126 research outputs found

    Modification and re-validation of the ethyl acetate-based multi-residue method for pesticides in produce

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    The ethyl acetate-based multi-residue method for determination of pesticide residues in produce has been modified for gas chromatographic (GC) analysis by implementation of dispersive solid-phase extraction (using primaryā€“secondary amine and graphitized carbon black) and large-volume (20Ā Ī¼L) injection. The same extract, before clean-up and after a change of solvent, was also analyzed by liquid chromatography with tandem mass spectrometry (LCā€“MSā€“MS). All aspects related to sample preparation were re-assessed with regard to ease and speed of the analysis. The principle of the extraction procedure (solvent, salt) was not changed, to avoid the possibility invalidating data acquired over past decades. The modifications were made with techniques currently commonly applied in routine laboratories, GCā€“MS and LCā€“MSā€“MS, in mind. The modified method enables processing (from homogenization until final extracts for both GC and LC) of 30 samples per eight hours per person. Limits of quantification (LOQs) of 0.01Ā mg kgāˆ’1 were achieved with both GCā€“MS (full-scan acquisition, 10Ā mg matrix equivalent injected) and LCā€“MSā€“MS (2Ā mg injected) for most of the pesticides. Validation data for 341 pesticides and degradation products are presented. A compilation of analytical quality-control data for pesticides routinely analyzed by GCā€“MS (135 compounds) and LCā€“MSā€“MS (136 compounds) in over 100 different matrices, obtained over a period of 15Ā months, are also presented and discussed. At the 0.05Ā mg kgāˆ’1 level acceptable recoveries were obtained for 93% (GCā€“MS) and 92% (LCā€“MSā€“MS) of pesticideā€“matrix combinations

    Science-Policy Interactions in MPA Site Selection in the Dutch Part of the North Sea

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    At the 7th conference of the parties to the Convention on Biological Diversity (CBD-COP7, Kuala Lumpur, 2004) it was agreed to establish a global network of marine and coastal protected areas by 2012. The defined objectives of this MPA-network are based on the ecosystem approach: to protect biodiversity and other ecological values, and to ensure sustainable use. The (inter)national policy guidelines state that the selection of MPAs should be based on scientific information and ecological criteria only. As a signatory to the Convention, the Netherlands is now faced with meeting this obligation, and the process of designating the first Marine Protected Areas (MPAs) in the Dutch part of the North Sea is currently in progress. We focus on the scienceā€“policy interactions that are part of this Dutch MPA selection process. By taking a closer look at the contemporary site selection process as well as its historical background, we show that ecological, socio-economic and political considerations cannot always be easily separated. Uncertainty is high and the ultimate selection and delimitation of candidate sites rather seems to be the result of a balancing act between ecological, socio-economic and political interests, in which scientific and policy guiding procedures blend with ad-hoc political decision making, and with expert judgment in cases where data is lacking. As such, this paper presents an example of present-day environmental policy making in action

    Debating the Desirability of New Biomedical Technologies: Lessons from the Introduction of Breast Cancer Screening in the Netherlands

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    Health technology assessment (HTA) was developed in the 1970s and 1980s to facilitate decision making on the desirability of new biomedical technologies. Since then, many of the standard tools and methods of HTA have been criticized for their implicit normativity. At the same time research into the character of technology in practice has motivated philosophers, sociologists and anthropologists to criticize the traditional view of technology as a neutral instrument designed to perform a specific function. Such research suggests that the tools and methods of more traditional forms of HTA are often inspired by an ā€˜instrumentalistā€™ conception of technology that does not fit the way technology actually works. This paper explores this hypothesis for a specific case: the assessments and deliberations leading to the introduction of breast cancer screening in the Netherlands. After reconstructing this history of HTA ā€˜in the makingā€™ the stepwise model of HTA that emerged during the process is discussed. This model was rooted indeed in an instrumentalist conception of technology. However, a more detailed reconstruction of several episodes from this history reveals how the actors already experienced the inadequacy of some of the instrumentalist presuppositions. The historical case thus shows how an instrumentalist conception of technology may result in implicit normative effects. The paper concludes that an instrumentalist view of technology is not a good starting point for HTA and briefly suggests how the fit between HTA methods and the actual character of technology in practice might be improved

    Patient attitudes towards medical students at Damascus University teaching hospitals

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    Background: The cooperation of patients and their consent to involve medical students in their care is vital to clinical education, but large numbers of students and lack of experience as well as loss of privacy may evoke negative attitudes of patients, which may sometimes adversely affect the clinical teaching environment. This study aimed to explore the attitudes of patients towards medical students at Damascus University hospitals, and to explore the determinants of those attitudes thus discussing possible implications applicable to clinical teaching. Methods: This cross-sectional study was conducted at three teaching hospitals affiliated to the Faculty of Medicine at Damascus University. Four hundred patients were interviewed between March and April 2011 by a trained sociologist using a structured questionnaire. Results: Of the patients interviewed, 67.8 % approved the presence of medical students during the medical consultation and 58.2 % of them felt comfortable with the presence of students, especially among patients with better socio-economic characteristics. 81.5 % of the patients agreed to be examined by students in the presence of the supervisor, while 40.2 % gave agreement even in the absence of the supervisor. Privacy was the most important factor in the patients ā€™ reticence towards examination by the students, whilst the relative safety and comfort if a supervisor was available determined patients ā€™ agreement

    Realizing autonomy in responsive relationships

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    The goal of this article is to augment the ethical discussion among nurses with the findings from empirical research on autonomy of older adults with type 2 diabetes mellitus. There are many factors influencing autonomy. These include: health conditions, treatment, knowledge, experience and skills, personal approach as well as familial patterns, type of relationship, life history and social context. Fifteen older adults with type 2 diabetes mellitus were interviewed in a nurse-led diabetes clinic. These participants perceive three processes which support autonomy in responsive relationships: preserving patterns of concern and interaction, nurturing collaborative responsibilities and being closely engaged in trustful and helpful family relations. People with diabetes realize autonomy in various responsive relationships in their unique life context. Next, we performed a literature review of care ethics and caring in nursing with regard to relational autonomy. We classified the literature in five strands of care: attitude-oriented, dialogue-oriented, activity-oriented, relationship-oriented and life-oriented. According to our respondents, autonomy in responsive relationships is fostered when patient, nurses, professionals of the health team and family members carry out care activities supported by a relational attitude of care. They can best realize autonomy in relationships with others when several essential aspects of care and caring are present in their lives. Therefore, we advocate a comprehensive approach to care and caring

    The potato developer (D) locus encodes an R2R3 MYB transcription factor that regulates expression of multiple anthocyanin structural genes in tuber skin

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    A dominant allele at the D locus (also known as I in diploid potato) is required for the synthesis of red and purple anthocyanin pigments in tuber skin. It has previously been reported that D maps to a region of chromosome 10 that harbors one or more homologs of Petuniaan2, an R2R3 MYB transcription factor that coordinately regulates the expression of multiple anthocyanin biosynthetic genes in the floral limb. To test whether D acts similarly in tuber skin, RT-PCR was used to evaluate the expression of flavanone 3-hydroxylase (f3h), dihydroflavonol 4-reductase (dfr) and flavonoid 3ā€²,5ā€²-hydroxylase (f3ā€²5ā€²h). All three genes were expressed in the periderm of red- and purple-skinned clones, while dfr and f3ā€²5ā€²h were not expressed, and f3h was only weakly expressed, in white-skinned clones. A potato cDNA clone with similarity to an2 was isolated from an expression library prepared from red tuber skin, and an assay developed to distinguish the two alleles of this gene in a diploid potato clone known to be heterozygous Dd. One allele was observed to cosegregate with pigmented skin in an F1 population of 136 individuals. This allele was expressed in tuber skin of red- and purple-colored progeny, but not in white tubers, while other parental alleles were not expressed in white or colored tubers. The allele was placed under the control of a doubled 35S promoter and transformed into the light red-colored cultivar DĆ©sirĆ©e, the white-skinned cultivar Bintje, and two white diploid clones known to lack the functional allele of D. Transformants accumulated pigment in tuber skin, as well as in other tissues, including young foliage, flower petals, and tuber flesh

    Optimization of Suture-Free Laser-Assisted Vessel Repair by Solder-Doped Electrospun Poly(Īµ-caprolactone) Scaffold

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    Poor welding strength constitutes an obstacle in the clinical employment of laser-assisted vascular repair (LAVR) and anastomosis. We therefore investigated the feasibility of using electrospun poly(Īµ-caprolactone) (PCL) scaffold as reinforcement material in LAVR of medium-sized vessels. In vitro solder-doped scaffold LAVR (ssLAVR) was performed on porcine carotid arteries or abdominal aortas using a 670-nm diode laser, a solder composed of 50% bovine serum albumin and 0.5% methylene blue, and electrospun PCL scaffolds. The correlation between leaking point pressures (LPPs) and arterial diameter, the extent of thermal damage, structural and mechanical alterations of the scaffold following ssLAVR, and the weak point were investigated. A strong negative correlation existed between LPP and vessel diameter, albeit LPP (484Ā Ā±Ā 111Ā mmHg) remained well above pathophysiological pressures. Histological analysis revealed that thermal damage extended into the medial layer with a well-preserved internal elastic lamina and endothelial cells. Laser irradiation of PCL fibers and coagulation of solder material resulted in a strong and stiff scaffold. The weak point of the ssLAVR modality was predominantly characterized by cohesive failure. In conclusion, ssLAVR produced supraphysiological LPPs and limited tissue damage. Despite heat-induced structural/mechanical alterations of the scaffold, PCL is a suitable polymer for weld reinforcement in medium-sized vessel ssLAVR

    Induction of labour versus expectant monitoring in women with pregnancy induced hypertension or mild preeclampsia at term: the HYPITAT trial

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    Contains fulltext : 53183.pdf ( ) (Open Access)BACKGROUND: Hypertensive disorders, i.e. pregnancy induced hypertension and preeclampsia, complicate 10 to 15% of all pregnancies at term and are a major cause of maternal and perinatal morbidity and mortality. The only causal treatment is delivery. In case of preterm pregnancies conservative management is advocated if the risks for mother and child remain acceptable. In contrast, there is no consensus on how to manage mild hypertensive disease in pregnancies at term. Induction of labour might prevent maternal and neonatal complications at the expense of increased instrumental vaginal delivery rates and caesarean section rates. METHODS/DESIGN: Women with a pregnancy complicated by pregnancy induced hypertension or mild preeclampsia at a gestational age between 36+0 and 41+0 weeks will be asked to participate in a multi-centre randomised controlled trial. Women will be randomised to either induction of labour or expectant management for spontaneous delivery. The primary outcome of this study is severe maternal morbidity, which can be complicated by maternal mortality in rare cases. Secondary outcome measures are neonatal mortality and morbidity, caesarean and vaginal instrumental delivery rates, maternal quality of life and costs. Analysis will be by intention to treat. In total, 720 pregnant women have to be randomised to show a reduction in severe maternal complications of hypertensive disease from 12 to 6%. DISCUSSION: This trial will provide evidence as to whether or not induction of labour in women with pregnancy induced hypertension or mild preeclampsia (nearly) at term is an effective treatment to prevent severe maternal complications. TRIAL REGISTRATION: The protocol is registered in the clinical trial register number ISRCTN08132825
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