Xylem plasticity in Pinus pinaster and Quercus ilex growing at sites with different water availability in the Mediterranean region: relations between Intra-Annual Density Fluctuations and environmental conditions.

Fluctuations in climatic conditions during the growing season are recorded in Mediterranean tree-rings and often result in intra-annual density fluctuations (IADFs). Dendroecology and quantitative wood anatomy analyses were used to characterize the relations between the variability of IADF traits and climatic drivers in Pinus pinaster Aiton and Quercus ilex L. growing at sites with different water availability on the Elba island in Central Italy. Our results showed that both species present high xylem plasticity resulting in the formation of L-type IADFs (L-IADFs), consisting of earlywood-like cells in latewood. The occurrence of such IADFs was linked to rain events following periods of summer drought. The formation of L-IADFs in both species increased the hydraulic conductivity late in the growing season, due to their larger lumen area in comparison to "true latewood". The two species expressed greater similarity under arid conditions, as unfavorable climates constrained trait variation. Wood density, measured as the percentage of cell walls over total xylem area, IADF frequency, as well as conduit lumen area and vessel frequency, specifically in the hardwood species, proved to be efficient proxies to encode climate signals recorded in the xylem. The response of these anatomical traits to climatic variations was found to be species- and site-specific

Thiourea Derivative of 2-[(1 R)-1-Aminoethyl]phenol: A Flexible Pocket-like Chiral Solvating Agent (CSA) for the Enantiodifferentiation of Amino Acid Derivatives by NMR Spectroscopy

Thiourea derivatives of 2-[(1R)-1-aminoethyl]phenol, (1S,2R)-1-amino-2,3-dihydro-1H-inden-2-ol, (1R,2R)-(1S,2R)-1-amino-2,3-dihydro-1H-inden-2-ol, and (R)-1-phenylethanamine have been compared as chiral solvating agents (CSAs) for the enantiodiscrimination of derivatized amino acids using nuclear magnetic resonance (NMR) spectroscopy. Thiourea derivative, prepared by reacting 2-[(1R)-1-aminoethyl]phenol with benzoyl isothiocyanate, constitutes an effective CSA for the enantiodiscrimination of N-3,5-dinitrobenzoyl (DNB) derivatives of amino acids with free or derivatized carboxyl functions. A base additive 1,4-diazabicyclo[2.2.2]octane(DABCO)/N,N-dimethylpyridin-4-amine (DMAP)/NBu4OH) is required both to solubilize amino acid derivatives with free carboxyl groups in CDCl3 and to mediate their interaction with the chiral auxiliary to attain efficient differentiation of the NMR signals of enantiomeric substrates. For ternary systems CSA/substrate/DABCO, the chiral discrimination mechanism has been ascertained through the NMR determination of complexation stoichiometry, association constants, and stereochemical features of the diastereomeric solvates

OSAS severity is associated to decreased heart rate turbulence slope

Obstructive sleep apnea syndrome (OSAS) has been associated to impaired baroreflex sensitivity (BRS) which has recently been shown to be non-invasively assessed by heart rate turbulence (HRT) analysis. Although HRT seems to be better suited than traditional heart rate variability indexes for autonomic assessment in presence of respiratory and arrhythmic disorders, very few papers addressed its evaluation in OSAS. Aim of the study is to find out whether and to which extend HRT is associated to OSAS severity. We studied HRT in polysomnographic recordings of 221 mild to severe OSAS pts. Results showed that, while HRT onset values did not significantly differ between mild (-0,78±1,50), moderate (-0,89±1,78) and severe (-0,70±1,28) pts., HRT slope significantly decreases (Kruskal-Wallis P value <0.05) from mild (3,27±2,7) to moderate (2,6±2,6) and severe (1,98±2,5) pts., with a significant Dunn's multiple comparisons post test only between mild vs. severe OSAS pts. Data indicate that the main BRS alterations do not appear in the early HRT phase triggered by transient vagal inhibition, but during the slow one, due to the sympathetic hyperactivity affecting the heart rate recovery. These findings support the conclusion that HRT assessment could have a prognostic value related to the development of cardiovascular disease in OSAS

Renewable Resources for Enantiodiscrimination: Chiral Solvating Agents for NMR Spectroscopy from Isomannide and Isosorbide

A new family of chiral selectors was synthesized in a single synthetic step with yields up to 84% starting from isomannide and isosorbide. Mono- or disubstituted carbamate derivatives were obtained by reacting the isohexides with electron-donating arylisocyanate (3,5-dimethylphenyl- or 3,5-dimethoxyphenyl-) and electron-withdrawing arylisocyanate (3,5-bis(trifluoromethyl)phenyl-) groups to test opposite electronic effects on enantiodifferentiation. Deeper chiral pockets and derivatives with more acidic protons were obtained by derivatization with 1-naphthylisocyanate and p-toluenesulfonylisocyanate, respectively. All compounds were tested as chiral solvating agents (CSAs) in H-1 NMR experiments with rac-N-3,5-dinitrobenzoylphenylglycine methyl ester in order to determine the influence of different structural features on the enantiodiscrimination capabilities. Some selected compounds were tested with other racemic analytes, still leading to enantiodiscrimination. The enantiodiscrimination conditions were then optimized for the best CSA/analyte couple. Finally, a 2D- and 1D-NMR study was performed employing the best performing CSA with the two enantiomers of the selected analyte, aiming to determine the enantiodiscrimination mechanism, the stoichiometry of interaction, and the complexation constant

2-Methyl-β-cyclodextrin grafted ammonium chitosan: synergistic effects of cyclodextrin host and polymer backbone in the interaction with amphiphilic prednisolone phosphate salt as revealed by NMR spectroscopy

Reduced molecular weight chitosan was quaternized with 2-chloro-N,N-diethylethylamine to obtain a water soluble derivative (N+-rCh). Methylated-β-cyclodextrin (MCD), with 0.5 molar substitution, was covalently linked to N+-rCh through 1,6-hexamethylene diisocyanate spacer to give the derivatized ammonium chitosan N+-rCh-MCD. To shed light on the role of the cyclodextrin pendant in guiding binding interactions with amphiphilic active ingredients, corticosteroid prednisolone phosphate salt (PN) was considered. The deep inclusion of PN into cyclodextrin in PN/MCD model system was pointed out by analysis of 1H NMR complexation shifts, 1D ROESY spectra, and diffusion measurements (DOSY). By using proton selective relaxation rates measurements as investigation tool, the superior affinity of N+-rCh-MCD towards PN was demonstrated in comparison with parent ammonium chitosan N+-rCh

Induced sputum cellularity. Reference values and distribution in normal volunteers.

Abstract Sputum induction has recently been proposed as the only direct noninvasive method for measuring airway inflammatory indices. The reference values and the distribution of cells in induced sputum in a control population have not yet been well defined. We therefore evaluated data from a large number of healthy volunteers. One hundred fourteen healthy, nonatopic, nonsmoking volunteers without airway hyperreactivity were enrolled (age: 38 +/- 13 yr [mean +/- SD]; FEV(1): 105 +/- 10% predicted; provocative dose of methacholine inducing a 20% decrease FEV(1) > 3,200 microgram). Ninety-six subjects (84%) produced adequate analysis samples. The subjects had a normal age distribution. Their induced sputum was rich in macrophages (69.2 +/- 13%) and neutrophils (27.3 +/- 13%), and poor in eosinophils (0.6 +/- 0.8%), lymphocytes (1.0 +/- 1.2%), and epithelial cells (1.5 +/- 1.8%). Only macrophages and neutrophils showed a normal distribution; total and differential counts of other cells did not. We propose that these data be used in comparison of the induced sputum cells of normal subjects and those of patients with airway inflammation

Severe Respiratory and Skeletal Muscles Involvement in a Carrier of Dysferlinopathy With Chronic Obstructive Pulmonary Disease

The natural course of progressive neuromuscular diseases can be complicated by respiratory muscle involvement. In muscular dystrophies such as Duchenne muscular dystrophy and myotonic dystrophy, respiratory muscle involvement is common. In others such as Becker, limb-girdle, and facioscapulo-humeral dystrophies, respiratory muscle involvement is infrequent and generally occurs in the more severe cases. Recently, it was reported that a mutation in the dysferlin gene and/or dysferlin deficiency causes proximal and distal forms of muscular dystrophy, which are known by the term dysferlinopathy. We describe a case of severe weakness of both limb-girdle and respiratory muscles in a patient who was carrier of the dysferlin gene mutation and who also had COPD. We suggest that the systemic inflammatory response of COPD and the dysferlin deficit interact and are responsible for both the skeletal and respiratory muscle impairment

Methylammonium-formamidinium reactivity in aged organometal halide perovskite inks

Over the past 10 years, organometal halide perovskites have revolutionized the field of optoelectronics, particularly of emerging photovoltaic technologies. Today's best perovskite solar cells use triple-cation compositions containing a mixture of formamidinium, methylammonium, and cesium to enable more reproducible and stable device performance. The common procedure uses as-prepared precursor ink to avoid an undesirable decrease in device performance, attributed recently to a chemical reaction between methylammonium and formamidinium in solution. Here we employ nuclear magnetic resonance spectroscopy to explore different experimental conditions that can significantly modify these reaction kinetics; in particular, we find that the presence of cesium as the third cation can substantially slow down methylammonium-formamidinium reactivity. Our findings allow us to draw up a protocol for extended overtime perovskite ink stabilization

Thiolated 2-Methyl-β-Cyclodextrin as a Mucoadhesive Excipient for Poorly Soluble Drugs: Synthesis and Characterization

Thiolated cyclodextrins are structurally simple mucoadhesive macromolecules, which are able to host drugs and increase their apparent water solubility, as well as interact with the mucus layer prolonging drug residence time on the site of absorption. The aim of this study was to synthesize through green microwave-assisted process a freely soluble thiolated 2-methyl-β-cyclodextrin (MβCD-SH). Its inclusion complex properties with dexamethasone (Dex), a poor water soluble drug, and mucoadhesive characteristics were also determined. The product was deeply characterized through NMR spectroscopy (2D COSY, 2D HSQC, 1D/2D TOCSY, and 1D ROESY), showing a thiolation degree of 67%, a selective thiolation on the C6 residues and a monomeric structure. The association constant of MβCD and MβCD-SH with Dex resulted in 2514.3 ± 32.3 M−1 and 2147.0 ± 69.3 M−1, respectively, indicating that both CDs were able to host the drug. Microrheological analysis of mucin in the presence of MBCD-SH showed an increase of complex viscosity, G′ and G′′, due to disulphide bond formation. The cytotoxicity screening on fibroblast BALB/3T3 clone A31 cells indicated an IC50 of 27.7 mg/mL and 30.0 mg/mL, for MβCD and MβCD-SH, respectively. Finally, MβCD-SH was able to self-assemble in water into nanometric structures, both in the presence and absence of the complexed drug

Carba-D,L-allal- and -D,L-galactal-derived vinyl N-nosyl aziridines as useful tools for the synthesis of 4-deoxy-4-(N-nosylamino)-2,3-unsaturated-5a-carbasugars

The novel carba-D,L-allal- and carba-D,L-galactal-derived vinyl N-nosyl aziridines were prepared and the regio- and stereoselective behavior in opening reactions with O- and N-nucleophiles examined. The carbaglycosylating ability of the novel aziridines, as deduced by the amount of 1,4-addition products (1,4-regioselectivity) obtained in the acid-catalyzed methanolysis taken as a model reaction, is similar or superior to that observed with the corresponding carba-D,L-allal- and -D,L-galactal-derived vinyl epoxides, respectively. In all 1,2- and 1,4-addition products obtained, a –(N-nosylamino) group is regio- and stereoselectively introduced at the C(4) carbon of a 1,2- or 2,3-unsaturated carbasugar, susceptible to further elaborations toward aminocyclitol derivatives. The stereoselective synthesis of the corresponding, enantiomerically pure carba-D,L-allal- and -D,L-galactal-derived vinyl N-acetyl aziridines is also described