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1.
Small ; 19(12): e2206379, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36642834

ABSTRACT

Heterostructured Au/CuS nanocrystals (NCs) exhibit localized surface plasmon resonance (LSPR) centered at two different wavelengths (551 and 1051 nm) with a slight broadening compared to respective homostructured Au and CuS NC spectra. By applying ultrafast transient absorption spectroscopy we show that a resonant excitation at the respective LSPR maxima of the heterostructured Au/CuS NCs leads to the characteristic hot charge carrier relaxation associated with both LSPRs in both cases. A comparison of the dual plasmonic heterostructure with a colloidal mixture of homostructured Au and CuS NCs shows that the coupled dual plasmonic interaction is only active in the heterostructured Au/CuS NCs. By investigating the charge carrier dynamics of the process, we find that the observed interaction is faster than phononic or thermal processes (< 100 fs). The relaxation of the generated hot charge carriers is faster for heterostructured nanocrystals and indicates that the interaction occurs as an energy transfer (we propose Landau damping or interaction via LSPR beat oscillations as possible mechanisms) or charge carrier transfer between both materials. Our results strengthen the understanding of multiplasmonic interactions in heterostructured Au/CuS NCs and will significantly advance applications where these interactions are essential, such as catalytic reactions.

2.
Front Neurosci ; 15: 768646, 2021.
Article in English | MEDLINE | ID: mdl-35046767

ABSTRACT

Improvements have been made in the diagnosis of Alzheimer's disease (AD), manifesting mostly in the development of in vivo imaging methods that allow for the detection of pathological changes in AD by magnetic resonance imaging (MRI) and positron emission tomography (PET) scans. Many of these imaging methods, however, use agents that probe amyloid fibrils and plaques-species that do not correlate well with disease progression and are not present at the earliest stages of the disease. Amyloid ß oligomers (AßOs), rather, are now widely accepted as the Aß species most germane to AD onset and progression. Here we report evidence further supporting the role of AßOs as pathological instigators of AD and introduce promising anti-AßO diagnostic probes capable of distinguishing the 5xFAD mouse model from wild type mice by PET and MRI. In a developmental study, Aß oligomers in 5xFAD mice were found to appear at 3 months of age, just prior to the onset of memory dysfunction, and spread as memory worsened. The increase of AßOs is prominent in the subiculum and correlates with concomitant development of reactive astrocytosis. The impact of these AßOs on memory is in harmony with findings that intraventricular injection of synthetic AßOs into wild type mice induced hippocampal dependent memory dysfunction within 24 h. Compelling support for the conclusion that endogenous AßOs cause memory loss was found in experiments showing that intranasal inoculation of AßO-selective antibodies into 5xFAD mice completely restored memory function, measured 30-40 days post-inoculation. These antibodies, which were modified to give MRI and PET imaging probes, were able to distinguish 5xFAD mice from wild type littermates. These results provide strong support for the role of AßOs in instigating memory loss and salient AD neuropathology, and they demonstrate that AßO selective antibodies have potential both for therapeutics and for diagnostics.

3.
J Public Econ ; 194: 104350, 2021 Feb.
Article in English | MEDLINE | ID: mdl-35702337

ABSTRACT

With the COVID-19 outbreak imposing stay at home and social distancing policies, warnings about the impact of lockdown and its economic consequences on domestic violence have surged. This paper disentangles the effect of forced cohabitation and economic stress on intimate partner violence. Using an online survey data set, we find a 23% increase of intimate partner violence during the lockdown. Our results indicate that the impact of economic consequences is twice as large as the impact of lockdown. We also find large but statistically imprecise estimates of a large increase of domestic violence when the relative position of the man worsens, especially in contexts where that position was already being threatened. We view our results as consistent with the male backlash and emotional cue effects.

4.
Diabetes ; 53(3): 654-62, 2004 Mar.
Article in English | MEDLINE | ID: mdl-14988249

ABSTRACT

Glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide (GIP) are important factors in the pathogenesis of type 2 diabetes and have a promising therapeutic potential. Alterations of their secretion, in vivo degradation, and elimination in patients with chronic renal insufficiency (CRI) have not yet been characterized. Ten patients with CRI (aged 47 +/- 15 years, BMI 24.5 +/- 2.2 kg/m(2), and serum creatinine 2.18 +/- 0.86 mg/dl) and 10 matched healthy control subjects (aged 44 +/- 12 years, BMI 24.9 +/- 3.4 kg/m(2), and serum creatinine 0.89 +/- 0.10 mg/dl) were included. On separate occasions, an oral glucose tolerance test (75 g), an intravenous infusion of GLP-1 (0.5 pmol. kg(-1). min(-1) over 30 min), and an intravenous infusion of GIP (1.0 pmol. kg(-1). min(-1) over 30 min) were performed. Venous blood samples were drawn for the determination of glucose (glucose oxidase), insulin, C-peptide, GLP-1 (total and intact), and GIP (total and intact; specific immunoassays). Plasma levels of GIP (3-42) and GLP-1 (9-36 amide) were calculated. Statistics were performed using repeated-measures and one-way ANOVA. After the oral glucose load, plasma concentrations of intact GLP-1 and intact GIP reached similar levels in both groups (P = 0.31 and P = 0.87, respectively). The concentrations of GIP (3-42) and GLP-1 (9-36 amide) were significantly higher in the patients than in the control subjects (P = 0.0021 and P = 0.027, respectively). During and after the exogenous infusion, GLP-1 (9-36 amide) and GIP (3-42) reached higher plasma concentrations in the CRI patients than in the control subjects (P < 0.001 and P = 0.0033, respectively), whereas the plasma levels of intact GLP-1 and GIP were not different between the groups (P = 0.29 and P = 0.27, respectively). Plasma half-lives were 3.4 +/- 0.6 and 2.3 +/- 0.4 min for intact GLP-1 (P = 0.13) and 5.3 +/- 0.8 and 3.3 +/- 0.4 min for the GLP-1 metabolite (P = 0.029) for CRI patients vs. healthy control subjects, respectively. Plasma half-lives of intact GIP were 6.9 +/- 1.4 and 5.0 +/- 1.2 min (P = 0.31) and 38.1 +/- 6.0 and 22.4 +/- 3.0 min for the GIP metabolite (P = 0.032) for CRI patients vs. healthy control subjects, respectively. Insulin concentrations tended to be lower in the patients during all experiments, whereas C-peptide levels tended to be elevated. These data underline the importance of the kidneys for the final elimination of GIP and GLP-1. The initial dipeptidyl peptidase IV-mediated degradation of both hormones is almost unaffected by impairments in renal function. Delayed elimination of GLP-1 and GIP in renal insufficiency may influence the pharmacokinetics and pharmacodynamics of dipeptidyl peptidase IV-resistant incretin derivatives to be used for the treatment of patients with type 2 diabetes.


Subject(s)
Gastric Inhibitory Polypeptide/metabolism , Glucagon/metabolism , Peptide Fragments/metabolism , Protein Precursors/metabolism , Renal Insufficiency/blood , Analysis of Variance , Creatinine/blood , Female , Gastric Inhibitory Polypeptide/blood , Glucagon/blood , Glucagon-Like Peptide 1 , Humans , Kinetics , Male , Middle Aged , Patient Selection , Peptide Fragments/blood , Protein Precursors/blood , Reference Values
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