Incoherent convergence of diffraction free fields

We describe a method for the synthesis of diffraction free fields by means of an ensemble of optical fields mutually incoherent. The constituent optical fields are generated by controlling the angular correlation function between two points distributed on a circle in the frequency space. The angular position and the separation between the points are considered as random variables. The implicit probability density function allows us to generate diffraction free beams with easily tunable profiles. Inverse problems are also analyzed, which consists in finding the joint probability density function for a known irradiance distribution. Experimental and computational results are shown.     

Synthesis,characterization and biological properties of vanadyl(IV) complexes of diclofenac and indomethacin: an experimental and theoretical study

Two new vanadyl(IV) complexes with the non‐steroidal antiinflammatory drugs Indomethacin and Diclofenac were synthesized and characterized by elemental analysis, electronic, diffuse reflectance and FTIR spectroscopies and thermal behavior. The structures of the oxo‐vanadium(IV) complexes were obtained by carrying out ab initio calculations (B3LY/3–21G**) owing to the difficulties of obtaining single crystals of good quality for X‐ray studies. Indomethacin and Diclofenac did not cause any effect when tested on cellular proliferation in two osteoblast‐cell lines in culture (MC3T3E1 and UMR106). The biological effect of the complexes depends on the cellular type and on the nature of the coordinated ligands. Copyright © 2005 John Wiley & Sons, Ltd.     

Determining the absolute configuration of secondary alcohols by means of a chiral auxiliary and NOESY

The absolute configuration of secondary alcohols can be determined by NOE between the diastereotopic protons of the lactam and the protons of the alcohol moieties in some 1-(alkoxymethyl)-methyl-2-pyrrolidone-5-carboxylate derivatives. Two simple methods based on conformational analysis and ¹H NMR data have been developed. The main conformer, in all cases, was established by means of MM, semi-empirical, and ab initio calculations.     

The Effectiveness of a Voice Treatment Approach for Teachers With Self-Reported Voice Problems

SUMMARY: Teachers are considered the professional group most at risk of developing voice-problems, but limited treatment effectiveness evidence exists. We studied prospectively the effectiveness of a 6-week combined treatment approach using vocal function exercises (VFEs) and vocal hygiene (VH) education with 20 teachers with self-reported voice problems. Twenty subjects were randomly assigned to a no-treatment control (n = 11) and a treatment group (n = 9). Fibreoptic endoscopic evaluation was carried out on all subjects before randomization. Two self-report voice outcome measures were used: the Voice-Related Quality of Life (VRQOL) and the Voice Symptom Severity Scale (VoiSS). A Voice Care Knowledge Visual Analogue Scale (VAS), developed specifically for the study, was also used to evaluate change in selected voice knowledge areas. A Student unpaired t test revealed a statistically significant (P < 0.05) improvement in the treatment group as measured by the VoiSS. There was not a significant improvement in the treatment group as measured by the V-RQOL. The difference in voice care knowledge areas was also significant for the treatment group (P < 0.05). This study suggests that a voice treatment approach of VFEs and VH education improved self-reported voice symptoms and voice care knowledge in a group of teachers.     

Second Dissociation Constant of Two Substituted Aminomethanesulfonic Acids in Water from 5 to 55°C

The equilibrium constants for the dissociation steps of (4-morpholineethanesulfonic acid) (MES) and (2-{[tris(hydroxymethyl)methyl]-1-ethanesulfonic acid (TES) have been determined at 12 and 7 different temperatures, respectively, from 5 to 55°C. The emf measurements were carried out by using a cell without liquid junction of the type:Pt; H₂ (g, 1 atm) | buffer(m₁), Na salt of buffer(m₂), NaCl(m₃) | AgCl, Ag.The pK ₂ values of MES and TES at 25°C are 6.269 and 7.550. The thermodynamic quantities for the dissociation process have been calculated. These zwitterionic compounds are useful for pH control as standard buffers in the physiological region of pH 5.50 to 6.50 for MES, 6.5 to 7.5 for TES, respectively. Reliable measurements of the pH at isotonic saline solution (I = 0.16m) such as blood and plasma are important for clinical diagnosis.     

Singlet oxygen reactions of 3-methoxy-2-pyrrole carboxylic acid tert-butyl esters. A route to 5-substituted pyrrole precursors of prodigiosin and analogs

Reaction of the tert-butyl ester of 3-methoxy-2-pyrrole carboxylic acid with singlet oxygen yields a peroxidic intermediate which undergoes coupling with a range of nucleophiles to yield 5-substituted pyrroles. Among these products are α,α′-bipyrroles which serve as precursors of prodigiosin, including A-ring substituted analogues.     

Nitrogen configuration determined by X-ray analysis on an homogeneous series of 3-Indolinones

The X-ray diffraction analyses of 2-methyl-2-phenylindolin-3-one 1 , 1,2-dimethyl-2-phenylindolin-3-one 2 , 1-hydroxy-2-methyl-2-phenylindolin-3-one 3 and 1-methoxy-2-methyl-2-phenylindolin-3-one 4 have been carried out and the structural data were compared with those of 1-oxyl-2-methyl-2-phenylindolin-3-one 5 . The results demonstrate that only compounds 2 and 5 show planar trigonal geometry which is coplanar with the conjugated benzene ring of the indolinic nucleus, whereas compounds 3 and 4 show a marked pyramidality of the nitrogen. Even if compound 1 shows a certain pyramidality of the nitrogen, it has been considered similar to compound 2 . The reactivity of all studied compounds fit the structural data.     

Plants and Natural Products with Activity against Various Types of Coronaviruses: A Review with Focus on SARS-CoV-2

COVID-19 is a pandemic disease caused by the SARS-CoV-2 virus, which is potentially fatal for vulnerable individuals. Disease management represents a challenge for many countries, given the shortage of medicines and hospital resources. The objective of this work was to review the medicinal plants, foods and natural products showing scientific evidence for host protection against various types of coronaviruses, with a focus on SARS-CoV-2. Natural products that mitigate the symptoms caused by various coronaviruses are also presented. Particular attention was placed on natural products that stabilize the Renin–Angiotensin–Aldosterone System (RAAS), which has been associated with the entry of the SARS-CoV-2 into human cells.