest University of Technology and Economics. The cover picture shows the thermally induced homolytic cleavage of the central P-P bond in a phosphorus-rich bis-ferrocenophane furnishing P-centered radicals (as evidenced by the computed spin-density highlighted in blue). The central P-6 unit in the title compound is a structural analog of the connecting unit in Hittorf's violet phosphorus, which links the orthogonally arranged tubular entities. A portrait of the German physicist Johann Wilhelm Hittorf is included. Read the full text of their Full Paper at 10.1002/open.201900182.
  • Miliutina, Elena; Guselnikova, Olga; S. Soldatova, Natalia; Bainova, Polina; Elashnikov, Roman; Fitl, Přemysl; Kurten, Theo; S. Yusubov, Mekhman; Švorčík, Václav; Valiev, Rashid; M. Chehimi, Mohamed; Lyutakov, Oleksiy; S. Postnikov, Pavel (2020)
    Plasmon-assisted transformations of organic compounds represent a novel opportunity for conversion of light to chemical energy at room temperature. However, the mechanistic insights of interaction between plasmon energy and organic molecules is still under debate. Herein, we proposed a comprehensive study of the plasmon-assisted reaction mechanism using unsymmetric iodonium salts (ISs) as an organic probe. The experimental and theoretical analysis allow us to exclude the possible thermal effect or hot electron transfer. We found that plasmon interaction with unsymmetrical ISs led to the intramolecular excitation of electron followed by the regioselective cleavage of C–I bond with the formation of electron-rich radical species, which cannot be explained by the hot electron excitation or thermal effects. The high regioselectivity is explained by the direct excitation of electron to LUMO with the formation of a dissociative excited state according to quantum-chemical modeling, which provides novel opportunities for the fine control of reactivity using plasmon energy.
  • Gorbikova, Elena; Kalendar, Ruslan (2020)
    Cytochrome c oxidase is terminal enzyme in the respiratory chain of mitochondria and many aerobic bacteria. It catalyzes reduction of oxygen to water. During its catalysis, CcO proceeds through several quite stable intermediates (R, A, PR/M, O/OH, E/EH). This work is concentrated on the elucidation of the differences between structures of oxidized intermediates O and OH in different CcO variants and at different pH values. Oxidized intermediates of wild type and mutated CcO from Paracoccus denitrificans were studied by means of static and time-resolved Fourier-transform infrared spectroscopy in acidic and alkaline conditions in the infrared region 1800–1000 cm−1. No reasonable differences were found between all variants in these conditions, and in this spectral region. This finding means that the binuclear center of oxygen reduction keeps a very similar structure and holds the same ligands in the studied conditions. The further investigation in search of differences should be performed in the 4000–2000 cm−1 IR region where water ligands absorb.
  • Wiktorowicz, Szymon; Damlin, Pia; Salomäki, Mikko; Kvarnström, Carita; Tenhu, Heikki; Aseyev, Vladimir (2019)
    A reductive coupling reaction employing sodium bis(2-methoxyethoxy) aluminum hydride is used to prepare main chain azo-polymers comprising of polycyclic aromatic hydrocarbons (naphthalene, anthraquinone, or fluorenone) from their dinitro-derivatives. The azo-bridges act as effective means of conjugation and all polymers exhibit differences in the ultra-violet-visible light absorption and photoluminescence emission spectra depending on the degree of polymerization. Furthermore, in the case of poly(azofluorenone)s and poly(azoanthraquinone)s, these spectra may be modified by changes in the protonation state of the polymers. The lowest unoccupied molecular orbital and highest occupied molecular orbital energy levels and the band gap of poly(azoanthraquinone) are estimated from cyclic voltammetry data and UV-visible absorption of films.
  • Poganitsch-Korhonen, M.; Masliukaite, I.; Nurmio, M.; Lahteenmaki, P.; van Wely, M.; van Pelt, A. M. M.; Jahnukainen, K.; Stukenborg, J-B (2017)
  • Kainulainen, S.; Tornwall, J.; Koivusalo, A. M.; Suominen, A. L.; Lassus, Patrik (2017)
    Objectives: Glucocorticoids are widely used in association with major surgery of the head and neck to improve postoperative rehabilitation, shorten intensive care unit and hospital stay, and reduce neck swelling. This study aimed to clarify whether peri-and postoperative use of dexamethasone in reconstructive head and neck cancer surgery is associated with any advantages or disadvantages. Materials and methods: This prospective double-blind randomized controlled trial comprised 93 patients. A total dose of 60 mg of dexamethasone was administered to 51 patients over three days peri-and post-operatively. The remaining 42 patients served as controls. The main primary outcome variables were neck swelling, length of intensive care unit and hospital stay, duration of intubation or tracheostomy, and delay to start of possible radiotherapy. Complications were also recorded. Results: No statistical differences emerged between the two groups in any of the main primary outcome variables. However, there were more major complications, especially infections, needing secondary surgery within three weeks of the operation in patients receiving dexamethasone than in control patients (27% vs. 7%, p = 0.012). Conclusions: The use of dexamethasone in oral cancer patients with microvascular reconstruction did not provide a benefit. More major complications, especially infections, occurred in patients receiving dexamethasone. Our data thus do not support the use of peri-and postoperative dexamethasone in oropharyngeal cancer patients undergoing microvascular reconstruction. (C) 2016 Elsevier Ltd. All rights reserved.
  • Saarinen, Aino I. L.; Keltikangas-Järvinen, Liisa; Hintsa, Taina; Pulkki-Råback, Laura; Ravaja, Niklas; Lehtimäki, Terho; Raitakari, Olli; Hintsanen, Mirka (2020)
    Background This study investigated (i) whether compassion is associated with blood pressure or hypertension in adulthood and (ii) whether familial risk for hypertension modifies these associations. Method The participants (N = 1112-1293) came from the prospective Young Finns Study. Parental hypertension was assessed in 1983-2007; participants' blood pressure in 2001, 2007, and 2011; hypertension in 2007 and 2011 (participants were aged 30-49 years in 2007-2011); and compassion in 2001. Results High compassion predicted lower levels of diastolic and systolic blood pressure in adulthood. Additionally, high compassion was related to lower risk for hypertension in adulthood among individuals with no familial risk for hypertension (independently of age, sex, participants' and their parents' socioeconomic factors, and participants' health behaviors). Compassion was not related to hypertension in adulthood among individuals with familial risk for hypertension. Conclusion High compassion predicts lower diastolic and systolic blood pressure in adulthood. Moreover, high compassion may protect against hypertension among individuals without familial risk for hypertension. As our sample consisted of comparatively young participants, our findings provide novel implications for especially early-onset hypertension.
  • Klovatch-Podlipsky, Ilana; Gazit, Tomer; Fahoum, Firas; Tsirelson, Boris; Kipervasser, Svetlana; Kremer, Uri; Ben-Zeev, Bruria; Goldberg-Stern, Hadassah; Eisenstein, Orna; Harpaz, Yuval; Levy, Ory; Kirschner, Adi; Neufeld, Miriam Y.; Fried, Itzhak; Hendler, Talma; Medvedovsky, Mordekhay (2016)
    Objective: Although simultaneous recording of EEG and MRI has gained increasing popularity in recent years, the extent of its clinical use remains limited by various technical challenges. Motion interference is one of the major challenges in EEG-fMRI. Here we present an approach which reduces its impact with the aid of an MR compatible dual-array EEG (daEEG) in which the EEG itself is used both as a brain signal recorder and a motion sensor. Methods: We implemented two arrays of EEG electrodes organized into two sets of nearly orthogonally intersecting wire bundles. The EEG was recorded using referential amplifiers inside a 3 T MR-scanner. Virtual bipolar measurements were taken both along bundles (creating a small wire loop and therefore minimizing artifact) and across bundles (creating a large wire loop and therefore maximizing artifact). Independent component analysis (ICA) was applied. The resulting ICA components were classified into brain signal and noise using three criteria: 1) degree of two-dimensional spatial correlation between ICA coefficients along bundles and across bundles; 2) amplitude along bundles vs. across bundles; 3) correlation with ECG. The components which passed the criteria set were transformed back to the channel space. Motion artifact suppression and the ability to detect interictal epileptic spikes following daEEG and Optimal Basis Set (OBS) procedures were compared in 10 patients with epilepsy. Results: The SNR achieved by daEEG was 11.05 +/- 3.10 and by OBS was 8.25 +/- 1.01 (p <0.00001). In 9 of 10 patients, more spikes were detected after daEEG than after OBS (p <0.05). Significance: daEEG improves signal quality in EEG-fMRI recordings, expanding its clinical and research potential. (C) 2016 Elsevier Inc. All rights reserved.
  • Barengo, Noel C.; Acosta, Tania; Arrieta, Astrid; Ricaurte, Carlos; Smits, Dins; Florez, Karen; Tuomilehto, Jaakko O. (2019)
    Background: The objective of the demonstration project for type 2 diabetes prevention in the Barranquilla and Juan Mina (DEMOJUAN) study was to investigate the extent to which it is possible to reach normal glucose metabolism with early lifestyle interventions in people at high risk of type 2 diabetes (prediabetes), compared with those who receive standard usual care. Methods: DEMOJUAN was a randomized controlled trial conducted in Juan Mina and Barranquilla, Northern Colombia. Eligible participants were randomized into one of three groups (control group, initial nutritional intervention, and initial physical activity intervention). The duration of the intervention was 24 months. The main study outcome in the present analysis was reversion to normoglycemia. Relative risks and their corresponding 95% confidence intervals were calculated for reversal to normoglycemia and T2D incidence. Results: There was no statistically significant association between the intervention groups and reversion to normoglycemia. The relative risk of reversion to normoglycemia was 0.88 (95% CI 0.70-1.12) for the initial nutritional intervention group participants and 0.95 (95% CI 0.75-1.20) for the initial physical activity intervention group participants. Conclusions: Our study did not find any statistically significant differences in reversion to normoglycemia or the development of type 2 diabetes between the intervention groups and the control group in this population.
  • Rönö, Kristiina; Grotenfelt, Nora Elisabeth; Klemetti, Miira Marjuska; Stach-Lempinen, Beata; Huvinen, Emilia; Meinilä, Jelena; Valkama, Anita; Tiitinen, Aila; Roine, Risto Paavo; Pöyhönen-Alho, Maritta; Andersson, Sture; Laivuori, Hannele; Kautiainen, Hannu; Eriksson, Johan Gunnar; Koivusalo, Saila Birgitta (2018)
    Objective To assess the effect of lifestyle counseling on perinatal outcomes among women at high risk for gestational diabetes. Study design A total of 492 women with obesity and/or prior gestational diabetes were allocated to intervention (four sessions of lifestyle counseling, n = 249) or usual care (n = 243) before 20 weeks' gestation. Result Lifestyle indicators, gestational weight gain, or obstetric and perinatal outcomes did not differ between the two groups. An oral glucose tolerance test in the first half of pregnancy was pathological in 37.7% (n = 87/144) of intervention and 36.5% (n = 72/197) of control group women (p = 0.81). The total incidence of gestational diabetes diagnosed in the first or second half of pregnancy was 44.8% (107/239) in the intervention and 48.1% (111/231) in the control group (p = 0.48). Conclusions The high prevalence of impaired glucose metabolism was observed already in early pregnancy, which may have contributed to the lack of effect of the intervention.
  • Ala-Mutka, Eero M.; Rimpelä, Jenni M.; Fyhrquist, Frej; Kontula, Kimmo K.; Hiltunen, Timo P. (2018)
    Aim: To recognize genetic associations of hydrochlorothiazide-induced change in serum uric acid (SUA) concentration. Patients & methods: We conducted a genome-wide association study on hydrochlorothiazide-induced change in SUA in 214 Finnish men from the GENRES study. Replication analyses were performed in 465 Finns from the LIFE study. Results: In GENRES, we identified 31 loci associated with hydrochlorothiazide-induced change in SUA at p <5 x 10(-5). rs1002976 near VEGFC associated with the change in GENRES and in LIFE. rs950569 near BRINP3 associated with the change in SUA in GENRES and LIFE. The analysis of previously reported SNPs and candidate genes provided some proof for PADI4 and ABCC4. Conclusion: We report genetic markers that may predict the increase in SUA concentration during thiazide treatment.
  • From, Svetlana; Liira, Helena; Leppävuori, Jenni Katariina; Remes-Lyly, Taina; Tikkanen, Heikki; Pitkala, Kaisu (2013)
  • Lindroth, Anders; Holst, Jutta; Linderson, Maj-Lena; Aurela, Mika; Biermann, Tobias; Heliasz, Michal; Chi, Jinshu; Ibrom, Andreas; Kolari, Pasi; Klemedtsson, Leif; Krasnova, Alisa; Laurila, Tuomas; Lehner, Irene; Lohila, Annalea; Mammarella, Ivan; Mölder, Meelis; Lofvenius, Mikaell Ottosson; Peichl, Matthias; Pilegaard, Kim; Soosaar, Kaido; Vesala, Timo; Vestin, Patrik; Weslien, Per; Nilsson, Mats (2020)
    The Nordic region was subjected to severe drought in 2018 with a particularly long-lasting and large soil water deficit in Denmark, Southern Sweden and Estonia. Here, we analyse the impact of the drought on carbon and water fluxes in 11 forest ecosystems of different composition: spruce, pine, mixed and deciduous. We assess the impact of drought on fluxes by estimating the difference (anomaly) between year 2018 and a reference year without drought. Unexpectedly, the evaporation was only slightly reduced during 2018 compared to the reference year at two sites while it increased or was nearly unchanged at all other sites. This occurred under a 40 to 60% reduction in mean surface conductance and the concurrent increase in evaporative demand due to the warm and dry weather. The anomaly in the net ecosystem productivity (NEP) was 93% explained by a multilinear regression with the anomaly in heterotrophic respiration and the relative precipitation deficit as independent variables. Most of the variation (77%) was explained by the heterotrophic component. Six out of 11 forests reduced their annual NEP with more than 50 g C m(-2)yr(-1)during 2018 as compared to the reference year. The NEP anomaly ranged between -389 and +74 g C m(-2)yr(-1)with a median value of -59 g C m(-2)yr(-1). This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.
  • Han, Liuyang; Tian, Xingling; Keplinger, Tobias; Zhou, Haibin; Li, Ren; Svedström, Kirsi; Burgert, Ingo; Yin, Yafang; Guo, Juan (2020)
    Structural and chemical deterioration and its impact on cell wall mechanics were investigated for visually intact cell walls (VICWs) in waterlogged archaeological wood (WAW). Cell wall mechanical properties were examined by nanoindentation without prior embedding. WAW showed more than 25% decrease of both hardness and elastic modulus. Changes of cell wall composition, cellulose crystallite structure and porosity were investigated by ATR-FTIR imaging, Raman imaging, wet chemistry, C-13-solid state NMR, pyrolysis-GC/MS, wide angle X-ray scattering, and N-2 nitrogen adsorption. VICWs in WAW possessed a cleavage of carboxyl in side chains of xylan, a serious loss of polysaccharides, and a partial breakage of beta -O-4 interlinks in lignin. This was accompanied by a higher amount of mesopores in cell walls. Even VICWs in WAW were severely deteriorated at the nanoscale with impact on mechanics, which has strong implications for the conservation of archaeological shipwrecks.
  • Chauhan, Chetna; Dhir, Amandeep; Akram, Manzoor Ul; Salo, Jari (2021)
    This study examines the state of the art of the literature in the domain of food loss and waste (FLW) in food supply chains (FSC). The authors used a systematic literature review (SLR) approach to examine and synthesise the findings of the existing literature to identify the key research themes, research gaps and avenues of future research on FLW in FSC. To this end, this SLR considered 152 articles relevant for the review. The authors uncovered the extant literature in the domain by presenting the research profile of the selected studies, along with thematic analysis. The authors identified eight key themes from the extant literature. The themes range from factors responsible for FLW generation to new, emerging areas of research such as digitalisation and food surplus redistribution. The study's findings will help clarify existing practices in FSC for waste mitigation and act as a foundation for strategic and policy initiatives in this area. The findings indicate that the major factors responsible for FLW include the poor management of perishable food items, stakeholder attitudes, buyer-supplier agreements and supply chain interruptions. Some of the important implications of the study include formal guidelines and policy-level interventions for assisting the accurate quantification of FLW along with an impetus on digitalisation to reduce FLW. The study concludes with the development of a research framework to assist future research in this domain. (c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).