1H, 19F, and 15N NMR study of the interaction between bis(pentafluorophenyl)borinic acid and nitrogen bases

Bis(pentafluorophenyl)borinic acid ((ArF)2BOH, ArF = C6F5, 1) is a molecule that, due to its multiple reactivity, can behave in different and not always straightforward ways in the presence of nucleophiles. It has been already shown its behaviour in dicloromethane solution in the presence of water, THF and methanol. Briefly, it exists as monomer and trimer (1m and 1t, see Chart 1), and the presence of nucleophiles strongly influence the thermodynamic and the kinetic of the monomer-trimer interconversion. Moreover, according to the nature of the nucleophile, 1 shows a camaleonic nature by forming several, sometimes unexpected, species.2,3 We have studied now the reaction of 1 in the presence of nitrogen bases, that can act as Lewis and Br\uf8nsted bases. Two nitrogen bases were studied, namely 1,8-bis(dimethylamino)naphthalene (DMAN), which can act as Br\uf8nsted base only, and pyridine, which is a good Lewis base but weak Br\uf8nsted base. First of all, the Br\uf8nsted base DMAN has been proved to be more efficient than oxygenated Lewis bases in catalyzing the trimerization process. Indeed it is enough a catalytic amount of base to cause the complete trimerization of 1. The so obtained trimeric deprotonated anion 2 (Chart 2) is unstable with respect to dearylation reactions, leading eventually (in the presence of more than 0.33 equiv of DMAN and at higher temperatures) to the tetrarylic species 3 (Chart 2). On the other hand, the behaviour of pyridine is quite different, since 0.33 equiv of base are requested to complete the trimerization of 1, and also in this case the obtained trimer is anionic. Moreover, the presence of 1 equivalent of pyridine does not cause the dearylation process but gives rise to the monomeric neutral 1:1 adduct 4 (Chart 2). Both the identification and the characterization of the involved species were performed by multiparametric and multinuclear low temperature NMR spectroscopy

1H NMR Characterization of Organic and Inorganic Nanoparticles

Drug delivery employing nano-object as liposomes, polymer conjugates, and nanoparticles suspended in solution is a subject of high current interest [1]. The characterization of the size and the surface functionalization of these nanoparticles is of primary importance. Microscopy techniques give information on deposited colloidal samples, after solvent evaporation, so that the correspondence with the nature of the species in solution is not granted. Dynamic Light Scattering (DLS), which is usually used to estimate the size of a colloidal sample in solution, can overestimate the radii of very small nanoparticles [2]. Diffusion NMR, and in particular Pulsed gradient spin-echo (PGSE) technique, has recently emerged as a valuable tool for colloids characterization [3], complementary to DLS from the point of view of the size evaluation, being highly reliable for the measurement of the smallest particles. Moreover, NMR provide information not only on the size, but also on the interaction between the capping ligands and the nanoparticle surface. In this work, we present the characterization through 1H PGSE NMR measurements of the size of spherical and rod-like TiO2/oleic acid nanoparticles and of conjugates between Re complexes and polyamidoamine nanoparticles. Moreover, by 1H NMR experiments the interaction between TiO2 and the capping oleic acid (OA) has been characterized. [1] a) A. H. Faraji, P. Wipf, Bioorganic and Medicinal Chemistry 2009, 17, 2950-2962; b) S. M. Garg, A. V. Deshmukh, Nano Science and Nano Technology 2007, 1(2), 45-58; c) C. Khemtong, C. W. Kessinger, J. Gao, Chem. Commun. 2009, 3497-3510. [2] C. Sanna, C. La Mesa, L. Mannina, P. Stano, S. Viel, A. Segre, Langmuir 2006, 22, 6031-6041. [3] a) F. Ribot, V. Escax, C. Roiland, C. Sanchez, J. C. Martins, M. Biesemans, I. Verbruggen, R. Willem, Chem. Commun. 2005, 1019-1021; b) M. Valentini, A. Vaccaro, A. Rehor, A. Napoli, J. A. Hubbell, N. Tirelli, J. Am. Chem. Soc. 2004, 126, 2142-2147

Morning Priming Exercise Strategy to Enhance Afternoon Performance in Young Elite Soccer Players.

PURPOSE: To compare the effects of different modalities of morning priming exercise on afternoon physical performance with the associated hormonal and psychophysiological responses in young soccer players. METHODS: In a randomized counterbalanced crossover design, 12 young soccer players completed 3 different morning conditions on 3 different days: repeated-sprint running (6 × 40 m), easy exercise (4 × 12 fast half squats, 6 speed ladder drills, and 20-m sprints), and control (no exercise). Blood testosterone and cortisol concentrations were assessed upon arrival (approximately 8:30AM) and approximately 5 hours and 30 minutes later. Body temperature, self-reported mood, quadriceps neuromuscular function (maximal voluntary contraction, voluntary activation, rate of torque development, and twitch contractile properties), jump, and sprint performance were evaluated twice per day, while rating of perceived exertion, motivation, and the Yo-Yo Intermittent Recovery level 2 (IR2) tests were assessed once per day. RESULTS: Compared with the control, repeated-sprint running induced a possible positive effect on testosterone (+11.6%) but a possible to very likely negative effect on twitch contractile properties (-13.0%), jump height (-1.4%), and Yo-Yo IR2 (-7.1%). On the other hand, easy exercise had an unclear effect on testosterone (-3.3%), resulted in lower self-reported fatigue (-31.0%) and cortisol (-12.9%), and had a possible positive effect on the rate of torque development (+4.3%) and Yo-Yo IR2 (+6.5%) compared with the control. CONCLUSIONS: Players' testosterone levels were positively influenced by repeated-sprint running, but this did not translate into better physical function, as both muscular and endurance performance were reduced. Easy exercise seemed to be suitable to optimize the physical performance and psychophysiological state of young soccer players

Aggregation and ionization equilibria of bis(pentafluorophenyl)borinic acid driven by hydrogen-bonding with tetrahydrofuran

Bis(pentafluophenyl)borinic acid, Ar2BOH (1, Ar = C6F5), in dichloromethane solution is present as an equilibrium mixture of monomeric (1m) and trimeric (1t) forms. Previous studies showed that water affects both the position and the rate of this equilibrium. Here, the behavior of 1 in the presence of tetrahydrofuran (THF), a nucleophile able to behave as a Lewis base and H-bond acceptor only, has been studied, by monitoring with H-1 and F-19 NMR the course of titrations performed directly into NMR tubes. The addition, at 183 K, of 0.33 equiv of THF caused the instantaneous and quantitative formation of the hydrogen-bonded adduct between the trimer 1t and one molecule of THF. Homo- and heteronuclear 2D NMR correlation experiments led to a solution structure consistent with the C2-optimized geometry obtained by PM3 computations. The H-bonding of the THF molecule causes major deformations of the molecular geometry of the trimer, so that only one molecule of THF can interact with the trimer, in spite of its three OH groups. Intra- and intermolecular exchange processes involving this adduct have been investigated by 2D EXSY experiments, showing flopping of the cycle conformation, rotation of the aromatic rings around their B-C bonds, and exchange of THF among the three OH groups, in addition to the exchange between free 1t and the adduct. When the amount of added THF was higher than 0.33 equiv, an unexpected ionization process occurred, leading to the cation [Ar2B(OH2)2]+ and to deprotonated 1t, i.e., to the anion [Ar6B3O3H2]- of Cs symmetry. On increasing the temperature, progressive partial fragmentation of the trimeric species was observed. Both B-11 NMR evidence and PM3 computations indicated that, at variance with what is observed in the interaction with H2O, the interaction between THF and 1m occurs preferentially via an H-bonded adduct, Ar2BO-H...THF, rather than a Lewis acid-base complex, Ar2B(OH)(THF). This confirms the poor Lewis acidity of the boron atom of 1m

Endobronchial Ultrasound Transbronchial Needle Aspiration In Thoracic Diseases: Much More Than Mediastinal Staging

Background and Objective. EBUS-TBNA has revolutionized the diagnostic approach to thoracic diseases from a surgical to minimally invasive procedure. In non small-cell lung cancer (NCSLC) patients, EBUS-TBNA is able to dictate the consecutive therapy both for early and advanced stages, providing pathological diagnosis, mediastinal staging, and even adequate specimens for molecular analysis. This study reports on the ability of EBUS-TBNA to make different diagnoses and dictates the consecutive therapy in a large cohort of patients presenting different thoracic diseases. Methods. All procedures performed from January 2012 to September 2016 were reviewed. Five groups of patients were created according to the main indications for the procedure. Group 1: lung cancer staging; Group 2: pathological diagnosis in advanced stage lung cancer; Group 3: lymphadenopathy in previous malignancies; Group 4: pulmonary lesions; Group 5: unknown origin lymphadenopathy. In each group, the diagnostic yield of the procedure was analysed. Non malignant diagnosis at EBUS-TBNA was confirmed by a surgical procedure or clinical and radiological follow-up. Results. 1891 patients were included in the analysis. Sensitivity, negative predictive value, and diagnostic accuracy in each group were 90.7%, 79.4%, and 93.1% in Group 1; 98.5%, 50%, and 98.5% in Group 2; 92.4%, 85.1%, and 94.7% in Group 3; 90.9%, 51.0%, and 91.7% in Group 4; and 25%, 83.3%, and 84.2% in Group 5. Overall sensitivity, negative predictive value, and accuracy were 91.7%, 78.5%, and 93.6%, respectively. Conclusions. EBUS-TBNA is the best approach for invasive mediastinal investigation, confirming its strategic role and high accuracy in thoracic oncology

Reduced mortality in COVID-19 patients treated with colchicine: Results from a retrospective, observational study

Objectives Effective treatments for coronavirus disease 2019 (COVID-19) are urgently needed. We hypothesized that colchicine, by counteracting proinflammatory pathways implicated in the uncontrolled inflammatory response of COVID-19 patients, reduces pulmonary complications, and improves survival. Methods This retrospective study included 71 consecutive COVID-19 patients (hospitalized with pneumonia on CT scan or outpatients) who received colchicine and compared with 70 control patients who did not receive colchicine in two serial time periods at the same institution. We used inverse probability of treatment propensity-score weighting to examine differences in mortality, clinical improvement (using a 7-point ordinary scale), and inflammatory markers between the two groups. Results Amongst the 141 COVID-19 patients (118 [83.7%] hospitalized), 70 (50%) received colchicine. The 21-day crude cumulative mortality was 7.5% in the colchicine group and 28.5% in the control group (P = 0.006; adjusted hazard ratio: 0.24 [95%CI: 0.09 to 0.67]); 21-day clinical improvement occurred in 40.0% of the patients on colchicine and in 26.6% of control patients (adjusted relative improvement rate: 1.80 [95%CI: 1.00 to 3.22]). The strong association between the use of colchicine and reduced mortality was further supported by the diverging linear trends of percent daily change in lymphocyte count (P = 0.018), neutrophilto- lymphocyte ratio (P = 0.003), and in C-reactive protein levels (P = 0.009). Colchicine was stopped because of transient side effects (diarrhea or skin rashes) in 7% of patients. Conclusion In this retrospective cohort study colchicine was associated with reduced mortality and accelerated recovery in COVID-19 patients. This support the rationale for current larger randomized controlled trials testing the safety/efficacy profile of colchicine in COVID-19 patients. Copyright

La hora del museo: la sala Uriburu del Museo Histórico y Colonial de la Provincia de Buenos Aires (Luján, 1932)

El artículo analiza el proceso de creación de la Sala Uriburu del Museo Histórico y Colonial de la Provincia de Buenos Aires instalado en la ciudad de Luján y abierto al público en 1923. La sala fue inaugurada el 4 de septiembre de 1932 y estaba destinada a honrar la memoria del líder de la "Revolución" del 6 de septiembre de 1930. El objetivo es dar cuenta de los múltiples factores que incidieron en su instalación considerando que ella no puede explicarse solamente a través de la relación directa entre coyuntura política, atmósfera nacionalista y la necesidad de crear un mito para perpetuar su memoria. Proponemos entonces explorar las prácticas y dispositivos colectivos indispensables en el proceso de creación de evidencias materiales para sustentar la visualización de un relato histórico.O artigo analisa o processo de instalação da Sala Uriburu, do Museu Histórico e Colonial da Província de Buenos Aires, fundado na cidade de Luján e aberto ao público em 1923. A sala foi inaugurada em 4 de setembro de 1932, e destinava-se a "honrar a memória" do líder da "Revolução" de 6 de setembro de 1930, poucos meses depois de sua morte. O objetivo é dar conta dos múltiplos fatores que incidiram na instalação, considerando que ela não pode ser explicada somente através da relação direta entre conjuntura política, atmosfera nacionalista e a necessidade de criar um mito para perpetuar sua memória. Propomos, então, explorar as práticas e dispositivos coletivos indispensáveis no processo de criação de evidências materiais para sustentar a visualização de um relato histórico.This article analyzes the installation of Uriburu's Hall at the Museo Histórico y Colonial de la Provincia de Buenos Aires, institution established in Luján in 1923. This hall was opened to the public in September 1932, to celebrate the name and memory of the hero of the Revolution of 1930. Far from proposing a direct relationship between politics and museum displays, this article wants to display the several elements that colluded in the creation of this hall

EBUS-TBNA in PET-positive lymphadenopathies in treated cancer patients

Mediastinal lymph node enlargement is common in the follow-up of patients with previously treated malignancies. The aim of this study is to assess the role of endobronchial ultrasound (EBUS) transbronchial needle aspiration (TBNA) for cyto-histological evaluation of positron emission tomography with 18fluorodeoxyglucose (PET) positive mediastinal and hilar lymph nodes developed in patients with previous malignancies. All EBUS-TBNA cases performed from January 2012 to May 2016 were retrospective reviewed. Results of EBUS-TBNA in patients with mediastinal and/or hilar lymphadenopathies were analysed. Non-malignant cytopathologies were confirmed with surgical procedures or clinical and radiological follow-up. Among 1780 patients, 176 were included in the analysis. 103 of these (58.5%) had a diagnosis of tumour recurrence whereas 73 (41.5%) had a different diagnosis: 63 (35.8%) had a non-neoplastic diagnosis and 8 patients (4.6%) had a different cell type malignancy. Samples were false-negative in 5 (2.8%) out of 176 patients. The overall sensitivity, specificity, negative predicted value and diagnostic accuracy were 95.7% (95% CI 90.2-98.6%), 100% (95% CI 94.0-100%), 92.3% (95% CI 83.2-96.7%) and 97.2% (95% CI 93.5-98.8%), respectively. EBUS-TBNA demonstrated a pathological diagnosis different from the previous tumour in a large percentage of patients, confirming its strategic role in the management of patients with previously treated malignancies

UbcH10 overexpression may represent a marker of anaplastic thyroid carcinomas

The hybridisation of an Affymetrix HG_U95Av2 oligonucleotide array with RNAs extracted from six human thyroid carcinoma cell lines and a normal human thyroid primary cell culture led us to the identification of the UbcH10 gene that was upregulated by 150-fold in all of the carcinoma cell lines in comparison to the primary culture cells of human normal thyroid origin. Immunohistochemical studies performed on paraffin-embedded tissue sections showed abundant UbcH10 levels in thyroid anaplastic carcinoma samples, whereas no detectable UbcH10 expression was observed in normal thyroid tissues, in adenomas and goiters. Papillary and follicular carcinomas were only weakly positive. These results were further confirmed by RT–PCR and Western blot analyses. The block of UbcH10 protein synthesis induced by RNA interference significantly reduced the growth rate of thyroid carcinoma cell lines. Taken together, these results would indicate that UbcH10 overexpression is involved in thyroid cell proliferation, and may represent a marker of thyroid anaplastic carcinomas