Plasmonic Temperature-Programmed Desorption

Temperature-programmed desorption (TPD) allows for the determination of the bonding strength and coverage of molecular mono- or multilayers on a surface and is widely used in surface science. In its traditional form using a mass spectrometric readout, this information is derived indirectly by analysis of resulting desorption peaks. This is problematic because the mass spectrometer signal not only originates from the sample surface but also potentially from other surfaces in the measurement chamber. As a complementary alternative, we introduce plasmonic TPD, which directly measures the surface coverage of molecular species adsorbed on metal nanoparticles at ultrahigh vacuum conditions. Using the examples of methanol and benzene on Au nanoparticle surfaces, the method can resolve all relevant features in the submonolayer and multilayer regimes. Furthermore, it enables the study of two types of nanoparticles simultaneously, which is challenging in a traditional TPD experiment, as we demonstrate specifically for Au and Ag

Proinflammatory Stimuli Enhance Phagocytosis of Apoptotic Cells by Neutrophil Granulocytes

Recently, we have reported that, in addition to macrophages, also neutrophil granulocytes can phagocytose apoptotic neutrophils. Based on this finding, we hypothesized that “cannibalistic” neutrophils at sites of acute infection/inflammation play a major role in the clearance of apoptotic neutrophils. Since at sites of infection/inflammation neutrophils are exposed to microbial constituents and proinflammatory cytokines, in the present study we analyzed the effect of TLR-ligands and cytokines on the ability of neutrophils to phagocytose apoptotic cells in vitro. We observed that exposure to ligands of TLR2 (Malp2, Pam3CSK4), TLR4 (LPS), TLR7/TLR8 (R848), and TLR9 (ODN 2006) led to increased phagocytosis of apoptotic cells by neutrophils. In addition, proinflammatory cytokines such as TNF and GM-CSF strongly enhanced the uptake of apoptotic cells by neutrophils. These results support the hypothesis that neutrophils acquire the ability to phagocytose apoptotic cells at sites of acute infection/inflammation and thereby can contribute to the resolution of inflammation

Dimethylfumarate Impairs Neutrophil Functions

Host defense against pathogens relies on neutrophil activation. Inadequate neutrophil activation is often associated with chronic inflammatory diseases. Neutrophils also constitute a significant portion of infiltrating cells in chronic inflammatory diseases, for example, psoriasis and multiple sclerosis. Fumarates improve the latter diseases, which so far has been attributed to the effects on lymphocytes and dendritic cells. Here, we focused on the effects of dimethylfumarate (DMF) on neutrophils. In vitro, DMF inhibited neutrophil activation, including changes in surface marker expression, reactive oxygen species production, formation of neutrophil extracellular traps, and migration. Phagocytic ability and autoantibody-induced, neutrophil-dependent tissue injury ex vivo was also impaired by DMF. Regarding the mode of action, DMF modulates—in a stimulus-dependent manner-neutrophil activation using the phosphoinositide 3-kinase/Akt-p38 mitogen-activated protein kinase and extracellular signal-regulated kinase 1/2 pathways. For in vivo validation, mouse models of epidermolysis bullosa acquisita, an organ-specific autoimmune disease caused by autoantibodies to type VII collagen, were employed. In the presence of DMF, blistering induced by injection of anti-type VII collagen antibodies into mice was significantly impaired. DMF treatment of mice with clinically already-manifested epidermolysis bullosa acquisita led to disease improvement. Collectively, we demonstrate a profound inhibitory activity of DMF on neutrophil functions. These findings encourage wider use of DMF in patients with neutrophil-mediated diseases

In Situ Plasmonic Nanospectroscopy of the CO Oxidation Reaction over Single Pt Nanoparticles

The ongoing quest to develop single-particle methods for the in situ study of heterogeneous catalysts is driven by the fact that heterogeneity in terms of size, shape, grain structure, and composition is a general feature among nanoparticles in an ensemble. This heterogeneity hampers the generation of a deeper understanding for how these parameters affect catalytic properties. Here we present a solution that in a single benchtop experimental setup combines single-particle plasmonic nanospectroscopy with mass spectrometry for gas phase catalysis under reaction conditions at high temperature. We measure changes in the surface state of polycrystalline platinum model catalyst particles in the 70 nm size range and the corresponding bistable kinetics during the carbon monoxide oxidation reaction via the peak shift of the dark-field scattering spectrum of a closely adjacent plasmonic nanoantenna sensor and compare these changes with the total reaction rate measured by the mass spectrometer from an ensemble of nominally identical particles. We find that the reaction kinetics of simultaneously measured individual Pt model catalysts are dictated by the grain structure and that the superposition of the individual nanoparticle response can account for the significant broadening observed in the corresponding nanoparticle ensemble data. In a wider perspective our work enables in situ plasmonic nanospectroscopy in controlled gas environments at high temperature to investigate the role of the surface state on transition metal catalysts during reaction and of processes such as alloying or surface segregation in situ at the single-nanoparticle level for model catalysts in the few tens to hundreds of nanometer size range

Predisposing factors for bacterial vaginosis, treatment efficacy and pregnancy outcome among term deliveries; results from a preterm delivery study

<p>Abstract</p> <p>Background</p> <p>Bacterial vaginosis (BV) during pregnancy is associated with an increased risk of preterm delivery but little is known about factors that could predict BV. We have analyzed if it is possible to identify a category of pregnant women that should be screened for BV, and if BV would alter the pregnancy outcome at term; we have also studied the treatment efficacy of clindamycin.</p> <p>Methods</p> <p>Prospective BV screening and treatment study of 9025 women in a geographically defined region in southeast Sweden. BV was defined as a modified Nugent score of 6 and above. Data was collected from the Swedish Medical Birth Register. Women allocated to treatment were supplied with vaginal clindamycin cream. The main outcome goals were to identify factors that could predict BV.</p> <p>Results</p> <p>Vaginal smears were consistent with BV criteria in 9.3%. Logistic regression indicates a significant correlation between smoking and BV (p < 0.001) and a greater prevalence of BV in the lower age groups (p < 0.001). We found no correlation between BV and history of preterm deliveries, previous miscarriages, extra-uterine pregnancies, infertility problems or reported history of urinary tract infections–factors that earlier have been associated with BV. Treatment with clindamycin cream showed a cure rate of 77%. Less than 1% of women with a normal vaginal smear in early pregnancy will develop BV during the pregnancy. There was no association between BV and the obstetric outcome among women who delivered at term. Women with BV, both treated patients and nontreated, had the same obstetric outcome at term as women with normal vaginal flora.</p> <p>Conclusion</p> <p>BV is more than twice as common among smokers, and there is a higher prevalence in the younger age group. However these two markers for BV do not suffice as a tool for screening, and considering the lack of other risk factors associated with BV, screening of all pregnant women might be a strategy to follow in a program intended to reduce the number of preterm births.</p

A Mitochondrial Polymorphism Alters Immune Cell Metabolism and Protects Mice from Skin Inflammation

Several genetic variants in the mitochondrial genome (mtDNA), including ancient polymorphisms, are associated with chronic inflammatory conditions, but investigating the functional consequences of such mtDNA polymorphisms in humans is challenging due to the influence of many other polymorphisms in both mtDNA and the nuclear genome (nDNA). Here, using the conplastic mouse strain B6-mtFVB, we show that in mice, a maternally inherited natural mutation (m.7778G > T) in the mitochondrially encoded gene ATP synthase 8 (mt-Atp8) of complex V impacts on the cellular metabolic profile and effector functions of CD4+ T cells and induces mild changes in oxidative phosphorylation (OXPHOS) complex activities. These changes culminated in significantly lower disease susceptibility in two models of inflammatory skin disease. Our findings provide experimental evidence that a natural variation in mtDNA influences chronic inflammatory conditions through alterations in cellular metabolism and the systemic metabolic profile without causing major dysfunction in the OXPHOS system

Crystal structure of ethyl (6-hydroxy-1-benzofuran-3-yl)acetate sesquihydrate

In the title hydrate, C12H12O4·1.5H2O, one of the water molecules in the asymmetric unit is located on a twofold rotation axis. The molecule of the benzofuran derivative is essentially planar (r.m.s. deviation for the non-H atoms = 0.021à ), with the ester group adopting a fully extended conformation. In the crystal, O-H�O hydrogen bonds between the water molecules and the hydroxy groups generate a centrosymmetric R6 6(12) ring motif. These R6 6(12) rings are fused, forming a one-dimensional motif extending along the c-axis direction

Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

Molecular beam study of non-adiabatic electron transfer in the Cl2+Ksurf surface reaction

Halogen molecules impinging on alkali metal surfaces constitute model systems for studies of charge transfer, dissociation dynamics and non-adiabatic energy dissipation in molecule-surface reactions. This thesis reports emission of exo-electrons and photons from the surface as a result of strong non-adabaticity in the Cl2 gas on K$^{solid}$ reaction. The high electron affinity of chlorine and low work function of potassium results in unusually high yields of emitted particles.This thesis contains three parts: (i) The building of the experimental equipment, (ii) experiments using the equipment, (iii)) and theoretical and numerical modelling of the system .The first and major part of this work was the building of a molecular beam apparatus for scattering of halogens on evaporated alkali surfaces. A supersonic nozzle source plus a velocity selector provided Cl2 molecules from 460 m/s to 1360 m/s (0.08-0.68 eV) by He seeding. The scattering chamber has facilities for measurements of energy resolved photon and electron emission, negative ions, UPS spectra and sticking coefficient.In the second part experimental emission yields and energy distributions of exo-electrons and photons were measured as a function of Cl2 velocity and surface exposure. The exo-electron yield increases by a factor of 4 for the range of molecular velocities mentioned above, while the photon yield did not show any significant change. A small shift towards higher energy of both the exo-electrons and the photons was observed. >98% of the negative charge emitted in the reaction consists of electrons, but some Cl- ions were detected. The initial sticking coefficient was unity for all velocities.The model calculation, based on classical trajectory calculations, includes all the steps of the reaction, from an initial electron transfer from the surface to the molecule (harpooning) that causes dissociation of the molecule, to a second and final electron transfer that, with certain probability and branching ratio, causes emission of an electron or a photon.By comparing the results from the molecular beam experiments with the model calculations, we are able to propose a detailed picture of the dissociation dynamics and of the electron and photon emission processes

Molecular beam study of non-adiabatic electron transfer in the Cl2+Ksurf surface reaction

Halogen molecules impinging on alkali metal surfaces constitute model systems for studies of charge transfer, dissociation dynamics and non-adiabatic energy dissipation in molecule-surface reactions. This thesis reports emission of exo-electrons and photons from the surface as a result of strong non-adabaticity in the Cl2 gas on K$^{solid}$ reaction. The high electron affinity of chlorine and low work function of potassium results in unusually high yields of emitted particles. This thesis contains three parts: (i) The building of the experimental equipment, (ii) experiments using the equipment, (iii)) and theoretical and numerical modelling of the system . The first and major part of this work was the building of a molecular beam apparatus for scattering of halogens on evaporated alkali surfaces. A supersonic nozzle source plus a velocity selector provided Cl2 molecules from 460 m/s to 1360 m/s (0.08-0.68 eV) by He seeding. The scattering chamber has facilities for measurements of energy resolved photon and electron emission, negative ions, UPS spectra and sticking coefficient. In the second part experimental emission yields and energy distributions of exo-electrons and photons were measured as a function of Cl2 velocity and surface exposure. The exo-electron yield increases by a factor of 4 for the range of molecular velocities mentioned above, while the photon yield did not show any significant change. A small shift towards higher energy of both the exo-electrons and the photons was observed. >98% of the negative charge emitted in the reaction consists of electrons, but some Cl- ions were detected. The initial sticking coefficient was unity for all velocities. The model calculation, based on classical trajectory calculations, includes all the steps of the reaction, from an initial electron transfer from the surface to the molecule (harpooning) that causes dissociation of the molecule, to a second and final electron transfer that, with certain probability and branching ratio, causes emission of an electron or a photon. By comparing the results from the molecular beam experiments with the model calculations, we are able to propose a detailed picture of the dissociation dynamics and of the electron and photon emission processes