Pr3+-doped YPO4 nanocrystal embedded into an optical fiber.

Optical fiber with YPO4:Pr3+ nanocrystals (NCs) is presented for the first time using the glass powder-NCs doping method. The method's advantage is separate preparation of NCs and glass to preserve luminescent and optical properties of NCs once they are incorporated into optical fiber. The YPO4:Pr3+ nanocrystals were synthesized by the co-precipitation and hydrothermal methods, optimized for size (< 100 nm), shape, Pr3+ ions concentration (0.2 mol%), and emission lifetime. The core glass was selected from the non-silica P2O5-containing system with refractive index (n = 1.788) close to the NCs (no = 1.657, ne = 1.838). Optical fiber was drawn by modified powder-in-tube method after pre-sintering of glass powder-YPO4:Pr3+ (wt 3%) mixture to form optical fiber preform. Luminescent properties of YPO4:Pr3+ and optical fiber showed their excellent agreement, including sharp Pr3+ emission at 600 nm (1D2-3H4) and 1D2 level lifetime (τ = 156 ± 5 µs) under 488 nm excitation. The distribution of the YPO4:Pr3+ NCs in optical fiber were analyzed by TEM-EDS in the core region (FIB-SEM-prepared). The successful usage of glass powder-NCs doping method was discussed in the aspect of promising properties of the first YPO4:Pr3+ doped optical fiber as a new way to develop active materials for lasing applications, among others.

Evaluating Strategies to Enhance Li Transference in Salt-in-Ionic Liquid Electrolytes: Mixed Anions, Coordinating Cations, and High Salt Concentration.

The increased safety of salt-in-ionic liquid electrolytes compared with established carbonate-based systems has promoted intense research in this field, but low conductivities, slow lithium transport, and unfavorable lithium anion correlations still prevent a mass market application. In particular, strong Li-anion correlations lead to dominant vehicular Li transport with the same drift direction for anions and lithium in the electric field. Here, three different strategies and their mutual interplay are evaluated, which could reduce Li-anion coordination, i.e., high salt concentration, a mixed-anion composition, as well as an ether functionalization of the organic cation. To this end, two series of highly concentrated IL-based electrolytes, based on either ethylmethylimidazolium (EMIM) or the ether-functionalized 1-methoxyethyl-1-methylpyrrolidinium (Pyr12O1) organic cation, and employing mixed bis(fluorosulfonyl)imide/bis(trifluoromethylsulfonyl)imide (FSI/TFSI) anions are investigated. Measurements of conductivities, diffusion coefficients, and electrophoretic mobilities reveal no beneficial effect due to the increased heterogeneity of the FSI/TFSI-based electrolyte matrix, generally showing improved transport properties with increasing FSI share. However, a combination of both the ether-functionalized cation and high FSI content is proven successful, as lithium mobilities are positive, and vehicular transport is overcome by structural Li transport. Our study demonstrates the decisive role of synergy of the different approaches: While the single effect of a high salt concentration, weakly lithium-coordinating anions, or organic cations with lithium-affine functional groups is too weak to prevent vehicular transport, their joint effect can overcome vehicular Li transport, leading to improved Li conduction in ionic liquids.

A volume-based description of transport in incompressible liquid electrolytes and its application to ionic liquids.

Transference numbers play an important role in understanding the dynamics of electrolytes and assessing their performance in batteries. Unfortunately, these transport parameters are difficult to measure in highly concentrated liquid electrolytes such as ionic liquids. Also, the interpretation of their sign and magnitude has provoked an ongoing debate in the literature further complicated by the use of different languages. In this work, we highlight the role of the reference frame for the interpretation of transport parameters using our novel thermodynamically consistent theory for highly correlated electrolytes. We argue that local volume conservation is a key principle in incompressible liquid electrolytes and use the volume-based drift velocity as a reference. We apply our general framework to electrophoretic NMR experiments. For ionic liquid based electrolytes, we find that the results of the eNMR measurements can be best described using this volume-based description. This highlights the limitations of the widely used center-of-mass reference frame which for example forms the basis for molecular dynamics simulations - a standard tool for the theoretical calculation of transport parameters. It shows that the assumption of local momentum conservation is incorrect in those systems on the macroscopic scale.

Local Volume Conservation in Concentrated Electrolytes Is Governing Charge Transport in Electric Fields.

While ion transport processes in concentrated electrolytes, e.g., based on ionic liquids (IL), are a subject of intense research, the role of conservation laws and reference frames is still a matter of debate. Employing electrophoretic NMR, we show that momentum conservation, a typical prerequisite in molecular dynamics (MD) simulations, is not governing ion transport. Involving density measurements to determine molar volumes of distinct ion species, we propose that conservation of local molar species volumes is the governing constraint for ion transport. The experimentally quantified net volume flux is found to be zero, implying a nonzero local momentum flux, as tested in pure ILs and IL-based electrolytes for a broad variety of concentrations and chemical compositions. This constraint is consistent with incompressibility, but not with a local application of momentum conservation. The constraint affects the calculation of transference numbers as well as comparisons of MD results to experimental findings.

2 MW peak power generation in fluorine co-doped Yb fiber prepared by powder-sinter technology.

We report on the first, to the best of our knowledge, implementation of a fluorine co-doped large-mode-area REPUSIL fiber for high peak power amplification in an ultrashort-pulse master oscillator power amplifier. The core material of the investigated step-index fiber with high Yb-doping level, 52 µm core and high core-to-clad ratio of 1:4.2 was fabricated by means of the REPUSIL powder-sinter technology. The core numerical aperture was adjusted by fluorine codoping to 0.088. For achieving high beam quality and for ensuring a monolithic seed path, the LMA fiber is locally tapered. We demonstrate an Yb fiber amplifier with near-diffraction-limited beam quality of M2=1.3, which remains constant up to a peak power of 2 MW. This is a record for a tapered single core fiber.

Acute Ischemic Stroke in Late Pregnancy Treated with Intravenous Thrombolysis and Endovascular Therapy.

Pregnancy has usually been an exclusion criterion in clinical trials with thrombolysis and endovascular therapy in acute ischemic stroke. For that reason, these therapies are not recommended causing lack of evidence and vice versa. In this case report, we describe a pregnant woman in week 33 + 3 presenting with acute ischemic stroke, which was successfully treated with systemic thrombolysis and endovascular therapy, resulting in a good clinical outcome for both mother and child. The altered fibrinolytic system and the risk factors related to pregnancy constitute a challenge for clinicians when choosing the most suitable treatment modality for treating acute ischemic stroke in pregnancy. It is still uncertain whether thrombolysis in combination with endovascular therapy or endovascular therapy alone is the most appropriate treatment option. However, there is slowly growing evidence that thrombolysis and thrombectomy in pregnancy are feasible and safe with a good clinical outcome for both the mother and the child.

Effect of a single dose of insulin glargine/lixisenatide fixed ratio combination (iGlarLixi) on postprandial glucodynamic response in Japanese patients with type 2 diabetes mellitus: A phase I randomized trial.

This report describes novel clinical data assessing the pharmacodynamics of insulin glargine/lixisenatide (iGlarLixi) compared with placebo and insulin glargine alone, to determine pharmacokinetics of lixisenatide, and to assess safety of iGlarLixi in Japanese people with type 2 diabetes mellitus (T2DM). In a single-centre, open-label, randomized, placebo-controlled cross-over study, participants received subcutaneous iGlarLixi 5 U/5 µg and 10 U/10 µg, placebo, and 5 U insulin glargine. The primary endpoint was area under the postprandial plasma glucose (PPG) curve (AUC0-2h ). A total of 20 participants completed all study periods. iGlarLixi 5 U/5 µg and 10 U/10 µg reduced mean PPG dose-dependently compared with placebo and insulin glargine 5 U. Both combinations significantly reduced PPG-AUC0-2h dose-dependently compared with placebo (least squares mean difference -7.48 mmol h/L for 5 U/5 µg, -10.75 mmol h/L for 10 U/10 µg; P < 0.0001). iGlarLixi 5 U/5 µg reduced PPG-AUC0-2h significantly compared with insulin glargine 5 U (-0.76 mmol h/L; P < 0.0001). No symptomatic hypoglycaemia occurred during the study. iGlarLixi single subcutaneous injections significantly and dose-dependently reduced PPG compared to placebo or insulin glargine in Japanese participants with T2DM. iGlarLixi was safe and well tolerated, and would be expected to provide the 24-hour plasma glucose-lowering effects of insulin glargine and the postprandial antihyperglycaemic effects of lixisenatide.

Impact of lixisenatide dose range on clinical outcomes with fixed-ratio combination iGlarLixi in patients with type 2 diabetes.

OBJECTIVE: To evaluate the lixisenatide dose range delivered by the iGlarLixi SoloSTAR pen (5-20 µg), alone or in fixed-ratio combination with insulin glargine (iGlar; iGlarLixi). METHODS: Data from three clinical studies were analyzed to assess lixisenatide efficacy and safety: a phase 2a trial assessing gastric emptying effects (ACT6011); a phase 2b dose-ranging trial (DRI6012); and a randomized controlled phase 3 trial comparing iGlarLixi with its components of iGlar and lixisenatide (LixiLan-O). Efficacy metrics included glycated hemoglobin A1c (A1C), post-prandial glucose (PPG) values following a standardized breakfast, fasting plasma glucose (FPG), and weight change. Occurrence of gastrointestinal adverse events was also assessed. RESULTS: ACT6011: lixisenatide doses from 5-20 µg once daily (QD) suppressed PPG; maximal reductions in mean PPG area under the curve were achieved with doses ≥12.5 µg QD, but doses as low as 5 µg achieved 44% of maximal reduction. DRI6012: lixisenatide doses 5-20 µg QD resulted in significant, dose-dependent decreases in A1C, percentage of patients achieving A1C <7.0%, and 2-h PPG levels; doses of 20 µg achieved complete suppression of PPG. LixiLan-O: iGlarLixi decreased 2-h PPG across the entire dose range. Lixisenatide dose was unrelated to reductions in FPG with iGlarLixi. Similar reductions in A1C were seen with iGlarLixi across all lixisenatide doses. CONCLUSIONS: This analysis demonstrates the clinical benefit of lixisenatide alone or in the formulation of iGlarLixi over the entire dose range of lixisenatide contained in iGlarLixi (5-20 µg), supporting the selection of the lixisenatide dose range delivered by the iGlarLixi SoloSTAR pen.

Yb-doped large mode area fiber for beam quality improvement using local adiabatic tapers with reduced dopant diffusion.

A newly designed all-solid step-index Yb-doped aluminosilicate large mode area fiber for achieving high peak power at near diffraction limited beam quality with local adiabatic tapering is presented. The 45µm diameter fiber core and pump cladding consist of active/passively doped aluminosilicate glass produced by powder sinter technology (REPUSIL). A deliberate combination of innovative cladding and core materials was aspired to achieve low processing temperature reducing dopant diffusion during fiber fabrication, tapering and splicing. By developing a short adiabatic taper, robust seed coupling is achieved by using this Yb-doped LMA fiber as final stage of a nanosecond fiber Master Oscillator Power Amplifier (MOPA) system while maintaining near diffraction limited beam quality by preferential excitation of the fundamental mode. After application of a fiber-based endcap, the peak power could be scaled up to 375 kW with high beam quality and a measured M2 value of 1.3~1.7.

Team Players or Opponents: Coadministration of Selective Glucagon and GLP-1 Receptor Agonists in Obese Diabetic Monkeys.

We assessed the therapeutic contribution of the individual components of glucagon-like peptide-1 receptor (GLP-1R) and glucagon receptor (GCGR) agonists alone and in combination upon energy homeostasis and glycemic control in diet-induced obese, diabetic nonhuman primates. The pharmacological active dose ranges of selective agonists were established through a dose-finding study, followed by a 6-week chronic study. Repeated subcutaneous administration of a selective GCGR agonist (30 µg/kg once daily) did not affect food intake or body weight, whereas the selective GLP-1R agonist (3 µg/kg once daily) alone decreased energy intake by 18% and body weight by 3.8% ± 0.9%. Combination of both agonists reduced significantly cumulative food intake by 27% and body weight by 6.6% ± 0.9%. Fasting plasma glucose (FPG) was improved by GLP-1R agonist (baseline vs end of study, 176.7 ± 34.0 vs 115.9 ± 16.1 mg/dL). In contrast, groups exposed to GCGR agonist experienced nonsignificant elevations of FPG. More accurate assessment of therapeutic interventions on glucose homeostasis was tested by an IV glucose tolerance test. Glucose excursion was significantly elevated by chronic GCGR agonist administration, whereas it was significantly decreased in GLP-1R agonist-treated monkeys. In the combination group, a nonsignificant increase of glucose excursion was seen, concomitantly with significantly increased insulin secretion. We conclude that chronic glucagon agonism does not affect energy homeostasis in nonhuman primates. In combination with GLP-1R agonism, glucagon agonism synergistically enhances negative energy balance with resulting larger body weight loss. However, adding GCGR to GLP-1R agonism diminishes glycemic control in diabetic monkeys. Therefore, long-term therapeutic implications of using GLP-1R/GCGR coagonists for weight management in diabetes warrants further scrutiny.

Running on mixed fuel-dual agonistic approach of GLP-1 and GCG receptors leads to beneficial impact on body weight and blood glucose control: A comparative study between mice and non-human primates.

AIM: We performed acute and chronic studies in healthy and diet-induced obese animals using mouse-specific or monkey-specific dual GLP-1R/GCGR agonists to investigate their effects on food intake, body weight, blood glucose control and insulin secretion. The selective GLP-1R agonist liraglutide was used as comparator. METHODS: The mouse-specific dual agonist and liraglutide were tested in lean wild type, GLP-1R knockout and diet-induced obese mice at different doses. A chronic study was performed in DIO mice to investigate the effect on body weight, food consumption and total energy expenditure (TEE) in obese and diabetic monkeys with a focus on body weight and energy intake. RESULTS: The mouse-specific dual agonist and liraglutide similarly affected glycaemic control. A higher loss in body weight was measured in dual agonist-treated obese mice. The dual agonist significantly enhanced plasma glucose excursion in overnight fed GLP-1R-/- mice, probably reflecting a potent GCGR agonist activity. It increased TEE and enhanced fat and carbohydrate oxidation, while liraglutide produced no effect on TEE. In obese and diabetic monkeys, treatment with the monkey-specific dual agonist reduced total energy intake to 60%-70% of baseline TEI during chronic treatment. A decrease in body weight and significant improvement in glucose tolerance was observed. CONCLUSIONS: In DIO mice and non-human primates, dual agonists elicited robust glycaemic control, similar to the marketed GLP-1R agonist, while eliciting greater effects on body weight. Results from DIO mice suggest that the increase in TEE is caused not only by increased fat oxidation but also by an increase in carbohydrate oxidation.

Dual Glucagon-like Peptide 1 (GLP-1)/Glucagon Receptor Agonists Specifically Optimized for Multidose Formulations.

Novel peptidic dual agonists of the glucagon-like peptide 1 (GLP-1) and glucagon receptor are reported to have enhanced efficacy over pure GLP-1 receptor agonists with regard to treatment of obesity and diabetes. We describe novel exendin-4 based dual agonists designed with an activity ratio favoring the GLP-1 versus the glucagon receptor. As result of an iterative optimization procedure that included molecular modeling, structural biological studies (X-ray, NMR), peptide design and synthesis, experimental activity, and solubility profiling, a candidate molecule was identified. Novel SAR points are reported that allowed us to fine-tune the desired receptor activity ratio and increased solubility in the presence of antimicrobial preservatives, findings that can be of general applicability for any peptide discovery project. The peptide was evaluated in chronic in vivo studies in obese diabetic monkeys as translational model for the human situation and demonstrated favorable blood glucose and body weight lowering effects.

Design of Novel Exendin-Based Dual Glucagon-like Peptide 1 (GLP-1)/Glucagon Receptor Agonists.

Dual activation of the glucagon-like peptide 1 (GLP-1) and glucagon receptor has the potential to lead to a novel therapy principle for the treatment of diabesity. Here, we report a series of novel peptides with dual activity on these receptors that were discovered by rational design. On the basis of sequence analysis and structure-based design, structural elements of glucagon were engineered into the selective GLP-1 receptor agonist exendin-4, resulting in hybrid peptides with potent dual GLP-1/glucagon receptor activity. Detailed structure-activity relationship data are shown. Further modifications with unnatural and modified amino acids resulted in novel metabolically stable peptides that demonstrated a significant dose-dependent decrease in blood glucose in chronic studies in diabetic db/db mice and reduced body weight in diet-induced obese (DIO) mice. Structural analysis by NMR spectroscopy confirmed that the peptides maintain an exendin-4-like structure with its characteristic tryptophan-cage fold motif that is responsible for favorable chemical and physical stability.

Differential effects of glucagon-like peptide-1 receptor agonists on heart rate.

While glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are known to increase heart rate (HR), it is insufficiently recognized that the extent varies greatly between the various agonists and is affected by the assessment methods employed. Here we review published data from 24-h time-averaged HR monitoring in healthy individuals and subjects with type 2 diabetes mellitus (T2DM) treated with either short-acting GLP-1 RAs, lixisenatide or exenatide, or long-acting GLP-1 RAs, exenatide LAR, liraglutide, albiglutide, or dulaglutide (N = 1112; active-treatment arms). HR effects observed in two independent head-to-head trials of lixisenatide and liraglutide (N = 202; active-treatment arms) are also reviewed. Short-acting GLP-1 RAs, exenatide and lixisenatide, are associated with a transient (1-12 h) mean placebo- and baseline-adjusted 24-h HR increase of 1-3 beats per minute (bpm). Conversely, long-acting GLP-1 RAs are associated with more pronounced increases in mean 24-h HR; the highest seen with liraglutide and albiglutide at 6-10 bpm compared with dulaglutide and exenatide LAR at 3-4 bpm. For both liraglutide and dulaglutide, HR increases were recorded during both the day and at night. In two head-to-head comparisons, a small, transient mean increase in HR from baseline was observed with lixisenatide; liraglutide induced a substantially greater increase that remained significantly elevated over 24 h. The underlying mechanism for increased HR remains to be elucidated; however, it could be related to a direct effect at the sinus node and/or stimulation of the sympathetic nervous system, with this effect related to the duration of action of the respective GLP-1 RAs. In conclusion, this review indicates that the effects on HR differ within the class of GLP-1 RAs: short-acting GLP-1 RAs are associated with a modest and transient HR increase before returning to baseline levels, while some long-acting GLP-1 RAs are associated with a more pronounced and sustained increase during the day and night. Findings from recently completed trials indicate that a GLP-1 RA-induced increase in HR, regardless of magnitude, does not present an increased cardiovascular risk for subjects with T2DM, although a pronounced increase in HR may be associated with adverse clinical outcomes in those with advanced heart failure.

Relationship between condensed tannin structures and their ability to precipitate feed proteins in the rumen.

BACKGROUND: Tannins can bind to and precipitate protein by forming insoluble complexes resistant to fermentation and with a positive effect on protein utilisation by ruminants. Three protein types, Rubisco, rapeseed protein and bovine serum albumin (a single high-molecular weight protein), were used to test the effects of increasing concentrations of structurally different condensed tannins on protein solubility/precipitation. RESULTS: Protein type (PT) influenced solubility after addition of condensed tannins (P < 0.001) in the order: Rubisco < rapeseed < BSA (P < 0.05). The type of condensed tannin (CT) affected protein solubility (P = 0.001) with a CT × PT interaction (P = 0.001). Mean degree of polymerisation, proportions of cis- versus trans-flavanol subunits or prodelphinidins versus procyanidins among CTs could not explain precipitation capacities. Increasing tannin concentration decreased protein solubility (P < 0.001) with a PT × CT concentration interaction. The proportion of low-molecular weight rapeseed proteins remaining in solution increased with CT concentration but not with Rubisco. CONCLUSIONS: Results of this study suggest that PT and CT type are both of importance for protein precipitation but that the CT structures investigated did not allow identification of parameters that contribute most to precipitation. It is possible that the three-dimensional structures of tannins and proteins may be more important factors in tannin-protein interactions.

Recent progress and future options in the development of GLP-1 receptor agonists for the treatment of diabesity.

The dramatic rise of the twin epidemics, type 2 diabetes and obesity is associated with increased mortality and morbidity worldwide. Based on this global development there is clinical need for anti-diabetic therapies with accompanied weight reduction. From the approved therapies, the injectable glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are the only class of agents which are associated with a modest weight reduction. Physiological effects of the gastro-intestinal hormone GLP-1 are improvement of glycemic control as well as a reduction in appetite and food intake. Different approaches are currently under clinical evaluation to optimize the therapeutic potential of GLP-1 RAs directed to once-weekly up to once-monthly administration. The next generation of peptidic co-agonists comprises the activity of GLP-1 plus additional gastro-intestinal hormones with the potential for increased therapeutic benefits compared to GLP-1 RAs.

Effects of lixisenatide once daily on gastric emptying in type 2 diabetes--relationship to postprandial glycemia.

OBJECTIVES: To determine the effects of lixisenatide, a new once-daily (QD) glucagon-like peptide-1 receptor agonist, on postprandial glucose (PPG) and gastric emptying, and the relationship between these effects in patients with type 2 diabetes mellitus (T2DM). METHODS: Data were obtained from a randomized, double-blind, placebo-controlled, parallel-group study with treatment duration of 28 days in patients with T2DM receiving ≤2 oral antidiabetic drugs. Lixisenatide was injected subcutaneously using an ascending dose range (5-20 µg) increased every fifth day in increments of 2.5 µg. Blood glucose was determined before and after three standardized meals (breakfast, lunch, and dinner). Gastric emptying of the standardized breakfast was determined by a (13)C-octanoic acid breath test at baseline (Day-1) and at Day 28. RESULTS: A total of 21 and 22 patients were randomized to lixisenatide 20 µg QD and placebo, respectively. With lixisenatide 20 µg QD, there was a reduction in PPG when compared with placebo after breakfast (p<0.0001), lunch (p<0.001) and dinner (p<0.05). Hence, lixisenatide 20 µg administered in the morning exhibited a pharmacodynamic effect on blood glucose throughout the day. Gastric emptying (50% emptying time) increased substantially from baseline with lixisenatide 20 µg QD, but not with placebo (change from baseline ± SD: -24.1 ± 133.1 min for placebo and 211.5 ± 278.5 min for lixisenatide; p<0.01). There was an inverse relationship between PPG area under the curve after breakfast and gastric emptying with lixisenatide 20 µg QD (n=17, r(2)=0.51, p<0.05), but not with placebo. CONCLUSIONS: In this study, lixisenatide at a dose of 20 µg QD reduced postprandial glycemic excursions in patients with T2DM, possibly as a result of sustained slowing of gastric emptying.