Secretome of the preimplantation human embryo by bottom-up label-free proteomics

A bottom-up label-free mass spectrometric proteomic strategy was used to analyse the protein profiles of the human embryonic secretome. Culture media samples used for embryonic culture of patients undergoing intracytoplasmic sperm injection cycles were selected as a test case for this exploratory proof-of-principle study. The media were stored after embryo transfer and then pooled into positive (n = 8) and negative (n = 8) implantation groups. The absolute quantitative bottom-up technique employed a multidimensional protein identification technology based on separation by nano-ultra-high pressure chromatography and identification via tandem nano-electrospray ionization mass spectrometry with data-independent scanning in a hydrid QqTOF mass spectrometer. By applying quantitative bottom-up proteomics, unique proteins were found exclusively in both the positive- and negative-implantation groups, which suggest that competent embryos express and secrete unique biomarker proteins into the surrounding culture medium. The selective monitoring of these possible secretome biomarkers could make viable procedures using single-embryo transfer.     

Phase equilibrium data and thermodynamic modelling of the system (propane + DMF + methanol) at high pressures

Reported in this work are phase equilibrium data at high pressures for the binary and ternary systems formed by {propane + N,N-dimethylformamide (DMF) + methanol}. Phase equilibrium measurements were performed in a high-pressure, variable-volume view cell, following the static synthetic method for obtaining the experimental bubble and dew points transition data over the temperature range of (363 to 393) K, pressures up to 11.5 MPa and overall mole fraction of the lighter component varying from 0.1 to 0.995. For the systems investigated, vapour–liquid (VLE), liquid–liquid (LLE) and vapour–liquid–liquid (VLLE) phase transitions were visually recorded. Results show that the systems investigated present UCST (upper critical solution temperature) phase transition curves with an UCEP (upper critical end point) at a temperature higher than the propane critical temperature. The experimental data were modelled using the Peng–Robinson equation of state with the Wong–Sandler and the classical quadratic mixing rules, affording a satisfactory representation of the experimental data.     

Cryptococcus gattii: in vitro susceptibility to photodynamic inactivation

Cryptococus gattii is an emergent primary human pathogen that causes meningismus, papilledema, high intracranial pressure and focal involvement of the central nervous system in immunocompetent hosts. Prolonged antifungal therapy is the conventional treatment, but it is highly toxic, selects for resistant strains, contributes to therapy failure and has a poor prognosis. Photodynamic inactivation (PDI) offers a promising possibility for the alternative treatment of cryptococcosis. The aim of this study was to test the effectiveness of toluidine blue O (TBO) and light-emitting diode (LED) against C. gattii strains with distinct susceptibility profile to antifungal drugs (amphotericin B: 0.015-1.0 μg mL(-1); itraconazole: 0.015-2 μg mL(-1); fluconazole: 4-64 μg mL(-1)). Using 25 μM (6.76 μg mL(-1)) TBO and LED energy density of 54 J cm(-2) these fungal isolates presented variable susceptibility to PDI. The production of reactive oxygen species (ROS)/peroxynitrite was determined, and the catalase and peroxidase activities were measured. After PDI, high amounts of ROS/peroxynitrite are produced and higher catalase and peroxidase activities could be correlated with a lower susceptibility of C. gattii isolates to PDI. These results indicate that PDI could be an alternative to C. gattii growth inhibition, even of isolates less susceptible to classical antifungal drugs, also pointing to mechanisms related to their variable susceptibility behavior.     

A new indirect method based on square-wave voltammetry for ceftiofur determination in bovine milk using an alkaline degradation product

In this paper we present a new electroanalytical method for determination of ceftiofur based on the hydrolysis of this antibiotic in 0.04 mol L⁻¹ Britton–Robinson buffer at pH 10 and 60 °C for 60 min (reduction peak at − 0.70 V). Conditions were optimized for complete hydrolysis and quantitative determination of ceftiofur in milk. The method can be successfully used for determination of the antibiotic directly from samples of fluid milk and powder milk spiked to concentrations of 6.0 × 10⁻⁸, 8.0 × 10⁻⁸, and 10 × 10⁻⁸ mol L⁻¹, respectively. Recovery test ranged from 98.28% to 100.83%. The limits of detection and quantification were 3.73 × 10⁻¹⁰ and 1.24 × 10⁻⁹ mol L⁻¹, respectively. The method has the advantage of eliminating interference from proteins present in the sample, thus obviating the need for exhaustive extraction, which often renders other procedures unfeasible in terms of time and reagent cost. In addition, waste generation was found to be lower than in other methods.     

Effects of supplemental UV-A on the development, anatomy and metabolite production of Phyllanthus tenellus cultured in vitro

Phyllanthus tenellus is widely used for its antiviral, analgesic and hepatoprotective properties. Although the production of several chemical classes of secondary metabolites is influenced by UV radiation, particularly phenolic compounds, we also know that UV radiation can result in anatomical and developmental damage. However, the morphological, anatomical and phytochemical changes in response to UV-A exposure are generally understudied in the Phyllanthaceae. Therefore, we evaluated the effects of UV-A radiation on plant development and leaf anatomy, as well as the production of secondary metabolites and the contents of carotenoids and chlorophylls a and b, in P. tenellus. To accomplish this, in vitro cultures of P. tenellus were maintained for 60 days under white light (WL) and WL plus UV-A radiation. Results showed different phenotypic responses under additional UV-A, such as high phenolic metabolite production, increasing dimensions of abaxial epidermis and thickness of palisade parenchyma. Compared to plants cultured under WL, UV-A radiation caused damage to plant morphogenesis, including a reduced number of branches and shoots, consequently reducing the rate of proliferation. On the other hand, geraniin, ellagic acid and carotenoid contents increased after UV-A exposure, indicating that this light source is an important resource for inducing phenolic compounds.     

Tandem catalysis for the synthesis of 2-alkylidene cyclohexenones

(5R,6S,E)-5-Alkyl-2-(2-(methoxymethoxy)ethylidene)-6-(phenylsulfonyl)cyclohex-3-enones, have been obtained by a domino reaction using tandem catalysis with a Nazarov reagent 3, and several unsaturated aldehydes.     

A straightforward synthesis of 2-aminobenzothiazoles from Herz compounds

2-Aminobenzothiazoles are readily synthesised from anilines, sulfur monochloride and isocyanides. The key step consists of an iodine-catalysed insertion of isocyanides into the S-S bond of hydrolysed Herz salts, with concomitant extrusion of sulfur monoxide.     

Reduction of CO2 and SO2 with low valent nickel compounds under mild conditions

The reaction of [(dippe)Ni(μ-H)](2) (A) (dippe = 1,2-bis(diisopropyl-phosphinoethane) with CO(2) in toluene afforded the carbonyl nickel(0) compounds of the type {(dippe)Ni(CO)](2)(μ-dippe)}(1) and (dippe)Ni(CO)(dippe==O)] (2), which were characterized by standard spectroscopic methods; complex (1) was also characterized by single crystal X-ray diffraction. Reaction of (A) with SO(2) yields the thiosulfate nickel(II) compound [Ni(dippe)(S(2)O(3))] (5), which was fully characterized by standard spectroscopic methods and X-ray crystallography. In both cases, a reduction reaction of CO(2) to CO and SO(2) to S(2)O(3)(2-) with (A) took place under mild conditions.     

Selective and sensitive chromo-fluorogenic sensing of anionic surfactants in water using functionalised silica nanoparticles

A new chromo-fluorogenic sensing protocol for anionic surfactants in aqueous environments using silica functionalised nanoparticles containing imidazolium and thiol groups has been developed.