Progression and variation of competitive 100 and 200m performance at the 2021 European Swimming Championships.

Competitive progressions are necessary to ensure that peak performance occurs when medals are decided. This study aimed to: i) study the coefficient of variation (CV) and performance changes (%Δ) among swimmers who participated in different rounds (i.e., heats, semi-finals and finals); ii) study the CV changes as a function of FINA-points. A total of 1447 performances were analysed in the 100 and 200 m-races during the Budapest 2021 European-Championships. Linear mixed-effects models were applied for total and split-times to obtain intra-athlete CV and %Δ. The FINA-points were studied with two-way ANOVA and Pearson's correlation assessed the relations with CV. The CV in 100 m-races was: 0.48 ± 0.21% for males and 0.50 ± 0.20% for females (Δ = -0.66%); in 200 m-races: 0.63 ± 0.36% and 0.60 ± 0.34% (Δ = -0.82%). There were differences in FINA-points between strokes and distances (p < 0.02) associated with higher CV for the 200 m-races (r = 0.37; p = 0.003), indicating changes in performance over the rounds. Swimmers' finalists performed easier during the heats by going slower in the first 50 m-lap; however, some of them would have little chance of qualifying during major championships because some events were below FINA-points world-standards.

Graphene catalyzes the reversible formation of a C-C bond between two molecules.

Carbon deposits are well-known inhibitors of transition metal catalysts. In contrast to this undesirable behavior, here we show that epitaxial graphene grown on Ru(0001) promotes the reversible formation of a C-C bond between -CH2CN and 7,7,8,8-tetracyano-p-quinodimethane (TCNQ). The catalytic role of graphene is multifaceted: First, it allows for an efficient charge transfer between the surface and the reactants, thus favoring changes in carbon hybridization; second, it holds the reactants in place and makes them reactive. The reaction is fully reversible by injecting electrons with an STM tip on the empty molecular orbitals of the product. The making and breaking of the C-C bond is accompanied by the switching off and on of a Kondo resonance, so that the system can be viewed as a reversible magnetic switch controlled by a chemical reaction.

Bromine soil/sediment enrichment in tidal salt marshes as a potential indicator of climate changes driven by solar activity: New insights from W coast Portuguese estuaries.

This paper aims at providing insight about bromine (Br) cycle in four Portuguese estuaries: Minho, Lima (in the NW coast) and Sado, Mira (in the SW coast). The focus is on their tidal marsh environments, quite distinct with regard to key biophysicochemical attributes. Regardless of the primary bromide (Br-) common natural source, i.e., seawater, the NW marshes present relatively higher surface soil/sediment Br concentrations than the ones from SW coast. This happens in close connection with organic matter (OM) content, and is controlled by their main climatic contexts. Yet, the anthropogenic impact on Br concentrations cannot be discarded. Regarding [Br] spatial patterns across the marshes, the results show a general increase from tidal flat toward high marsh. Maxima [Br] occur in the upper driftline zone, at transition from highest low marsh to high marsh, recognized as a privileged setting for OM accumulation. Based on the discovery of OM ubiquitous bromination in marine and transitional environments, it is assumed that this Br occurs mainly as organobromine. Analysis of two dated sediment cores indicates that, despite having the same age (AD ~1300), the Caminha salt marsh (Minho estuary) evidences higher Br enrichment than the Casa Branca salt marsh (Mira estuary). This is related to a greater Br storage ability, which is linked to OM build-up and rate dynamics under different climate scenarios. Both cores evidence a fairly similar temporal Br enrichment pattern, and may be interpreted in light of the sun-climate coupling. Thereby, most of the well-known Grand Solar Minima during the Little Ice Age appear to have left an imprint on these marshes, supported by higher [Br] in soils/sediments. Besides climate changes driven by solar activity and impacting marsh Br biogeodynamics, those Br enrichment peaks might also reflect inputs of enhanced volcanic activity covarying with Grand Solar Minima.

Tackling pollution by organic farming is capable of increasing fortified foods.

The global pollution stage is poisoning the biosphere and causing global temperatures to rise, necessitating a drastic change in the way man is dealing with nature. One change that may produce many beneficial effects on the biosphere and human health is the use of specific organic farming to produce food in a more integrated way in nature and to increase the capacity of man's own response. Despite many experts' opinion another way to deal with environmental contamination is possible: organic farming, which can increase man's ability to fortify foods. After more than 20 years working under this discipline, Bodegas Dagon is able to achieve the highest stilbenes concentrations (as resveratrol). Versus 14.3 mg/l, "Bodegas Dagón" wines contain resveratrol (HPLC and UV-spectroscopy) up to 1611.73 ± 72.66 mg/l, standing as world's potentially healthiest wine reported to date.

1-Hexyl-3-methyl imidazolium tetrafluoroborate: an efficient column enhancer for the separation of basic drugs by reversed-phase liquid chromatography.

Ionic liquids are dual modifiers composed by a large anion and a large cation, which interact with both the hydrophobic alkyl-bonded phase and the anionic residual silanols in C18 columns. The deactivation of the silanol groups has important implications on the chromatographic analysis of basic drugs, being the improvement of peak profiles and shorter retention times the most noticeable features. However, other characteristics as selectivity or resolution are not usually considered, or are only examined for selected chromatographic conditions. In this work, the effect of the addition of the ionic liquid 1-hexyl-3-methyl imidazolium tetrafluoroborate to acetonitrile-water mixtures in a wide range of concentrations, using three C18 columns (Zorbax SB-C18, Nucleosil and Spherisorb) was studied for the separation of a group of ß-adrenolytic drugs. The extremely poor chromatographic performance was highly improved in the presence of the ionic liquid, giving rise to shorter analysis times, smaller consumption of acetonitrile, significantly narrower and more symmetric peaks, and high resolution. The improvement was especially noteworthy for the Spherisorb column, which yielded the poorest results in the absence of additive.

Measurement of the elution strength and peak shape enhancement at increasing modifier concentration and temperature in RPLC.

Two approaches are proposed to measure the effect of different experimental factors (such as the modifier concentration and temperature) on the elution strength and peak shape in reversed-phase liquid chromatography, which quantify the percentage change in the retention factor and peak width (referred to the weakest conditions) per unit change in the experimental factor. The approaches were applied to the separation of a set of flavonoids with aqueous micellar mobile phases of the surfactant Brij-35 (polyoxyethylene(23)dodecanol), in comparison with acetonitrile-water mixtures, using an Eclipse XDB-C18 column. The particular interaction of each flavonoid with the oxyethylene chains of Brij-35 molecules (adsorbed on the stationary phase or forming micelles) changed the elution window, distribution of chromatographic peaks and partitioning kinetics, depending on the hydroxyl substitution in the aromatic rings of flavonoids. At 25 °C, peak shape with Brij-35 mobile phases was significantly poorer with regard to acetonitrile-water mixtures. At increasing temperature, the efficiency of Brij-35 increased, approaching at 80 °C the values obtained at equilibrium conditions, already reached with acetonitrile at 25 °C.

Silanol suppressing potency of alkyl-imidazolium ionic liquids on C18 stationary phases.

Residual silanols on C18 columns yield undesirable slow-kinetics ion-exchange interactions with positively charged basic compounds that result in asymmetrical peaks, low efficiencies and long retention times. The purity of the silica employed as supporting material, and the technique used to form the bonded phase, which varies with the brand and manufacturer, give rise to different amounts of residual silanols in the packings, and consequently, different chromatographic performance. One of the most efficient and widespread strategies to reduce or even eliminate the different performance among columns is the addition of a reagent to the mobile phase to block the silanol sites. However, the intrinsic nature of both stationary phase and additive leads to particular results. In this work, a group of basic compounds were analysed using six C18 stationary phases (Zorbax SB-C18, X-Terra MS C18, Kromasil, Lichrospher, Nucleosil, and Spherisorb) and acetonitrile-water mixtures. Two ionic liquids (ILs), 1-butyl- and 1-hexyl-3-methyl-imidazolium tetrafluoroborates, were added to the mobile phases to evaluate their silanol suppressing potency, based on the decreased retention of the basic compounds when the silanols are blocked (described by the Horváth equation), and the improvement in peak profile (described by the plots of the peak half-widths at diverse retention times). The suppressing potency based on the retention can be misleading when the adsorption of the IL anion is not negligible, since the anion attracts the cationic basic compounds increasing the retention. However, the accessibility of basic compounds to the silanols is prevented by both IL cation and anion, improving the peak profiles for all stationary phases. This was especially remarkable for Spherisorb, which in the absence of additive yielded by far the worst performance. 1-Hexyl-3-methyl-imidazolium tetrafluoroborate was the best additive in terms of retention and peak profile (width and asymmetry).

The role of the dual nature of ionic liquids in the reversed-phase liquid chromatographic separation of basic drugs.

The cationic nature of basic drugs gives rise to broad asymmetrical chromatographic peaks with conventional C18 columns and hydro-organic mixtures, due to the ionic interaction of the positively charged solutes with the free silanol groups on the alkyl-bonded reversed-phase packing. Ionic liquids (ILs) have recently attracted some attention to reduce this undesirable silanol activity. ILs are dual modifiers (with a cationic and anionic character), which means that both cation and anion can be adsorbed on the stationary phase, giving rise to interesting interactions with the anionic free silanols and the cationic basic drugs. A comparative study of the performance of four imidazolium-based ILs as modifiers of the chromatographic behaviour of a group of ß-blockers is shown. The ILs differed in the adsorption capability of the cation and anion on C18 columns. Mobile phases without additive and containing a cationic (triethylamine, TEA) or anionic (sodium dodecyl sulphate, SDS) additive were used as references for the interpretation of the behaviours. The changes in the nature of the chromatographic system, at increasing concentration of the additives, were followed based on the changes in retention and peak shape of the ß-blockers. The silanol suppressing potency of the additives, and the association constants between the solutes and modified stationary phase or additive in the mobile phase, were estimated. The study revealed that SDS and the ionic liquid 1-hexyl-3-methylimidazolium tetrafluoroborate are the best enhancers of chromatographic peak shape among those studied.

[Evolution of serological characteristics in 26 patients with tularemia three years after the outbreak]. / Análisis serológico evolutivo de 26 pacientes con tularemia tres años después del brote.

INTRODUCTION: Tularemia was an unknown zoonosis in our region until the first quarter of 1998. The outbreak that took place on those dates has made possible to study some scantly known characteristics of the disease, as are the determinants for the persistence of a high antibody titer. MATERIAL AND METHODS: Between March and May, 2001, a clinical-analytical control was carried out in 26 patients who showed tularemia in the first quarter of 1998. RESULTS: The clinical forms during the acute phase were: ulceroglandular (46.2% of patients), nodal (26.9%), typhoid (15.4%) and pharyngeal (11.5%). Antibiotics most prescribed were streptomycin and doxycycline. Nine patients showed sequelae three years later. The arithmetical mean of antibody titer declined from 1/1011 in 1998 to 1/187 in 2001. 76.92% of the patients maintained an antibody titer equal or higher than 1/160 three years after the acute phase. A significant relation between the initial antibody titer and the antibody titer registered in the late phase was observed. A relationship between final antibody titer and prescribed antibiotic, presence of sequelae, gender, or age was not demonstrated. CONCLUSIONS: The antibody titer in the presence of Francisella tularensis is high in an important percentage of the patients along years. We should reconsider the standard diagnostic criteria to our community, accepting as a certainty diagnosis exclusively the presence of a demonstrative culture or the existence of seroconversion.

[Transurethral thermotherapy with microwaves in patients with benign prostatic hypertrophy and urinary retention: comparative study between high energy (25) and standard energy (2.0)]. / Termoterapia transuretral con microondas en pacientes con hipertrofia benigna prostática y retención urinaria: estudio comparativo entre alta energía (25) y energía standard (2.0).

OBJECTIVES: During a 36-month period, 63 patients with benign prostatic hypertrophy (BPH) who presented urinary retention, were treated on an outpatient basis by transurethral microwave thermotherapy (TUMT) with the Prostatron device using analgosedation. METHODS: Treatment consisted of a single one hour session with Prostasoft 2.0 for the first group of 11 patients. The second group of 19 patients received 2 hours Prostasoft 2.0. The third group comprised of 33 patients were treated with higher energy TUMT (Prostasoft 2.5/1 h 30 min). The number of sessions (144) depended on prostate length: L < 45 mm: one session (Prostanec catheter); L < 55 mm: two sessions (additional black catheter session); L < 65 mm: three sessions (additional white catheter session). RESULTS: In the first group of patients, 54% were catheter-free after one year (5 TURP); 84% (3 TURP) in the second group; 96% (1 TURP) in the third group. The morbidity was similar for all groups. CONCLUSIONS: Only high energy TUMT (Prostasoft 2.5/1 h 30 min) appears to be a minimally reasonable alternative to surgery in elderly patients with urinary retention secondary to prostatism and concomitant diseases. Longer followup is warranted to determine if the beneficial effects will persist.

[Transurethral thermotherapy with microwaves in symptomatic prostatic benign hypertrophy: comparison between the high-energy (2.5) protocol and the standard protocol (2.0)]. / Termoterapia transuretral con microondas en la hipertrofia benigna prostática sintomática: comparación entre el protocolo de alta energía (2.5) y el protocolo standard (2.0).

OBJECTIVES: The efficacy of three therapeutic protocols of transurethral microwave thermotherapy (TUMT), was compared in a study comprised of 355 patients that had been treated for benign prostatic hypertrophy (BPH) between March, 1992 and March, 1995. METHODS: TUMT were performed with the Prostatron device with intravenous analgosedation and on an outpatient basis. In the first group (Protocol A), 122 patients received a standard treatment (Prostasoft 2.0/hour); the second group of 81 patients were included into Protocol B (Prostasoft 2.0/2 hours); 152 patients were treated with higher-energy in Protocol C (Prostasoft 2.5/1 hour). The number of sessions (635) performed were based on prostatic length: L < 45 mm - one session (Prostanec catheter); L < 55 mm - two sessions (additional black catheter session); L < 65 mm - three session (additional white catheter session). RESULTS: All groups improved significantly for subjective symptoms (symptom score) and objective parameters (peak flow, residual urine). Comparison of the results between the three groups at 6 and 12 months showed a significantly better clinical outcome in protocol C >> B > A: Morbidity was higher in group C than in group B than in group A. CONCLUSION: Our results indicate that transurethral microwave thermotherapy is a safe and effective procedure which improves objective and subjective parameters. Better outcomes were obtained with long session times (2H) and overall higher energy (2.5) input, which may be explained by the creation by cavities within the prostate, but at the cost of increased morbidity. However, TUMT can still be delivered as an anesthesia-free and outpatient non-surgical alternative treatment for BPH.

Synthesis and pharmacology of two new histamine receptor antagonists related to ranitidine.

Pyridyl and 1,6-dihydropyridyl ranitidine analogues 1 and 2 were obtained by applying an improved modification of ranitidine synthesis. Compound 1 shows a selective H2 antagonistic activity while compound 2 is a non-selective histamine antagonist.

[Transurethral prostatic thermotherapy with microwaves (prostatron system) in bladder obstruction secondary to benign prostatic hypertrophy]. / Termoterapia prostática transuretral con microndas (sistema prostatron) en la obstrucción vesical secundaria a hipertrofia benigna prostática.

Since April, 1992, 178 patients with symptomatic benign prostatic hyperplasia were treated by TUMT (363 treatments). Before entering the study, all patients had a Madsen symptom score of > 8, peak flow rate of < 15 ml/s, or average flow rate of < 10 ml/s, and post voiding residual urine of < 300 ml/s. The prostatic length was classified into group I < 50 mm (101 patients) and group II < 50 mm (77 patients). TUMT with the Prostatron device (Technomed) was performed in one, two or three session(s) of one or two hour(s) with analgosedation and on an outpatient basis. After treatment all patients were catheterized for 1-3 weeks; the morbidity rate was very low. Three and six months after treatment, the Madsen symptom score, peak flow rate, average flow rate and postvoiding residual urine improved to a high statistical significance in both groups. TUMT for benign prostatic outflow obstruction proved to be an effective treatment throughout the study period, with minimum morbidity. It must be emphasized that the degree of prostatic enlargement or the severity of the symptoms does not indicate clinical success or failure. However, the degree of bladder outflow obstruction and the quality of treatment achieved are very important: a) In patients with severe obstruction, TURP or open surgery continues to be the treatment that affords rapid relief of their symptoms. b) The clinical response to TUMT is dose-dependent; i.e., higher thermal dose, longer session (2 h) and the use of different catheters enhance the therapeutic efficacy.

[Schönlein-Henoch purpura. A report of 55 cases]. / Púrpura de Henoch-Schönlein. Informe de 55 casos.

The clinical, histological and laboratory data from a series of 55 pediatric patients with Henoch-Schönlein purpura studied at the Hospital General de Mexico in a 16-years period are presented herein. Even when there are a few clinical features in this example of Mexican children, the clinical presentation and the course of the disease are similar to what is found in the literature.

[Hemangiopericytoma of the maxillary sinus: apropos of a case]. / Hemangiopericitoma del seno maxilar: a propósito de un caso.

Haemangiopericytoma is a rare vascular tumour arising from the proliferation of pericytes which are cells surrounding the capillaries. Since 1949 only 54 cases of haemangiopericytomas of the nose and paranasal sinuses have been reported in the literature. Of the latter, only 8 cases originated from the maxillary sinus. We report a further case originated from the maxillary sinus.

[Chemodectomas of the carotid body. Apropos 2 cases]. / Quemodectomas del corpúsculo carotídeo. A propósito de dos casos.

The chemodectoma a paragangliomas of the carotid body are infrequent tumors in the daily medical practice, but they must be taken into account in the differential diagnosis of any lateral neck mass. We present two new cases, reconsidering the existing literature.