Comparison of the Effect of Two Different Handling Conditions at Slaughter in Saliva Analytes in Pigs.

In this report, different handling conditions at slaughterhouse were studied to assess changes in salivary biomarkers. For this purpose, finishing pigs were divided into two groups, one in which handling was improved to minimize stress (Group A, n = 24, transported and stabled at the slaughterhouse at low density without mixing with unfamiliar animals throughout the whole process) and another one in which animals had a more stressful handling process (Group B, n = 24, transported and stabled at high density with unfamiliar animals). Saliva samples were taken the day before transport to the slaughterhouse at 8:00 a.m. (B0) and 12:00 a.m. (B4), and the day of slaughter just after unloading animals at the slaughterhouse at approximately 8:00 a.m. (S0) and after 4 h of lairage at approximately 12:00 a.m. (S4). Group B showed significantly higher cortisol, total esterase activity, oxytocin, adenosine deaminase and haptoglobin levels than the Group A at both S0 and S4 sampling times, and higher levels of calprotectin and creatine kinase at S4 sampling time. This report indicates that differences in the way in which the pigs are handled at the slaughterhouse can lead to changes in salivary biomarkers and opens the possibility of the use of biomarker at slaughter to monitor handling conditions.

Development of gold(I) phosphorescent tweezers for sensing applications.

The synthesis of the gold(I) alkynyl-fluorene compound 2 containing a diphosphane (dppb = 1,4-bisdiphenylphosphanebutane) has been easily achieved by the treatment of the previously synthesized [2-ethynylfluorene-Au]n polymer (1) and the corresponding dppb diphosphane in an adequate 2 : 1 stoichiometry. Compound 2 shows a boat-tweezer conformation that makes it ideal for being used as a host in molecular recognition processes. Different polyaromatic hydrocarbons (PAHs) and polyfluorinated compounds (PFCs) have been used as guests and a stronger interaction has been detected for PAHs, especially for anthracene, in agreement with spectrofluorometric titrations and the calculated values of the association constants, which is confirmed by DFT calculations. Compound 2 has then been immobilized in different organic matrices, in order to enhance room temperature phosphorescence (RTP). This promotes sensing with dual emission and furthermore in the case of the analytes under investigation, phosphorescence is observed in a range of wavelengths that do not coincide with the fluorescence emission of PAHs and PFCs.

Gold(i)-doped films: new routes for efficient room temperature phosphorescent materials.

The synthesis of four novel gold(i)-phosphane complexes coordinated to 9-phenanthrene chromophore has been carried out through the reaction of 9-phenanthreneboronic acid and the corresponding AuClPR3 (PR3 = PPh3 for triphenylphosphane (1a); 1,4-bis(diphenylphosphanyl)butane or dppb (2b); bis(diphenylphosphanyl)acetylene or dppa (2c); (AuCl)2(diphos) (diphos = bis(diphenylphosphanyl)methane or dppm (3)) sources. The X-ray crystal structures of compounds 1a and 2b show the existence of MOF-like intermolecular assemblies that contain empty inner cavities in the absence of aurophilic contacts. In contrast, the formation of a tetranuclear complex with intramolecular aurophilic interactions was evidenced for 3. Photophysical characterization indicates dual emission in all gold(i) complexes when oxygen is removed from the sample, while only fluorescence emission is recorded for the uncoordinated ligand. The introduction of the compounds within PMMA and Zeonex was assayed, and luminescent films containing gold(i) complexes where phosphorescence is the sole pathway for emission are obtained, instead of the dual emission (with significant fluorescence contribution) recorded in solution.

Effect of Gold(I) on the Room-Temperature Phosphorescence of Ethynylphenanthrene.

The synthesis of two series of gold(I) complexes with the general formulae PR3 -Au-C≡C-phenanthrene (PR3 =PPh3 (1 a/2 a), PMe3 (1 b/2 b), PNaph3 (1 c/2 c)) or (diphos)(Au-C≡C-phenanthrene)2 (diphos=1,1-bis(diphenylphosphino)methane, dppm (1 d/2 d), 1,4-bis(diphenylphosphino)butane, dppb (1 e/2 e)) has been realized. The two series differ in the position of the alkynyl substituent on the phenanthrene chromophore, being at the 9-position (9-ethynylphenanthrene) for the L1 series and at the 2-position (2-ethynylphenanthrene) for the L2 series. The compounds have been fully characterized by 1 H, 31 P NMR, and IR spectroscopy, mass spectrometry, and single-crystal X-ray diffraction resolution in the case of compounds 1 a, 1 e, 2 a, and 2 c. The emissive properties of the uncoordinated ligands and corresponding complexes have been studied in solution and within organic matrixes of different polarity (polymethylmethacrylate and Zeonex). Room-temperature phosphorescence (RTP) is observed for all gold(I) complexes whereas only fluorescence can be detected for the pure organic chromophore. In particular, the L2 series presents better luminescent properties regarding the intensity of emission, quantum yields, and RTP effect. Additionally, although the inclusion of all the compounds in organic matrixes induces an enhancement of the observed RTP owing to the decrease in non-radiative deactivation, only the L2 series completely suppresses the fluorescence, giving rise to pure phosphorescent materials.

Luminescent Tetranuclear Gold(I) Dibenzo[g,p]chrysene Derivatives: Effect of the Environment on Photophysical Properties.

A new 2,7,10,15-tetraethynyldibenzo[g,p]chrysene ligand (1) and two tetranuclear gold(I) derivatives containing PPh3 (3) and PMe3 (4) phosphines were synthesized and characterized by 1H and 31P NMR, IR spectroscopy, and high-resolution mass spectrometry. The compounds were studied in order to analyze the effect of the introduction of gold(I) on the supramolecular aggregation and photophysical properties. Absorption and emission spectra displayed broad bands due to the establishment of π π interactions as an indication of intermolecular contacts and the formation of aggregates. A decrease of the recorded quantum yield (QY) of the gold(I) derivatives was observed compared to the uncomplexed ligand. The introduction of the complexes into poly methyl methacrylate (PMMA) and Zeonex 480R matrixes was analyzed, and an increase of the measured QY of 4 in Zeonex was observed. No phosphorescent emission was detected.

Aggregation induced emission of a new naphthyridine-ethynyl-gold(i) complex as a potential tool for sensing guanosine nucleotides in aqueous media.

A new organometallic alkynyl-gold(i) complex capable of exhibiting aggregation induced emission was designed and synthesized. The linear complex structure possesses a central Au(i) atom, bearing two axial ligands: (1) 1,3,5-triaza-7-phosphaadamantane and (2) 2-acetamido-7-ethynyl-1,8-naphthyridine. While the former accounts for its partial solubility in an aqueous environment, the latter acts as a receptor unit for binding guanosine nucleotides and derivatives via multiple hydrogen bonding interactions. At high concentrations, aggregation of the complex was observed by the formation of new absorption (λmax∼ 400 nm) and emission bands (550-700 nm). Formation of aggregates of ca. 60 nm diameter was confirmed by Small Angle X-ray Scattering (SAXS). Disruption of the aggregates in the presence of guanosine derivatives resulted in a ratiometric signal with apparent association constants in the order of 105 M-1 and high sensitivity (around 63% signal change) which are, to the best of our knowledge, in line with the highest values recorded for nucleotide sensors based on hydrogen bonding and capable of working in water. Computational studies indicate the presence of additional hydrogen bonding interactions that account for the strong binding of the Au(i) complex to phosphorylated guanosine nucleotides.