The polymer polydimethylsiloxane (PDMS) is widely used to build microfluidic devices compatible with cell culture. Whilst convenient in manufacture, PDMS has the disadvantage that it can absorb small ...molecules such as drugs. In microfluidic devices like “Organs-on-Chip”, designed to examine cell behavior and test the effects of drugs, this might impact drug bioavailability. Here we developed an assay to compare the absorption of a test set of four cardiac drugs by PDMS based on measuring the residual non-absorbed compound by High Pressure Liquid Chromatography (HPLC). We showed that absorption was variable and time dependent and not determined exclusively by hydrophobicity as claimed previously. We demonstrated that two commercially available lipophilic coatings and the presence of cells affected absorption. The use of lipophilic coatings may be useful in preventing small molecule absorption by PDMS.
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•Binding of different compounds to PDMS varies greatly.•Previous reported correlations of absorption and LogP values could not be repeated.•Topological polar surface area possibly related to compound absorption.•A lipid based coating partially obviates compound absorption.•Presence of cultured cells affects free drug concentration, but less than substrate.
Recent studies in PKU patients identified alternative biomarkers in blood using untargeted metabolomics. To test the added clinical value of these novel biomarkers, targeted metabolomics of 11 PKU ...biomarkers (phenylalanine, glutamyl-phenylalanine, glutamyl-glutamyl-phenylalanine, N-lactoyl-phenylalanine, N-acetyl-phenylalanine, the dipeptides phenylalanyl-phenylalanine and phenylalanyl-leucine, phenylalanine-hexose conjugate, phenyllactate, phenylpyruvate, and phenylacetate) was performed in stored serum samples of the well-defined PKU patient-COBESO cohort and a healthy control group. Serum samples of 35 PKU adults and 20 healthy age- and sex-matched controls were analyzed using ultra-high performance liquid chromatography quadrupole time-of-flight mass spectrometry. Group differences were tested using the Mann-Whitney U test. Multiple linear regression analyses were performed with these biomarkers as predictors of (neuro-)cognitive functions working memory, sustained attention, inhibitory control, and mental health. Compared to healthy controls, phenylalanine, glutamyl-phenylalanine, N-lactoyl-phenylalanine, N-acetyl-phenylalanine, phenylalanine-hexose conjugate, phenyllactate, phenylpyruvate, and phenylacetate were significant elevated in PKU adults (p < 0.001). The remaining three were below limit of detection in PKU and controls. Both phenylalanine and N-lactoyl-phenylalanine were associated with DSM-VI Attention deficit/hyperactivity (R
= 0.195, p = 0.039 and R
= 0.335, p = 0.002, respectively) of the ASR questionnaire. In addition, N-lactoyl-phenylalanine showed significant associations with ASR DSM-VI avoidant personality (R
= 0.265, p = 0.010), internalizing (R
= 0.192, p = 0.046) and externalizing problems (R
= 0.217, p = 0.029) of the ASR questionnaire and multiple aspects of the MS2D and FI tests, reflecting working memory with R
between 0.178 (p = 0.048) and 0.204 (p = 0.033). Even though the strength of the models was not considered strong, N-lactoyl-phenylalanine outperformed phenylalanine in its association with working memory and mental health outcomes.
The paper presents an autonomous robot for removing the leaves from cucumber plants grown in a high-wire cultivation system. Leaves at the lower end of the plants are removed because of their reduced ...vitality, their negligible contribution to canopy photosynthesis and their increased sensitivity to fungal diseases. Consuming 19% of the total labour input, leaf removal is considered by the growers and their staff as a tedious, repetitive and costly task. Automation alleviates their job and results in a significant cost reduction. The paper describes a functional model and preliminary results of a field test of a de-leafing robot. Despite the small number of repetitions during the field test, the favourable results confirmed the feasibility of the concept of the de-leafing robot. The vision system and manipulator control performed relatively well. However, particularly, the mechanics of the end-effector were failure prone and need re-engineering. With a cycle time of 140
s per two leaves on average, the execution time of the de-leafing robot is approximately 35 times slower than manual leaf picking. For economic feasibility this cycle time should be reduced.
Based on the authors’ previous work an attempt has been made to study water flow in the lipid matrix during pollen hydration. The present study has demonstrated that in the presence of small amounts ...of water, the type of lipids used defined the time of hydration of pollen in vivo on the stigma and in vitro. Several approaches were used including cryo‐scanning electron microscopy, magnetic resonance imaging and Fourier transform infrared microspectroscopic imaging, with the purpose of detecting very small amounts of water. The results show that no water is detectable in the lipid matrix. It was observed and concluded that the water for pollen hydration accumulates as a thin layer at the contact side between pollen and stigma, during the normal process of pollination in plant species with a wet stigma. However, using the same species deprived of the stigma by cell ablation, it was shown that the layer of water observed in wild‐type plants is not necessary for pollen hydration.
In Costa Rica as many other tropical countries, the disposal problem of agricultural wastes is widely recognized but efforts to find solutions are not equal for different sectors. This study ...describes the situation of major agricultural residues in Costa Rica, identifying the activities with higher amounts produced and, the potential use of these residues in fish feeds. In Costa Rica, during the 1993–1994 production season, major agricultural sectors (crop and livestock) generated a total amount of 3.15–3.25 million MT of residues (classified in by-products: used residues and wastes: not used residues). Some residues are treated to turn them into valuable items or to diminish their polluting effects (e.g., the so-called by-products). About 1.56–1.63 million MT of by-products were used for different purposes (e.g. fertilization, animal feeding, fuel, substrates in greenhouses). However, the remainder (1.59–1.62 million MT) was discharged into environment causing pollution. About 1.07–1.2 million MT wastes came from major crop systems (banana, coffee, sugarcane and oil palm) whereas the remainder came from animal production systems (porcine and poultry production, slaughtering). These data are further compared to residues estimates for the 2001–2002 production season coming from the biggest crops activities. Unfortunately, most of the studied wastes contain high levels of moisture and low levels of protein, and also contain variable amounts of antinutritional factors (e.g., polyphenols, tannins, caffeine), high fibre levels and some toxic substances and pesticides. All these reasons may limit the use of these agricultural wastes for animal feeding, especially in fish feeds. The potential use of the major vegetable and animal residues in fish feeds is discussed based on their nutritional composition, on their amount available over the year and on their pollution risks. Other constraints to use these wastes in fish feeds are the extra costs of drying and, in most cases, of transportation from several dispersed locations. It was stated that most interesting wastes are rejected green banana and coffee pulp.
The accuracy of textile damage analyses was evaluated by laboratory tests carried out by trained experts. The analyzed damages were prepared by various methods, including stabbing, cutting, shooting, ...heating/burning, etc. A number of damages were aged by household washing and tumble-drying procedures, addition of blood, or burying. The samples were analyzed by routine laboratory evaluation. The results indicate that the properties of a damage provide a good indication of the way a textile had been damaged. Nevertheless, scoring of the answers is not straightforward. Results indicated that examiners evaluated damages on different levels of specificity and thereby showed the latent need for a more systematic approach to damage classification. The second part of the current contribution therefore presents the classification scheme we developed. This classification scheme aims to guide examiners during examination and accommodates the vast majority of textile damages observed in forensic casework. Each of the proposed classes is defined, relevant literature in each of the classes is reviewed, and the characteristics that can be expected after different damaging actions are explained. Finally, we share some ideas for further investigations.
Van der Weerd, A.J. and Wijnberg, K.M., 2016. Aeolian sediment flux derived from a natural sand trap. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the ...14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 338–342. Coconut Creek (Florida), ISSN 0749-0208. In 2011, a mega-nourishment (the ‘Sand Motor’) was constructed along the Dutch Coast. Since it is a pilot project, its evolution is closely monitored. This paper presents first results on the temporal variation in aeolian sediment transport across the nourishment, based on (a) the rate of infill over a 4 year period of a small lake in the nourishment, (b) one year of semi-hourly collected video imagery and (c) four year of hourly-averaged wind data. It appeared that, apart from approximately the first half year, the infill occurred quite linearly over time at an average rate of about 1.9·104 m3/yr. The rate of infill in the first half year period was equivalent to an annual rate of 8.4·104 m3/yr. From the combination of video image data and wind data, it was derived that aeolian sand transport (by saltation) was only observed at hourly averaged wind speeds of at least 7 m/s. The monthly frequency of occurrence of above 7 m/s wind speed, was reasonably well correlated with monthly frequency of occurrence of aeolian transport (r=0.79). Nevertheless, when hourly wind speed exceeded 7 m/s, transport was only observed about 23% of the time, indicating the importance of supply limiting conditions for aeolian transport from the Sand Motor.
An ongoing outbreak of scabies in and outside a nursing home in Amsterdam is described. Despite standard treatment with lindane and ivermectin, many recurrences were observed which suggested ...resistance to these drugs. After treatment with 5% permethrine, the patients were finally cured.
Epigenetic factors and cardiac development van Weerd, Jan Hendrick; Koshiba-Takeuchi, Kazuko; Kwon, Chulan ...
Cardiovascular research,
07/2011, Volume:
91, Issue:
2
Journal Article
Peer reviewed
Open access
Congenital heart malformations remain the leading cause of death related to birth defects. Recent advances in developmental and regenerative cardiology have shed light on a mechanistic understanding ...of heart development that is controlled by a transcriptional network of genetic and epigenetic factors. This article reviews the roles of chromatin remodelling factors important for cardiac development with the current knowledge of cardiac morphogenesis, regeneration, and direct cardiac differentiation. In the last 5 years, critical roles of epigenetic factors have been revealed in the cardiac research field.
Dialogue between supervisor and employee is of great importance for occupational rehabilitation.
To evaluate the effectiveness of a convergence dialogue meeting (CDM) of employee, therapist and ...supervisor aimed at facilitating return to work (RTW) as part of cognitive-behavioural treatment.
Randomized controlled trial including 60 employees sick-listed with common mental disorders and referred for specialized mental healthcare. Employees were randomly allocated either to an intervention group (n = 31) receiving work-focused cognitive-behavioural therapy plus CDM or a control group (n = 29) receiving work-focused cognitive-behavioural therapy without CDM.
The time to first RTW was 12 days shorter (p = 0.334) in the intervention group, although full (i.e., at equal earnings as before reporting sick) RTW took 41 days longer (p = 0.122) than the control group. The odds of full RTW at the end of treatment were only 7% higher (p = 0.910) in the intervention group as compared to the control group.
CDM did not significantly reduce the time to RTW. We recommend that therapists who are trained on CDM focus on barriers and solutions for RTW.
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