The characteristic shapes, structures and properties of biominerals arise from their interplay with a macromolecular matrix. The developing mineral interacts with acidic macromolecules, which are ...either dissolved in the crystallization medium or associated with insoluble matrix polymers, that affect growth habits and phase selection or completely inhibit precipitation in solution. Yet little is known about the role of matrix-immobilized acidic macromolecules in directing mineralization. Here, by using in situ liquid-phase electron microscopy to visualize the nucleation and growth of CaCO3 in a matrix of polystyrene sulphonate (PSS), we show that the binding of calcium ions to form Ca-PSS globules is a key step in the formation of metastable amorphous calcium carbonate (ACC), an important precursor phase in many biomineralization systems. Our findings demonstrate that ion binding can play a significant role in directing nucleation, independently of any control over the free-energy barrier to nucleation.
A classical view on nonclassical nucleation Smeets, Paul J. M.; Finney, Aaron R.; Habraken, Wouter J. E. M. ...
Proceedings of the National Academy of Sciences - PNAS,
09/2017, Letnik:
114, Številka:
38
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Understanding and controlling nucleation is important for many crystallization applications. Calcium carbonate (CaCO₃) is often used as a model system to investigate nucleation mechanisms. Despite ...its great importance in geology, biology, and many industrial applications, CaCO₃ nucleation is still a topic of intense discussion, with new pathways for its growth from ions in solution proposed in recent years. These new pathways include the so-called nonclassical nucleation mechanism via the assembly of thermodynamically stable prenucleation clusters, as well as the formation of a dense liquid precursor phase via liquid–liquid phase separation. Here, we present results from a combined experimental and computational investigation on the precipitation of CaCO₃ in dilute aqueous solutions. We propose that a dense liquid phase (containing 4–7 H₂O per CaCO₃ unit) forms in supersaturated solutions through the association of ions and ion pairs without significant participation of larger ion clusters. This liquid acts as the precursor for the formation of solid CaCO₃ in the form of vaterite, which grows via a net transfer of ions from solution according to z Ca2+ + z CO₃2− → z CaCO₃. The results show that all steps in this process can be explained according to classical concepts of crystal nucleation and growth, and that long-standing physical concepts of nucleation can describe multistep, multiphase growth mechanisms.
The primary objective of this study is to identify which modifiable and non-modifiable factors are independent predictors of the development of chronic pain in patients with acute- or subacute ...nonspecific idiopathic, non-traumatic neck pain, and secondly, to combine these to develop and internally validate a prognostic prediction model.
A prospective cohort study will be conducted by physiotherapists in 30 primary physiotherapy practices between January 26, 2020, and August 31, 2022, with a 6-month follow-up until March 17, 2023. Patients who consult a physiotherapist with a new episode of acute- (0 to 3 weeks) or subacute neck pain (4 to 12 weeks) will complete a baseline questionnaire. After their first appointment, candidate prognostic variables will be collected from participants regarding their neck pain symptoms, prior conditions, work-related factors, general factors, psychological and behavioral factors. Follow-up assessments will be conducted at six weeks, three months, and six months after the initial assessment. The primary outcome measure is the Numeric Pain Rating Scale (NPRS) to examine the presence of chronic pain. If the pain is present at six weeks, three months, and six months with a score of NPRS ≥3, it is classified as chronic pain. An initial exploratory analysis will use univariate logistic regression to assess the relationship between candidate prognostic factors at baseline and outcome. Multiple logistic regression analyses will be conducted. The discriminative ability of the prognostic model will be determined based on the Area Under the receiver operating characteristic Curve (AUC), calibration will be assessed using a calibration plot and formally tested using the Hosmer and Lemeshow goodness-of-fit test, and model fit will be quantified as Nagelkerke's R2. Internal validation will be performed using bootstrapping-resampling to yield a measure of overfitting and the optimism-corrected AUC.
The results of this study will improve the understanding of prognostic and potential protective factors, which will help clinicians guide their clinical decision making, develop an individualized treatment approach, and predict chronic neck pain more accurately.
This paper reports that strongly coupled bimetallic core–shell nanoparticle arrays show photoelectrocatalytic activity for hydrogen evolution reactions (HER). We fabricated large-area Cu–Pt ...nanoparticle lattices by combining top-down lithography and solution-based chemistry. These coupled lattices support two different types of plasmon modes, localized surface plasmons from individual particles and surface lattice resonances (SLRs) from the 2D lattice, that increased HER catalytic activity under white-light illumination up to 60%. Comparing photoelectrocatalytic performances of the two plasmon modes at different wavelength ranges, we found that SLRs had two-fold activity enhancement over that from localized surface plasmons.
Objective To assess the long term effects of multidisciplinary biopsychosocial rehabilitation for patients with chronic low back pain.Design Systematic review and random effects meta-analysis of ...randomised controlled trials.Data sources Electronic searches of Cochrane Back Review Group Trials Register, CENTRAL, Medline, Embase, PsycINFO, and CINAHL databases up to February 2014, supplemented by hand searching of reference lists and forward citation tracking of included trials.Study selection criteria Trials published in full; participants with low back pain for more than three months; multidisciplinary rehabilitation involved a physical component and one or both of a psychological component or a social or work targeted component; multidisciplinary rehabilitation was delivered by healthcare professionals from at least two different professional backgrounds; multidisciplinary rehabilitation was compared with a non- multidisciplinary intervention.Results Forty one trials included a total of 6858 participants with a mean duration of pain of more than one year who often had failed previous treatment. Sixteen trials provided moderate quality evidence that multidisciplinary rehabilitation decreased pain (standardised mean difference 0.21, 95% confidence interval 0.04 to 0.37; equivalent to 0.5 points in a 10 point pain scale) and disability (0.23, 0.06 to 0.40; equivalent to 1.5 points in a 24 point Roland-Morris index) compared with usual care. Nineteen trials provided low quality evidence that multidisciplinary rehabilitation decreased pain (standardised mean difference 0.51, −0.01 to 1.04) and disability (0.68, 0.16 to 1.19) compared with physical treatments, but significant statistical heterogeneity across trials was present. Eight trials provided moderate quality evidence that multidisciplinary rehabilitation improves the odds of being at work one year after intervention (odds ratio 1.87, 95% confidence interval 1.39 to 2.53) compared with physical treatments. Seven trials provided moderate quality evidence that multidisciplinary rehabilitation does not improve the odds of being at work (odds ratio 1.04, 0.73 to 1.47) compared with usual care. Two trials that compared multidisciplinary rehabilitation with surgery found little difference in outcomes and an increased risk of adverse events with surgery.Conclusions Multidisciplinary biopsychosocial rehabilitation interventions were more effective than usual care (moderate quality evidence) and physical treatments (low quality evidence) in decreasing pain and disability in people with chronic low back pain. For work outcomes, multidisciplinary rehabilitation seems to be more effective than physical treatment but not more effective than usual care.
Aim Recently, the level of growth differentiation factor 15 (GDF-15) in blood, was proposed as biomarker to detect mitochondrial dysfunction. In the current study, we evaluate this biomarker in ...open-angle glaucoma (OAG), as there is increasing evidence that mitochondrial dysfunction plays a role in the pathophysiology of this disease. Methods Plasma GDF-15 concentrations were measured with ELISA in 200 OAG patients and 61 age-matched controls (cataract without glaucoma). The OAG patient group consisted of high tension glaucoma (HTG; n = 162) and normal tension glaucoma (NTG; n = 38). Groups were compared using the Kruskal-Wallis nonparametric test with Dunn's multiple comparison post-hoc correction. GDF-15 concentration was corrected for confounders identified with forward linear regression models. Results Before correcting for confounders, median plasma GDF-15 levels was significantly lower in the combined OAG group (p = 0.04), but not when analysing HTG and NTG patients separately. Forward linear regression analysis showed that age, gender, smoking and systemic hypertension were significant confounders affecting GDF-15 levels. After correction for these confounders, GDF-15 levels in OAG patients were no longer significantly different from controls. Subgroup analysis of the glaucoma patients did not show a correlation between disease severity and plasma GDF-15, but did reveal that for NTG patients, intake of dietary supplements, which potentially improve mitochondrial function, correlated with lower plasma GDF-15. Conclusion The present study suggests that plasma GDF-15 is not suited as biomarker of mitochondrial dysfunction in OAG patients.
This paper reports how the spectral linewidths of plasmon resonances can be narrowed down to a few nanometers by optimizing the morphology, surface roughness, and crystallinity of metal nanoparticles ...(NPs) in two-dimensional (2D) lattices. We developed thermal annealing procedures to achieve ultranarrow surface lattice resonances (SLRs) with full-width at half-maxima linewidths as narrow as 4 nm from arrays of Au, Ag, Al, and Cu NPs. Besides annealing, we developed a chemical vapor deposition process to use Cu NPs as catalytic substrates for graphene growth. Graphene-encapsulated Cu NPs showed the narrowest SLR linewidths (2 nm) and were stable for months. These ultranarrow SLR nanocavity modes supported even narrower lasing emission spectra and high nonlinearity in the input–output light–light curves.
The determinants of food choice Leng, Gareth; Adan, Roger A H; Belot, Michele ...
Proceedings of the Nutrition Society,
08/2017, Letnik:
76, Številka:
3
Journal Article
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Health nudge interventions to steer people into healthier lifestyles are increasingly applied by governments worldwide, and it is natural to look to such approaches to improve health by altering what ...people choose to eat. However, to produce policy recommendations that are likely to be effective, we need to be able to make valid predictions about the consequences of proposed interventions, and for this, we need a better understanding of the determinants of food choice. These determinants include dietary components (e.g. highly palatable foods and alcohol), but also diverse cultural and social pressures, cognitive-affective factors (perceived stress, health attitude, anxiety and depression), and familial, genetic and epigenetic influences on personality characteristics. In addition, our choices are influenced by an array of physiological mechanisms, including signals to the brain from the gastrointestinal tract and adipose tissue, which affect not only our hunger and satiety but also our motivation to eat particular nutrients, and the reward we experience from eating. Thus, to develop the evidence base necessary for effective policies, we need to build bridges across different levels of knowledge and understanding. This requires experimental models that can fill in the gaps in our understanding that are needed to inform policy, translational models that connect mechanistic understanding from laboratory studies to the real life human condition, and formal models that encapsulate scientific knowledge from diverse disciplines, and which embed understanding in a way that enables policy-relevant predictions to be made. Here we review recent developments in these areas.
Segmentation of the high-need, high-cost (HNHC) population is required for reorganizing care to accommodate person-centered, integrated care delivery. Therefore, we aimed to identify and characterize ...relevant subgroups of the HNHC population in primary care by using demographic, biomedical, and socioeconomic patient characteristics.
This was a retrospective cohort study within a Dutch primary care group, with a follow-up period from September 1, 2014 to August 31, 2017. Chronically ill patients were included in the HNHC population if they belonged to the top 10% of care utilizers and/or suffered from multimorbidity and had an above-average care utilization. In a latent class analysis, forty-one patient characteristics were initially used as potential indicators of heterogeneity in HNHC patients' needs.
Patient data from 12 602 HNHC patients was used. A 4-class model was considered statistically and clinically superior. The classes were named according to the characteristics that were most dominantly present and distinctive between the classes (i.e. mainly age, household position, and source of income). Class 1 ('older adults living with partner') included 39.3% of patients, class 2 ('older adults living alone') included 25.5% of patients, class 3 ('middle-aged, employed adults with family') included 23.3% of patients, and class 4 ('middle-aged adults with social welfare dependency') included 11.9% of patients. Diabetes was the most common condition in all classes; the second most prevalent condition differed between osteoarthritis in class 1 (21.7%) and 2 (23.8%), asthma in class 3 (25.3%), and mood disorders in class 4 (23.1%). Furthermore, while general practitioner (GP) care utilization increased during the follow-up period in the classes of older adults, it remained relatively stable in the middle-aged classes.
Although the HNHC population is heterogeneous, distinct subgroups with relatively homogeneous patterns of mainly demographic and socioeconomic characteristics can be identified. This calls for tailoring care and increased attention for social determinants of health.
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