61 research outputs found

    Trapping of drops by wetting defects

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    Controlling the motion of drops on solid surfaces is crucial in many natural phenomena and technological processes including the collection and removal of rain drops, cleaning technology and heat exchangers. Topographic and chemical heterogeneities on solid surfaces give rise to pinning forces that can capture and steer drops in desired directions. Here we determine general physical conditions required for capturing sliding drops on an inclined plane that is equipped with electrically tunable wetting defects. By mapping the drop dynamics on the one-dimensional motion of a point mass, we demonstrate that the trapping process is controlled by two dimensionless parameters, the trapping strength measured in units of the driving force and the ratio between a viscous and an inertial time scale. Complementary experiments involving superhydrophobic surfaces with wetting defects demonstrate the general applicability of the concept. Moreover, we show that electrically tunable defects can be used to guide sliding drops along actively switchable tracks—with potential applications in microfluidic

    Serological biomarkers of type I, III, and IV collagen turnover are associated with the presence and future progression of stricturing and penetrating Crohn's disease

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    Background: Increased collagen remodelling is a key pathophysiological component underlying intestinal stricture and fistula development in Crohn's disease (CD). Aims: To investigate associations between serological biomarkers of collagen turnover and disease behaviour according to the Montreal classification in patients with CD. Methods: Serological biomarkers of type III/IV collagen formation (PRO-C3, PRO-C4) and matrix metalloproteinase (MMP) or granzyme-B (GrzB)-mediated type I, III, IV and VI collagen degradation (C1M, C3M, C4M, C4G, C6Ma3) were measured using neo-epitope protein fingerprint assays in 101 patients with CD (Montreal B1: n = 37; B2: n = 27; B3: n = 37) and 96 controls. Patients were followed up until their last outpatient visit to monitor stricturing/penetrating disease progression and recurrence and the occurrence of surgical interventions. Results: C1M, C3M and C4M were significantly reduced in patients with stricturing disease (Montreal B2) and accurately differentiated them from patients with either non-stricturing, non-penetrating (B1) or penetrating (B3) disease (all p < 0.001, multivariable analysis). Similarly, the type IV collagen formation/degradation (PRO-C4/C4M) ratio demonstrated high discriminative capacity (B1/B2: AUC = 0.90; B1/B3: AUC = 0.87, both p < 0.001, multivariable analysis). Prospectively, higher baseline levels of C1M and C4G were associated with an increased risk of penetrating disease progression (C4G: hazard ratio [HR] 1.71 [1.05–2.81], p < 0.05). Conclusions: Elevated degradation of type I, III and IV collagen and excessive (relative) formation of type IV collagen strongly associates with stricturing CD. Type I and IV collagen fragments show predictive potential for the risk of penetrating disease progression. These biomarkers may become valuable tools for detection and prediction of stricturing and penetrating CD

    The effect of a lifestyle intervention on type 2 diabetes pathophysiology and remission: the Stevenshof pilot study

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    Although lifestyle interventions can lead to diabetes remission, it is unclear to what extent type 2 diabetes (T2D) remission alters or improves the underlying pathophysiology of the disease. Here, we assess the effects of a lifestyle intervention on T2D reversal or remission and the effects on the underlying pathology. In a Dutch primary care setting, 15 adults with an average T2D duration of 13.4 years who were (pharmacologically) treated for T2D received a diabetes subtyping ("diabetyping") lifestyle intervention (DLI) for six months, aiming for T2D remission. T2D subtype was determined based on an OGTT. Insulin and sulphonylurea (SU) derivative treatment could be terminated for all participants. Body weight, waist/hip ratio, triglyceride levels, HbA1c, fasting, and 2h glucose were significantly improved after three and six months of intervention. Remission and reversal were achieved in two and three participants, respectively. Indices of insulin resistance and beta cell capacity improved, but never reached healthy values, resulting in unchanged T2D subtypes. Our study implies that achieving diabetes remission in individuals with a longer T2D duration is possible, but underlying pathology is only minimally affected, possibly due to an impaired beta cell function. Thus, even when T2D remission is achieved, patients need to continue adhering to lifestyle therapy.Diabetes mellitus: pathophysiological changes and therap

    Peptidoglycan Remodeling Enables Escherichia coli To Survive Severe Outer Membrane Assembly Defect

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    Gram-negative bacteria have a tripartite cell envelope with the cytoplasmic membrane (CM), a stress-bearing peptidoglycan (PG) layer, and the asymmetric outer membrane (OM) containing lipopolysaccharide (LPS) in the outer leaflet. Cells must tightly coordinate the growth of their complex envelope to maintain cellular integrity and OM permeability barrier function. The biogenesis of PG and LPS relies on specialized macromolecular complexes that span the entire envelope. In this work, we show that Escherichia coli cells are capable of avoiding lysis when the transport of LPS to the OM is compromised, by utilizing LD-transpeptidases (LDTs) to generate 3-3 cross-links in the PG. This PG remodeling program relies mainly on the activities of the stress response LDT, LdtD, together with the major PG synthase PBP1B, its cognate activator LpoB, and the carboxypeptidase PBP6a. Our data support a model according to which these proteins cooperate to strengthen the PG in response to defective OM synthesis.IMPORTANCE In Gram-negative bacteria, the outer membrane protects the cell against many toxic molecules, and the peptidoglycan layer provides protection against osmotic challenges, allowing bacterial cells to survive in changing environments. Maintaining cell envelope integrity is therefore a question of life or death for a bacterial cell. Here we show that Escherichia coli cells activate the LD-transpeptidase LdtD to introduce 3-3 cross-links in the peptidoglycan layer when the integrity of the outer membrane is compromised, and this response is required to avoid cell lysis. This peptidoglycan remodeling program is a strategy to increase the overall robustness of the bacterial cell envelope in response to defects in the outer membrane

    Age-dependent differences in diabetes and acute hyperglycemia between men and women with ST-elevation myocardial infarction: a cohort study

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    Contains fulltext : 119180.pdf (publisher's version ) (Open Access)BACKGROUND: Both acute hyperglycemia as diabetes results in an impaired prognosis in ST-elevation myocardial infarction (STEMI) patients. It is unknown whether there is a different prevalence of diabetes and acute hyperglycemia in men and women within age-groups. METHODS: Between 2004 and 2010, 4640 consecutive patients (28% women) with STEMI, were referred for primary PCI. Patients were stratified into two age groups, /=65 years (2193 patients). Separate analyses were performed in 3901 patients without diabetes. Diabetes was defined as known diabetes or HbA1c >/=6.5 mmol/l at admission. RESULTS: The prevalence of diabetes was comparable between women and men in the younger age group (14% vs 12%, p = 0.52), whereas in the older age group diabetes was more prevalent in women (25% vs 17% p < 0.001). In patients without diabetes, admission glucose was comparable between both genders in younger patients (8.1 +/- 2.0 mmol/l vs 8.0 +/- 2.2 mmol/l p = 0.36), but in older patients admission glucose was higher in women than in men (8.7 +/- 2.1 mmol/l vs 8.4 +/- 2.1 mmol/l p = 0.028). After multivariable analyses, the occurrence of increased admission glucose was comparable between men and women in the younger age group (OR 1.1, 95%CI 0.9-1.5), but increased in women in the older age group (OR 1.3, 95% CI 1.1-1.7). Both diabetes and hyperglycemia were associated with a higher one-year mortality in both men and women. CONCLUSIONS: The differences between men and women in hyperglycemia and diabetes in patients with STEMI are age dependent and can only be observed in older patients. This may have implications for medical treatment and should be investigated further
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