Ammonium affects the wet chemical network of HCN: feedback between prebiotic chemistry and materials science.

Prebiotic chemistry one-pot reactions, such as HCN-derived polymerizations, have been used as stimulating starting points for the generation of new multifunctional materials due to the simplicity of the processes, use of water as solvent, and moderate thermal conditions. Slight experimental variations in this special kind of polymerization tune the final properties of the products. Thus, herein, the influence of NH4Cl on the polymerization kinetics of cyanide under hydrothermal conditions and on the macrostructures and properties of this complex system is explored. The kinetics of the process is consistent with an autocatalytic model, but important variations in the polymerization reaction are observed according to a simple empirical model based on a Hill equation. The differences in the kinetic behaviour against NH4Cl were also revealed when the structural, morphological, thermal, electronic and magnetic properties of the synthesized cyanide polymers were compared, and these properties were evaluated by elemental analysis, FTIR, XPS, UV-vis, and ESR spectroscopies, X-ray diffraction, SEM and thermoanalytical techniques. As a result, this hydrothermal prebiotic polymerization is not only pH dependent, as previously thought, but also ammonium subservient. From this result, a hypothetical reaction mechanism was proposed, which involves the active participation of ammonium cations via formamidine and serves as a remarkable point against previous reports. The results discussed here expand the knowledge on HCN wet chemistry, offer an extended view of the relevant parameters during the simulation of hydrothermal scenarios and describe the production of promising paramagnetic and semiconducting materials inspired by prebiotic chemistry.

Kinetic Study of the Effective Thermal Polymerization of a Prebiotic Monomer: Aminomalononitrile.

Aminomalononitrile (AMN), the HCN formal trimer, is a molecule of interest in prebiotic chemistry, in fine organic synthesis, and, currently, in materials science, mainly for bio-applications. Herein, differential scanning calorimetry (DSC) measurements by means of non-isothermal experiments of the stable AMN p-toluenesulfonate salt (AMNS) showed successful bulk AMN polymerization. The results indicated that this thermally stimulated polymerization is initiated at relatively low temperatures, and an autocatalytic kinetic model can be used to appropriately describe, determining the kinetic triplet, including the activation energy, the pre-exponential factor, and the mechanism function (Eα, A and f(α)). A preliminary structural characterization, by means of Fourier transform infrared (FTIR) spectroscopy, supported the effective generation of HCN-derived polymers prepared from AMNS. This study demonstrated the autocatalytic, highly efficient, and straightforward character of AMN polymerization, and to the best of our knowledge, it describes, for the first time, a systematic and extended kinetic analysis for gaining mechanistic insights into this process. The latter was accomplished through the help of simultaneous thermogravimetry (TG)-DSC and the in situ mass spectrometry (MS) technique for investigating the gas products generated during these polymerizations. These analyses revealed that dehydrocyanation and deamination processes must be important elimination reactions involved in the complex AMN polymerization mechanism.

Semiconducting Soft Submicron Particles from the Microwave-Driven Polymerization of Diaminomaleonitrile.

The polymers based on diaminomaleonitrile (DAMN polymers) are a special group within an extensive set of complex substances, namely HCN polymers (DAMN is the formal tetramer of the HCN), which currently present a growing interest in materials science. Recently, the thermal polymerizability of DAMN has been reported, both in an aqueous medium and in bulk, offering the potential for the development of capacitors and biosensors, respectively. In the present work, the polymerization of this plausible prebiotic molecule has been hydrothermally explored using microwave radiation (MWR) via the heating of aqueous DAMN suspensions at 170-190 °C. In this way, polymeric submicron particles derived from DAMN were obtained for the first time. The structural, thermal decomposition, and electrochemical properties were also deeply evaluated. The redox behavior was characterized from DMSO solutions of these highly conjugated macromolecular systems and their potential as semiconductors was described. As a result, new semiconducting polymeric submicron particles were synthetized using a very fast, easy, highly robust, and green-solvent process. These results show a new example of the great potential of the polymerization assisted by MWR associated with the HCN-derived polymers, which has a dual interest both in chemical evolution and as functional materials.

Anakinra versus Baricitinib: Different Strategies for Patients Hospitalized with COVID-19.

BACKGROUND: Immunomodulatory drugs have been used in patients with severe COVID-19. The objective of this study was to evaluate the effects of two different strategies, based either on an interleukin-1 inhibitor, anakinra, or on a JAK inhibitor, such as baricitinib, on the survival of patients hospitalized with COVID-19 pneumonia. METHODS: Individuals admitted to two hospitals because of COVID-19 were included if they fulfilled the clinical, radiological, and laboratory criteria for moderate-to-severe disease. Patients were classified according to the first immunomodulatory drug prescribed: anakinra or baricitinib. All subjects were concomitantly treated with corticosteroids, in addition to standard care. The main outcomes were the need for invasive mechanical ventilation (IMV) and in-hospital death. Statistical analysis included propensity score matching and Cox regression model. RESULTS: The study subjects included 125 and 217 individuals in the anakinra and baricitinib groups, respectively. IMV was required in 13 (10.4%) and 10 (4.6%) patients, respectively (p = 0.039). During this period, 22 (17.6%) and 36 (16.6%) individuals died in both groups (p = 0.811). Older age, low functional status, high comorbidity, need for IMV, elevated lactate dehydrogenase, and use of a high flow of oxygen at initially were found to be associated with worse clinical outcomes. No differences according to the immunomodulatory therapy used were observed. For most of the deceased individuals, early interruption of anakinra or baricitinib had occurred at the time of their admission to the intensive care unit. CONCLUSIONS: Similar mortality is observed in patients treated with anakinra or baricitinib plus corticosteroids.

A dual perspective on the microwave-assisted synthesis of HCN polymers towards the chemical evolution and design of functional materials.

In this paper, the first study on NH4CN polymerization induced by microwave radiation is described, where a singular kinetic behaviour, especially when this reaction is conducted in the absence of air, is found. As a result, a complex conjugated N-heterocyclic polymer system is obtained, whose properties are very different, and even improved according to morphological features, characterized by their X-ray diffraction patterns and scanning electron microscopy analysis, with respect to those produced under conventional thermal treatment. In addition, a wide variety of relevant bioorganics have been identified, such as amino acids, nucleobases, co-factors, etc., from the synthetized NH4CN polymers. These particular families of polymers are of high interest in the fields of astrobiology and prebiotic chemistry and, more recently, in the development of smart multifunctional materials. From an astrobiological perspective, microwave-driven syntheses may simulate hydrothermal environments, which are considered ideal niches for increasing organic molecular complexity, and eventually as scenarios for an origin of life. From an industrial point of view and for potential applications, a microwave irradiation process leads to a notable decrease in the reaction times, and tune the properties of these new series macromolecular systems. The characteristics found for these materials encourage the development of further systematic research on this alternative HCN polymerization.

A Comparative Study on HCN Polymers Synthesized by Polymerization of NH4 CN or Diaminomaleonitrile in Aqueous Media: New Perspectives for Prebiotic Chemistry and Materials Science.

HCN polymers are a group of complex and heterogeneous substances that are widely known in the fields of astrobiology and prebiotic chemistry. In addition, they have recently received considerable attention as potential functional material coatings. However, the real nature and pathways of formation of HCN polymers remain open questions. It is well established that the tuning of macromolecular structures determines the properties and practical applications of a polymeric material. Herein, different synthetic conditions were explored for the production of HCN polymers from NH4 CN or diaminomaleonitrile in aqueous media with different concentrations of the starting reactants and several reaction times. By using a systematic methodology, both series of polymers were shown to exhibit similar, but not identical, spectroscopic and thermal fingerprints, which resulted in a clear differentiation of their morphological and electrochemical properties. New macrostructures are proposed for HCN polymers, and promising insights are discussed for prebiotic chemistry and materials science on the basis of the experimental results.

Modelling the kinetics and structural property evolution of a versatile reaction: aqueous HCN polymerization.

The kinetics of the reaction of the synthesis of HCN polymers in aqueous medium at high temperatures have been analysed to ascertain a suitable model for this material, for which it was recently demonstrated that prebiotic chemistry may now be adapted in the development of a new generation of high performance coatings and adhesives with biomedical applications. These experimental conditions were chosen for the simplicity of the reagents, being particularly convenient in regard to potential industrial scale-up of coating technology, where these polymers have revealed an interesting field of application. The kinetics of the precipitation polymerization of HCN in water were studied under isothermal conditions at four different temperatures between 75 °C and 90 °C throughout gravimetric measurements. The use of the Kamal-Sourour autocatalytic kinetic model was proposed, properly describing the overall formation process of this insoluble HCN polymer. All of the kinetic parameters, including reaction orders, kinetic constants and activation energy, were determined for the cross-linking polymerization reaction under study, and a relevant autocatalysis effect was observed. An isoconversion method was also used to analyse the variation of the global activation energy with conversion; and characterization by means of elemental analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) was carried out. This study demonstrates the autocatalytic, robust and straightforward character of this heterogeneous aqueous HCN polymerization, and to the best of our knowledge, this report describes the first time that a systematic and extended kinetic analysis has been conducted to obtain a more comprehensive and deeper understanding of this complex reaction, which is of great interest to the origin of life and, currently, to materials science.

Experimental conditions affecting the kinetics of aqueous HCN polymerization as revealed by UV-vis spectroscopy.

HCN polymerization is one of the most important and fascinating reactions in prebiotic chemistry, and interest in HCN polymers in the field of materials science is growing. However, little is known about the kinetics of the HCN polymerization process. In the present study, a first approach to the kinetics of two sets of aqueous HCN polymerizations, from NH4CN and NaCN, at middle temperatures between 4 and 38°C, has been carried out. For each series, the presence of air and salts in the reaction medium has been systematically explored. A previous kinetic analysis was conducted during the conversion of the insoluble black HCN polymers obtained as gel fractions in these precipitation polymerizations for a reaction of one month, where a limit conversion was achieved at the highest polymerization temperature. The kinetic description of the gravimetric data for this complex system shows a clear change in the linear dependence with the polymerization temperature for the reaction from NH4CN, besides a relevant catalytic effect of ammonium, in comparison with those data obtained from the NaCN series. These results also demonstrated the notable influence of air, oxygen, and the saline medium in HCN polymer formation. Similar conclusions were reached when the sol fractions were monitored by UV-vis spectroscopy, and a Hill type correlation was used to describe the polymerization profiles obtained. This technique was chosen because it provides an easy, prompt and fast method to follow the evolution of the liquid or continuous phase of the process under study.

Characterization of Patients With Lupus Nephritis Included in a Large Cohort From the Spanish Society of Rheumatology Registry of Patients With Systemic Lupus Erythematosus (RELESSER).

The aim of the study was to profile those patients included in the RELESSER registry with histologically proven renal involvement in order to better understand the current state of lupus nephritis (LN) in Spain. RELESSER-TRANS is a multicenter cross-sectional registry with an analytical component. Information was collected from the medical records of patients with systemic lupus erythematosus who were followed at participating rheumatology units. A total of 359 variables including demographic data, clinical manifestations, disease activity, severity, comorbidities, LN outcome, treatments, and mortality were recorded. Only patients with a histological confirmation of LN were included. We performed a descriptive analysis, chi-square or Student's t tests according to the type of variable and its relationship with LN. Odds ratio and confidence intervals were calculated by using simple logistic regression. LN was histologically confirmed in 1092/3575 patients (30.5%). Most patients were female (85.7%), Caucasian (90.2%), and the mean age at LN diagnosis was 28.4 ±â€Š12.7 years. The risk for LN development was higher in men (M/F:47.85/30.91%, P < 0.001), in younger individuals (P < 0.001), and in Hispanics (P = 0.03). Complete response to treatment was achieved in 68.3% of patients; 10.35% developed ESRD, which required a kidney transplant in 45% of such cases. The older the patient, the greater was the likelihood of complete response (P < 0.001). Recurrences were associated with persistent lupus activity at the time of the last visit (P < 0.001) and with ESRD (P < 0.001). Thrombotic microangiopathy was a risk factor for ESRD (P = 0.04), as for the necessity of dialysis (P = 0.01) or renal transplantation (P = 0.03). LN itself was a poor prognostic risk factor of mortality (OR 2.4 [1.81-3.22], P < 0.001). Patients receiving antimalarials had a significantly lower risk of developing LN (P < 0.001) and ESRD (P < 0.001), and responded better to specific treatments for LN (P = 0.014). More than two-thirds of the patients with LN from a wide European cohort achieved a complete response to treatment. The presence of positive anti-Sm antibodies was associated with a higher frequency of LN and a decreased rate of complete response to treatment. The use of antimalarials reduced both the risk of developing renal disease and its severity, and contributed to attaining a complete renal response.

New insights into the characterization of 'insoluble black HCN polymers'.

The data presented here provide a novel contribution to the understanding of the structural features of HCN polymers and could be useful in further development of models for prebiotic chemistry. The interpretation of spectroscopic and analytical data, along with previous results reported by other authors, allowed us to propose a mechanism for the aqueous polymerization of HCN from its primary and simplest isolated oligomer, the diaminomaleonitrile (DAMN) tetramer. We suggest that 'insoluble black HCN polymers' are formed by an unsaturated complex matrix, which retains a significant amount of H(2) O and important bioorganic compounds or their precursors. This polymeric matrix can be formed by various motifs of imidazoles and cyclic amides, among others. The robust formation of HCN polymers assayed under several conditions seems to explain the plausible ubiquity of these complex substances in space.

[Consensus on the Use of Rituximab in Rheumatoid Arthritis. A document with evidence-based recommendations. Grupo de Expertos en Rituximab. ]. / Consenso de uso de rituximab en artritis reumatoide. Un documento con recomendaciones basadas en la evidencia.

INTRODUCTION: Rituximab has been employed successfully for the treatment of Rheumatoid Arthritis (RA). However, its particular mechanism of action, as well as a lack of concrete guidelines for its management have generated doubts on its use. OBJECTIVE: To establish recommendations that facilitates the use of rituximab in common clinical practice. METHODS: In a first Delphi round, 9 expert rheumatologists got together to develop questions on those subjects generating most doubts on the efficacy and safety of the drug. These were adapted to perform a systematic review of the evidence, which was presented in a second meeting. Nominal groups were formed to respond to each question and give a recommendation. These recommendations were presented in a second Delphi round to a larger group of experts in rheumatology. Once again recommendations were discussed, modified and voted upon. Once approved, a vote on the degree of agreement for each recommendation was carried out. RESULTS: 17 recommendations were established, 10 regarding efficacy and 7 safety. All of the efficacy recommendations except 3 presented a good or moderate degree of evidence. Among the safety recommendations, 3 had a good or moderate degree of evidence while in the rest it was indirect, scarce or non-existent and a product of expert recommendation. The degree of agreement between experts was elevated for most of the recommendations. CONCLUSIONS: These recommendations attempt to clear doubts on the use of rituximab and establish guidelines for its use in daily practice. Efficacy recommendations have a high degree of evidence, allowing the clinician to be guided in therapeutic decisions. Safety recommendations have a lower degree of evidence.

Consenso de uso de rituximab en artritis reumatoide. Un documento con recomendaciones basadas en la evidencia / Consensus on the use of Rituximab in Rheumatoid Arthritis. A document with evidence based recommendations

Introducción. El rituximab se ha empleado con éxito en el tratamiento de la artritis reumatoide (AR). Sin embargo, su particular mecanismo de acción, así como la ausencia de pautas concretas en su manejo, hace que se hayan generado dudas sobre su utilización. Objetivo. Establecer recomendaciones que faciliten el empleo de rituximab en la práctica clínica habitual. Métodos. En una primera ronda Delphi, se reunieron nueve reumatólogos expertos que desarrollaron preguntas sobre los temas con mayor duda sobre eficacia y seguridad del fármaco. Estas se adecuaron para hacer una revisión sistemática de la evidencia, que se presentó en una segunda reunión. Se formaron grupos nominales para dar respuesta a cada pregunta y emitir la recomendación. Estas recomendaciones fueron presentadas en una segunda ronda Delphi a un grupo ampliado de reumatólogos expertos. De nuevo se discutieron, se modificaron y se votaron las recomendaciones. Una vez aprobada cada recomendación, se votó el grado de acuerdo. Resultados. Se establecieron 17 recomendaciones: diez de eficacia y siete de seguridad. Todas las recomendaciones de eficacia, excepto tres, presentaron un nivel de evidencia bueno o moderado. Entre las recomendaciones de seguridad, tres presentaron un nivel de evidencia bueno o moderado, mientras que para el resto la evidencia fue indirecta, escasa o nula y son producto de las recomendaciones de los expertos. El grado de acuerdo entre expertos fue elevado para la mayoría de las recomendaciones. Conclusiones. Estas recomendaciones pretenden aclarar dudas sobre el uso de rituximab y establecer pautas de empleo en la práctica clínica. Las recomendaciones de eficacia tienen un nivel de evidencia alto y permiten guiar al médico en decisiones terapéuticas. Las recomendaciones de seguridad tienen un nivel de evidencia menor (AU)

Introduction. Rituximab has been employed successfully for the treatment of Rheumatoid Arthritis (RA). However, its particular mechanism of action, as well as a lack of concrete guidelines for its management have generated doubts on its use. Objective. To establish recommendations that facilitates the use of rituximab in common clinical practice. Methods. In a first Delphi round, 9 expert rheumatologists got together to develop questions on those subjects generating most doubts on the efficacy and safety of the drug. These were adapted to perform a systematic review of the evidence, which was presented in a second meeting. Nominal groups were formed to respond to each question and give a recommendation. These recommendations were presented in a second Delphi round to a larger group of experts in rheumatology. Once again recommendations were discussed, modified and voted upon. Once approved, a vote on the degree of agreement for each recommendation was carried out. Results. 17 recommendations were established, 10 regarding efficacy and 7 safety. All of the efficacy recommendations except 3 presented a good or moderate degree of evidence. Among the safety recommendations, 3 had a good or moderate degree of evidence while in the rest it was indirect, scarce or non-existent and a product of expert recommendation. The degree of agreement between experts was elevated for most of the recommendations. Conclusions. These recommendations attempt to clear doubts on the use of rituximab and establish guidelines for its use in daily practice. Efficacy recommendations have a high degree of evidence, allowing the clinician to be guided in therapeutic decisions. Safety recommendations have a lower degree of evidence (AU)

Antagonistas del TNF. Nuevos datos de eficacia / Anti-TNF drugs: new results on efficacy

Los antagonistas del TNF (tumor necrosis factor ‘factor de necrosis tumoral’) han significado un gran avance en el tratamiento de la artritis reumatoide (AR) desde su introducción a finales de la década de 1990. El desarrollo de producto ha sido similar para los 3 anti-TNF licenciados en la actualidad para el tratamiento de la AR: etanercept, infliximab y adalimumab. Los primeros estudios se centraron en los pacientes con enfermedad activa y refractaria a varios tratamientos modificadores de la enfermedad, por lo que se han obtenido diferencias muy significativas frente a placebo o metotrexato (MTX) en los índices de mejoría del American College of Rheumatology (ACR). Los ensayos en los pacientes no tratados con MTX muestran una diferencia menos notable entre los anti-TNF y el MTX, que se hace más significativa para la combinación de MTX con anti-TNF. En este manuscrito se analizan los resultados de los estudios de registro de los anti-TNF así como otros índices de mejoría, como calidad de vida, reducción del riesgo cardiovascular, efectividad mantenida en el tiempo y progresión de lesiones articulares. También se plantea la posibilidad de tratar con dosis menores a las autorizadas para AR y se analiza la afección de mal pronóstico de los pacientes refractarios a MTX, que actualmente es la indicación para el uso de anti-TNF en AR según el consenso de la Sociedad Española de Reumatología (AU)

Anti-TNF drugs have represented a great advancement in the treatment of rheumatoid arthritis since their introduction in the late 1990s. The development of these products has been very similar for etanercept, infliximab and adalimumab, the 3 approved TNF blockers for the treatment of RA. The first studies centered their attention on patients with active disease and refractory to several disease modifying treatments, finding very significant differences when compared to placebo or methotrexate in the ACR improvement scores. Trials in patients who had not been previously treated with methotrexate show less differences between anti-TNF and methotrexate, but becomes more significant when the two drugs are used combined. In this manuscript we analyze the results of the registry of anti-TNF studies with regard to other improvement indexes such as quality of life, reduction in cardiovascular risk, maintained efficacy through time and progression of joint erosions. We also contemplate the possibility of using lower doses than those authorized for rheumatoid arthritis and analyze factors related to a poor prognosis in patients refractory to methotrexate, which is currently the indication for the use of anti-TNF in RA accordiong to the SER consensus (AU)

[Anti-TNF drugs: New results on efficacy]. / Antagonistas del TNF. Nuevos datos de eficacia.

Anti-TNF drugs have represented a great advancement in the treatment of rheumatoid arthritis since their introduction in the late 1990s. The development of these products has been very similar for etanercept, infliximab and adalimumab, the 3 approved TNF blockers for the treatment of RA. The first studies centered their attention on patients with active disease and refractory to several disease modifying treatments, finding very significant differences when compared to placebo or methotrexate in the ACR improvement scores. Trials in patients who had not been previously treated with methotrexate show less differences between anti-TNF and methotrexate, but becomes more significant when the two drugs are used combined. In this manuscript we analyze the results of the registry of anti-TNF studies with regard to other improvement indexes such as quality of life, reduction in cardiovascular risk, maintained efficacy through time and progression of joint erosions. We also contemplate the possibility of using lower doses than those authorized for rheumatoid arthritis and analyze factors related to a poor prognosis in patients refractory to methotrexate, which is currently the indication for the use of anti-TNF in RA accordiong to the SER consensus.

III Actualización del Consenso de la Sociedad Española de Reumatología sobre terapia biológica en la artritis reumatoide / No disponible

No disponible