Factors associated with diabetic foot ulcers and lower limb amputations in type 1 and type 2 diabetes supported by real-world data from the German/Austrian DPV registry.

AIMS: Diabetic foot ulcer (DFU) is a leading cause of lower limb amputations in people with diabetes. This study was aimed to retrospectively analyze factors affecting DFU using real-world data from a large, prospective central-European diabetes registry (DPV [Diabetes-Patienten-Verlaufsdokumentation]). MATERIALS AND METHODS: We matched adults with type 1 (T1D) or type 2 diabetes (T2D) and DFU to controls without DFU by diabetes type, age, sex, diabetes duration, and treatment year to compare possible risk factors. Cox regression was used to calculate hazard ratios for amputation among those with DFU. RESULTS: In our cohort (N = 63 464), male sex, taller height, and diabetes complications such as neuropathy, peripheral artery disease, nephropathy, and retinopathy were associated with DFU (all p < .001). Glycated hemoglobin (HbA1c) was related to DFU only in T1D (mean with 95% confidence interval [CI]: 7.8 [6.9-9.0] % vs 7.5 [6.8-8.5] %, p < .001). High triglycerides and worse low-density lipoprotein/high-density lipoprotein ratio were also associated with DFU in T1D, whereas smoking (14.7% vs 13.1%) and alcohol abuse (6.4% vs 3.8%, both p < .001) were associated with DFU in T2D. Male sex, higher Wagner grades, and high HbA1c in both diabetes types and insulin use in T2D were associated with increased hazard ratios for amputations. CONCLUSIONS: Sex, body height, and diabetes complications were associated DFU risk in adults with T1D and T2D. Improvement in glycemic control and lipid levels in T1D and reduction of smoking and drinking in T2D may be appropriate interventions to reduce the risk for DFU or amputations.

From Zero to Hero: Type 2 Diabetes Mellitus Patients Hike on the Way of St. James-A Feasibility Study with Analyses of Patients' Quality of Life, Diabetes Distress and Glucose Profile.

This study investigates the feasibility of an accompanied 5-day hiking tour (Way of St. James) for type 2 diabetes mellitus (T2DM) patients and its impact on their quality of life/well-being, diabetes distress and glucose profile. Twenty-three T2DM patients (with and without insulin therapy) participated in the study. The 120 km pilgrimage (from Ferrol to Santiago de Compostela, Spain) was accompanied by three physicians, two diabetes counselors and one sports scientist. Quality of life/well-being was assessed by the World Health Organization's (WHO)-5 questionnaire, and diabetes distress was evaluated based on the Problem Areas in Diabetes (PAID) scale. The glucose levels of six insulin-treated patients were measured using continuous glucose monitoring (CGM) devices, considering that insulin-treated patients can be at increased risk of exercise-induced hypoglycemia. A significant improvement in quality of life/well-being was reported (p < 0.001), while diabetes distress did not change significantly (p = 0.203). Only two of the six insulin-treated patients showed moderate hypoglycemic episodes between 0.97% and 5.21% time below range per day, with glucose levels between 53−70 mg/dL. Hiking tours such as the one organized for this study can improve quality of life/well-being without increasing diabetes distress and are considered relatively safe for T2DM patients, even for those being treated with insulin.

Validation of a risk prediction model for early chronic kidney disease in patients with type 2 diabetes: Data from the German/Austrian Diabetes Prospective Follow-up registry.

AIM: To validate a recently proposed risk prediction model for chronic kidney disease (CKD) in type 2 diabetes (T2D). MATERIALS AND METHODS: Subjects from the German/Austrian Diabetes Prospective Follow-up (DPV) registry with T2D, normoalbuminuria, an estimated glomerular filtration rate of 60 ml/min/1.73m2 or higher and aged 39-75 years were included. Prognostic factors included age, body mass index (BMI), smoking status and HbA1c. Subjects were categorized into low, moderate, high and very high-risk groups. Outcome was CKD occurrence. RESULTS: Subjects (n = 10 922) had a mean age of 61 years, diabetes duration of 6 years, BMI of 31.7 kg/m2 , HbA1c of 6.9% (52 mmol/mol); 9.1% had diabetic retinopathy and 16.3% were smokers. After the follow-up (~59 months), 37.4% subjects developed CKD. The area under the curve (AUC; unadjusted base model) was 0.58 (95% CI 0.57-0.59). After adjustment for diabetes and follow-up duration, the AUC was 0.69 (95% CI 0.68-0.70), indicating improved discrimination. After follow-up, 15.0%, 20.1%, 27.7% and 40.2% patients in the low, moderate, high and very high-risk groups, respectively, had developed CKD. Increasing risk score correlated with increasing cumulative risk of incident CKD over a median of 4.5 years of follow-up (P < .0001). CONCLUSIONS: The predictive model achieved moderate discrimination but good calibration in a German/Austrian T2D population, suggesting that the model may be relevant for determining CKD risk.

Elevated liver enzymes and comorbidities in type 2 diabetes: A multicentre analysis of 51 645 patients from the Diabetes Prospective Follow-up (DPV) database.

AIM: To assess the prevalence of elevated liver enzymes and associated diabetes-related comorbidities in type 2 diabetes (T2D). SUBJECTS AND METHODS: Between 2010 and 2019, 281 245 patients with T2D (aged 18-75 years) from 501 Diabetes Prospective Follow-up (DPV) centres were evaluated, resulting in analysis of 51 645 patients with complete data on demographics and liver enzymes. RESULTS: Elevated liver enzymes were found in 40.2% of all patients. However, only 8.6% of these patients had International Classification of Diseases-10 codes for nonalcoholic fatty liver disease and/or nonalcoholic steatohepatitis. Adjusted for age, sex, diabetes duration, body mass index and glycated haemoglobin, a higher prevalence of arterial hypertension (P < 0.0001), dyslipidaemia (P < 0.0001), peripheral artery disease (P = 0.0029), myocardial infarction (P = 0.0003), coronary artery disease (P = 0.0001), microalbuminuria (P < 0.0001) and chronic kidney disease (P < 0.0001) was seen in patients with elevated versus normal liver enzymes. The prevalence of elevated liver enzymes was lowest in patients receiving sodium-glucose cotransporter-2 (SGLT2) inhibitors or a combination of SGLT2 inhibitors and glucagon-like peptide-1 receptor agonists. CONCLUSION: Elevated liver enzymes are common in patients with T2D and clearly correlate with a higher prevalence of clinically relevant comorbidities. Assessing liver enzymes should be standard clinical routine in T2D due to a possible predictive role for comorbidities and complications.

A Difference Between Bedtime and Pre-Breakfast Plasma Glucose Levels Indicates the Need for Prandial Insulin in Basal Insulin-Treated Type 2 Diabetic Patients with Normal Fasting Glucose.

AIM: In the present analysis, we characterised the efficacy and safety of adding a single daily injection of insulin glulisine to optimised basal-supported oral therapy (BOT) in patients with a high BeAM value, defined as a more than 50 mg/dl difference between bedtime and pre-breakfast blood glucose. METHODS: The BeAM value was retrospectively calculated for patients pooled from two clinical trials that supplemented BOT with glulisine. Data regarding changes in HbA1c, fasting plasma glucose (FPG), and postprandial glucose (PPG) levels from observation periods of 3 to 6 months were assessed. RESULTS: Out of 358 patients that received BOT/glulisine, 182 had a high BeAM value. Patients with a high BeAM value were older and had a longer diabetes duration than patients with a medium BeAM value. Significant reductions in HbA1c (7.5% to 7.2% [59 to 55 mmol/mol], p<0.0001) and PPG (202 to 143 mg/dl, p<0.0001) levels were documented. The proportion of patients with a high BeAM value achieving an HbA1c <7% [53 mmol/mol], alone or in combination with no hypoglycaemia, was lower than that of patients with a medium BeAM value. CONCLUSION: The analysis indicates that the supplementation of BOT with a single daily injection of prandial insulin is safe and effective for reducing HbA1c and PPG levels in patients with a high BeAM value (more than 50 mg/dl). However, patients with a medium BeAM value also responded well, which suggests that they should also be considered candidates for this change in therapy.

Preulcerous Risk Situation in Diabetic Foot Syndrome: Proposal for a Simple Ulcer Prevention Score.

BACKGROUND: Preulcerous risk situations in patients with diabetes are often undiagnosed and care administered too late. Even with regular medical check-ups and status documentation, foot examinations have not been given enough attention. Diagnosing an individual patients' risk of developing diabetic foot ulcers may increase vigilance for diabetic foot syndrome (DFS), and the appropriate prevention measures matching the risk involved may prevent the emergence of diabetic ulcers. The classical DFS risk factors are well established and have been extensively covered in the literature; however, there is a lack of efficient screening tools that could be used for a rapid assessment of diabetic foot ulcer risk. METHODS: A methodical literature search was conducted to assess relevant publications for the preparation of a simple risk score for amputation related to diabetic foot ulcer. We then analyzed the risk factors for predictive value as odds ratios in foot ulcers and/or amputation. We used the available data to deduce a mean value to reflect the authors' consensus. RESULTS: In view of the current literature on the matter, we have developed a semi-quantitative scoring system using just a few items to allow rapid and visual risk assessment for diabetic foot ulcers alongside recommendations for prevention and a sensible follow-up strategy to match the risk. CONCLUSION: This relatively simple score enables rapid risk classification for patients that can ease the way for both physicians and patients in gaining an insight into individual risk situations. The score provides more effective preventative measures for high-risk patients against future complications.

Defect-Tolerant Plasmonic Elliptical Resonators for Long-Range Energy Transfer.

Energy transfer allows energy to be moved from one quantum emitter to another. If this process follows the Förster mechanism, efficient transfer requires the emitters to be extremely close (<10 nm). To increase the transfer range, nanophotonic structures have been explored for photon- or plasmon-mediated energy transfer. Here, we fabricate high-quality silver plasmonic resonators to examine long-distance plasmon-mediated energy transfer. Specifically, we design elliptical resonators that allow energy transfer between the foci, which are separated by up to 10 µm. The geometry of the ellipse guarantees that all plasmons emitted from one focus are collected and channeled through different paths to the other focus. Thus, energy can be transferred even if a micrometer-sized defect obstructs the direct path between the focal points. We characterize the spectral and spatial profiles of the resonator modes and show that these can be used to transfer energy between green- and red-emitting colloidal quantum dots printed with subwavelength accuracy using electrohydrodynamic nanodripping. Rate-equation modeling of the time-resolved fluorescence from the quantum dots further confirms the long-distance energy transfer.

A higher blood glucose level pre-breakfast in comparison to bedtime is a contraindication for intensification of prandial insulin therapy in patients with type 2 diabetes - The impact of a negative BeAM value.

AIMS: The BeAM value refers to the difference between a patient's blood glucose level at bedtime (Be) and the following morning before breakfast (AM). The clinical impact of a negative BeAM value (AM blood glucose reading compared to that taken at bedtime) is unknown. METHODS: T2DM patients of the OPAL and POC trials were pooled and their BeAM values calculated. RESULTS: From a total of 358 patients, 31 were calculated as having a negative BeAM value at baseline, while 182 had a high value. Patients in the negative BeAM group were younger, had shorter diabetes duration, and lower HbA1c levels. Fasting blood glucose levels were higher in the negative BeAM group, and these increased to a greater extent during the trial periods. No significant differences in hypoglycaemia occurrence were observed. Multivariate adjusted analysis indicated no association between a negative BeAM value and achievement of HbA1c < 7%, or composite endpoints that additionally included no hypoglycaemia and no weight gain. CONCLUSIONS: Supplementation of BOT with prandial insulin is not beneficial for patients who have a higher blood glucose reading before breakfast in comparison to before bedtime. Further investigation into the cause of the high morning reading in these patients is indicated.

A customizable class of colloidal-quantum-dot spasers and plasmonic amplifiers.

Colloidal quantum dots are robust, efficient, and tunable emitters now used in lighting, displays, and lasers. Consequently, when the spaser-a laser-like source of high-intensity, narrow-band surface plasmons-was first proposed, quantum dots were specified as the ideal plasmonic gain medium for overcoming the significant intrinsic losses of plasmons. Many subsequent spasers, however, have required a single material to simultaneously provide gain and define the plasmonic cavity, a design unable to accommodate quantum dots and other colloidal nanomaterials. In addition, these and other designs have been ill suited for integration with other elements in a larger plasmonic circuit, limiting their use. We develop a more open architecture that decouples the gain medium from the cavity, leading to a versatile class of quantum dot-based spasers that allow controlled generation, extraction, and manipulation of plasmons. We first create aberration-corrected plasmonic cavities with high quality factors at desired locations on an ultrasmooth silver substrate. We then incorporate quantum dots into these cavities via electrohydrodynamic printing or drop-casting. Photoexcitation under ambient conditions generates monochromatic plasmons (0.65-nm linewidth at 630 nm, Q ~ 1000) above threshold. This signal is extracted, directed through an integrated amplifier, and focused at a nearby nanoscale tip, generating intense electromagnetic fields. More generally, our device platform can be straightforwardly deployed at different wavelengths, size scales, and geometries on large-area plasmonic chips for fundamental studies and applications.

An intrinsic growth instability in isotropic materials leads to quasi-two-dimensional nanoplatelets.

Colloidal nanoplatelets are atomically flat, quasi-two-dimensional sheets of semiconductor that can exhibit efficient, spectrally pure fluorescence. Despite intense interest in their properties, the mechanism behind their highly anisotropic shape and precise atomic-scale thickness remains unclear, and even counter-intuitive for commonly studied nanoplatelets that arise from isotropic crystal structures (such as zincblende CdSe and lead halide perovskites). Here we show that an intrinsic instability in growth kinetics can lead to such highly anisotropic shapes. By combining experimental results on the synthesis of CdSe nanoplatelets with theory predicting enhanced growth on narrow surface facets, we develop a model that explains nanoplatelet formation as well as observed dependencies on time and temperature. Based on standard concepts of volume, surface and edge energies, the resulting growth instability criterion can be directly applied to other crystalline materials. Thus, knowledge of this previously unknown mechanism for controlling shape at the nanoscale can lead to broader libraries of quasi-two-dimensional materials.

Confocal reference free traction force microscopy.

The mechanical wiring between cells and their surroundings is fundamental to the regulation of complex biological processes during tissue development, repair or pathology. Traction force microscopy (TFM) enables determination of the actuating forces. Despite progress, important limitations with intrusion effects in low resolution 2D pillar-based methods or disruptive intermediate steps of cell removal and substrate relaxation in high-resolution continuum TFM methods need to be overcome. Here we introduce a novel method allowing a one-shot (live) acquisition of continuous in- and out-of-plane traction fields with high sensitivity. The method is based on electrohydrodynamic nanodrip-printing of quantum dots into confocal monocrystalline arrays, rendering individually identifiable point light sources on compliant substrates. We demonstrate the undisrupted reference-free acquisition and quantification of high-resolution continuous force fields, and the simultaneous capability of this method to correlatively overlap traction forces with spatial localization of proteins revealed using immunofluorescence methods.

Printable Nanoscopic Metamaterial Absorbers and Images with Diffraction-Limited Resolution.

The fabrication of functional metamaterials with extreme feature resolution finds a host of applications such as the broad area of surface/light interaction. Nonplanar features of such structures can significantly enhance their performance and tunability, but their facile generation remains a challenge. Here, we show that carefully designed out-of-plane nanopillars made of metal-dielectric composites integrated in a metal-dielectric-nanocomposite configuration can absorb broadband light very effectively. We further demonstrate that electrohydrodynamic printing in a rapid nanodripping mode is able to generate precise out-of-plane forests of such composite nanopillars with deposition resolutions at the diffraction limit on flat and nonflat substrates. The nanocomposite nature of the printed material allows the fine-tuning of the overall visible light absorption from complete absorption to complete reflection by simply tuning the pillar height. Almost perfect absorption (∼95%) over the entire visible spectrum is achieved by a nanopillar forest covering only 6% of the printed area. Adjusting the height of individual pillar groups by design, we demonstrate on-demand control of the gray scale of a micrograph with a spatial resolution of 400 nm. These results constitute a significant step forward in ultrahigh resolution facile fabrication of out-of-plane nanostructures, important to a broad palette of light design applications.

Charge effects and nanoparticle pattern formation in electrohydrodynamic NanoDrip printing of colloids.

Advancing open atmosphere printing technologies to produce features in the nanoscale range has important and broad applications ranging from electronics to photonics, plasmonics and biology. Recently an electrohydrodynamic printing regime has been demonstrated in a rapid dripping mode (termed NanoDrip), where the ejected colloidal droplets from nozzles of diameters of O (1 µm) can controllably reach sizes an order of magnitude smaller than the nozzle and can generate planar and out-of-plane structures of similar sizes. Despite the demonstrated capabilities, our fundamental understanding of important aspects of the physics of NanoDrip printing needs further improvement. Here we address the topics of charge content and transport in NanoDrip printing. We employ quantum dot and gold nanoparticle dispersions in combination with a specially designed, auxiliary, asymmetric electric field, targeting the understanding of charge locality (particles vs. solvent) and particle distribution in the deposits as indicated by the dried nanoparticle patterns (footprints) on the substrate. We show that droplets of alternating charge can be spatially separated when applying an ac field to the nozzle. The nanoparticles within a droplet are distributed asymmetrically under the influence of the auxiliary lateral electric field, indicating that they are the main carriers. We also show that the ligand length of the nanoparticles in the colloid affects their mobility after deposition (in the sessile droplet state).

Wedge Waveguides and Resonators for Quantum Plasmonics.

Plasmonic structures can provide deep-subwavelength electromagnetic fields that are useful for enhancing light-matter interactions. However, because these localized modes are also dissipative, structures that offer the best compromise between field confinement and loss have been sought. Metallic wedge waveguides were initially identified as an ideal candidate but have been largely abandoned because to date their experimental performance has been limited. We combine state-of-the-art metallic wedges with integrated reflectors and precisely placed colloidal quantum dots (down to the single-emitter level) and demonstrate quantum-plasmonic waveguides and resonators with performance approaching theoretical limits. By exploiting a nearly 10-fold improvement in wedge-plasmon propagation (19 µm at a vacuum wavelength, λvac, of 630 nm), efficient reflectors (93%), and effective coupling (estimated to be >70%) to highly emissive (~90%) quantum dots, we obtain Ag plasmonic resonators at visible wavelengths with quality factors approaching 200 (3.3 nm line widths). As our structures offer modal volumes down to ~0.004λvac(3) in an exposed single-mode waveguide-resonator geometry, they provide advantages over both traditional photonic microcavities and localized-plasmonic resonators for enhancing light-matter interactions. Our results confirm the promise of wedges for creating plasmonic devices and for studying coherent quantum-plasmonic effects such as long-distance plasmon-mediated entanglement and strong plasmon-matter coupling.

Plasmonic Films Can Easily Be Better: Rules and Recipes.

High-quality materials are critical for advances in plasmonics, especially as researchers now investigate quantum effects at the limit of single surface plasmons or exploit ultraviolet- or CMOS-compatible metals such as aluminum or copper. Unfortunately, due to inexperience with deposition methods, many plasmonics researchers deposit metals under the wrong conditions, severely limiting performance unnecessarily. This is then compounded as others follow their published procedures. In this perspective, we describe simple rules collected from the surface-science literature that allow high-quality plasmonic films of aluminum, copper, gold, and silver to be easily deposited with commonly available equipment (a thermal evaporator). Recipes are also provided so that films with optimal optical properties can be routinely obtained.

Individual Template-Stripped Conductive Gold Pyramids for Tip-Enhanced Dielectrophoresis.

Gradient fields of optical, magnetic, or electrical origin are widely used for the manipulation of micro- and nanoscale objects. Among various device geometries to generate gradient forces, sharp metallic tips are one of the most effective. Surface roughness and asperities present on traditionally produced tips reduce trapping efficiencies and limit plasmonic applications. Template-stripped, noble metal surfaces and structures have sub-nm roughness and can overcome these limits. We have developed a process using a mix of conductive and dielectric epoxies to mount template-stripped gold pyramids on tungsten wires that can be integrated with a movable stage. When coupled with a transparent indium tin oxide (ITO) electrode, the conductive pyramidal tip functions as a movable three-dimensional dielectrophoretic trap which can be used to manipulate submicrometer-scale particles. We experimentally demonstrate the electrically conductive functionality of the pyramidal tip by dielectrophoretic manipulation of fluorescent beads and concentration of single-walled carbon nanotubes, detected with fluorescent microscopy and Raman spectroscopy.

Near-field light design with colloidal quantum dots for photonics and plasmonics.

Colloidal quantum-dots are bright, tunable emitters that are ideal for studying near-field quantum-optical interactions. However, their colloidal nature has hindered their facile and precise placement at desired near-field positions, particularly on the structured substrates prevalent in plasmonics. Here, we use high-resolution electro-hydrodynamic printing (<100 nm feature size) to deposit countable numbers of quantum dots on both flat and structured substrates with a few nanometer precision. We also demonstrate that the autofocusing capability of the printing method enables placement of quantum dots preferentially at plasmonic hot spots. We exploit this control and design diffraction-limited photonic and plasmonic sources with arbitrary wavelength, shape, and intensity. We show that simple far-field illumination can excite these near-field sources and generate fundamental plasmonic wave-patterns (plane and spherical waves). The ability to tailor subdiffraction sources of plasmons with quantum dots provides a complementary technique to traditional scattering approaches, offering new capabilities for nanophotonics.