The evidence that exposure to ozone air pollution causes acute cardiovascular effects is mixed. We postulated that exposure to ambient levels of ozone would increase blood markers of systemic ...inflammation, prothrombotic state, oxidative stress, and vascular dysfunction in healthy older subjects, and that absence of the glutathione S-transferase Mu 1 (GSTM1) gene would confer increased susceptibility. This double-blind, randomized, crossover study of 87 healthy volunteers 55-70 years of age was conducted at three sites using a common protocol. Subjects were exposed for 3 h in random order to 0 parts per billion (ppb) (filtered air), 70 ppb, and 120 ppb ozone, alternating 15 min of moderate exercise and rest. Blood was obtained the day before, approximately 4 h after, and approximately 22 h after each exposure. Linear mixed effect and logistic regression models evaluated the impact of exposure to ozone on pre-specified primary and secondary outcomes. The definition of statistical significance was p<0.01. There were no effects of ozone on the three primary markers of systemic inflammation and a prothrombotic state: C-reactive protein, monocyte-platelet conjugates, and microparticle-associated tissue factor activity. However, among the secondary endpoints, endothelin-1, a potent vasoconstrictor, increased from pre- to post-exposure with ozone concentration (120 vs 0 ppb: 0.07 pg/mL, 95% confidence interval CI 0.01, 0.14; 70 vs 0 ppb: -0.03 pg/mL, CI -0.09, 0.04; p = 0.008). Nitrotyrosine, a marker of oxidative and nitrosative stress, decreased with increasing ozone concentrations, with marginal significance (120 vs 0 ppb: -41.5, CI -70.1, -12.8; 70 vs 0 ppb: -14.2, CI -42.7, 14.2; p = 0.017). GSTM1 status did not modify the effect of ozone exposure on any of the outcomes. These findings from healthy older adults fail to identify any mechanistic basis for the epidemiologically described cardiovascular effects of exposure to ozone. The findings, however, may not be applicable to adults with cardiovascular disease.
In the same context of lattice gauge theory, a notion of cellular automaton (CA) is considered as a description of the underlying dynamics of fields evaluated on a discrete lattice. The explorative ...approach of this work is initiated by taking the automata evolution as an elementary description of fields dynamics on one side and pivotal role of locality on other side to connect the notion of states and transformations to density operators in quantum electrodynamics. In order to parameterize the definition of proposed model in the context of lattice field theory the nonlinear interaction is introduced with neighboring cells. In this paper, analytical and explicit expression of atomic density matrix for single trapped ion interacting with laser field based on cellular automata dynamics are discussed. The definition is further explored by introducing some probabilistic theories as the theoretical framework then it is concluded that the graph of cellular automata in continuum time limit of the CA dynamics leads to Maxwell–Bloch equation.
Explicit treatment of density operator in a quantized radiation field based on graph‐theoretic interpretation of cellular automaton is discussed. This definition implies the sequence of causal foliation on hypergraph defines the states of the system and graph geodesic recover the rule of the propagator of the field.
Background and aim
Dexamethasone Suppression Test (DST), recommended for Cushing’s Syndrome (CS) diagnosis, explores the pituitary feedback to glucocorticoids. Its diagnostic accuracy could be ...affected by dexamethasone bioavailability, and therefore, we have developed and validated a dexamethasone threshold after 1-mg DST.
Materials and methods
We studied 200 subjects: 125 patients were considered retrospectively and 75 were enrolled prospectively as the validation cohort. Serum dexamethasone, Late Night Salivary Cortisol (LNSC), and Urinary Free Cortisol (UFC) were measured with LC–MS/MS. Normal LNSC and UFC levels were used to exclude CS. The lower 2.5th percentile of dexamethasone distribution in non-CS patients with cortisol ≤ 50 nmol/L after 1-mg DST was used as threshold.
Results
16 patients were CS and 184 non-CS (108 adrenal incidentaloma and 76 excluded CS); 4.5 nmol/L resulted the calculated threshold. Cortisol after 1-mg DST confirmed high sensitivity (100% at 50 nmol/L cut-off) and moderate–low specificity (63%, increased to 91% at 138 nmol/L) to diagnose CS in the whole cohort of patients. We could reduce the number of false-positive results (from 10 to 6 and from 7 to 4 in AI and excluded CS) considering adequate dexamethasone levels. Dexamethasone levels were not affected by hypercortisolism, age, gender, smoke, weight, and creatinine. 6% of non-CS patients did not achieve adequate dexamethasone levels (40% of tests with serum cortisol > 138 nmol/L after 1-mg DST).
Conclusions
We developed and validated the routine dexamethasone measurement during 1-mg DST: it is independent from patient’s clinical presentation, and it should be used to increase the specificity of serum cortisol levels.
The results are presented of a detailed combined experimental and theoretical investigation of the influence of coadsorbed electron-donating alkali atoms and the prototypical electron acceptor ...molecule 7,7,8,8-tetracyanoquinodimethane (TCNQ) on the Ag(100) surface. Several coadsorption phases were characterized by scanning tunneling microscopy, low-energy electron diffraction, and soft X-ray photoelectron spectroscopy. Quantitative structural data were obtained using normal-incidence X-ray standing wave (NIXSW) measurements and compared with the results of density functional theory (DFT) calculations using several different methods of dispersion correction. Generally, good agreement between theory and experiment was achieved for the quantitative structures, albeit with the prediction of the alkali atom heights being challenging for some methods. The adsorption structures depend sensitively on the interplay of molecule–metal charge transfer and long-range dispersion forces, which are controlled by the composition ratio between alkali atoms and TCNQ. The large difference in atomic size between K and Cs has negligible effects on stability, whereas increasing the ratio of K/TCNQ from 1:4 to 1:1 leads to a weakening of molecule–metal interaction strength in favor of stronger ionic bonds within the two-dimensional alkali–organic network. A strong dependence of the work function on the alkali donor–TCNQ acceptor coadsorption ratio is predicted.
Wood is a hygroscopic, multi-scale and anisotropic natural material composed of pores with different size and differently oriented. In particular, archaeologically excavated wood generally is ...waterlogged wood with very high moisture content (400%–800%) that need to have a rapid investigation at the microstructural level to obtain the best treatment with preservative agents. Time-dependent diffusion coefficient D(t) quantified by Pulse Field Gradient (PFG) Nuclear Magnetic Resonance (NMR) techniques provides useful information about complex porous media, such as the tortuosity (τ) describing pore connectivity and fluid transport through media, the average-pore size, the anisotropic degree (an). However, diffusion NMR is intrinsically limited since it is an indirect measure of medium microstructure and relies on inferences from models and estimation of relevant diffusion parameters. Therefore, it is necessary to validate the information obtained from NMR diffusion parameters through complementary investigations. In this work, the structures of five waterlogged wood species were studied by PFG of absorbed water. D(t) and τ of water diffusing along and perpendicular to vessels/tracheids main axes together with relaxation times and an were quantified. From these parameters, the pore sizes distribution and the wood microstructure characterization were obtained. Results among wood species were compared, validated and integrated by micro-imaging NMR (μ-MRI), environmental-scanning electron-microscope (ESEM) images, wood dry density and imbibition times measurement of all woods. The work suggests that an vs τ rather than the estimated pore size diversifies and characterize the different wood species. As a consequence diffusion-anisotropy vs tortuosity could be an alternative method to characterize and differentiate wood species of waterlogged wood when high resolution images (μ-MRI and ESEM) are not available. Moreover, the combined use of D(t) and micro-MRI expands the scale of dimensions observable by NMR covering all the interesting length scales of wood.
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The results of a quantitative experimental structural investigation of the adsorption phases formed by 2,3,5,6-tetrafluoro-7,7′,8,8′-tetracyanoquinodimethane (F4TCNQ) on Cu(111) are reported. A ...particular objective was to establish whether Cu adatoms are incorporated into the molecular overlayer. A combination of normal incidence X-ray standing waves, low-energy electron diffraction, scanning tunneling microscopy, and X-ray photoelectron spectroscopy measurements, complemented by dispersion-inclusive density functional theory calculations, demonstrates that F4TCNQ on Cu(111) does cause Cu adatoms to be incorporated into the overlayer to form a two-dimensional metal–organic framework (2D-MOF). This conclusion is shown to be consistent with the behavior of F4TCNQ adsorption on other coinage metal surfaces, despite an earlier report concluding that the adsorption structure on Cu(111) is consistent with the absence of any substrate reconstruction.
The K free light chains index (K-FLC index) has been proposed as an alternative test for intrathecal immunoglobulin synthesis in MS diagnosis. Aim of the study was to assess the accuracy of the K-FLC ...index in differentiating MS from other immune-mediated CNS disorders and NMOSD.
Data were available from a cohort of 371 patients. K-FLC index was significantly higher in MS: MS mean K-FLC index 90.897 ± 134.198; NMOSD 17.992 ± 15.103; other immune-mediated CNS disorders 12.568 ± 24.440. The overall diagnostic accuracy of the K-FLC index was similar to intrathecal oligoclonal bands detection. However, as a quantitative variable, K-FLC index allowed easier discrimination of MS from other immune-mediated CNS disorders: highest K-FLC index values (> 100) were observed almost only in MS and are therefore strongly predictive of MS, in patients with the appropriate clinical presentation.
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•K-FLC index can diagnose MS with sensibility and specificity comparable to CSF OBs•K-FLC index is higher in MS compared to NMOSD or other immune-mediated CNS disorders.•While some overlap exists, highest K-FLC index values are characteristic only of MS•K-FLC index provides added diagnostic value in OBs negative MS patients
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