Investigation of encapsulated water wire within self-assembled hydrophilic nanochannels, in a modified γ4-amino acid crystals: Tracking thermally induced changes of intermolecular interactions within a crystalline hydrate.

Nanostructures formed by the self-assembly of modified/unmodified amino acids have the potential to be useful in several biological/nonbiological applications. In that regard, the greater conformational space provided by γ-amino acids, owing to their additional backbone torsional degrees of freedom and enhanced proteolytic stability, compared to their α-counterparts, should be explored. Though, modified single amino acid-based nanomaterials such as nanobelts or hydrogels are developed by utilizing the monosubstituted γ-amino acids derived from the backbone homologation of phenylalanine (Phe). Examples of a single γ-amino acid-based porous nanostructure capable of accommodating solvent molecules are not really known. The crystal structures of a modified γ4(R)Phe residue, Boc-γ4(R)Phe-OH, at different temperatures, showed that hydrogen-bonded water molecules are forming a wire inside hydrophilic nanochannels. The dynamics of intermolecular interactions between the water wire and the inner wall of the channel with relation to the temperature change was investigated by analyzing the natural bonding orbital (NBO) calculation results performed with the single crystal structures obtained at different temperature points. The NBO results showed that from 325 K onward, the strength of water-water interactions in the water wire are getting weaker, whereas, for the water-inner wall interactions, it getting stronger, suggesting a favorable change in the orientation of water molecules with temperatures, for the latter.

Crystal structure of 2-methyl-1H-imidazol-3-ium 3,5-di-carb-oxy-benzoate.

The structure of the title salt, C4H7N2 +·C9H5O6 - (1), is reported. The compound is built from a protonated 2-methyl-imidazole and a singly deprotonated trimesic acid. Detailed analysis of bond distances and angles for both ions reveals subtle differences compared with their neutral mol-ecule counterpart. Analysis of the crystal packing in compound 1 reveals the formation of undulating chains by the ions through hydrogen bonding. The chains stack along the b axis through π-π inter-actions and inter-connect with other chains in an out-of-phase arrangement along the ac plane through further hydrogen-bonding inter-actions.

Structural dynamics of a thermally silent triiron(II) spin crossover defect grid complex.

The structural evolution of spin crossover (SCO) complexes during their spin transition at equilibrium and out-of-equilibrium conditions needs to be understood to enable their successful utilisation in displays, actuators and memory components. In this study, diffraction techniques were employed to study the structural changes accompanying the temperature increase and the light irradiation of a defect [2 × 2] triiron(II) metallogrid of the form [FeII3LH2(HLH)2](BF4)4·4MeCN (FE3), LH = 3,5-bis{6-(2,2'-bipyridyl)}pyrazole. Although a multi-temperature crystallographic investigation on single crystals evidenced that the compound does not exhibit a thermal spin transition, the structural analysis of the defect grid suggests that the flexibility of the grid, provided by a metal-devoid vertex, leads to interesting characteristics that can be used for intermolecular cooperativity in related thermally responsive systems. Time-resolved photocrystallography results reveal that upon excitation with a ps laser pulse, the defect grid shows the first two steps of the out-of-equilibrium process, namely the photoinduced and elastic steps, occurring at the ps and ns time scales, respectively. Similar to a previously reported [2 × 2] tetrairon(II) metallogrid, FE3 exhibits a local distortion of the entire grid during the photoinduced step and a long-range distortion of the lattice during the elastic step. Although the lifetime of the pure photoinduced high spin (HS) state is longer in the tetranuclear grid than in the defect grid, suggesting that the global nuclearity plays a crucial role for the lifetime of the photoinduced species, the influence of the co-crystalising solvent on the lifetime of the photoinduced HS state remains unknown. This study sheds light on the out-of-equilibrium dynamics of a thermally silent defect triiron SCO metallogrid.

Axial vs equatorial: Capturing the intramolecular charge transfer state geometry in conformational polymorphic crystals of a donor-bridge-acceptor dyad in nanosecond-time-scale.

Two conformational polymorphs of a donor-bridge-acceptor (D-B-A) dyad, p-(CH3)2N-C6H4-(CH2)2-(1-pyrenyl)/PyCHDMA, were studied, where the electron donor (D) moiety p-(CH3)2N-C6H4/DMA is connected through a bridging group (B), -CH2-CH2-, to the electron acceptor (A) moiety pyrene. Though molecular dyads like PyCHDMA have the potential to change solar energy into electrical current through the process of photoinduced intramolecular charge transfer (ICT), the major challenge is the real-time investigation of the photoinduced ICT process in crystals, necessary to design solid-state optoelectronic materials. The time-correlated single photon counting (TCSPC) measurements with the single crystals showed that the ICT state lifetime of the thermodynamic form, PyCHDMA1 (pyrene and DMA: axial), is ∼3 ns, whereas, for the kinetic form, PyCHDMA20 (pyrene and DMA: equatorial), it is ∼7 ns, while photoexcited with 375 nm radiation. The polymorphic crystals were photo-excited and subsequently probed with a pink Laue x-ray beam in time-resolved x-ray diffraction (TRXRD) measurements. The TRXRD results suggest that in the ICT state, due to electron transfer from the tertiary N-atom in DMA moiety to the bridging group and pyrene moiety, a decreased repulsion between the lone-pair and the bond-pair at N-atom induces planarity in the C-N-(CH3)2 moiety, in both polymorphs. The Natural Bond Orbital calculations and partial atomic charge analysis by Hirshfeld partitioning also corroborated the same. Although the interfragment charge transfer (IFCT) analysis using the TDDFT results showed that for the charge transfer excitation in both conformers, the electrons were transferred from the DMA moiety to mostly the pyrene moiety, the bridging group has little role to play in that.

Short- vs. long-range elastic distortion: structural dynamics of a [2 × 2] tetrairon(II) spin crossover grid complex observed by time-resolved X-Ray crystallography.

Spin crossover complexes (SCO) are among the most studied molecular switches due to their potential use in displays, sensors, actuators and memory components. A prerequisite to using these materials is the understanding of the structural changes following the spin transition at out-of-equilibrium conditions. So far, out-of-equilibrium studies in SCO solids have been focused on mononuclear complexes, though a growing number of oligonuclear SCO complexes showing cooperative effects are being reported. Here, we use time-resolved pink Laue crystallography to study the out-of-equilibrium dynamics of a [2 × 2] tetranuclear metallogrid of the form [FeII4LMe4](BF4)4·2MeCN ([LMe]- = 4-methyl-3,5-bis{6-(2,2'-bipyridyl)}pyrazolate). The out-of-equilibrium spin state switching induced by a ps laser pulse demonstrates that the metallogrid exhibits a multi-step response similar to that reported for mononuclear complexes. Contrary to the mononuclear complexes, the metallogrid shows two types of elastic distortions at different time scales. The first is a short-range distortion that propagates over the entire Fe4 grid complex during the ps time scale, and it is caused by the rearrangement of the coordination sphere of the photo-switching ion and the constant feedback between strongly linked metal ions. The second is a long-range distortion caused by the anisotropic expansion of the lattice during the ns time scale, observed in mononuclear materials. The structural analysis demonstrates that the long-range prevails over the short-range distortion, inducing the largest deformation of both the entire grid and the coordination sphere of each metal ion. The present study sheds light on the out-of -equilibrium dynamics of a non-cooperative oligonuclear complex.

Unravelling the synthesis of a rare-earth cluster-based metal-organic framework with spn topology.

Y-CU-45, an analogue of Zr-MOF-808, is synthesized for the first time. Several reaction conditions are tested demonstrating that two fluorinated modulators are required for a reproducible synthesis yielding high quality material. Y-CU-45 shows high crystallinity and surface area, shining light on the potential for rare-earth cluster-based MOFs with open metal sites.

Synthesis and structure of hexa-aqua-cobalt bis-(2-methyl-1H-imidazol-3-ium) tetra-aqua-bis-(benzene-1,3,5-tri-carboxyl-ato-κO)cobalt.

The title compound, (C4H7N2)2[Co(H2O)6][Co(C9H3O6)2(H2O)4] (1), was synthesized from cobalt(II) chloride, 1,3,5-benzene tri-carb-oxy-lic acid (Hbtc) and 2-methyl-imidazole (H-2mIm) under ambient conditions. The structure of 1 is here reported and compared with the parent complex hexa-aqua-cobalt bis-(1H-imidazol-3-ium) tetra-aqua-bis-(benzene-1,3,5-tri-carboxyl-ato)cobalt (2).

Structural Capture of η1-OSO to η2-(OS)O Coordination Isomerism in a New Ruthenium-Based SO2-Linkage Photoisomer That Exhibits Single-Crystal Optical Actuation.

Recent discoveries of a range of single-crystal optical actuators are feeding a new form of materials chemistry, given their broad range of potential applications, from light-induced molecular motors to light sensors and optical-memory media. A series of ruthenium-based coordination complexes that exhibit sulfur dioxide linkage photoisomerization is of particular interest because they exhibit single-crystal optical actuation via either optical switching or nano-optomechanical transduction processes. We report the discovery of a new complex in this series of chemicals, [Ru(SO2)(NH3)4(3-fluoropyridine)]tosylate2 (1), which forms an η1-OSO photoisomer with 70% photoconversion upon the application of 505 nm light. The uncoordinated oxygen atom in this η1-OSO photoisomer impinges on one of the arene rings in a neighboring tosylate counter ion of 1 just enough that incipient nano-optomechanical transduction is observed. The structure and optical properties of this actuator are characterized via in situ light-induced single-crystal X-ray diffraction (photocrystallography), single-crystal optical absorption spectroscopy and microscopy, as well as single-crystal Raman spectroscopy. These materials-characterization methods were also used to track thermally induced reverse isomerization processes in 1. One of these processes involves an η1-OSO to η2-(OS)O transition, which was found to proceed sufficiently slowly at 110 K that its structural mechanism could be determined via a time sequence of photocrystallography experiments. The resulting data allowed us to structurally capture the transition, which was shown to occur via a form of coordination isomerism. Our newfound knowledge about this structural mechanism will aid the molecular design of new [RuSO2] complexes with functional applications.

Metal-to-metal communication during the spin state transition of a [2 × 2] Fe(II) metallogrid at equilibrium and out-of-equilibrium conditions.

Spin crossover (SCO) complexes are prototypes of materials with bi- or multi-stability in the solid state. The structural evolution during their spin transition is a key feature to establish the foundations of how to utilize this type of material. So far, ultrafast time-resolved structural investigations of SCO solids have been focused on monometallic complexes, though an increasing number of oligometallic SCO complexes showing cooperativity effects are being reported. Here, we used single crystal X-ray crystallography and time-resolved pink Laue photocrystallography to study the molecular reorganisation during the thermal and photoinduced SCO of a [2 × 2] tetranuclear metallogrid of the form [FeII4LMe4](BF4)4·2MeCN ([LMe]- = 4-methyl-3,5-bis{6-(2,2'-bipyridyl)}pyrazolate). A multitemperature crystallographic investigation on single crystals reveals an effective communication between the metal centres during thermal SCO, observed by the simultaneous transformation of the coordination polyhedra of both crystallographic-symmetry independent metal atoms accompanying the SCO in only one of them. Time-resolved photocrystallography results reveal the different molecular responses between mononuclear and oligonuclear complexes, after light irradiation with a picosecond laser pulse. While mononuclear SCO complexes reorganise once during the first nanosecond after excitation, the tetranuclear metallogrid exhibits a multiple structural rearrangement in the same span of time. Such behaviour is attributed to the elastic communication between metal atoms, which allows the propagation of a short-range elastic distortion over the entire Fe4 grid complex. The present study sheds light on the importance of strong elastic coupling of metal atoms during the correlated spin transition of oligometallic complexes.

[Factors associated to death in patients hospitalized due to COVID-19]. / Factores asociados a defunción en pacientes hospitalizados por COVID-19.

BACKGROUND: SARS-CoV-2 virus was notified by the World Health Organization in January 2020 as a global emergency, due to its intense transmission, and clinical picture, that is aggravated in susceptible people. OBJECTIVE: To describe the factors associated with death in COVID-19 and pneumonia patients hospitalized in a thirdlevel center. MATERIAL AND METHODS: An undivided case-control study was carried out. It was conducted an interview to obtain general information; from the medical record were collected hospitalization data, radiological images, laboratory parameters, and treatments used. It was used descriptive statistics. Student's t, Mann-Whitney U, and chi-squared were used to identify variables associated with death, and models of adjusted binary logistic regression to propose which variables of the patient's history, clinical parameters and treatments explained the death. RESULTS: We treated 5339 patients with suspicion of COVID-19: 3117 positive (59%), 1029 hospitalized due to pneumonia, and 513 deaths (16.46%). For the analysis, 1110 patients were taken, 399 death cases were selected and 357 controls discharged due to improvement. The average age was 57.8 years; 59% were male. CONCLUSIONS: The variables associated with mortality were: patients older than 40 years, chest radiography image > 50% involvement, intubation, lactic dehydrogenase > 500, C-reactive protein > 10, and organ failure; variables associated with improvement were: stay in the intensive care unit, use of broad spectrum parenteral antibiotics, steroids, and use of the anticoagulant enoxyheparin. Sex, diabetes, and comorbidities did not show significant association.

INTRODUCCIÓN: el SARS-CoV-2 fue notificado por la Organización Mundial de la Salud en enero de 2020 como emergencia mundial debido a su intenso contagio y cuadro clínico, que se agrava en personas susceptibles. OBJETIVO: describir factores asociados a defunción en pacientes con COVID-19 y neumonía hospitalizados en tercer nivel. MATERIAL Y MÉTODOS: estudio de casos y controles no pareado. Se obtuvo información general mediante entrevista; del expediente se tomaron datos de hospitalización, imágenes radiológicas, parámetros de laboratorio y tratamientos. Se empleó estadística descriptiva, t de student, U de Mann-Whitney y chi cuadrada para identificar variables asociadas a defunción, y modelos de regresión logística binaria ajustada para proponer variables de antecedentes del paciente, parámetros clínicos y tratamientos que explicaran la defunción. RESULTADOS: atendimos 5339 pacientes sospechosos de COVID-19: 3117 positivos (59%), 1029 hospitalizados por neumonía y 513 defunciones (16.46%). Para el análisis, se tomaron 1110, se seleccionaron 399 casos de defunción y 357 controles egresados por mejoría. La edad promedio fue 57.8 años; 59% fueron hombres. CONCLUSIONES: las variables asociadas a mortalidad fueron: mayores de 40 años, radiografía de tórax > 50% de afectación, intubación, deshidrogenasa láctica > 500, proteína C reactiva > 10 e insuficiencia orgánica; las asociadas a mejoría: estancia en unidad de cuidados intensivos, uso de antibióticos parenterales de amplio espectro, esteroides y anticoagulante enoxiheparina. El sexo, la diabetes y las comorbilidades no mostraron asociación.

[Blood groups and SARS-CoV-2 in health professionals from a single center]. / Grupos sanguíneos y SARS-CoV-2 en personal de salud de un solo centro.

BACKGROUND: The possibility that the blood group (BG) predisposes to SARS-CoV-2 infection is controversial. OBJECTIVE: To compare the prevalence of BG, anti-IgG SARS-CoV-2, and more frequent symptoms in convalescent health personnel vs controls prior to vaccination. MATERIAL AND METHODS: Analytical cross-sectional design of cases and controls, which included health personnel, from March to June 2020, confirmed with (polymerase chain reaction) PCR-SARS-CoV-2 and negative controls with PCR and anti-IgG-SARS-CoV-2. Participants were questioned concerning symptoms and BG was determined. It was used descriptive statistics and comparative analysis with chi squared, Fisher's exact test, Student's t, and Mann Whitney's U tests. RESULTS: Of 218 workers, 102 (46.8%) were confirmed cases for SARS-CoV-2 (convalescent) and 116 controls. The distribution of BG was similar between cases and controls, being BG-O + the most frequent (52.9%). The risk of becoming infected by SARS-CoV-2 for BG-O compared to BGNo-O showed a lower trend (odds ratio [OR] 0.725, 95% confidence interval [95% CI] 0.416-1.261, p = ns). The BG-A (28.4%) compared with BG-No-A (71.6%) showed a trend of increased risk in BG-A (OR 1.523, 95% CI 0.818-2.837, p = ns). The presence of SARS-CoV-2 IgG antibodies was 85% in the convalescent group. CONCLUSIONS: The prevalence of infected was proportionally higher for BG-A and lower for BG-O. About 15% did not develop SARS-CoV-2 antibodies after overcoming COVID-19 disease.

INTRODUCCIÓN: la posibilidad de que el grupo sanguíneo (GS) predisponga a infección por SARS-CoV-2 es controversial. OBJETIVO: comparar prevalencia de GS, anti-IgG SARSCoV-2 y síntomas más frecuentes, en personal de salud convaleciente frente a controles previo a la vacunación. MATERIAL Y MÉTODOS: diseño transversal analítico de casos y controles, que incluyó personal de salud, de marzo a junio de 2020, confirmados con reaccion en cadena de la polimerasa (PCR-SARS-CoV-2) y controles negativos con PCR y anti-IgG-SARS-COV-2. Se les interrogó sobre los síntomas y se determinó el GS. Se empleó estadística descriptiva y análisis comparativo con chi cuadrada o prueba exacta de Fisher y t de Student o U de Mann-Whitney. RESULTADOS: de 218 trabajadores, 102 (46.8%) fueron casos confirmados para SARS-CoV-2 (convalecientes) y 116 controles. La distribución de GS fue similar entre los casos y los controles y el GS-O+ fue el más frecuente (52.9%). El riesgo de infectarse de SARS-CoV-2 para el GS-O, comparado con GS-No-O mostró menor tendencia: razón de momios [RM] 0.725 (intervalo de confianza del 95% [IC 95%] 0.416-1.261; p = ns). El GS-A (28.4%) comparado con GSNo-A (71.6%) mostró tendencia de incremento del riesgo en GS-A, RM 1.523 (IC 95% 0.818-2.837, p = ns). La presencia de anticuerpos IgG de SARS-CoV-2 fue del 85% en el grupo de convalecientes. CONCLUSIONES: la prevalencia de infectados fue proporcionalmente mayor para GS-A y menor para GS-O. Alrededor de 15% no desarrollaron anticuerpos de SARS-CoV-2 después de recuperarse de COVID-19.

Ultrafast sorting: Excimeric π-π stacking distinguishes pyrene-N-methylacetamide isomers on the ultrafast time scale.

Pyrene based molecules are inclined to form excimers through self-association upon photoexcitation. In this work, the pyrene core is functionalized with the N-methylacetamide group at the position 1 or 2 to develop pyren-1-methylacetamide (PyMA1) and pyren-2-methylacetamide (PyMA2), respectively. Upon photoexcitation with 345 nm, a portion of molecules in PyMA1 and PyMA2 solutions at ≥1.0 mM have formed static excimers. The steady state spectroscopic measurements suggest that, whether it is the dimerization of molecules in the ground state (GS) or in excimer formation, characteristic signs are more pronounced in PyMA1 than its isomeric counterpart, PyMA2. The shift of the excimer band in their respective emission spectra suggests that the extent of overlap in π-π stacking is greater for PyMA1 than for PyMA2 in the excited state. The optimized geometry of dimers in toluene shows that the overlapping area between the pyrene moieties in π-π stacking between the dimers is greater for PyMA1 than for PyMA2 in GS. The natural bond orbital analysis with the optimized GS geometries shows that the stabilization/interaction energy between the dimers in π-π stacking is higher in PyMA1 compared to PyMA2 in toluene. The transient absorption (TA) measurements in toluene over the fs-ps regime (fs-TA) showed that the formation of static excimers with pre-associated dimers in PyMA1 happens in ∼700 fs whereas the excimers for the pre-associated dimers in PyMA2 have formed in slightly slower time scale (∼1.95 ps). Contrary to what was observed in solution, the extent of overlap in π-π stacking is lower for PyMA1 dimers (∼17%) than for PyMA2 dimers (∼37%) in single crystals.

Grupos sanguíneos y SARS-CoV-2 en personal de salud de un solo centro / Blood groups and SARS-CoV-2 in health professionals from a single center

Introducción: la posibilidad de que el grupo sanguíneo (GS) predisponga a infección por SARS-CoV-2 es controversial. Objetivo: comparar prevalencia de GS, anti-IgG SARS-CoV-2 y síntomas más frecuentes, en personal de salud convaleciente frente a controles previo a la vacunación. Material y métodos: diseño transversal analítico de casos y controles, que incluyó personal de salud, de marzo a junio de 2020, confirmados con reaccion en cadena de la polimerasa (PCR-SARS-CoV-2) y controles negativos con PCR y anti-IgG-SARS-COV-2. Se les interrogó sobre los síntomas y se determinó el GS. Se empleó estadística descriptiva y análisis comparativo con chi cuadrada o prueba exacta de Fisher y t de Student o U de Mann-Whitney. Resultados: de 218 trabajadores, 102 (46.8%) fueron casos confirmados para SARS-CoV-2 (convalecientes) y 116 controles. La distribución de GS fue similar entre los casos y los controles y el GS-O+ fue el más frecuente (52.9%). El riesgo de infectarse de SARS-CoV-2 para el GS-O, comparado con GS-No-O mostró menor tendencia: razón de momios [RM] 0.725 (intervalo de confianza del 95% [IC 95%] 0.416-1.261; p = ns). El GS-A (28.4%) comparado con GS-No-A (71.6%) mostró tendencia de incremento del riesgo en GS-A, RM 1.523 (IC 95% 0.818-2.837, p = ns). La presencia de anticuerpos IgG de SARS-CoV-2 fue del 85% en el grupo de convalecientes. Conclusiones: la prevalencia de infectados fue proporcionalmente mayor para GS-A y menor para GS-O. Alrededor de 15% no desarrollaron anticuerpos de SARS-CoV-2 después de recuperarse de COVID-19.

Background: The possibility that the blood group (BG) predisposes to SARS-CoV-2 infection is controversial. Objective: To compare the prevalence of BG, anti-IgG SARS-CoV-2, and more frequent symptoms in convalescent health personnel vs controls prior to vaccination. Material and methods: Analytical cross-sectional design of cases and controls, which included health personnel, from March to June 2020, confirmed with (polymerase chain reaction) PCR-SARS-CoV-2 and negative controls with PCR and anti-IgG-SARS-CoV-2. Participants were questioned concerning symptoms and BG was determined. It was used descriptive statistics and comparative analysis with chi squared, Fisher's exact test, Student's t, and Mann Whitney's U tests. Results: Of 218 workers, 102 (46.8%) were confirmed cases for SARS-CoV-2 (convalescent) and 116 controls. The distribution of BG was similar between cases and controls, being BG-O + the most frequent (52.9%). The risk of becoming infected by SARS-CoV-2 for BG-O compared to BG-No-O showed a lower trend (odds ratio [OR] 0.725, 95% confidence interval [95% CI] 0.416-1.261, p = ns). The BG-A (28.4%) compared with BG-No-A (71.6%) showed a trend of increased risk in BG-A (OR 1.523, 95% CI 0.818-2.837, p = ns). The presence of SARS-CoV-2 IgG antibodies was 85% in the convalescent group. Conclusions: The prevalence of infected was proportionally higher for BG-A and lower for BG-O. About 15% did not develop SARS-CoV-2 antibodies after overcoming COVID-19 disease.

Factores asociados a defunción en pacientes hospitalizados por COVID-19 / Factors associated to death in patients hospitalized due to COVID-19

Introducción: el SARS-CoV-2 fue notificado por la Organización Mundial de la Salud en enero de 2020 como emergencia mundial debido a su intenso contagio y cuadro clínico, que se agrava en personas susceptibles. Objetivo: describir factores asociados a defunción en pacientes con COVID-19 y neumonía hospitalizados en tercer nivel.Material y métodos: estudio de casos y controles no pareado. Se obtuvo información general mediante entrevista; del expediente se tomaron datos de hospitalización, imágenes radiológicas, parámetros de laboratorio y tratamientos. Se empleó estadística descriptiva, t de student, U de Mann-Whitney y chi cuadrada para identificar variables asociadas a defunción, y modelos de regresión logística binaria ajustada para proponer variables de antecedentes del paciente, parámetros clínicos y tratamientos que explicaran la defunción.Resultados: atendimos 5339 pacientes sospechosos de COVID-19: 3117 positivos (59%), 1029 hospitalizados por neumonía y 513 defunciones (16.46%). Para el análisis, se tomaron 1110, se seleccionaron 399 casos de defunción y 357 controles egresados por mejoría. La edad promedio fue 57.8 años; 59% fueron hombres. La estancia hospitalaria en casos fue 9.8 (DE 10.9) y en controles 12.5 (DE 10.2).Conclusiones: las variables asociadas a mortalidad fueron: mayores de 40 años, radiografía de tórax > 50% de afectación, intubación, deshidrogenasa láctica > 500, proteína C reactiva > 10 e insuficiencia orgánica; las asociadas a mejoría: estancia en unidad de cuidados intensivos, uso de antibióticos parenterales de amplio espectro, esteroides y anticoagulante enoxiheparina. El sexo, la diabetes y las comorbilidades no mostraron asociación.

Background: SARS-CoV-2 virus was notified by the World Health Organization in January 2020 as a global emergency, due to its intense transmission, and the clinical picture, that is aggravated in susceptible people.Objective: To describe the factors associated with death in COVID-19 and pneumonia patients hospitalized in a third-level center. Material and methods: An undivided case-control study was conducted. It was conducted an interview to obtain general information; from the medical record were collected hospitalization data, radiological images, laboratory parameters, and treatments used. It was used descriptive statistics. Student's t, Mann-Whitney U, and chi-squared were used to identify variables associated with death, and models of adjusted binary logistic regression to propose which variables of the patient's history, clinical parameters and treatments explained the death. Results: We treated 5339 patients with suspicion of COVID-19: 3117 positive (59%), 1029 hospitalized due to pneumonia, and 513 deaths (16.46%). For the analysis, 1110 patients were taken, 399 death cases were selected and 357 controls discharged due to improvement. The average age was 57.8 years; 59% were male. The hospital stay in cases was 9.8 (SD 10.9), and in controls 12.5 (SD 10.2). Conclusions: The variables associated with mortality were: patients older than 40 years, chest radiography image > 50% involvement, intubation, lactic dehydrogenase > 500, C-reactive protein > 10, and organ failure; variables associated with improvement were: stay in the intensive care unit, use of broad spectrum parenteral antibiotics, steroids, and use of the anticoagulant enoxyheparin. Sex, diabetes, and comorbidities did not show significant association.

Nanooptomechanical Transduction in a Single Crystal with 100% Photoconversion.

Materials that exhibit nanooptomechanical transduction in their single-crystal form have prospective use in light-driven molecular machinery, nanotechnology, and quantum computing. Linkage photoisomerization is typically the source of such transduction in coordination complexes, although the isomers tend to undergo only partial photoconversion. We present a nanooptomechanical transducer, trans-[Ru(SO2)(NH3)4(3-bromopyridine)]tosylate2, whose S-bound η1-SO2 isomer fully converts into an O-bound η1-OSO photoisomer that is metastable while kept at 100 K. Its 100% photoconversion is confirmed structurally via photocrystallography, while single-crystal optical absorption and Raman spectroscopies reveal its metal-to-ligand charge-transfer and temperature-dependent characteristics. This perfect optical switching affords the material good prospects for nanooptomechanical transduction with single-photon control.

Rapid build up of nanooptomechanical transduction in single crystals of a ruthenium-based SO2 linkage photoisomer.

Single-crystal nanooptomechanical transduction occurs in [Ru(SO2)(NH3)4(H2O)]chlorobenzenesulfonate2, reaching maximal levels within 40 s at 100 K when photostimulated by 505 nm light. Its in situ light-induced crystal structure reveals the molecular origins of this optical actuation: 26.0(3)% of the η1-SO2 ligand photoconverts into an η1-OSO photoisomer which, in turn, induces a 49.6(9)° arene ring rotation in its neighbouring counter ion.

Association of depression and anxiety with characteristics related to the training of medical residents / Asociación de depresión y ansiedad con características relacionadas con el adiestramiento de médicos residentes

Abstract Introduction Higher rates of depression and anxiety have been reported in resident physicians compared to the general population. The association with characteristics related to training has been poorly studied. Objective To know the association of depression and anxiety with characteristics related to training in a group in medical residents. Method 542 resident physicians of different grade and specialty were included. They answered the Mini International Neuropsychiatric Interview to identify depression and anxiety. The training characteristics evaluated were: work performance; use of tobacco, alcohol, and drugs; grade of residence; frequency of guards; type of specialty; and emotional exhaustion. Other factors assessed by their possible association were: personal antecedent of depression and/or anxiety and presence of any medical illness. Results 277 women and 265 men with an average age of 28 were evaluated. The prevalence of depression and anxiety found was 12.2% and 47.1%, respectively, and was associated with work fatigue, decreased socio-labor performance, emotional exhaustion, harmful alcohol consumption, and personal history of depression and/or anxiety. Discussion and conclusion There are training-related characteristics that could promote depression and anxiety in physicians vulnerable to depression and/or anxiety.

Resumen Introducción Se han reportado más altas tasas de depresión y ansiedad en médicos residentes que en la población en general. La asociación con características relacionadas con el adiestramiento ha sido poco estudiada. Objetivo Conocer la asociación de depresión y ansiedad con características relacionadas con el adiestramiento en un grupo de médicos residentes. Método Se incluyeron 542 médicos residentes de diferente grado y especialidad. Se les aplicó la Mini Entrevista Neuropsiquiátrica Internacional para identificar depresión y ansiedad. Las características relacionadas con el adiestramiento que se evaluaron fueron: fatiga laboral y reducción del desempeño laboral por sueño insatisfactorio; consumo de tabaco, alcohol y drogas; año de residencia; frecuencia de guardias; tipo de especialidad y agotamiento emocional. Otros factores evaluados por su posible asociación fueron: antecedente personal de depresión y/o ansiedad y presencia de cualquier enfermedad médica. Resultados Se evaluaron 277 mujeres y 265 hombres con edad media de 28 años; la prevalencia de depresión y ansiedad encontrada fue de 12.2% y 47.1%, respectivamente, y se asoció con fatiga laboral, disminución del desempeño socio laboral, agotamiento emocional, consumo perjudicial de alcohol y antecedente personal de depresión y/o ansiedad. Discusión y conclusión Existen características relacionadas con el adiestramiento que pudieran favorecer la presencia de depresión y ansiedad en médicos residentes vulnerables por el antecedente de depresión y/o ansiedad.

η2-SO2 Linkage Photoisomer of an Osmium Coordination Complex.

We report the discovery of an η2-SO2 linkage photoisomer in the osmium pentaammine coordination complex, [Os(NH3)5(SO2)][Os(NH3)5(HSO3)]Cl4 (1). Its dark- and light-induced crystal structures are determined via synchrotron X-ray crystallography, at 100 K, where the photoinduced state is metastable in a single crystal that has been stimulated by 505 nm light for 2.5 h. The SO2 photoisomer in the [Os(NH3)5(SO2)]2+ cation contrasts starkly with the photoinactivity of the HSO3 ligand in its companion [Os(NH3)5(HSO3)]+ cation within the crystallographic asymmetric unit of this single crystal. Panchromatic optical absorption characteristics of this single crystal are revealed in both dark- and light-induced states, using concerted absorption spectroscopy and optical microscopy. Its absorption halves across most of its visible spectrum, upon exposure to 505 nm light. The SO2 ligand seems to be responsible for this photoinduced bleaching effect, judging from a comparison of the dark- and light-induced crystal structures of 1. The SO2 photoisomerism is found to be thermally reversible, and so 1 presents a rare example of an osmium-based solid-state optical switch. Such switching in an osmium complex is significant because bottom-row transition metals stand to offer linkage photoisomerism with the greatest photoconversion levels and thermal stability. The demonstration of η2-SO2 bonding in this complex also represents a fundamental contribution to osmium coordination chemistry.

Laparoscopic resection of a gastric schwannoma: A case report.

INTRODUCTION: Mesenchymal tumors of the gastrointestinal tract are a group spindle cell tumors which include gastrointestinal stromal tumors, leiomyomas, leiomyosarcomas and schwannomas (Nishida and Hirota, 2000). Schwannomas generally present as a slow and asymptomatic growing mass in the gastrointestinal tract typically arising in the gastric submucosa accounting for up to 0.2% of gastric tumors (Melvin and Wilkinson, 1993; Sarlomo-Rikala M, Miettinen, 1995). TREATMENT: with negative surgical margin resection (as approached in this case) is considered the standard treatment. PRESENTATION OF CASE: A 60-year-old woman was referred to our general surgery service for dyspepsia. During her evaluation a gastric mass was incidentally found on upper GI endoscopy which showed a submucosal exophytic neoplasm at the gastric antrum. The patient was discharged following an uneventful recovery from a successful surgical laparoscopic tumor resection. DISCUSSION: Schwannomas are benign neurogenic tumors that originate from Schwann cells. They commonly occur in the head and neck but are rare in the GI tract (Menno et al., 2010). The differential diagnosis between gastric schwannomas and GISTs can be difficult in the preoperative assessment. With the advent of immunohistochemical staining techniques it is now possible to make a differential diagnosis based on their distinctive immunophenotypes. Gastric schwannomas are consistently positive for S-100 protein and negative for c-kit; conversely, 95% of GISTs are positive for c-kit and negative for S-100 protein in up to 98 to 99% of the cases. CONCLUSION: Gastric schwannomas should be included in the differential diagnosis of any gastric submucosal mass. Negative margin resection as seen with this patient is the standard surgical treatment as there is low malignant transformation potential.

Obscure gastrointestinal bleeding due to multifocal intestinal angiosarcoma.

INTRODUCTION: Intestinal angiosarcomas are an extremely rare and aggressive vascular tumors, with a few cases reported in the literature. PRESENTATION OF CASE: A 45 years-old male arrived to our hospital with intermittent gastrointestinal bleeding presenting melena and weight loss, he has antecedent of pelvic radiotherapy ten years before admission for an unknown pelvic tumor. Emergency surgery was required because of uncontrolled bleeding and hemodynamic instability. Histopathological findings revealed a multifocal high-grade epithelioid angiosarcoma, with cells reactive for CD31, keratins CKAE 1/AE3 and factor VIII. DISCUSSION: Angiosarcomas are aggressive tumors with a high rate of lymph node metastasis and peripheral organs. The diagnosis is difficult because it present nonspecific clinical presentation, radiological and histopathological findings. There are few reports of angiosarcoma involving the small intestine and the most common presentation are abdominal pain and gastrointestinal bleeding. There is not enough information for intestinal angiosarcoma secondary to radiation therapy, but there have been proposed criteria for diagnosis: no microscopic or clinical evidence of antecedent malignant lesion, angiosarcoma presented in the field of irradiation, long latency period between radiation and angiosarcoma and histological confirmation. We suspect our patient course with a secondary form of angiosarcoma. Therapy for bleeding angiosarcoma consists in control of bleeding and medical management to stabilize the patient. Once accomplished surgical resection is required. CONCLUSION: We should keep in mind this tumors as a cause of obscure intestinal bleeding in patients with medical history of radiation therapy.