Millimeter-Scale Zn(3-ptz)2 Metal-Organic Framework Single Crystals: Self-Assembly Mechanism and Growth Kinetics.

The solvothermal synthesis of metal-organic frameworks (MOFs) often proceeds through competing crystallization pathways, and only partial control over the crystal nucleation and growth rates is possible. It challenges the use of MOFs as functional devices in free-space optics, where bulk single crystals of millimeter dimensions and high optical quality are needed. We develop a synthetic protocol to control the solvothermal growth of the MOF [Zn(3-ptz)2] n (MIRO-101), to obtain large single crystals with projected surface areas of up to 25 mm2 in 24 h, in a single reaction with in situ ligand formation. No additional cooling and growth steps are necessary. We propose a viable reaction mechanism for the formation of MIRO-101 crystals under acidic conditions, by isolating intermediate crystal structures that directly connect with the target MOF and reversibly interconverting between them. We also study the nucleation and growth kinetics of MIRO-101 using ex situ crystal image analysis. The synthesis parameters that control the size and morphology of our target MOF crystal are discussed. Our work deepens our understanding of MOF growth processes in solution and demonstrates the possibility of building MOF-based devices for future applications in optics.

Por una Educación Física virtual en tiempos de COVID / Para uma Educação Física virtual em tempos de COVID / In favor of a virtual Physical Education in times of COVID

Resumen El virus Sars-Cov-2 ha provocado inevitablemente la enfermedad Covid-19. Ha sido una de las peores noticias que le ha acontecido a la humanidad en estos duros inicios del siglo XXI. Los daños materiales y pérdidas de vidas humanas han sido significativos, así como los efectos colaterales desde el punto de vista social y psicológico. En respuesta a contener o contrarrestar estas elevadas afectaciones, diversas áreas del saber y de la actividad humana se activan, se multiplican y crean nuevas estrategias de mitigación. Una de las áreas que más ha aportado durante los períodos de cuarentena y posteriores a este, es el área de la Cultura Física, el deporte y específicamente la didáctica de la Educación Física. El objetivo de este trabajo es realizar una sistematización sobre un grupo de publicaciones científicas referidas a la actividad física, el deporte y la Educación Física en tiempos de COVID, enfocadas en el entorno virtual y el empleo de las TICs. Con este estudio, se pretende realizar un análisis sobre las principales posiciones de los autores en función de obtener un criterio sobre las potencialidades de la Educación Física virtual para enfrentar los embates de la COVID-19. Unido a esta periodización se añadirá un grupo de recomendaciones metodológicas dirigidas a perfeccionar el trabajo del docente de Educación Física con el empleo de las Tics en estos momentos excepcionales que atraviesa la humanidad.

Resumo O vírus Sars-Cov-2 levou inevitavelmente à doença de Covid-19. Tem sido uma das piores notícias que tem acontecido à humanidade nestes duros começos do século XXI. Os danos materiais e a perda de vidas humanas têm sido significativos, bem como os efeitos colaterais do ponto de vista social e psicológico. Em resposta a conter ou contrariar estes elevados impactos, várias áreas do conhecimento e da atividade humana são ativadas, multiplicando-se e criando novas estratégias de mitigação. Uma das áreas que mais contribuiu durante os períodos de quarentena e pós quarentena foi a área da Cultura Física, desporto e especificamente o ensino da Educação Física. O objetivo deste trabalho é sistematizar um grupo de publicações científicas relacionadas com a atividade física, desporto e Educação Física no tempo da COVID, centrando-se no ambiente virtual e na utilização das TIC. O objetivo deste estudo é analisar as principais posições dos autores a fim de obter um critério sobre o potencial da Educação Física virtual para enfrentar os ataques da COVID-19. Juntamente com esta periodização, será acrescentado um grupo de recomendações metodológicas, destinadas a aperfeiçoar o trabalho do professor de Educação Física com a utilização das TIC nestes momentos excepcionais que a humanidade está a atravessar.

Abstract The Sars-Cov-2 virus has inevitably caused the Covid-19 disease. It has been one of the worst news that has happened to humanity at the beginning of the 21st century. The material damage and loss of human life has been significant, as well as the collateral effects from the social and psychological point of view. In response to contain or counteract these high affectations, various areas of knowledge and human activity are activated, multiplying and creating new mitigation strategies. One of the areas that has contributed the most during the quarantine periods and after it, is the area of Physical Culture, sports and specifically the didactics of Physical Education. The aim of this work is to systematize a group of scientific publications referred to physical activity, sport and Physical Education in times of COVID, focused on the virtual environment and the use of ICTs. With this study, it is intended to carry out an analysis of the main positions of the authors in order to obtain a criterion about the potentialities of virtual Physical Education to face the COVID-19 attacks. Together with this periodization, a group of methodological recommendations will be added, aimed at perfecting the work of Physical Education teachers with the use of ICTs in these exceptional moments that humanity is going through.

Azide-Based High-Energy Metal-Organic Frameworks with Enhanced Thermal Stability.

We describe the structure and properties of [Zn(C6H4N5)N3] n , a new nonporous three-dimensional high-energy metal-organic framework (HE-MOF) with enhanced thermal stability. The compound is synthesized by the hydrothermal method with in situ ligand formation under controlled pH and characterized using single-crystal X-ray diffraction, elemental analysis, and Fourier transform infrared. The measured detonation temperature (T det = 345 °C) and heat of detonation (ΔH det = -0.380 kcal/g) compare well with commercial explosives and other nitrogen-rich HE-MOFs. The velocity and pressure of denotation are 5.96 km/s and 9.56 GPa, respectively. Differential scanning calorimetry analysis shows that the denotation of [Zn(C6H4N5)N3] n occurs via a complex temperature-dependent mechanism.

Hexa-aqua-zinc(II) dinitrate bis-[5-(pyridinium-3-yl)tetra-zol-1-ide].

Hexa-aqua-zinc(II) dinitrate 5-(pyridinium-3-yl)tetra-zol-1-ide, [Zn(H2O)6](NO3)2·2C6H5N5, crystallizes in the space group P . The asymmetric unit contains one zwitterionic 5-(pyridinium-3-yl)tetra-zol-1-ide mol-ecule, one NO3- anion and one half of a [Zn(H2O)6]2+ cation ( symmetry). The pyridinium and tetra-zolide rings in the zwitterion are nearly coplanar, with a dihedral angle of 5.4 (2)°. Several O-H⋯N and N-H⋯O hydrogen-bonding inter-actions exist between the [Zn(H2O)6]2+ cation and the N atoms of the tetra-zolide ring, and between the nitrate anions and the N-H groups of the pyridinium ring, respectively, giving rise to a three-dimensional network. The 5-(pyridinium-3-yl)tetra-zol-1-ide mol-ecules show parallel-displaced π-π stacking inter-actions; the centroid-centroid distance between adjacent tetra-zolide rings is 3.6298 (6) Šand that between the pyridinium and tetra-zolide rings is 3.6120 (5) Å.

pH-Controlled Assembly of 3D and 2D Zinc-Based Metal-Organic Frameworks with Tetrazole Ligands.

We report the synthesis and structural diversity of Zn(II) metal-organic framework (MOF) with in situ formation of tetrazole ligand 3-ptz [3-ptz = 5-(3-pyridyl)tetrazolate] as a function pH. By varying the initial reaction pH, we obtain high-quality crystals of the noncentrosymmetric three-dimensional MOF Zn(3-ptz)2 , mixed phases involving the zinc-aqua complex [Zn(H2O)4(3-ptz)2]·4H2O, and two-dimensional MOF crystals Zn(OH)(3-ptz) with a tunable microrod morphology, keeping reaction time, temperature, and metal-ligand molar ratio constant. Structures are characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and UV-vis spectroscopy. We discuss the observed structural diversity in terms of the relative abundance of hydroxo-zinc species in solution for different values of pH.

[Blunt chest trauma with pneumomediastinum and pneumoperitoneum secondary to Macklin effect. Case report]. / Trauma contuso de tórax con neumomediastino y neumoperitoneo secundario a efecto Macklin. Reporte de un caso.

BACKGROUND: Pneumomediastinum is the presence of free air around mediastinal structures, which may be spontaneous or secondary, and can occur in 10% of patients with blunt chest trauma, with the Macklin effect being its main pathophysiology. CLINICAL CASE: A 21 year old male, hit by motor vehicle, with alvéolopalatal fracture and blunt chest trauma, who, 72 hrs after admission, shows subcutaneous emphysema in the anterior chest. A simple tomography of the chest and abdomen was performed, finding a pneumomediastinum, bilateral pulmonary contusions and pneumoperitoneum. Oesophageal, tracheobronchial or intra-abdominal viscera injuries were ruled out, establishing the cause of pneumomediastinum and pneumoperitoneum due to the Macklin effect. This required conservative management in intensive care unit, with a favourable clinical course and discharged after a 10 day hospital stay. DISCUSSION: Macklin effect is caused by dissection of air medially along the bronchoalveolar sheath (interstitial emphysema), secondary to alveolar breakdown and extending into mediastinal and other anatomical structures (pneumoperitoneum). It has been documented in blunt trauma, as well as in acute asthma, positive pressure ventilation, or after Valsalva manoeuvres. The imaging method of choice is computed tomography, and its characteristic findings, interstitial emphysema adhering to a bronchus and pulmonary blood vessel. CONCLUSIONS: In the presence of pneumomediastinum and pneumoperitoneum is necessary to rule out oesophageal and tracheobronchial injury before establishing the Macklin effect as its cause. The diagnosis is made with computed tomography and managed conservatively.

[Concept maps as a tool for the diagnosis of rare diseases]. / Mapas conceptuales para el diagnóstico de enfermedades raras en atención primaria.

Rare diseases are a real public health problem for hospitals and also for primary care. We describe some metaphor-based diagnosis procedures, such as: "When you hear hoof beats don't always think horses, sometimes they could be zebras", or that one about the antiquarian who recognised a museum masterpiece while walking in the Rastro (Madrid). The "lightning diagnoses" by Skoda are an important historic record. T. Greenhalgh has tried to cover the gap between evidence based medicine and the intuitive diagnosis. We point out some clinical epidemiology rules in order to improve their early detection by family practitioners and paediatricians. In our opinion, the training in the diagnosis of rare diseases has to be different for primary care level and for hospital doctors. Concept maps are useful for diagnosis in primary care clinics.

[Infection by the pandemic virus (H1N1) 2009 in Andalusia]. / Infección por virus pandémico (H1N1) 2009 en Andalucía.

In April 2009, in response to the WHO's alert due to the existence of human infection cases with a new AH1N1 influenza virus, known as swine flu, Andalusian Health Authorities trigger an specific action plan. The surveillance actions developped provided us with appropriate clinical, epidemiological and virological characteristics of the disease. During the first few days, contingency plans were set up based on epidemiological surveillance and outbreak control measures were adopted through early alert and rapid response systems. After phase 6 was declared, influenza sentinel and severe cases surveillance were used in order to plan healthcare services, to reduce transmission and to identify and protect the most vulnerable population groups. Behaviour of pandemic influenza in Andalusia was similar to that observed in the rest of the world. Atack rate was similar to a seasonal flu and the peak was reached at the 46th/2009 week. Most of them were mild cases and affected particularly to young people. The average age of hospitalised patients was 32. Prior pulmonary disease, smoking and morbid obesity (BMI > 40) were the most common pathologies and risk factors in severe cases. An impact scenario of pandemic wave in Andalusia, with an expected attack rate from 2 to 5%, was prepared considering watt observed in the southern hemisphere. Characteristics of the epidemic concerning its extent, severity and mortality rate were adjusted to this scenario.

[An epidemic outbreak with respiratory symptoms in the province of Almeria [Spain] due to toxic microalgae exposure]. / Brote con síntomas respiratorios en la provincia de Almería por una posible exposición a microalgas tóxicas.

AIM: To describe an outbreak with symptoms of respiratory tract irritation reported in a village located on the Almerian coast in August 2006, as well as the etiological research performed. METHODS: We performed a descriptive case-control study. The village was divided into three areas (from 1 to 3) according to the distance from the sea. Symptomatology was subjectively assessed on an ascending severity scale (from 1 to 3). Attack rates (AR) were estimated. To correlate symptom severity by areas and type of exposure, odds ratios (OR) with 95% confidence intervals were estimated. The chi-square test and Fisher's exact test were used. Environmental research was performed. RESULTS: Fifty-seven cases and 26 controls were surveyed. An AR of 69% was estimated. The most frequent symptom was sneezing (87.7%). Residents in area 1 had a higher risk of more severe symptoms than those in area 3 (OR = 46.7; 95%CI: 4.7-2,067.4). Residents who reported having spent more time outside had a higher risk of more severe symptoms (OR = 12.2; 95%CI: 1.1-615.1). A concentration of dinoflagellates Ostreopsis of 1200 cells/l was determined in sea water. CONCLUSIONS: An outbreak with respiratory symptoms and with differing severity depending on the distance of housing from the sea occurred. According to the environmental and epidemiological research, the symptoms were probably related to the presence of Ostreopsis toxic microalgae.

Biogenic sulphide plays a major role on the riboflavin-mediated decolourisation of azo dyes under sulphate-reducing conditions.

The effect of high concentrations of sulphate on the reductive decolourisation of different azo dyes by anaerobic sludge was studied in batch cultures. Sludge cultures were pre-incubated under sulphate-reducing conditions prior addition of dyes. Little or no effects of sulphate (5-10 g sulphate l(-1)) on the rate of decolourisation of Reactive Orange 14 (RO14), Direct Blue 53 (DB53) and Direct Blue 71 (DB71) were observed when no external redox mediator was provided. However, an increase in sulphate concentration, in the presence of riboflavin (20 microM), enhanced the decolourisation of all dyes. The first-rate constant of decolourisation (k) was increased up to 2-, 3.6- and 2-fold for RO14, DB53 and DB71, respectively, by supplying high sulphate concentrations, compared to the controls lacking sulphate, in the presence of the redox mediator. Sulphate reduction did not take place during the course of azo reductions, but was only evident before dye addition and after complete decolourisation, suggesting azo dyes reduction out-competed sulphate reduction for the available reducing equivalents. The experimental data suggest that reduction of azo dyes by riboflavin, which had been reduced by biogenic sulphide, was the major mechanism implicated during decolourisations, which was corroborated by abiotic incubations. Riboflavin greatly accelerated the abiotic reduction of RO14, so that the k value was increased up to 44-fold compared to the control lacking riboflavin.