Publications by authors named "Dirk Jonker"

Chemically synthesized metal nanoparticles (MNPs) have been widely used as surface-enhanced Raman spectroscopy (SERS) substrates for monitoring catalytic reactions. In some applications, however, the SERS MNPs, besides being plasmonically active, can also be catalytically active and result in Raman signals from undesired side products. The MNPs are typically insulated with a thin (∼3 nm), in principle pin-hole-free shell to prevent this.

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The electrochemical synthesis of -amino acids at room temperature and pressure is a sustainable alternative to conventional methods like microbial fermentation and Strecker synthesis. A custom-built zero-gap flow electrolyzer was used to study the electrosynthesis of alanine via the electrocatalytic reductive amination (ERA) of the corresponding biomass-derivable -keto acid precursor - pyruvic acid (PA), and hydroxylamine (NHOH) at very low pH. Non-toxic, abundant, and easy to prepare TiO/Ti electrocatalysts were utilized as the cathode.

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Background: Occupational Health Service (OHS) is a service that should support employers and employees with their work environment. Previous research indicates the need for deeper knowledge about the effect of workplace interventions with a focus on planning, organizing and designing the workplace to improve work conditions in hospital settings.

Objective: The aim was to evaluate the outcomes, workplace interventions and intervention strategies in hospital settings.

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Surface-enhanced Raman spectroscopy (SERS) substrates are of utmost interest in the analyte detection of biological and chemical diagnostics. This is primarily due to the ability of SERS to sensitively measure analytes present in localized hot spots of the SERS nanostructures. In this work, we present the formation of 67 ± 6 nm diameter gold nanoparticles supported by vertically aligned shell-insulated silicon nanocones for ultralow variance SERS.

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Convex cylindrical silicon nanostructures, also referred to as silicon nanocones, find their value in many applications ranging from photovoltaics to nanofluidics, nanophotonics, and nanoelectronic applications. To fabricate silicon nanocones, both bottom-up and top-down methods can be used. The top-down method presented in this work relies on pre-shaping of silicon nanowires by ion beam etching followed by self-limited thermal oxidation.

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Background: Scientific research has identified a lack of psychometrically well-tested methods for evaluation of the work environment in healthcare settings. The Structured Multidisciplinary Work Evaluation Tool (SMET) questionnaire has been evaluated and has shown good content validity, as well as intra-rater and test-retest reliability. There are, however, still unknowns regarding the psychometric properties.

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Background: The work environment is a complex phenomenon in which many factors interact. Scientific research indicates a relation between the work environment and employee health, staff turnover, patient satisfaction, and patient safety. There is a great need for knowledge on how to conduct work environment interventions and practical work environment management to maximize benefits to the employees.

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A new health surveillance protocol for work-related upper-extremity musculoskeletal disorders has been validated by comparing the results with a reference protocol. The studied protocol, Health Surveillance in Adverse Ergonomics Conditions (HECO), is a new version of the reference protocol modified for application in the Occupational Health Service (OHS). The HECO protocol contains both a screening part and a diagnosing part.

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The aim of the study was to investigate, in a group of 77 Swedish dentists (36 males, 41 females) working in dental clinics, possible effects of psychosocial work environmental factors, personality traits, and social desirability tendencies on their reporting of their workload and of the physical demands placed on them. Participants were given questionnaires for assessing their workload, the physical and psychosocial demands of their job, their social support at work, and their control over their work situation, using a 10-cm visual analogue scale (V.A.

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Dentists reported high perceived physical work conditions. Working postures and movements of the head and upper extremities during dental work were registered with inclinometry measurements during four hours. The aim was to clarify the relationship between measured working postures/movements and perceived physical work conditions.

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In an earlier questionnaire study, dentists reported high experienced physical work load in their profession, but low to moderate complaints from their musculoskeletal system. The correlation between reported physical work load and pain from the musculoskeletal system was weak. This discrepancy could not be satisfactorily explained.

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In a previous study, dentists reported very high scores for perceived physical workload, but only low to moderate scores for the musculoskeletal system. This is difficult to explain when other occupational groups in the dental services are compared, and is the main reason why the present study was performed. To measure muscular activity, a surface electromyography (sEMG) study was done, and included the subjects who reported neck and shoulder complaints in the previous study.

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