How log-normal is your country? An analysis of the statistical distribution of the exported volumes of products

We have considered the statistical distributions of the volumes of 1131 products exported by 148 countries. We have found that the form of these distributions is not unique but heavily depends on the level of development of the nation, as expressed by macroeconomic indicators like GDP, GDP per capita, total export and a recently introduced measure for countries’ economic complexity called fitness. We have identified three major classes: a) an incomplete log-normal shape, truncated on the left side, for the less developed countries, b) a complete log-normal, with a wider range of volumes, for nations characterized by intermediate economy, and c) a strongly asymmetric shape for countries with a high degree of development. Finally, the log-normality hypothesis has been checked for the distributions of all the 148 countries through different tests, Kolmogorov-Smirnov and Cramér-Von Mises, confirming that it cannot be rejected only for the countries of intermediate economy.     

Enantioselective Routes to Sulfoxides Based upon Carbon-for-Carbon Substitution Reactions on the Sulfinyl Group

Abstract

Grignard reagents were found to displace carbanionic leaving groups from suitable sulfinyl compounds. Because the process occurred with full inversion at the sulfinyl group, it was possible to set up an easy and straightforward route to chiral nonracemic sulfoxides. The starting compounds were easily produced, mainly by enantioselective oxidation of prochiral sulfides, and then the carbon-for-carbon displacement was effected with formation of a variety of new enantiopure sulfoxides.     

Abscisic acid identification in Okra,Abelmoschus esculentus L. (Moench): perspective nutraceutical use for the treatment of diabetes

Abstract

Okra, Abelmoschus esculentus L. (Moench), also known as Lady's Fingers, gombo, or bamje, is an annual plant belonging to the Malvaceae family. Traditional olistic medicine since centuries directly associates this plant and its parts to a beneficial health hypoglycemic effect. Since the abscisic acid (ABA) has been associated to an interesting hypoglycemic effect, this triggered us to verify and quantify the presence of the abscisic acid in the okra phytocomplex. In particular, ABA, a plant derived hormone, has been proven by recent studies to be effective on mammals. To determine and quantify the ABA content, different parts of the Okra plant extracts have been evaluated, and HPLC-DAD analysis has been used allowing us to report for the first time the presence of this isoprenoid compound. Bioaccessibility has been also investigated using a simulated gastro intestinal (GI) digestion protocol with the aim of explore the possibility of okra extract as nutraceutical.     

Carexanes: prenyl stilbenoid derivatives from Carex distachya

Metabolites with a new molecular skeleton, named carexane, have been isolated from the leaves of Carex distachya. The structures have been determined on the basis of the spectroscopic characteristics of the compounds. Bidimensional NMR has furnished important data useful for the characterization and the stereochemistry of the molecules. The compounds have a tetracyclic skeleton derived from the coupling of the prenyl moiety on a stilbenoid structure.     

Furofuranic glycosylated lignans: a gas-phase ion chemistry investigation by tandem mass spectrometry

Alkali metal cation adducts, [M+Alk](+), and [M-H](-) ions of four known glycosylated furofuran lignans, (+)-pinoresinol 4-O-beta-D-glucopyranoside, (+)-phylliroside, (+)-8-hydroxypinoresinol 4-O-beta-D-glucopyranoside, and (+)-8-hydroxypinoresinol 8-O-beta-D-glucopyranoside, recently isolated from Carex distachya, were generated by electrospray ionization and allowed to undergo collisionally activated dissociation (CAD) in a quadrupole ion trap (QIT) and in a triple quadrupole (TQ) mass spectrometer. CAD mass spectra of [M+Na](+) and [M+Li](+) adducts revealed the presence of structurally diagnostic product ions. CAD mass spectra of deprotonated glycosylated furofuran lignans showed the typical neutral loss of 162 Da when the glucose residue was bound to a phenolic oxygen atom. When glycosylation occurred at an alcoholic oxygen, as for (+)-8-hydroxypinoresinol 8-O-beta-D-glucopyranoside, a neutral loss of 180 Da represented the main fragmentation pathway. Selective hydrogen/deuterium (H/D) exchange of all the acidic hydrogen atoms of furofuran glycosides, performed by introducing lignan glycosides in D(2)O/CH(3)OD solutions, were employed to obtain information on the nature of the product ions generated during TQ/CAD processes. Energy-resolved TQ/CAD mass spectra of deprotonated lignan glycosides and their deprotonated aglycones were used in a qualitative way to infer information on the integrated energetic picture of CAD fragmentations and to investigate the mechanism of the predominant dissociation/isomerization processes. On the basis of the hypothesized fragmentation mechanisms, gas-phase features of the furofuran ring were derived. The presence of an OH substituent in the C8 position decreased the electron density in the adjacent C8' position, modifying the fragmentation pathway.     

Determination of preferential interaction parameters by multicomponent diffusion. applications to poly(ethylene glycol)-salt-water ternary mixtures

Poly(ethylene glycol) (PEG) is a hydrophilic nonionic polymer used in many biochemical and pharmaceutical applications. We report the four diffusion coefficients for the PEG-KCl-water ternary system at 25 degrees C using precision Rayleigh interferometry. Here, the molecular weight of PEG is 20 kg mol(-1), which is comparable to that of proteins. The four diffusion coefficients are examined and used to determine thermodynamic preferential interaction coefficients. We find that the PEG preferential hydration in the presence of KCl is 1 order of magnitude larger than that previously obtained under the same conditions for lysozyme, a protein of similar molecular weight. In correspondence, the coupled diffusion in the PEG case was greater than that observed in the lysozyme case. We attribute this difference to the greater exposure of polymer coils to the surrounding fluid compared to that of globular compact proteins. Moreover, we observe that the PEG preferential hydration significantly decreases as salt concentration increases and attribute this behavior to the polymer collapse. Finally, we have also employed the equilibrium isopiestic method to validate the accuracy of the preferential interaction coefficients extracted from the diffusion coefficients. This experimental comparison represents an important contribution to the relation between diffusion and equilibrium thermodynamics.     

Urinary peptides as a diagnostic tool for renal failure detected by matrix-assisted laser desorption/ionisation mass spectrometry: an evaluation of their clinical significance

The development of new analytical methodologies related to the proteome for the evaluation of renal physiology and pathology is surely of wide interest for physicians, giving them new tools for monitoring complications associated with diabetes, such as end-stage renal disease. In the present study, the clinical significance of the urinary abundance of two peptides, SGSVIDQSRVLNLGPITR (the uromodulin precursor, m/z 1912) and IGPHypGPHypGLMGPP [present in the collagen-α-5(IV) chain precursor, m/z 1219], detected by matrix- assisted laser desorption/ionisation mass spectrometry (MALDI/MS) in microalbuminuric or nephropathic diabetic patients and in non-diabetic nephropathic patients was evaluated. A progressive increase in the abundance of the ion at m/z 1219 and a decrease in the abundance of the ion at m/z 1912 have been found in diabetic microalbuminuric, diabetic-nephropathic and nephropathic patients. Linear correlations are present between serum creatinine values and the abundances of the ions at m/z 1219 (positive correlation, r=0.3645, P<0.0001) and at m/z 1912 (negative correlation, r=-0.3053, P<0.0005). Correlations between the MALDI data and the estimated glomerular filtration rate were also found, while relationships with urinary albumin excretion were found only in sub-sets of patients. Analysis of receiver operating characteristic curves showed a sensitivity up to 96% and a specificity of up to 84% for the two ionic species, or their ratio, for distinguishing diabetic patients with different degrees of nephropathy from healthy subjects, proving that the urinary abundance of the two peptides at m/z 1219 and m/z 1912, determined with MALDI/MS, may be considered as a possible diagnostic tool for the determination of progression toward renal failure, also with the aim of monitoring kidney function, in diabetic patients.     

Is the placental proteome impaired in well‐controlled gestational diabetes?

In pregnancy complicated by gestational diabetes mellitus (GDM), the human placenta shows several pathological functional and structural changes, but the extent to which maternal glycemic control contributes to placental abnormalities remains unclear. The aim of this study was to profile and compare the proteome of placentas from healthy pregnant women and those with GDM, to investigate the placenta‐specific protein composition and possible changes of its function in presence of GDM. Quantitative proteomic analysis, based on LC‐MS^E approach, revealed that higher (approximately 15% increase) levels of galectin 1 and collagen alpha‐1 XIV chain (although the difference regarding the latter was at the limit of significance) were present in GDM samples, while heat shock 70 kDa protein 1A/1B was less abundant in GDM placental tissue. These data seem to indicate that GDM, when well controlled, did not markedly affect the placental proteome.