In Obese Patients With Type 2 Diabetes, Mast Cells in Omental Adipose Tissue Decrease the Surface Expression of CD45, CD117, CD203c, and FcϵRI.

The paradigm of mast cells in type 2 diabetes is changing. Although they were first considered deleterious inflammatory cells, now they seem to be important players driving adipose tissue homeostasis. Here we have employed a flow cytometry-based approach for measuring the surface expression of 4 proteins (CD45, CD117, CD203c, and FcϵRI) on mast cells of omental (o-WAT) and subcutaneous white adipose tissue (s-WAT) in a cohort of 96 patients with morbid obesity. The cohort was split into three groups: non-T2D, pre-T2D, and T2D. Noteworthy, patients with T2D have a mild condition (HbA1c <7%). In o-WAT, mast cells of patients with T2D have a decrease in the surface expression of CD45 (p=0.0013), CD117 (p=0.0066), CD203c (p=0.0025), and FcϵRI (p=0.043). Besides, in s-WAT, the decrease was seen only in CD117 (p=0.046). These results indicate that T2D affects more to mast cells in o-WAT than in s-WAT. The decrease in these four proteins has serious effects on mast cell function. CD117 is critical for mast cell survival, while CD45 and FcϵRI are important for mast cell activation. Additionally, CD203c is only present on the cell surface after granule release. Taking together these observations, we suggest that mast cells in o-WAT of patients with T2D have a decreased survival, activation capacity, and secretory function.

Constrained parsimonious model-based clustering.

A new methodology for constrained parsimonious model-based clustering is introduced, where some tuning parameter allows to control the strength of these constraints. The methodology includes the 14 parsimonious models that are often applied in model-based clustering when assuming normal components as limit cases. This is done in a natural way by filling the gap among models and providing a smooth transition among them. The methodology provides mathematically well-defined problems and is also useful to prevent us from obtaining spurious solutions. Novel information criteria are proposed to help the user in choosing parameters. The interest of the proposed methodology is illustrated through simulation studies and a real-data application on COVID data.

In Patients With Obesity, the Number of Adipose Tissue Mast Cells Is Significantly Lower in Subjects With Type 2 Diabetes.

Type 2 diabetes (T2D) is a rising global health problem mainly caused by obesity and a sedentary lifestyle. In healthy individuals, white adipose tissue (WAT) has a relevant homeostatic role in glucose metabolism, energy storage, and endocrine signaling. Mast cells contribute to these functions promoting WAT angiogenesis and adipogenesis. In patients with T2D, inflammation dramatically impacts WAT functioning, which results in the recruitment of several leukocytes, including monocytes, that enhance this inflammation. Accordingly, the macrophages population rises as the WAT inflammation increases during the T2D status worsening. Since mast cell progenitors cannot arrive at WAT, the amount of WAT mast cells depends on how the new microenvironment affects progenitor and differentiated mast cells. Here, we employed a flow cytometry-based approach to analyze the number of mast cells from omental white adipose tissue (o-WAT) and subcutaneous white adipose tissue (s-WAT) in a cohort of 100 patients with obesity. Additionally, we measured the number of mast cell progenitors in a subcohort of 15 patients. The cohort was divided in three groups: non-T2D, pre-T2D, and T2D. Importantly, patients with T2D have a mild condition (HbA1c <7%). The number of mast cells and mast cell progenitors was lower in patients with T2D in both o-WAT and s-WAT in comparison to subjects from the pre-T2D and non-T2D groups. In the case of mast cells in o-WAT, there were statistically significant differences between non-T2D and T2D groups (p = 0.0031), together with pre-T2D and T2D groups (p=0.0097). However, in s-WAT, the differences are only between non-T2D and T2D groups (p=0.047). These differences have been obtained with patients with a mild T2D condition. Therefore, little changes in T2D status have a huge impact on the number of mast cells in WAT, especially in o-WAT. Due to the importance of mast cells in WAT physiology, their decrease can reduce the capacity of WAT, especially o-WAT, to store lipids and cause hypoxic cell deaths that will trigger inflammation.

Monitoring of chlorsulfuron in biological fluids and water samples by molecular fluorescence using rhodamine B as fluorophore.

A new simple methodology is proposed for chlorsufuron (CS) traces quantification based upon enhancement of rhodamine B (RhB) fluorescent signal. Experimental variables that influence fluorimetric sensitivity have been studied and optimized. The zeroth order regression calibration was linear from 0.866 to 35.800µgL(-1) CS, with a correlation coefficient of 0.99. At optimal experimental conditions, a limit of detection of 0.259µgL(-1) and a limit of quantification of 0.866µgL(-1) were obtained. The method showed good sensitivity and adequate selectivity and was applied to the determination of trace amounts of CS in plasma, serum and water samples with satisfactory results analyzed by ANOVA test. The proposed methodology represents an alternative to traditional chromatographic techniques for CS monitoring in complex samples, using an accessible instrument in control laboratories.

Assembling nonplanar polyaromatic units by click chemistry. Study of multicorannulene systems as host for fullerenes.

Novel compounds with two or three corannulene subunits have been obtained by "click chemistry". These exotic systems were synthesized in high yields using the ethynylcorannulene as common reagent. The synergistic action as receptors for fullerenes of several corannulene blocks has been evaluated. It was found that the three-armed derivatives showed efficient complexation abilities toward C60. Furthermore, a new compound having two corannulene subunits linked to a hexahelicene scaffold has a remarkable affinity constant. Finally, theoretical calculations have been performed to evaluate the formation of their relative adducts containing a C60 molecule.

Copper nanoparticles applied to the preconcentration and electrochemical determination of ß-adrenergic agonist: an efficient tool for the control of meat production.

A novel method for preconcentration and electrochemical detection of zinterol in bovine urine samples was developed. In order to improve the limit of detection, the surface of a screen-printed carbon electrode was modified with electrodeposited metal copper nanoparticles. The experimental electrodeposition optimization was performed using a central composite design (CCD), involving the variables: precursor concentration, potential and time applied. Copper nanoparticles were characterized by transmission electron microscopy, scanning electron microscopy, cyclic voltammetry, and energy dispersive X-ray spectroscopy. Mesoporous shuttle-like copper oxide nanoparticles were used for the preconcentration step to avoid interferences with many compounds present in the sample matrix. The optimal working conditions for the preconcentration approach were found by means of both two-level fractional factorial and CCD designs. The obtained enhancement factor for a sample volume of 30 mL was 35 fold. The calibration curve showed linearity between 0.5 and 45 ng mL(-1) and the limit of detection was 0.16 ng mL(-1). The intra and inter assay coefficients of variability were below 4% and 5%; respectively.

Development of a FI-HG-ICP-OES solid phase preconcentration system for inorganic selenium speciation in Argentinean beverages.

A preconcentration system has been developed to determine inorganic selenium species. Selenium was retained by a column filled with polyvinyl chloride (PVC) with lanthanum hydroxide co-precipitation. Speciation was achieved by selective photoreduction previous Se preconcentration. The retention pH was optimized at 10.0. Two multivariate calibrations and a central composite design were employed for optimization of the system. Sample, reagents and acid flow rates are significant variables affecting the system. Employing HG-ICP-OES as detection, the optimized system reached a detection limit of 0.03µg/L, and an enhancement factor of 14875 (25 for preconcentration system, 595 for hydride generation). To verify the method' accuracy, two certified reference materials, BCR® 414 Plankton & IRMM-804 Rice Flour, were analysed. The system was applied to inorganic selenium speciation in several Argentinean beverages to estimate their selenium contribution to diet.

Enhanced association for C70 over C60 with a metal complex with corannulene derivate ligands.

The geometry imposed by the coordination sphere around the metal, together with the choice of the "arms" can be advantageously used to build corannulene-based molecular tweezers, which show great affinities for C60 and C70, as revealed by NMR titration experiments, mass spectroscopy, DFT calculations and the single crystal X-ray structural analysis of the compound C60 ⊂1.

Schiff plus click: one-pot preparation of triazole-substituted iminopyridines and ring opening of the triazole ring.

The use of Schiff condensation followed by CuAAC affords complexes containing iminopyridine ligands functionalized either with a triazole ring or with a sulfonyl amido group via ring opening of the unstable sulfonyl triazole.

η6-Hexahelicene complexes of iridium and ruthenium: running along the helix.

The first η(6)-complexes of iridium and ruthenium coordinated to helicenes have been obtained. Hexahelicene (1), 2,15-dimethylhexahelicene (2), and 2,15-dibromohexahelicene (3) react with [Cp*IrCl(2)](2) and AgBF(4) in CD(3)NO(2) to afford quantitatively the complexes [Cp*Ir(η(6)-1)][BF(4)](2) (4A), [Cp*Ir(η(6)-2)][BF(4)](2) (5A), and [Cp*Ir(η(6)-3)][BF(4)](2) (6A), respectively. In all cases, the final thermodynamic products are similar, and they exhibit coordination between the 12 e(-) metal fragment [IrCp*](2+) and the terminal ring of the helicene. Monitoring the reaction by NMR shows formation of intermediates, some of which have been fully characterized in solution. These intermediates exhibit the metal fragment coordinated to the internal rings. We have also synthesized the bimetallic complex [(Cp*Ir)(2)(µ(2)-η(6):η(6)-2)][BF(4)](4) (7), achieving coordination between two units [IrCp*](2+) and the helicene 2. Following an analogous methodology, we have prepared the complex [(η(6)-cymene)Ru(η(6)-2)][BF(4)](2) (8), which has been studied by X-ray diffraction, confirming the preferential binding to the terminal aromatic ring.

Beyond click chemistry: spontaneous C-triazolyl transfer from copper to rhenium and transformation into mesoionic C-triazolylidene carbene.

The exceptional versatility of the 1,2,3-triazole ring in tridentate carbonyl rhenium complexes has been explored starting from a "click chemistry" unexpected product obtained from the spontaneous copper to rhenium transmetalation, which opens the way to successive transformation to C-triazolyl and triazolylidene mesoionic carbene.

Factorial design optimization of experimental variables in the on-line separation/preconcentration of copper in water samples using solid phase extraction and ICP-OES determination.

An on-line preconcentration procedure using solid phase extraction (SPE) for the determination of copper in different water samples by inductively coupled plasma optical emission spectrometry (ICP-OES) is proposed. The copper was retained on a minicolumn filled with ethyl vinyl acetate (EVA) at pH 8.0 without using any complexing reagent. The experimental optimization step was performed using a two-level full factorial design. The results showed that pH, sample loading flow rate, and their interaction (at the tested levels) were statistically significant. In order to determine the best conditions for preconcentration and determination of copper, a final optimization of the significant factors was carried out using a central composite design (CCD). The calibration graph was linear with a regression coefficient of 0.995 at levels near the detection limit up to at least 300 µg L(-1). An enrichment factor (EF) of 54 with a preconcentration time of 187.5 s was obtained. The limit of detection (3σ) was 0.26 µg L(-1). The sampling frequency for the developed methodology was about 15 samples/h. The relative standard deviation (RSD) for six replicates containing 50 µg L(-1) of copper was 3.76%. The methodology was successfully applied to the determination of Cu in tap, mineral, river water samples, and in a certified VKI standard reference material.

Synthesis of new copper(I) complexes with tris(2-pyridyl) ligands. Applications to carbene and nitrene transfer reactions.

New copper(I) complexes with tris(2-pyridyl)methane (TPC), tris(2-pyridyl)methoxymethane (TPM) and tris(2-pyridyl)amine (TPN) ligands have been synthesized and characterized, including structural determinations by X-ray diffraction of some examples. Their activity as catalysts in carbene and nitrene transfer reactions was studied.