5,563 research outputs found

    Thermodynamics of the ATPase Cycle of GlcV, the Nucleotide-Binding Domain of the Glucose ABC Transporter of Sulfolobus solfataricus

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    ATP-binding cassette transporters drive the transport of substrates across the membrane by the hydrolysis of ATP. They typically have a conserved domain structure with two membrane-spanning domains that form the transport channel and two cytosolic nucleotide-binding domains (NBDs) that energize the transport reaction. Binding of ATP to the NBD monomer results in formation of a NBD dimer. Hydrolysis of the ATP drives the dissociation of the dimer. The thermodynamics of distinct steps in the ATPase cycle of GlcV, the NBD of the glucose ABC transporter of the extreme thermoacidophile Sulfolobus solfataricus, were studied by isothermal titration calorimetry using the wild-type protein and two mutants, which are arrested at different steps in the ATP hydrolytic cycle. The G144A mutant is unable to dimerize, while the E166A mutant is defective in dimer dissociation. The ATP, ADP, and AMP-PNP binding affinities, stoichiometries, and enthalpies of binding were determined at different temperatures. From these data, the thermodynamic parameters of nucleotide binding, NBD dimerization, and ATP hydrolysis were calculated. The data demonstrate that the ATP hydrolysis cycle of isolated NBDs consists of consecutive steps where only the final step of ADP release is energetically unfavorable.

    Geometry-adapted hexahedral meshes improve accuracy of finite-element-method-based EEG source analysis

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    Melkstal voor onderzoek van reiniging

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    Bij de bouw of renovatie van een melkstal wordt vooral aandacht geschonken aan de melktechniek, dat wil zeggen een dusdanige aanleg van de installatie dat er zo goed mogelijk gemolken kan worden. Het kunnen reinigen van de installatie wordt vaak onderbelicht

    Changes in self-reported pre- to postinjury coping styles in the first 3 years after traumatic brain injury and the effects on psychosocial and emotional functioning and quality of life

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    OBJECTIVE:: To examine the influence of self-reported preinjury coping on postinjury coping, psychosocial functioning, emotional functioning, and quality of life at 1 year following traumatic brain injury (TBI). SETTING:: Inpatient hospital and community. PARTICIPANTS:: One hundred seventy-four participants with TBI. DESIGN:: Prospective, longitudinal design. Participants were assessed at 5 time points: after emerging from posttraumatic amnesia, and at 6, 12, 24, and 36 months postinjury. MAIN MEASURES:: Coping Scale for Adults-Short Version; Quality of Life Inventory; Sydney Psychosocial Reintegration Scale; Hospital Anxiety and Depression Scale. RESULTS:: High preinjury use of nonproductive coping style predicted high use of nonproductive coping, more anxiety, and lower psychosocial functioning at 1 year postinjury. Increased use of nonproductive coping and decreased use of productive coping predicted poorer psychosocial outcome at 1 year post-TBI. Use of both productive and nonproductive coping decreased in the first 6 to 12 months post-TBI relative to preinjury. Unlike productive coping, nonproductive coping reached preinjury levels within 3 years postinjury. CONCLUSION:: The findings support identification of individuals at risk of relying on nonproductive coping and poorer psychosocial outcome following TBI. In addition, the results emphasize the need to implement timely interventions to facilitate productive coping and reduce the use of nonproductive coping in order to maximize favorable long-term psychosocial outcome

    Houd de reiniging onder controle

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    Het resultaat van iedere reiniging van melkleidinginstallatie en melkkoeltank wordt bepaald door de welbekende factoren dosering, temperatuur, mechanische werking, tijdsduur en de mens. Zonder afstemming op elkaar, zal dit in de praktijk resulteren ineen verhoogd kiemgeta

    Milieuvriendelijke melkkoeling op de boerderij

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    Natuurlijke koolwaterstoffen zijn goed bruikbaar als koelmiddel in melkkoeltanks. De invloed op het broeikaseffect is nihil en het energieverbruik van dit koelsysteem lijkt gunstiger dan huidige systemen

    Coping styles within the family system in the chronic phase following acquired brain injury: its relation to families’ and patients’ functioning

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    OBJECTIVE: To investigate how the functioning of family members and the coping styles they use are related to the psychosocial functioning both of the family members and of the person who has sustained a brain injury. DESIGN: Cross-sectional study. SUBJECTS: Primary caregivers (n = 61) and other family members (n = 15) of 61 patients with brain injury. METHODS: Primary caregivers completed the Utrecht Coping List, the Life Satisfaction Questionnaire 9, and the Caregiver Strain Index. All family members completed the Family Assessment Device. Data for the patients were collected retrospectively. RESULTS: Primary caregivers who had a preference for passive coping styles reported that they experienced a lower level of family functioning, a lower quality of life, and a higher strain. Neither the coping styles nor the psychosocial outcomes of the primary caregivers were significantly associated with patients' self-reported quality of life. Furthermore, there was no correlation between the level of family functioning and a patient's quality of life. CONCLUSION: Coping styles of caregivers are important determinants for their own psychosocial functioning, but not for patients' psychosocial functioning, although causality cannot be inferred. To enhance caregivers' psychosocial functioning, rehabilitation should focus on changing their coping styles into ones that are less passive. Furthermore, distinct or additional interventions may be needed to change the patient's coping style

    Integrated Array Tomography for 3D Correlative Light and Electron Microscopy

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    Volume electron microscopy (EM) of biological systems has grown exponentially in recent years due to innovative large-scale imaging approaches. As a standalone imaging method, however, large-scale EM typically has two major limitations: slow rates of acquisition and the difficulty to provide targeted biological information. We developed a 3D image acquisition and reconstruction pipeline that overcomes both of these limitations by using a widefield fluorescence microscope integrated inside of a scanning electron microscope. The workflow consists of acquiring large field of view fluorescence microscopy (FM) images, which guide to regions of interest for successive EM (integrated correlative light and electron microscopy). High precision EM-FM overlay is achieved using cathodoluminescent markers. We conduct a proof-of-concept of our integrated workflow on immunolabelled serial sections of tissues. Acquisitions are limited to regions containing biological targets, expediting total acquisition times and reducing the burden of excess data by tens or hundreds of GBs
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