Novel Microwave-Assisted Synthesis of COFs: 2020-2022.

Covalent organic frameworks (COFs) have emerged as a new type of crystalline porous polymers of great interest. However, their preparation requires long reaction times. Microwave-assisted synthesis (MAS) offers an interesting approach to increasing the reaction rate of chemical processes. Thus, microwaves can be a key tool for the fast and scalable synthesis of COFs. Since our previous review on the topic, the preparation of COFs with microwaves has been evolving. Herein, we present a compilation of COFs studies and experiments published in the last three years on the synthesis of COFs using microwave-assisted synthesis as a source of energy. The articles include imine, triazine, and other 2D COFs synthesized using MAS. The 3D COFs have also been compiled. The chemical structure of the monomers and the COFs and their main parameters of synthesis and application are summarized for each article.

Fast Microwave-Assisted Synthesis, Calcination and Functionalization of a Silica Mesoporous Nanomaterial: UVM-7.

We report here, for the first time, the use of a solid state microwave source for the synthesis, calcination and functionalization of a UVM-7 based hybrid mesoporous silica material. The synthesis of the UVM-7 material is obtained in 2 min at low power (50 W) by the combination of a microwave irradiation and the atrane route. Moreover, it has been successfully calcined and functionalized in just 13 and 4 min respectively with microwave assisted procedures. A total synthesis comprising each individually optimized step, can be executed in only 4 h including work-up, by contrast to a typical synthesis that comprises several days. Savings higher than one order or magnitude are obtained in time and energy. Our example is a proof of concept of the potential use of solid state microwave generators for the ultrafast on-command preparation of hybrid nanomaterials due to their accurate control and accelerating properties.

Harmonious Passion at Work: Personal Resource for Coping with the Negative Relationship between Burnout and Intrinsic Job Satisfaction in Service Employees.

Research about harmonious passion as a personal resource that can have a protective effect in situations of stress and burnout is scarce but growing. Considering the job demands-resources (JD-R) model, the present study aims to address the above gaps by exploring the moderating role of harmonious passion at work in the relationship between burnout (physical fatigue, cognitive weariness, and emotional exhaustion) and intrinsic job satisfaction. The study sample consisted of 748 workers from service organizations (front-line employees) in southern Spain (Mage = 35.51, SD = 10.06, 52% women). Using statistical program R (R Core Team, 2022), the results of the regression models showed the moderating role of harmonious passion on the negative relationships between physical fatigue and intrinsic job satisfaction. In particular, at high levels of physical fatigue, employees with high scores on harmonious passion at work presented higher levels of intrinsic satisfaction compared with employees with low passion at work. That is, although service employees have high levels of physical fatigue, when they are passionate, they still possess satisfaction with their work. Therefore, our findings extend the JD-R theory by considering harmonious passion as a motivational resource that reduce feelings of burnout in service employees. Hence, it shows the importance of promoting the autonomous internalization of work, (through, i.e., job enrichment), which allows the development of harmonious passion at work and, therefore, increasing intrinsic job satisfaction.

Pharmacological characterization of a novel peptide inhibitor of the Keap1-Nrf2 protein-protein interaction.

LAS200813 is a novel bicyclic lipopeptide that activates Nrf2 by binding to Keap1, thereby antagonising the Keap1-Nrf2 protein-protein interaction. In this work we report the pharmacological characterization of LAS200813 in Nrf2-dependent translational preclinical models. LAS200813 binds to Keap1 with high affinity (IC50: 0.73 nM) and is able to induce the translocation of Nrf2 to the nucleus. Furthermore, LAS200813 increases the expression of Nrf2 target genes in human bronchial epithelial cells (EC50 of 96 and 70 nM for srxn1 and nqo1, respectively). Similarly, the intratracheal administration of LAS200813 to rats increases the expression of Nrf2-dependent genes in lung tissue, an effect that lasts for a few hours. Moreover, in cells exposed to cigarette smoke, LAS200813 shows an antioxidant effect by increasing the production of glutathione and prevents cellular apoptosis. In conclusion, the results described herein demonstrate that LAS200813 is a potent non-electrophilic Nrf2-activating peptide designed to be administered by inhaled route which may be a potential therapeutic strategy for respiratory diseases driven by oxidative stress.

Batch and Flow Synthesis of CeO2 Nanomaterials Using Solid-State Microwave Generators.

Microwave-assisted synthesis in combination with flow synthesis offers an interesting approach to develop faster and more sustainable procedures for the preparation of homogeneous nanomaterials. Recently, solid-state generators of microwaves appeared as a tool with improved control over power and frequency. Cerium oxide, despite its excellent catalytic activity, has not been prepared before using solid-state generators or microwave-assisted flow chemistry. We report a procedure for the preparation of nanoparticulated CeO2 (around 4 nm) under 2.45 GHz microwaves in only 30 s. The materials are further calcined at 800 °C to increase particle size, with a better defined particle size and crystallinity. The procedure was tested in batch at pH 11 and 12 and diverse potencies, and the products were characterized by TEM, XRD, DLS, and N2 adsorption-desorption isotherms. The materials were similar at the diverse pH values and potencies. XRD confirms the crystallinity of the CeO2 material with a fluorite-like structure. They are composed of particles around 40 nm that aggregate as structures of around 100 nm. The procedure was successfully adapted to flow synthesis, obtaining materials with structure and properties equivalent to batch synthesis. The batch and flow materials offer peroxidase properties, opening the door for their use as ROS scavengers.

Interpersonal Conflicts in the Unit Impact the Service Quality Rated by Customers: The Mediating Role of Work-Unit Well-Being.

Social dynamics at work are crucial for understanding how internal processes in an organization are related to their performance and productivity. Following the Service-Profit Chain (SPC) theory, this study analyses, at the work-unit level, how interpersonal conflicts are related to service quality in the hospitality and tourism industry through the shared experience of well-being in the work unit. In other words, we examine the mediating role of two main aspects of work-related well-being in the unit (job satisfaction and burnout) on the relationship between interpersonal conflicts in the unit and customers' perceptions of service quality. To do so, we conducted a cross-sectional survey study that collected data from 398 service employees (91 work units) and 1233 customers from three and four-star hotels with restaurant in Spain. Using path analysis in Structural Equation Models, our results supported a full mediation model at the work-unit level: interpersonal conflicts in the work unit are related to customers' service quality perceptions through the work-unit's well-being (job satisfaction and burnout). Therefore, our findings extend the SPC theory by integrating group dynamics and employees' experiences, which should be enhanced through occupational health-oriented policies and practices to increase service quality. In this sense, this study has implications for the development of intervention programs aiming at improving the occupational well-being and quality of service in hospitality and tourism settings.

Understanding the link between work engagement and affective organisational commitment: The moderating effect of role stress.

This study aimed to explore the moderating effect of role ambiguity and role conflict on the relationship between work engagement and affective organisational commitment. Using convenience sampling, a final sample of 179 IT-specialists of services companies in southern Spain was obtained. Moderation analyses were performed using the hierarchical regressions and bootstrapping method (Bias-Corrected confidence intervals). Results showed that work engagement was positively related to affective commitment while role ambiguity and role conflict were negatively related to it. However, only role conflict moderated the relationship between work engagement and affective commitment. That is, at high levels of role conflict, IT-specialists perceiving higher levels of work engagement reported lower levels of affective commitment. This study highlights the hindrance effect of role conflict on one of the most important consequences of work engagement: affective commitment with the organisation. An adequate definition of role and positions could help to reduce the levels of role conflict, increasing the emotional bond to the organisation.

Understanding acid lability of cysteine protecting groups.

Cys-disulfide bonds contribute to the stabilization of peptide and protein structures. The synthesis of these molecules requires a proper protection of Cys residues, which is crucial to prevent side-reactions and also to achieve the correct Cys connectivity. Here we undertook a mechanistic study of a set of well-known acid-labile Cys protecting groups, as well other new promising groups, in order to better understand the nature of their acid-lability. The stability of the carbocation generated during the acid treatment was found to have a direct impact on the removal of the protective groups from the corresponding protected Cys-containing peptides. Hence a combination of steric and conjugative effects determines the stability of the carbocations generated. Here we propose diphenylmethyl (Dpm) as a promising protecting group on the basis of its intermediate relative carbocation stability. All the optimized geometries and energies presented in this study were determined using a B3LYP/6-31G(d,p) calculation. The results discussed herein may be of broader applicability for the development of new protecting groups.

Handles for Fmoc solid-phase synthesis of protected peptides.

Protected peptide fragments are valuable building blocks for the assembly of large peptide sequences through fragment condensation approaches, whereas protected peptides are typically synthesized for the preparation of amide-bridge cyclic peptides in solution. Efficient synthesis of both protected peptides and protected peptide fragments by solid-phase peptide synthesis methodology requires handles that attach the growing peptides to the polymeric support and can be cleaved under appropriate conditions, while maintaining intact the side-chain protecting groups. Here, we provide an overview of attachment methods described in the literature for the preparation of protected peptides using Fmoc/tBu chemistry, including the most commonly used acid-labile linkers along with the most recent and sophisticated.

Constella™(EU)-Linzess™(USA): the last milestone in the long journey of the peptide linaclotide and its implications for the future of peptide drugs.

Irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) are highly prevalent gastrointestinal disorders associated with health, economical and social problems. Recently, after a long journey of preclinical studies and clinical trials, linaclotide, a first-in-class GC-C receptor peptide agonist, has received the approval in the USA and Europe for the treatment of IBS-C and CIC. This article provides an overview of clinical, economic and biological aspects of IBS-C and CIC and covers the current and emerging therapeutic agents for treating these conditions. Particularly, the pharmacodynamic and pharmacokinetic properties of linaclotide, a small, disulfide-rich peptide, and its implications in the future of peptide drug discovery and development are discussed.

Eco-friendly combination of the immobilized PGA enzyme and the S-Phacm protecting group for the synthesis of Cys-containing peptides.

Enzyme-labile protecting groups have emerged as a green alternative to conventional protecting groups. These groups introduce a further orthogonal dimension and eco-friendliness into protection schemes for the synthesis of complex polyfunctional organic molecules. S-Phacm, a Cys-protecting group, can be easily removed by the action of a covalently immobilized PGA enzyme under very mild conditions. Herein, the versatility and reliability of an eco-friendly combination of the immobilized PGA enzyme and the S-Phacm protecting group has been evaluated for the synthesis of diverse Cys-containing peptides.

Acid-labile Cys-protecting groups for the Fmoc/tBu strategy: filling the gap.

To address the existing gap in the current set of acid-labile Cys-protecting groups for the Fmoc/tBu strategy, diverse Fmoc-Cys(PG)-OH derivatives were prepared and incorporated into a model tripeptide to study their stability against TFA. S-Dpm proved to be compatible with the commonly used S-Trt group and was applied for the regioselecive construction of disulfide bonds.

La gestión de conflictos relacionales en las organizaciones de servicios / The management of relationship conflicts in service organizations

En el presente trabajo se explora la relación entre el conflicto relacional y el clima de servicio analizando el papel modulador de los estilos de gestión del conflicto y tomando como nivel de análisis la unidad de trabajo. La muestra está compuesta por 397 empleados de contacto directo con el cliente (recepcionistas y camareros) pertenecientes a 91 unidades de trabajo de hoteles y restaurantes de la Comunidad Autónoma Andaluza. Los resultados muestran los efectos perjudiciales que el conflicto relacional tiene sobre el clima de servicio y el papel modulador que ejerce el estilo de gestión integración en dicha relación. En concreto, cuando las unidades de trabajo, ante un conflicto relacional, utilizan la integración a niveles altos, éste no se relaciona negativamente con el clima de servicio. Así, se concluye que es la integración y no la evitación el estilo de gestión más eficaz para aminorar los efectos negativos del conflicto relacional en estos contextos (AU)

The main goal of this study was to explore the relationship between relationship conflict and service climate. To this end, we have studied which specific conflict management styles reduce or increase the relationship between relationship conflict and service climate at the work-unit level. Hypotheses were tested by tracking 91 work-units (397 employees) from 42 hotels and restaurants in southern Spain. Results revealed that relationship conflict is negatively related to service climate and that an integrating conflict management conflict style plays a moderating role in this relationship. This means that, when work-units use an integrating style to manage relationship conflict this conflict type is not related to service climate. Thus, the present study supports the idea that it is integrating and not avoiding the most effective style to manage the relationship conflict in these contexts (AU)

A universal strategy for preparing protected C-terminal peptides on the solid phase through an intramolecular click chemistry-based handle.

A new universal strategy exploits DKP formation in a dipeptide moiety whose C-terminal residue is blocked by a leaving group. It enables both synthesis of C-terminal protected peptides that are useful for convergent synthesis of large peptides and use of a C-terminal permanent protecting group that can be cleaved by catalytic hydrogenation to release the peptide.

Effective behaviors to de-escalate organizational conflicts in the process of escalation.

The goal of the present study was to determine what behaviors negotiators can use to help to quell an escalating conflict. In doing so, we formed a sample of professionals who took on the role of negotiator when we provoked an organizational conflict between a superior and subordinate that escalates due to the intervention of research confederates. Trained judges analyzed the negotiators' behaviors that most effectively mitigated the intensity of the conflict in which they were involved. The results demonstrate that the behaviors most effective at de-escalating an escalating conflict are problem-solving and accommodation, especially when said conflict has escalated considerably. Similarly, jointly employing problem-solving and direct fighting behaviors also seems to help de-escalate conflict. The results do not, however, consistently support using a forceful behavioral strategy to de-escalate a conflict in the early stages of escalation.

Effective behaviors to de-escalate organizational conflicts in the process of escalation

The goal of the present study was to determine what behaviors negotiators can use to help to quell an escalating conflict. In doing so, we formed a sample of professionals who took on the role of negotiator when we provoked an organizational conflict between a superior and subordinate that escalates due to the intervention of research confederates. Trained judges analyzed the negotiators’ behaviors that most effectively mitigated the intensity of the conflict in which they were involved. The results demonstrate that the behaviors most effective at de-escalating an escalating conflict are problem-solving and accommodation, especially when said conflict has escalated considerably. Similarly, jointly employing problem-solving and direct fighting behaviors also seems to help deescalate conflict. The results do not, however, consistently support using a forceful behavioral strategy to de-escalate a conflict in the early stages of escalation (AU)

La finalidad de este trabajo fue estudiar qué comportamientos permiten la reducción del conflicto cuando los negociadores se enfrentan a un proceso de conflicto que crece en intensidad. Para ello, y mediante una muestra de negociadores profesionales, se ha provocado un conflicto organizacional entre un superior y un subordinado, que crece en intensidad mediante las intervenciones de cómplices de los investigadores. Jueces entrenados han analizado los comportamientos más efectivos de los negociadores para mitigar la intensidad del conflicto al que se veían sometidos. Los resultados muestran que para reducir un conflicto escalado los comportamientos más efectivos son la solución de problemas y la acomodación, sobre todo cuando el conflicto es muy elevado. Del mismo modo, el uso conjunto de las conductas de solución de problemas y lucha directa también permite reducir la intensidad de los conflictos. Por el contrario, los resultados no apoyan una estrategia consistente en utilizar conductas de dominación durante las primeras etapas del escalamiento del conflicto para reducir la intensidad de los conflictos (AU)

Intramolecular oxidation of the alcohol functionalities in hydroxyalkyl-N-heterocyclic carbene complexes of iridium and rhodium.

A series of hydroxyalkyl-functionalized imidazolium salts have been coordinated to Rh and Ir to afford the corresponding MCp*-(NHC) (Cp*=pentamethylcyclopentadienyl) complexes. The reactivity of the new complexes has been studied with special attention to the transformations that deal with the alcohol functionality. The metal-mediated intramolecular transformations allowed the formation of several products that resulted from the oxidation of the alcohols to aldehydes and esters. All the new complexes have been fully characterized, and the crystal structures of the most representative complexes have been resolved.