Searching for quantum functionalities requires access to the electronic structure, constituting the foundation of exquisite spin-valley-electronic, topological, and many-body effects. All-optical ...band-structure reconstruction could directly connect electronic structure with the coveted quantum phenomena if strong lightwaves transported localized electrons within preselected bands. Here, we demonstrate that harmonic sideband (HSB) generation in monolayer tungsten diselenide creates distinct electronic interference combs in momentum space. Locating these momentum combs in spectroscopy enables super-resolution tomography of key band-structure details in situ. We experimentally tuned the optical-driver frequency by a full octave and show that the predicted super-resolution manifests in a critical intensity and frequency dependence of HSBs. Our concept offers a practical, all-optical, fully three-dimensional tomography of electronic structure even in microscopically small quantum materials, band by band.
When intense lightwaves accelerate electrons through a solid, the emerging high-order harmonic (HH) radiation offers key insights into the material
. Sub-optical-cycle dynamics-such as dynamical ...Bloch oscillations
, quasiparticle collisions
, valley pseudospin switching
and heating of Dirac gases
-leave fingerprints in the HH spectra of conventional solids. Topologically non-trivial matter
with invariants that are robust against imperfections has been predicted to support unconventional HH generation
. Here we experimentally demonstrate HH generation in a three-dimensional topological insulator-bismuth telluride. The frequency of the terahertz driving field sharply discriminates between HH generation from the bulk and from the topological surface, where the unique combination of long scattering times owing to spin-momentum locking
and the quasi-relativistic dispersion enables unusually efficient HH generation. Intriguingly, all observed orders can be continuously shifted to arbitrary non-integer multiples of the driving frequency by varying the carrier-envelope phase of the driving field-in line with quantum theory. The anomalous Berry curvature warranted by the non-trivial topology enforces meandering ballistic trajectories of the Dirac fermions, causing a hallmark polarization pattern of the HH emission. Our study provides a platform to explore topology and relativistic quantum physics in strong-field control, and could lead to non-dissipative topological electronics at infrared frequencies.
Summary Objective To investigate the combination of mild mechanical stimuli and a disease modifying osteoarthritis drug (DMOAD) in inflammatory activated chondrocytes and to study the combination of ...drug and mechanical tension on the cellular level as a model for an integrated biophysical approach for osteoarthritis (OA) treatments. Methods Interleukin-1beta (IL-1β) stimulated C28/I2 cells underwent mild mechanically treatment while cultured in the presence of the DMOAD diacerein. The pharmacological input of diacerein was evaluated by cell viability and cell proliferation measurements. Inflammation and treatment induced changes in key regulatory proteins and components of the extracellular matrix (ECM) were characterized by quantitative real-time PCR (qPCR). The effects on metalloproteinase-1 (MMP-1) activity and glycosaminoglycan (GAG) concentration in cell supernatants of treated cells were investigated. Results C28/I2 cells demonstrated significant changes in expression of inflammatory and cartilage destructive proteins in response to IL-1β stimulation. The chondroprotective action of diacerein in mechanically stimulated cells was mediated by a decrease in interleukin-8 (IL-8), fibronectin-1 (FN-1), collagen type I (Col 1) and MMP-1 expression levels, respectively. Augmented expression of interleukin-6 receptor (IL-6R) and the fibroblast growth factor receptors (FGFRs) by diacerein was not abolished by mechanical treatment. The observed effects were accompanied by a reduced cell proliferation rate, attenuated cell viability and extenuated MMP-1 activity. Conclusion Diacerein diversely regulates the expression of main regulatory proteins as well as components important to regenerate and set up ECM. Mechanical stimulation does not negatively influence the chondroprotective effect induced by diacerein treatment in immortalized human C28/I2 chondrocytes.
Background: We aimed to determine the prevalence of contact sensitization in the general population and to investigate associations with important sociodemographic and medical characteristics. ...Methods: Within a population-based nested, case-control study in Germany, we performed patch tests with 25 standard allergens in 1141 adults (50.4% female, age median 50 years). Additional information was obtained by a dermatologic examination, a standardized interview, and blood analysis. Results: At least one positive reaction was exhibited by 40.0% of the subjects, with reactions most frequently observed to fragrance mix (15.9%), nickel (13.1%), thimerosal (4.7%), and balsam of Peru (3.8%). Women were sensitized more often than men (50.2% vs 29.9%, OR 2.36, CI 1.84-3.03), and this was also significant for fragrance mix, nickel, turpentine, cobalt chloride, and thimerosal. Contact sensitization was more frequent in subjects who reported adverse skin reactions (53.8% vs. 32.6%; OR 2.41, CI 1.85-3.14), and this was particularly true for sensitization to nickel (45.5% vs 8.8%, OR 8.64, CI 5.67-13.17) and fragrance mix (29.0% vs 14.0%, OR 2.51, CI 1.60-3.91) and the corresponding intolerance of fashion jewelry and fragrances. Contact sensitization decreased with increasing degree of occupational training (unskilled 45.9%, apprenticeship 40.1%, technical college 40.4%, and school of engineering 12.5%; P=0.023; trend test P=0.042). Significant associations of contact sensitization and presence of allergen-specific IgE antibodies, atopic eczema, or psoriasis were not observed. Frequency estimates for the general adult population based on these findings were 28.0% for overall contact sensitization and 11.4% for fragrance mix, 9.9% for nickel, and 3.2% for thimerosal. Conclusions: It is concluded that contact allergy is influenced by sociodemographic parameters and plays an important role in the general population.
Background: Food allergy and food intolerance (FA/FI) are believed to be frequent medical problems; however, information from epidemiologic studies in adults is scarce. The objective was to determine ...the frequency of FA/FI and allergic sensitization to food in a large adult sample. Furthermore, the associations between FA/FI and other outcomes of atopy were studied.
Methods: Within a population‐based, nested, case‐control study, a standardized interview was performed to obtain detailed information on FA/FI and the history of atopic diseases. In addition, a skin prick test with 10 common food and nine aeroallergens was performed.
Results: Overall, 20.8% of the 1537 studied subjects (50.4% female, age median 50 years) reported FA/FI (women 27.5%, men 14.0%; OR 2.35, CI 1.80–3.08). Nuts, fruits, and milk most frequently led to adverse effects, and the sites of manifestation were oral (42.9%), skin (28.7%), gastrointestinal (13.0%), systemic (3.2%), and multiple (12.2%). One‐quarter of the subjects (25.1%) were sensitized to at least one food allergen in the prick test, with hazelnut (17.8%), celery (14.6%), and peanut (11.1%) accounting for most of the positive reactions. The corresponding frequency estimates for the representative study base (n=4178) were 15.5% for reported adverse reactions and 16.8% for allergic sensitization. Relevant concomitant sensitization to food and aeroallergens was observed. Food‐allergic subjects (positive history and sensitization to corresponding allergen) suffered significantly more often from urticaria, asthma, atopic eczema, and especially hay fever (73.1%) than controls (3.0%). Furthermore, hay fever was treated significantly more often in subjects who suffered from concomitant food allergy.
Conclusions: FA/FI in adults is frequently reported and associated with other manifestations of atopy. Hay fever in conjunction with FA/FI tends to be clinically more severe since therapeutic needs are enhanced.
G protein-gated inwardly rectifying potassium channels (GIRKs) are a family of homo- and hetero-oligomeric K + channels composed of different subunits (GIRK1 to 4 in mammals). GIRK4 and GIRK1 are ...found mainly in the atrium, whereas
neuronal cells predominantly express the GIRK1, GIRK2, and GIRK3 isoforms. When activated, GIRK channels slow the firing rate
of atrial myocytes and neuronal cells. Because of their key role in controlling excitability, we investigated the influence
of a prototypic anesthetic, halothane, on GIRK channels of different subunit composition expressed in Xenopus laevis oocytes. Halothane enhanced background currents through hetero-oligomeric GIRK1/GIRK4 and homo-oligomeric GIRK1 F137S channels but not through homo-oligomeric GIRK2 channels. This activation of basal current did not depend on the presence
of coexpressed G protein-coupled receptors but instead required the presence of G β
/γ . In contrast to basal GIRK currents, the agonist-induced GIRK current (via coexpressed m 2 muscarinic receptors) was inhibited by halothane. For GIRK1/GIRK4 and GIRK1 F137S channels this inhibition was most pronounced at low concentrations of the anesthetic (0.1â0.3 mM) and occurred also when
channels had been activated by guanosine-5â²- O -(3-thio)triphosphate. This inhibition, however, was overridden by high concentrations of halothane (0.9 mM) and augmentation
of the agonist-induced current was observed. This increase in agonist-induced current was never seen with GIRK2 homo-oligomeric
channels. Agonist-induced currents mediated by GIRK2 channels were always inhibited by halothane with an IC 50 value of approximately 60 μM. These data suggest a direct interaction of halothane with GIRK channels.
Summary
Background
The increase in allergic diseases is still unexplained. It was hypothesized that the intake of unsaturated fatty acids is a contributing cause of this development. We investigated ...the relationship between serum cholesterol levels, intake of polyunsaturated fatty acids (PUFA) and manifestations of atopy in a population‐based setting.
Methods
A nested case–control study was performed within the population of the 3rd MONICA survey in Augsburg (Germany). The serum levels of total, high‐density lipoprotein (HDL) and low‐density lipoprotein (LDL) cholesterol of 1537 adults (aged 28–78 years, response 61.4%) and the estimated intake of PUFA in a subset of 139 men were compared with the frequency of a doctor's diagnosis of asthma, allergic rhinoconjunctivitis (AR), atopic eczema (AE) and allergic sensitization as measured by skin prick and Radio Allergo Sorbent Test.
Findings
In bivariate analyses, we obtained a negative linear association between total and LDL cholesterol levels and the frequency of AR and sensitization, which was no longer significant after adjustment for important confounders. In contrast, positive linear associations were found between HDL cholesterol levels and AR and AE and, furthermore, between the intake of PUFA and allergic sensitization in men (P<0.01). After adjustment, an increasing risk for atopic diseases with increasing levels of HDL cholesterol and an increasing risk for allergic sensitization with increasing intakes of PUFA remained statistically significant.
Interpretation
There is indication that HDL cholesterol also plays a role in the complex interaction of fat intake, metabolism and the manifestation of atopy in adults. These findings may contribute to the understanding of time trends and regional differences of allergies.
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