Interference effects in photoreflectance of epitaxial layers grown on semi-insulating substrates

Interferences were observed in the photoreflectance spectra of homoepitaxial layers grown on semi‐insulating GaAs and InP substrates. The modulation mechanism responsible for the interference effect was studied from the frequency and temperature dependence of the interference amplitude and the effect of continuous wave illumination. The results are in agreement with the model that the modulation is due to electrons drifting to the interface from the surface. A simple model was used to fit the interference spectra to the Lorentzian wave forms from the substrate and the epitaxial layer.Peer reviewe

The Price and Market Share Evolution of the Original Biologics and Their Biosimilars in Finland

Background Biological drugs are generally expensive and produce a continuously growing share of drug costs. Yet they are essential in the treatment of many chronic diseases. Biosimilars, clinically equivalent to biological originator products, are expected to restrain drug costs in the biological market. Objective This study aimed to examine the impact of the biosimilar market entry on the prices of the reference products in outpatient care in Finland, investigate the impact of biosimilar market entries on price competition among biological medicinal products, and examine how the prices and market shares of outpatient biosimilars have developed in Finland during 2009-2020. Methods This retrospective register study applied data from IQVIA covering national community pharmacy wholesale data between 1 January, 2009, and 31 August, 2020, for somatropin, epoetin, filgrastim, follitropin, insulin glargine, insulin lispro, etanercept, pegfilgrastim, adalimumab, teriparatide, and enoxaparin biosimilars and their reference products, in addition to two relevant insulin products. We determined the monthly wholesale amounts in defined daily doses and wholesale weighted average prices (excluding value-added tax) per defined daily dose for each product. We analyzed the evolution of the price and market shares. We performed a linear segmented regression analysis to examine the impact of the market entry of biosimilars on the prices of reference products. Results The prices of the reference products mainly decreased after the biosimilar entered the market. If the reference product price was not reduced, it was no longer reimbursable after evaluation under the Health Insurance Act, leading to marginal market shares. The changes in the prices of biosimilars were not as remarkable as the changes in the prices of reference products after the biosimilar market entry. For most active substances, biosimilar prices were stable or decreased. The utilization of biosimilars varied widely between different active substances at the end of the observation period. Conclusions Changes in pricing policy and the public reimbursement scheme related to the market entry of biosimilars were the main reasons for the decrease in the prices of reference products. Therefore, biosimilars did not generate genuine price competition between biological products. In many of the drug groups examined, the market shares of biosimilars have growth potential in the future.Peer reviewe

Simulating atomic force microscopy imaging of the ideal and defected TiO2 (110) surface

In this study we simulate noncontact atomic force microscopy imaging of the TiO2 (110) surface using first-principles and atomistic methods. We use three different tip models to investigate the tip-surface interaction on the ideal surface, and find that agreement with experiment is found for either a silicon tip or a tip with a net positive electrostatic potential from the apex. Both predict bright contrast over the bridging oxygen rows. We then study the interaction of this tip with a bridging oxygen vacancy on the surface, and find that the much weaker interaction observed would result in vacancies appearing as dark contrast along the bright rows in images.Peer reviewe

Medication safety risks to be managed in national implementation of automatic substitution of biological medicines : a qualitative study

Peer reviewe

Levodopa-Induced Changes in Electromyographic Patterns in Patients with Advanced Parkinson's Disease

Levodopa medication is the most efficient treatment for motor symptoms of Parkinson's disease (PD). Levodopa significantly alleviates rigidity, rest tremor, and bradykinesia in PD. The severity of motor symptoms can be graded with UPDRS-III scale. Levodopa challenge test is routinely used to assess patients' eligibility to deep-brain stimulation (DBS) in PD. Feasible and objective measurements to assess motor symptoms of PD during levodopa challenge test would be helpful in unifying the treatment. Twelve patients with advanced PD who were candidates for DBS treatment were recruited to the study. Measurements were done in four phases before and after levodopa challenge test. Rest tremor and rigidity were evaluated using UPDRS-III score. Electromyographic (EMG) signals from biceps brachii and kinematic signals from forearm were recorded with wireless measurement setup. The patients performed two different tasks: arm isometric tension and arm passive flexion-extension. The electromyographic and the kinematic signals were analyzed with parametric, principal component, and spectrum-based approaches. The principal component approach for isometric tension EMG signals showed significant decline in characteristics related to PD during levodopa challenge test. The spectral approach on passive flexion-extension EMG signals showed a significant decrease on involuntary muscle activity during the levodopa challenge test. Both effects were stronger during the levodopa challenge test compared to that of patients' personal medication. There were no significant changes in the parametric approach for EMG and kinematic signals during the measurement. The results show that a wireless and wearable measurement and analysis can be used to study the effect of levodopa medication in advanced Parkinson's disease.Peer reviewe

A Focus Group Study about Oral Drug Administration Practices at Hospital Wards-Aspects to Consider in Drug Development of Age-Appropriate Formulations for Children

Oral drug administration to pediatric patients is characterized by a lack of age-appropriate drug products and the off-label use of medicines. However, drug administration practices at hospital wards is a scarcely studied subject. The aim of this study was to explore the oral drug administration practices at pediatric hospital wards, with a focus on experiences and challenges faced, methods used to mitigate existing problems, drug manipulation habits, perceptions about oral dosage forms and future needs of oral dosage forms for children. This was a qualitative study consisting of focus group discussions with physicians, nurses and clinical pharmacists in a tertiary university hospital with the objective of bringing forward a holistic view on this research topic. These healthcare professionals recognized different administration challenges that were classified as either dosage form-related or patient-related ones. A lack of depot formulations developed especially for children as well as oral pediatric dosage forms of drug substances currently available as intravenous dosage forms was recognized. The preferred oral dosage forms were oral liquids and orodispersible tablets. Patient-centered drug administration practices including factors facilitating drug administration both at hospital wards and at home after patient discharge were identified. Among all healthcare professionals, the efficient cooperation in drug prescribing and administration as well as in educating the child's caregivers in correct administration techniques before discharge and improving the overall discharge process of patients was emphasized. This study complements the prevalent understanding that new dosage forms for children of varying ages and stages of development are still needed. It also brings a holistic view on different aspects of oral drug administration to pediatric patients and overall patient-centered drug administration practices.Peer reviewe

Signal features of surface electromyography in advanced Parkinson's disease during different settings of deep brain stimulation

Objective: Electromyography (EMG) and acceleration (ACC) measurements are potential methods for quantifying efficacy of deep brain stimulation (DBS) treatment in Parkinson's disease (PD). The treatment efficacy depends on the settings of DBS parameters (pulse amplitude, frequency and width). This study quantified, if EMG and ACC signal features differ between different DBS settings and if DBS effect is unequal between different muscles. Methods: EMGs were measured from biceps brachii (BB) and tibialis anterior (TA) muscles of 13 PD patients. ACCs were measured from wrists. Measurements were performed during seven different settings of DBS and analyzed using methods based on spectral analysis, signal morphology and nonlinear dynamics. Results: The results showed significant within-subject differences in the EMG signal kurtosis, correlation dimension, recurrence rate and EMG-ACC coherence between different DBS settings for BB but not for TA muscles. Correlations between EMG feature values and clinical rest tremor and rigidity scores were weak but significant. Conclusions: Surface EMG features differed between different DBS settings and DBS effect was unequal between upper and lower limb muscles. Significance: EMG changes pointed to previously defined optimal settings in most of patients, which should be quantified even more deeply in the upcoming studies. (C) 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.Peer reviewe

Prediction of bullying at work: A data-driven analysis of the Finnish public sector cohort study

AIM: To determine the extent to which change in (i.e., start and end of) workplace bullying can be predicted by employee responses to standard workplace surveys. METHODS: Responses to an 87-item survey from 48,537 Finnish public sector employees at T1 (2017–2018) and T2 (2019–2020) were analyzed with least-absolute-shrinkage-and-selection-operator (LASSO) regression. The predictors were modelled both at the individual- and the work unit level. Outcomes included both the start and the end of bullying. Predictive performance was evaluated with C-indices and density plots. RESULTS: The model with best predictive ability predicted the start of bullying with individual-level predictors, had a C-index of 0.68 and included 25 variables, of which 6 remained in a more parsimonious model: discrimination at work unit, unreasonably high workload, threat that some work tasks will be terminated, working in a work unit where everyone did not feel they are understood and accepted, having a supervisor who was not highly trusted, and a shorter time in current position. Other models performed even worse, either from the point of view of predictive performance, or practical useability. DISCUSSION: While many bivariate associations between socioeconomic characteristics, work characteristics, leadership, team climate, and job satisfaction were observed, reliable individualized detection of individuals at risk of becoming bullied at workplace was not successful. The predictive performance of the developed risk scores was suboptimal, and we do not recommend their use as an individual-level risk prediction tool. However, they might be useful tool to inform decision-making when planning the contents of interventions to prevent bullying at an organizational level