158 research outputs found

    An Alternate Method for Fourier Transform Infrared (FTIR) Spectroscopic Determination of Soil Nitrate Using Derivative Analysis and Sample Treatments

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    This study aimed at examining effective sample treatments and spectral processing for an alternate method of soil nitrate determination using the attenuated total reflectance (ATR) of Fourier transform infrared (FTIR) spectroscopy. Prior to FTIR measurements, soil samples were prepared as paste to enhance adhesion between the ATR crystal and sample. The similar nitrate peak heights of soil pastes and their supernatants indicated that the nitrate in the liquid portion of the soil paste mainly responded to the FTIR signal. Using a 0.01-M CaSO4 solution for the soil paste, which has no interference bands in the characteristic spectra of the analyte, increased the concentration of the nitrates to be measured. Second-order derivatives were used in the prediction model to minimize the interference effects and enhance the performance. The second-order derivative spectra contained a unique nitrate peak in a range of 1,400-1,200 cm(-1) without interference of carbonate. A partial least square regression model using second-order derivative spectra performed well (R (2) = 0.995, root mean square error (RMSE) = 23.5, ratio of prediction to deviation (RPD) = 13.8) on laboratory samples. Prediction results were also good for a test set of agricultural field soils with a CaCO3 concentration of 6% to 8% (R (2) = 0.97, RMSE = 18.6, RPD = 3.5). Application of the prediction model based on soil paste samples to nitrate stock solution resulted in an increased RMSE (62.3); however, validation measures were still satisfactory (R (2) = 0.99, RPD = 3.0

    Modeling of RTS noise in MOSFETs under steady-state and large-signal excitation

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    The behavior of RTS noise in MOSFETs under large-signal excitation is experimentally studied. Our measurements show a significant transient effect, in line with earlier reports. We present a new physical model to describe this transient behavior and to predict RTS noise in MOSFETs under large-signal excitation. With only three model parameters the behavior is well described, contrary to existing models

    Review - Late toxicity of abdominal and pelvic radiotherapy for childhood cancer

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    As survival improves in childhood cancer, prevention of late treatment-related toxicity in survivors becomes increasingly relevant. Radiotherapy is an important contributor to late toxicity. Therefore, minimizing radiation exposure to normal tissues is an important step towards improving the long-term therapeutic window of childhood cancer treatment. Since children are growing and developing, they are particularly vulnerable to radiation exposure. This makes the 'as low as reasonably achievable (ALARA)' principle even more important. In order to guide and achieve clinically meaningful dose reductions through advanced and emerging radiation techniques, it is important to investigate age-dependent relationships between radiation exposure to healthy tissues and late radiation-induced toxicity. In this review, we provide an overview of literature on the association between radiotherapy dose and late toxicity after abdominal and pelvic irradiation in childhood cancer. With this information, we aim to aid in decision-making regarding radiotherapy for childhood cancer. (c) 2022 The Author(s). Published by Elsevier B.V. Radiotherapy and Oncology 170 (2022) 27-36 This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

    Effective low-dose sirolimus regimen for kaposiform haemangioendothelioma with Kasabach-Merritt phenomenon in young infants

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    Aims Management of kaposiform haemangioendotheliomas (KHE) with Kasabach-Merritt phenomenon is challenging in young infants who are subjected to developmental pharmacokinetic changes. Sirolimus, sometimes combined with corticosteroids, can be used as an effective treatment of KHE. Simultaneously, toxicities such as interstitial pneumonitis related to the use of sirolimus may be fatal. As infants have a very low CYP3-enzyme expression at birth, which rises during ageing, we hypothesize that a reduced metabolization of sirolimus might lead to high sirolimus serum levels and low dose may be sufficient without the side effects. Methods A case series of 5 infants with kaposiform haemangioendothelioma with Kasabach-Merritt phenomenon was analysed retrospectively. All infants were treated with sirolimus 0.2 mg/m(2) every 24 or 48 hours according to their age. Prednisone was added to the therapy for additional effect in 4 patients. Results In all patients, low dose of sirolimus led to therapeutic sirolimus levels (4-6 ng/mL). All infants (aged 4 days-7 months) had a complete haematological response, without serious adverse events. In all patients, the Kasabach-Merritt phenomenon resolved, the coagulation profile normalized and tumour size reduction was seen. Conclusion Low-dose sirolimus treatment is safe for infants with kaposiform haemangioendothelioma and Kasabach-Merritt phenomenon. It is essential to realize that during the first months of life, metabolism is still developing and enzymes necessary to metabolise drugs like sirolimus still have to mature. To avoid toxic levels, the sirolimus dosage should be based on age and the associated pharmacological developments

    Remifentanil patient controlled analgesia versus epidural analgesia in labour. A multicentre randomized controlled trial

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    Background Pain relief during labour is a topic of major interest in the Netherlands. Epidural analgesia is considered to be the most effective method of pain relief and recommended as first choice. However its uptake by pregnant women is limited compared to other western countries, partly as a result of non-availability due to logistic problems. Remifentanil, a synthetic opioid, is very suitable for patient controlled analgesia. Recent studies show that epidural analgesia is superior to remifentanil patient controlled analgesia in terms of pain intensity score; however there was no difference in satisfaction with pain relief between both treatments. Methods/design The proposed study is a multicentre randomized controlled study that assesses the cost-effectiveness of remifentanil patient controlled analgesia compared to epidural analgesia. We hypothesize that remifentanil patient controlled analgesia is as effective in improving pain appreciation scores as epidural analgesia, with lower costs and easier achievement of 24 hours availability of pain relief for women in labour and efficient pain relief for those with a contraindication for epidural analgesia. Eligible women will be informed about the study and randomized before active labour has started. Women will be randomly allocated to a strategy based on epidural analgesia or on remifentanil patient controlled analgesia when they request pain relief during labour. Primary outcome is the pain appreciation score, i.e. satisfaction with pain relief. Secondary outcome parameters are costs, patient satisfaction, pain scores (pain-intensity), mode of delivery and maternal and neonatal side effects. The economic analysis will be performed from a short-term healthcare perspective. For both strategies the cost of perinatal care for mother and child, starting at the onset of labour and ending ten days after delivery, will be registered and compared. Discussion This study, considering cost effectiveness of remifentanil as first choice analgesia versus epidural analgesia, could strongly improve the care for 180.000 women, giving birth in the Netherlands yearly by giving them access to pain relief during labour, 24 hours a day.Liv M Freeman, Kitty WM Bloemenkamp, Maureen TM Franssen, Dimitri NM Papatsonis, Petra J Hajenius, Marloes E van Huizen, Henk A Bremer, Eline SA van den Akker, Mallory D Woiski, Martina M Porath, Erik van Beek, Nico Schuitemaker, Paulien CM van der Salm, Bianca F Fong, Celine Radder, Caroline J Bax, Marko Sikkema, M Elske van den Akker-van Marle, Jan MM van Lith, Enrico Lopriore, Renske J Uildriks, Michel MRF Struys, Ben Willem J Mol, Albert Dahan, and Johanna M Middeldor

    Patient controlled analgesia with remifentanil versus epidural analgesia in labour: Randomised multicentre equivalence trial

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    Objective To determine women’s satisfaction with pain relief using patient controlled analgesia with remifentanil compared with epidural analgesia during labour. Design Multicentre randomised controlled equivalence trial. Setting 15 hospitals in the Netherlands. Participants Women with an intermediate to high obstetric risk with an intention to deliver vaginally. To exclude a clinically relevant difference in satisfaction with pain relief of more than 10%, we needed to include 1136 women. Because of missing values for satisfaction this number was increased to 1400 before any analysis. We used multiple imputation to correct for missing data. Intervention Before the onset of active labour consenting women were randomised to a pain relief strategy with patient controlled remifentanil or epidural analgesia if they requested pain relief during labour. Main outcome measures Primary outcome was satisfaction with pain relief, measured hourly on a visual analogue scale and expressed as area under the curve (AUC), thus providing a time weighted measure of total satisfaction with pain relief. A higher AUC represents higher satisfaction with pain relief. Secondary outcomes were pain intensity scores, mode of delivery, and maternal and neonatal outcomes. Analysis was done by intention to treat. The study was defined as an equivalence study for the primary outcome. Results 1414 women were randomised, of whom 709 were allocated to patient controlled remifentanil and 705 to epidural analgesia. Baseline characteristics were comparable. Pain relief was ultimately used in 65% (447/687) in the remifentanil group and 52% (347/671) in the epidural analgesia group (relative risk 1.32, 95% confidence interval 1.18 to 1.48). Cross over occurred in 7% (45/687) and 8% (51/671) of women, respectively. Of women primarily treated with remifentanil, 13% (53/402) converted to epidural analgesia, while in women primarily treated with epidural analgesia 1% (3/296) converted to remifentanil. The area under the curve for total satisfaction with pain relief was 30.9 in the remifentanil group versus 33.7 in the epidural analgesia group (mean difference −2.8, 95% confidence interval −6.9 to 1.3). For who actually received pain relief the area under the curve for satisfaction with pain relief after the start of pain relief was 25.6 in the remifentanil group versus 36.1 in the epidural analgesia group (mean difference −10.4, −13.9 to −7.0). The rate of caesarean section was 15% in both groups. Oxygen saturation was significantly lower (SpO2 <92%) in women who used remifentanil (relative risk 1.5, 1.4 to 1.7). Maternal and neonatal outcomes were comparable between both groups. Conclusion In women in labour, patient controlled analgesia with remifentanil is not equivalent to epidural analgesia with respect to scores on satisfaction with pain relief. Satisfaction with pain relief was significantly higher in women who were allocated to and received epidural analgesia.L.M. Freeman, K.W. Bloemenkamp, M.T. Franssen, D.N. Papatsonis, P.J. Hajenius, M.W. Hollmann, M.D. Woiski, M. Porath, H.J. van den Berg, E. van Beek, O.W.H.M. Borchert, N. Schuitemaker, J.M. Sikkema, A.H.M. Kuipers, S.L.M. Logtenberg, P.C.M van der Salm, K.O. Rengerink, E. Lopriore, M.E. van den Akker-van Marle, S. le Cessie, J.M van Lith, M.M. Struys, B.W.J. Mol, A. Dahan, J.M. Middeldor

    The alteration of intra-ligand donor-acceptor interactions through torsional connectivity in substituted Re-dppz complexes

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    The ground and excited properties of a series of [ReCl(CO)3(dppz)] complexes with substituted donor groups have been investigated. Alteration of donor-acceptor communication through modulation of torsional angle and the number and nature of the donor substituent allowed the effects on the photophysical properties to be characterized though both computational and spectroscopic techniques, including TD-DFT, resonance Raman and time resolved infrared. The ground state optical properties show significant variation as a result of donor group modulation, with increased angle between the donor and acceptor blue-shifting and depleting the intensity of the lowest energy transition, which was consistently ILCT in nature. However, across all complexes studied there was minimal perturbation to the excited state properties and dynamics. Three excited states on the picosecond, nanosecond and microsecond time scales were observed in all cases, corresponding to 1ILCT, ππ* and 3ILCT respectively
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