Cation–π complexes between alkaline cations and molecular bowls related with fullerene: a DFT study

The 14th International Electronic Conference on Synthetic Organic Chemistry session Computational ChemistryThe formation of complexes between alkaline cations and molecular bowls (MBs), curved conjugated systems related with fullerene (C 60 ), is studied using DFT calculations. The series of MBs is constructed starting with benzene and additional hexagonal or pentagonal rings are added symmetrically to complete the C 60 structure. All the MBs studied form stable cation–π complexes by both of its sides: concave and convex. In all cases complexes with the cation in the convex side are more stable than their corresponding partner inside the bowl. The stability of the complexes is determined by the polarizing power of the cation and by the molecular electrostatic potential and the polarizability of the bowl. Additionally, size effects are observed when bulky cations are placed in the concave side of the largest bowl

Influence of the substitution on the inversion barrier of corannulene: a theoretical study.

The 15th International Electronic Conference on Synthetic Organic Chemistry session Computational ChemistryThe lower molecular weight hydrocarbons that can be mapped on the buckminsterfullerene (C60) structure are commonly known as "buckybowls" or "geodesic polyarenes" and have the distinctive characteristics of preserving the curvature and aromaticity of fullerene. These bowl-shaped structures are expected to be quite rigid. Nevertheless, the smaller members of the family, in spite of its substantial curvature are surprisingly flexible undergoing rapid bowl-to-bowl inversion in solution as evidenced by the dynamic NMR behavior of C20H10 (corannulene) and several of its derivatives. With the aim of gaining understanding in the bowl-to-bowl inversion, the present theoretical study has explored the effect that substitution of some of the hydrogen atoms of corannulene has on this process. The model systems studied have the formula C20H10-nRn with R = -Cl, -Br, -C≡CH, -CH3 and n = 0, 2, 4, 5, 6, 8, and 10. It is observed that the bowl depth is reduced only by high substitution levels or by a substitution pattern that conduces to important peri interactions. Full substitution with bulky groups causes a pronounced repulsion and the deformation of the transition structure for bowl inversion that otherwise is planar. The activation barrier for the inversion – bowl depth data fit an empirical quartic/quadratic function used previously in similar systems but the coefficients of the fitting don\'t follow the predicted substituent independenc

Computational Study of the interaction between Sumanene and Cations as a function of the cation–π separation

With the aim of enhancing the comprehension of the cation-π interaction, a computational study of the interaction established between sumanene molecule and various cations was performed. Sumanene is a polycyclic aromatic hydrocarbon with a bowl-shaped structure. The curvature of the molecule causes an asymmetry in the distribution of its molecular electrostatic potential that is more negative in its outer (convex) side. This feature allows testing the role of the electrostatic contribution to cation-π interaction using the same molecule. Five cations with different sizes and shapes were selected for the study: sodium, potassium, ammonium, tetramethylammonium, guanidinium and imidazolium. These are monoatomic cations and models of cationic amino acids side-chains, all of which are known to participate in the formation of cation-π complexes in biological systems. The polyatomic cations were placed in different orientations with respect to the sumanene molecule including the “T-shaped” and “stacked” configurations of the flat cations. The study was accomplished at the RI‑MP2/aug-cc-pVTZ level of calculation, to ensure the correct retrieving of the correlation energy and also that the wavefunction size is appropriate for the modeling of effects more complicated than the electrostatic contribution. The interaction energy (Eint) was computed at different sumanene-cation distances following the C3v symmetry axe of sumanene and exploring it’s both sides: concave and convex. The rigid scans of the potential energy surface indicate that at sumanene-cation distances around the Eint minima, the complexes are more stable with the cation placed by the inner (concave) side of sumanene, with the only exception of the complexes with Na+, the smallest of the cations studied. This result is the opposite of that expected from the pure electrostatic interpretation of the cation-π interaction. As the cation moves away from the sumanene molecule the situation is reversed, and at long distances the outer complexes are more stable than its inner partners. These findings suggest that at long cation-molecule separations the electrostatic contribution dominates because its influence propagates to long distances but at short distances the cation-π interaction is controlled by other stabilizing contributions (induction and dispersion) defining the minimum of the Eint profile. The results obtained contribute to a better understanding the cation-π interaction and emphasize the importance of using the correct level of calculations in its theoretical modelin

Theoretical Study of the Solvent Effect on the properties of Indole‑Cation‑Anion Complexes

The 18th International Electronic Conference on Synthetic Organic Chemistry session Computational ChemistryThe properties of ternary indole-cation-anion (IMX) complexes are theoretically studied as simplified models of real systems in which some of the fragments used are parts of bigger and complicated structures, like proteins. The electro-neutrality of real systems and the presence of ions of both charges interacting simultaneously with aromatic residues in the proteins modeled justify the move from cation-π or anion-π (non-bonding interactions analyzed by our group in previous studies) to cation-π-anion complexes. With the intention of approaching more the model to reality, the solvent was also included in the study: aqueous solvent was represented by a combination of PCM + explicit addition of one water molecule to some IMX complexes. As model systems for this study the complexes with indole and the following cations and anions were selected: M = Na+, NH4+; X = HCOO–, NO3– or Cl–. The effect of the solvent was studied not only on the energy but as well on some structural parameters like the proton transfer from the ammonium cation to the basic anion and the cation-anion separation. The results indicate that the PCM method alone properly reproduces the main energetic and geometrical changes, even at quantitative level, but the explicit hydration allows refining the solvent effect and detecting cases that do not follow the general tren

Fire tests on polyester polymer mortars

Composite materials made from organic matrices are generally combustible. It is necessary to determine in each case their behaviour under fire and determine whether they fulfil the requirements of the applicable standards in order to match each material to each specific application. Polyester polymer mortar is a material that provides much better mechanical characteristics than traditional mortars but one of its weak points is fire reaction, in this paper, fire reaction of a particular polyester polymer mortar is determined based on Spanish standards, in order to establish its suitability as a coating and cladding material for building constructio

Novel Horizons in Postbiotics: Lactobacillaceae Extracellular Vesicles and Their Applications in Health and Disease

Lactobacillus probiotics contained in dietary supplements or functional foods are wellknown for their beneficial properties exerted on host health and diverse pathological situations. Their capacity to improve inflammatory bowel disease (IBD) and regulate the immune system is especially remarkable. Although bacteria–host interactions have been thought to occur directly, the key role that extracellular vesicles (EVs) derived from probiotics play on this point is being unveiled. EVs are lipid bilayer-enclosed particles that carry a wide range of cargo compounds and act in different signalling pathways. Notably, these EVs have been recently proposed as a safe alternative to the utilisation of live bacteria since they can avoid the possible risks that probiotics may entail in vulnerable cases such as immunocompromised patients. Therefore, this review aims to give an updated overview of the existing knowledge about EVs from different Lactobacillus strains, their mechanisms and effects in host health and different pathological conditions. All of the information collected suggests that EVs could be considered as potential tools for the development of future novel therapeutic approaches.Junta de Andalucia CTS 164 PY20_01157Instituto de Salud Carlos III European Commission PI19/01058 European Commissio

Discovery of Colossal Breathing-Caloric Effect under Low Applied Pressure in the Hybrid Organic–Inorganic MIL-53(Al) Material

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] In this work, “breathing-caloric” effect is introduced as a new term to define very large thermal changes that arise from the combination of structural changes and gas adsorption processes occurring during breathing transitions. In regard to cooling and heating applications, this innovative caloric effect appears under very low working pressures and in a wide operating temperature range. This phenomenon, whose origin is analyzed in depth, is observed and reported here for the first time in the porous hybrid organic–inorganic MIL-53(Al) material. This MOF compound exhibits colossal thermal changes of ΔS ∼ 311 J K–1 kg–1 and ΔH ∼ 93 kJ kg–1 at room temperature (298 K) and under only 16 bar, pressure which is similar to that of common gas refrigerants at the same operating temperature (for instance, p(CO2) ∼ 64 bar and p(R134a) ∼ 6 bar) and noticeably lower than p > 1000 bar of most solid barocaloric materials. Furthermore, MIL-53(Al) can operate in a very wide temperature range from 333 K down to 254 K, matching the operating requirements of most HVAC systems. Therefore, these findings offer new eco-friendly alternatives to the current refrigeration systems that can be easily adapted to existing technologies and open the door to the innovation of future cooling systems yet to be developed.This work was financially supported by Ministerio de Economía y Competitividad MINECO and EU-FEDER (projects MAT2017-86453-R and PDC2021-121076-I00), Xunta de Galicia and IACOBUS Programme. Funding for open access fee was provided by Universidade da Coruña/CISU

Las inundaciones recientes en Galicia

Las inundaciones en Galicia tienen un carácter particular. Los factores que intervienen en su desarrollo son variados pero, en general, están más asociadas a eventos derivados de un largo período de abundante precipitación, propios de las condiciones climáticas en que se inscribe\ud la región, que a aquellos otros, menos frecuentes, de corta duradón y elevada intensidad. Por otra parte, al tratarse de un territorio en donde la casi totalidad de sus principales cursos fluviales se encuentran regularizados por embalses para el aprovechamiento hidroeléctrico, los efectos de estas crecidas sólo se dejan sentir en los pequeños cursos que carecen de dicho aprovechamiento, por lo que las consecuencias hidrológicas son limitadas en el espacio y en el tiempo. Finalmente, la ausencia de infomnación hidrométríca de base en estos pequeños cursos fluviales, nos ha llevado a presentar simulaciones de eventos en una de las cuencas más afectadas por las tradicionales inundaciones como es la del río Sar, en la comarca de A Mahía, que se extiende entre la ciudad de Santiago de Compostela y el núcleo urbano de Padrón, en el fondo de la ría de Arousa.The inundations in Galicia have a particular character. The factors that intervene in the development\ud are varied but, generally, are most associated to derived events of a long period of\ud abundant precipitation, proper of the climatic conditions in that inscribes the region, that those\ud other, less frequented, of short duration and elevated intensity.\ud On the other hand, upon be tried of a territory in where the almost totality of the course fluvial principals find regularized by dammed for profit hydroelectric, the grown effects of these alone let to feel in the little courses\ud that lack of tell profit, why the consequences hydro are limited in the space and in the time. Finally,\ud the absence of information hydrologic of little base in these fluvial courses, has at us carried\ud to present simulations of events in one of the most affected basins by traditional inundations\ud as is of the "río Sar", in the "comarca de A Mahía", that extend between the city of "Santiago de\ud Compostela" and the urban nucleus of "Padrón", in the background of to "ría de Arousa"

Thin healthy women have a similar low bone mass to women with anorexia nervosa.

An association between anorexia nerviosa (AN) and low bone mass has been demonstrated. Bone loss associated with AN involves hormonal and nutritional impairments, though their exact contribution is not clearly established. We compared bone mass in AN patients with women of similar weight with no criteria for AN, and a third group of healthy, normal-weight, age-matched women. The study included forty-eight patients with AN, twenty-two healthy eumenorrhoeic women with low weight (LW group; BMI 18.5 kg/m2 (control group), all of similar age. We measured lean body mass, percentage fat mass, total bone mineral content (BMC) and bone mineral density in lumbar spine (BMD LS) and in total (tBMD). We measured anthropometric parameters, leptin and growth hormone. The control group had greater tBMD and BMD LS than the other groups, with no differences between the AN and LW groups. No differences were found in tBMD, BMD LS and total BMC between the restrictive (n 25) and binge-purge type (n 23) in AN patients. In AN, minimum weight (P = 0.002) and percentage fat mass (P = 0.02) explained BMD LS variation (r2 0.48) and minimum weight (r2 0.42; P = 0.002) for tBMD in stepwise regression analyses. In the LW group, BMI explained BMD LS (r2 0.72; P = 0.01) and tBMD (r2 0.57; P = 0.04). We concluded that patients with AN had similar BMD to healthy thin women. Anthropometric parameters could contribute more significantly than oestrogen deficiency in the achievement of peak bone mass in AN patients

Autotransfusión predepósito en cirugía ortopédica mayor en España

Objetivo: Analizar las comunicaciones a congresos nacionales e internacionales de grupos multidisciplinarios españoles, y realizar un metaanálisis para estimar el posible beneficio de la autotransfusión predepósito (ATPD) en nuestro entorno. Material y métodos: Se han revisado los resúmenes de las comunicaciones de los congresos de la AEHH y de la SETS desde 1995, de la AABB y de la NATA (2000, 2001 y 2002). Variables recogidas: período de estudio, números de pacientes, tipo de cirugía, tasa de rechazo, unidades autólogas solicitadas, extraídas y transfundidas, total transfundido, rendimiento (unidades transfundidas/extraídas) y efectividad. Resultados: La selección incluyó en Cirugía Ortopédica Programada, 2933 pacientes, con una tasa de rechazo del 9,3% (IC95%: 8,1-10,7) (extremos: 5,5-19,5%), con un rendimiento67,8% (IC95%: 66,1-69,5) (extremos: 17-94%), donando2,35 U (IC95%: 2,337-2,367) (extremos 1,73-3,6), transfundiendo1,84 U unidades autólogas/paciente (IC95%: 1,818-1,853) (extremos 0,74-2,85) y sólo con autóloga al 75,9% (IC95%: 74,2-77,6) (extremos 10-100%). Conclusiones: Creemos que hay una escasa comunicación de la experiencias transfusional con ATDP en España. Los resultados resultan bastante dispares entre los diferentes centros de trabajo. En los estudios finalmente seleccionados por su calidad metodológica, se podría afirmar que en nuestro país se excluye a un pacientes de cada 10, transfundiéndose dos de cada tres unidades extraídas y evitando transfundir con sangre alogénica en cuatro de cada cinco pacientes.Objetive: Reviewed and analyzed the Spanish communications defended at different national and international congress or meetings, and done an meta-analysis to estimate the possible preoperative autologous blood donation (PABD) benefit at Spain. Patients and Methods: We hav reviewed abstracts presented by Spanish groups in several national (AEHH and SETS from 1995) and international congresses and meetings (AABB and NATA from 2000 to 2002). A meta-analysis estimating the benefit of PABD in our country has been performed. The variables analyzed were: period, number, surgery, rejection rate, autologous units wished, drawn and transfused; total transfusion; yield (transfused/drawn) and effectiveness. Results: The selection (only Orthopedic Surgery) included 2,933 patients, rejected rate 9.3% (C95%: 8.1-10.7) (range: 5.5 and 19.5%), yield 67.8% (CI95%: 66.1-69.5) (range: 17-94), donation 2.35 U (CI95%: 2.337-2.367) (range 1.73-3.6), transfused 1.84 autologous U (CI95%: 1.818-1.853) (range 0.74-2.85), and only autologous 75.9% (CI95%: 74.2- 77.6) (range 10-100%). Conclusion: There is little communication of the Spanish National transfusion experience of PABD which shows the large differences between groups and regions. In our analysis we found that in Spain one patient in 10 is rejected; we transfuse 2 of 3 autologous drawn, avoiding allogeneic use in 4 of each 5 of our patients