Colloidal assembly is an attractive means to control material properties via hierarchy of particle composition, size, ordering, and macroscopic form. However, despite well‐established methods for ...assembling colloidal crystals as films and patterns on substrates, and within microscale confinements such as droplets or microwells, it has not been possible to build freeform colloidal crystal structures. Direct‐write colloidal assembly, a process combining the bottom‐up principle of colloidal self‐assembly with the versatility of direct‐write 3D printing, is introduced in the present study. By this method, centimeter‐scale, free‐standing colloidal structures are built from a variety of materials. A scaling law that governs the rate of assembly is derived; macroscale structural color is tailored via the size and crystalline ordering of polystyrene particles, and several freestanding structures are built from silica and gold particles. Owing to the diversity of colloidal building blocks and the means to control their interactions, direct‐write colloidal assembly could therefore enable novel composites, photonics, electronics, and other materials and devices.
Direct‐write colloidal assembly enables the fabrication of freestanding structures with centimeter‐scale dimensions. The 3D colloidal structures are polycrystalline and display structural color, which is tunable by particle size. By controlling the macroscale form via the direct‐write tool‐path, and controlling the particle arrangement via self‐assembly, this technique could broadly enable additive manufacturing of ordered colloidal solids for photonics, electronics, and other applications.
Aims/hypothesis
In this study we aimed to replicate the previously reported association between the glycaemic response to metformin and the SNP rs11212617 at a locus that includes the ataxia ...telangiectasia mutated (
ATM
) gene in multiple additional populations.
Methods
Incident users of metformin selected from the Diabetes Care System West-Friesland (DCS,
n
= 929) and the Rotterdam Study (
n
= 182) from the Netherlands, and the CARDS Trial (
n
= 254) from the UK were genotyped for rs11212617 and tested for an association with both HbA
1c
reduction and treatment success, defined as the ability to reach the treatment target of an HbA
1c
≤7 % (53 mmol/mol). Finally, a meta-analysis including data from literature was performed.
Results
In the DCS cohort, we observed an association between rs11212617 genotype and treatment success on metformin (OR 1.27, 95% CI 1.03, 1.58,
p
= 0.028); in the smaller Rotterdam Study cohort, a numerically similar but non-significant trend was observed (OR 1.45, 95% CI 0.87, 2.39,
p
= 0.15); while in the CARDS cohort there was no significant association. In meta-analyses of these three cohorts separately or combined with the previously published cohorts, rs11212617 genotype is associated with metformin treatment success (OR 1.24, 95% CI 1.04, 1.49,
p
= 0.016 and OR 1.25, 95% CI 1.33, 1.38,
p
= 7.8 × 10
−6
, respectively).
Conclusions/interpretation
A gene variant near
ATM
is significantly associated with metformin treatment response in type 2 diabetic patients from the Netherlands and the UK. This is the first robustly replicated common susceptibility locus found to be associated with metformin treatment response.
Evaporative self-assembly of semiconducting polymers is a low-cost route to fabricating micrometer and nanoscale features for use in organic and flexible electronic devices. However, in most cases, ...rate is limited by the kinetics of solvent evaporation, and it is challenging to achieve uniformity over length- and time-scales that are compelling for manufacturing scale-up. In this study, we report high-throughput, continuous printing of poly(3-hexylthiophene) (P3HT) by a modified doctor blading technique with oscillatory meniscus motionmeniscus-oscillated self-assembly (MOSA), which forms P3HT features ∼100 times faster than previously reported techniques. The meniscus is pinned to a roller, and the oscillatory meniscus motion of the roller generates repetitive cycles of contact-line formation and subsequent slip. The printed P3HT lines demonstrate reproducible and tailorable structures: nanometer scale thickness, micrometer scale width, submillimeter pattern intervals, and millimeter-to-centimeter scale coverage with highly defined boundaries. The line width as well as interval of P3HT patterns can be independently controlled by varying the polymer concentration levels and the rotation rate of the roller. Furthermore, grazing incidence wide-angle X-ray scattering (GIWAXS) reveals that this dynamic meniscus control technique dramatically enhances the crystallinity of P3HT. The MOSA process can potentially be applied to other geometries, and to a wide range of solution-based precursors, and therefore will develop for practical applications in printed electronics.
In recent years, health psychology has received significant attention within the health sector, due to its application to understanding influences on health and well-being and translation of health ...psychology into interventions to support behaviour change. The number of health psychologists in public health and healthcare settings is growing but remains limited, and is it unclear why. This study aimed to explore the views of potential and current employers of health psychologists, to elucidate barriers and facilitators of employing health psychologists in healthcare settings.
Semi-structured interviews were carried out to explore the experiences of working with and/or employing health psychologists. Opportunities and barriers were explored for increasing access to health psychology expertise in the NHS and public health. Interviews were analysed using inductive thematic analysis.
Fifteen participants took part in interviews. Participants were mid-senior-level professionals working in varied healthcare settings and/or academic institutions. The majority had experience of health psychology/working with health psychologists, whilst others had limited experience but an interest in employing health psychologists. Three key themes were identified: (1) the organizational fit of health psychologists, (2) perception of competition for roles and (3) ideas for changing hearts, minds and processes.
Barriers exist to employing health psychologists in healthcare settings. These barriers include misunderstandings of the role of health psychologists and the need to preserve other disciplines due to perceived competition. Recommendations for change included showcasing the benefits and skills of health psychologists and having transparent conversations with employees and multi-disciplinary colleagues about roles.
Materials made by directed self‐assembly of colloids can exhibit a rich spectrum of optical phenomena, including photonic bandgaps, coherent scattering, collective plasmonic resonance, and wave ...guiding. The assembly of colloidal particles with spatial selectivity is critical for studying these phenomena and for practical device fabrication. While there are well‐established techniques for patterning colloidal crystals, these often require multiple steps including the fabrication of a physical template for masking, etching, stamping, or directing dewetting. Here, the direct‐writing of colloidal suspensions is presented as a technique for fabrication of iridescent colloidal crystals in arbitrary 2D patterns. Leveraging the principles of convective assembly, the process can be optimized for high writing speeds (≈600 µm s−1) at mild process temperature (30 °C) while maintaining long‐range (cm‐scale) order in the colloidal crystals. The crystals exhibit structural color by grating diffraction, and analysis of diffraction allows particle size, relative grain size, and grain orientation to be deduced. The effect of write trajectory on particle ordering is discussed and insights for developing 3D printing techniques for colloidal crystals via layer‐wise printing and sintering are provided.
Planar direct‐write assembly is presented as a technique for fabricating high‐quality iridescent colloidal crystals directly from a digital template, without the need for masks or etching. Quantitative information on grain size and orientation is obtained by analyzing the optical properties of printed crystals. By stacking multiple print passes, direct‐write assembly provides a pathway toward 3D printing of colloidal crystals.
Therapeutic response to metformin, a first‐line drug for type 2 diabetes (T2D), is highly variable, in part likely due to genetic factors. To date, metformin pharmacogenetic studies have mainly ...focused on the impact of variants in metformin transporter genes, with inconsistent results. To clarify the significance of these variants in glycemic response to metformin in T2D, we performed a large‐scale meta‐analysis across the cohorts of the Metformin Genetics Consortium (MetGen). Nine candidate polymorphisms in five transporter genes (organic cation transporter OCT1, OCT2, multidrug and toxin extrusion transporter MATE1, MATE2‐K, and OCTN1) were analyzed in up to 7,968 individuals. None of the variants showed a significant effect on metformin response in the primary analysis, or in the exploratory secondary analyses, when patients were stratified according to possible confounding genotypes or prescribed a daily dose of metformin. Our results suggest that candidate transporter gene variants have little contribution to variability in glycemic response to metformin in T2D.
Aims/hypothesis Variation in fasting plasma glucose (FPG) within the normal range is a known risk factor for the development of type 2 diabetes. Several reports have shown that genetic variation in ...the genes for glucokinase (GCK), glucokinase regulatory protein (GCKR), islet-specific glucose 6 phosphatase catalytic subunit-related protein (G6PC2) and melatonin receptor type 1B (MTNR1B) is associated with FPG. In this study we examined whether these loci also contribute to type 2 diabetes susceptibility. Methods A random selection from the Dutch New Hoorn Study was used for replication of the association with FGP (2,361 non-diabetic participants). For the genetic association study we extended the study sample with 2,628 participants with type 2 diabetes. Risk allele counting was used to calculate a four-gene risk allele score for each individual. Results Variants of the GCK, G6PC2 and MTNR1B genes but not GCKR were associated with FPG (all, p <= 0.001; GCKR, p = 0.23). Combining these four genes in a risk allele score resulted in an increase of 0.05 mmol/l (0.04-0.07) per additional risk allele (p = 2 x 10⁻¹³). Furthermore, participants with less than three or more than five risk alleles showed significantly different type 2 diabetes susceptibility compared with the most common group with four risk alleles (OR 0.77 0.65-0.93, p = 0.005 and OR 2.05 1.50-2.80, p = 4 x 10⁻⁶ respectively). The age at diagnosis was also significantly associated with the number of risk alleles (p = 0.009). Conclusions A combined risk allele score for single-nucleotide polymorphisms in four known FPG loci is significantly associated with FPG and HbA₁c in a Dutch population-based sample of non-diabetic participants. Carriers of low or high numbers of risk alleles show significantly different risks for type 2 diabetes compared with the reference group.
This study determined the concentrations of heavy metals in blood collected from Pacific Ridley sea turtles (Lepidochelys olivacea) inhabiting the coast of Guasave, Mexico, in the Gulf of California. ...The highest reported metal concentration in blood was Zn, followed by Se. Of nonessential toxic metals, As was reported in higher percentage compared to Cd. The concentrations of metals detected were present as follows: Zn > Se > Mn > As > Ni > Cd > Cu. Cd concentration in blood is higher in our population in comparison with other populations of L. olivacea, and even higher in other species of sea turtles. Our study reinforces the usefulness of blood for the monitoring of the levels of contaminating elements, and is easily accessible and nonlethal for sea turtles.
Aims/hypothesis Genome-wide association studies have recently identified novel type 2 diabetes susceptibility gene regions. We assessed the effects of six of these regions on insulin secretion as ...determined by a hyperglycaemic clamp. Methods Variants of the HHEX/IDE, CDKAL1, SLC30A8, IGF2BP2 and CDKN2A/CDKN2B genes were genotyped in a cohort of 146 participants with NGT and 126 with IGT from the Netherlands and Germany, who all underwent a hyperglycaemic clamp at 10 mmol/l glucose. Results Variants of CDKAL1 and IGF2BP2 were associated with reductions in first-phase insulin secretion (34% and 28%, respectively). The disposition index was also significantly reduced. For gene regions near HHEX/IDE, SLC30A8 and CDKN2A/CDKN2B we did not find significant associations with first-phase insulin secretion (7-18% difference between genotypes; all p > 0.3). None of the variants showed a significant effect on second-phase insulin secretion in our cohorts (2-8% difference between genotypes, all p > 0.3). Furthermore, the gene variants were not associated with the insulin sensitivity index. Conclusions Variants of CDKAL1 and IGF2BP2 attenuate the first phase of glucose-stimulated insulin secretion but show no effect on the second phase of insulin secretion. Our results, based on hyperglycaemic clamps, provide further insight into the pathogenic mechanism behind the association of these gene variants with type 2 diabetes.
The concentration of heavy metals (Zn, Cd, Ni, Cu, Mn) and selenium (Se) was analyzed in blood collected from 12 black turtles (
Chelonia mydas agasiizzi
) captured in Canal del Infiernillo, Punta ...Chueca, Mexico. The most abundant metals were Zn (63.58 μg g
−1
) and Se (7.66 μg g
−1
), and Cd was the lower (0.99 μg g
−1
). The sequential concentrations of trace metals were Zn > Se > Cu > Mn > Ni > Cd. In conclusion, this information is important as a baseline when using blood as tissue analysis of heavy metals; however, these levels could represent recent exposure in foraging grounds of black turtles in the Sea of Cortez.
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