Precise monitoring of the humidity level is important for the living comfort and for many applications in various industrial sectors. Humidity sensors have thus become one among the most extensively ...studied and used chemical sensors by targeting a maximal device performance through the optimization of the components and working mechanism. Among different moisture‐sensitive systems, supramolecular nanostructures are ideal active materials for the next generation of highly efficient humidity sensors. Their noncovalent nature guarantees fast response, high reversibility, and fast recovery time in the sensing event. Herein, the most enlightening recent strategies on the use of supramolecular nanostructures for humidity sensing are showcased. The key performance indicators in humidity sensing, including operation range, sensitivity, selectivity, response, and recovery speed are discussed as milestones for true practical applications. Some of the most remarkable examples of supramolecular‐based humidity sensors are presented, by describing the finest sensing materials, the operating principles, and sensing mechanisms, the latter being based on the structural or charge‐transport changes triggered by the interaction of the supramolecular nanostructures with the ambient humidity. Finally, the future directions, challenges, and opportunities for the development of humidity sensors with performance beyond the state of the art are discussed.
The state of the art of supramolecular nanostructures as active components for the fabrication of high‐performance humidity sensors is reviewed. The different sensing mechanisms that exploit structural or electronic/ionic‐transport changes resulting from the interaction of the supramolecular nanostructures with water molecules to read out the environmental humidity with key performance indicators beyond the state of the art are discussed.
Two‐dimensional covalent organic frameworks (COFs) have emerged as promising materials for energy storage applications exhibiting enhanced electrochemical performance. While most of the reported ...organic cathode materials for zinc‐ion batteries use carbonyl groups as electrochemically‐active sites, their high hydrophilicity in aqueous electrolytes represents a critical drawback. Herein, we report a novel and structurally robust olefin‐linked COF‐TMT‐BT synthesized via the aldol condensation between 2,4,6‐trimethyl‐1,3,5‐triazine (TMT) and 4,4′‐(benzothiadiazole‐4,7‐diyl)dibenzaldehyde (BT), where benzothiadiazole units are explored as novel electrochemically‐active groups. Our COF‐TMT‐BT exhibits an outstanding Zn2+ storage capability, delivering a state‐of‐the‐art capacity of 283.5 mAh g−1 at 0.1 A g−1. Computational and experimental analyses reveal that the charge‐storage mechanism in COF‐TMT‐BT electrodes is based on the supramolecularly engineered and reversible Zn2+ coordination by the benzothiadiazole units.
We report a novel and structurally robust olefin‐linked covalent organic frameworks (COFs), where benzothiadiazole units are explored as novel electrochemically‐active groups. Our COFs exhibit an outstanding Zn2+ storage capability, delivering a state‐of‐the‐art capacity of 283.5 mAh g−1 at 0.1 A g−1. We shed light onto the charge‐storage mechanism through the benzothiadiazole units in the COFs electrodes via computational and experimental analyses.
NMSC (non-melanoma skin cancer) is a common tumor in the Caucasian population, accounting for 90% of skin cancers. Among them, squamous cell carcinomas (SCCs) can metastasize and, due to its high ...incidence, constitute a severe health problem. It has been suggested that cutaneous SCCs with more risk to metastasize express high levels of nuclear IKKα. However, the molecular mechanisms that lead to this enhanced aggressiveness are largely unknown. To understand in depth the influence of nuclear IKKα in skin SCC progression, we have generated murine PDVC57 skin carcinoma cells expressing exogenous IKKα either in the nucleus or in the cytoplasm to further distinguish the tumor properties of IKKα in both localizations. Our results show that IKKα promotes changes in both subcellular compartments, resembling EMT (epithelial-mesenchymal transition), which are more pronounced when IKKα is in the nucleus of these tumor cells. These EMT-related changes include a shift toward a migratory phenotype and induction of the expression of proteins involved in cell matrix degradation, cell survival and resistance to apoptosis. Additionally, we have found that apigenin, a flavonoid with anti-cancer properties, inhibits the expression of IKKα and attenuates most of the pro-tumoral EMT changes induced by IKKα in mouse tumor keratinocytes. Nevertheless, we have found that apigenin only inhibits the expression of the IKKα protein when it is localized in the cytoplasm.
In this minireview, we summarize current research dealing with the combination of noble‐metal nanoparticles and different families of supramolecular macrocycles (cyclodextrins, cucurbitnurils, ...calixarenes, and pillarnarenes). We intended to select relevant publications on the synthesis of noble‐metal nanoparticles with macrocycles acting as capping agents or/and reducing agents, as well as on the post‐synthetic metal‐nanoparticle modification with macrocycles. We also discuss strategies in which supramolecular chemistry is applied to direct the self‐assembly of nanoparticles and formation of polymer composites. We finally describe the main applications of these materials in various fields.
Nanoparticles and macrocycles: Recent literature regarding the combination of supramolecular macrocycles and metal nanoparticles is reviewed, with particular emphasis on the synthesis, surface modification and assembly, as well as the potential applications of the obtained nanocomposites (SERS = surface‐enhanced Raman spectroscopy).
The objective of this study is to describe the characteristics and outcomes of rheumatic and musculoskeletal disease (RMD) patients who were treated with rituximab and had suspected or confirmed ...severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In this descriptive study, RMD patients who were treated with rituximab in the last 12 months at the Rheumatology Department of our hospital were screened for SARS-CoV-2 infection via telephone interview and a comprehensive review of clinical health records (01/02/2020–26/05/2020). Those with probable or confirmed SARS-CoV-2 infection were included. In total, 76 patients were screened. Of these, 13 (17.1%) had suspected or confirmed SARS-CoV-2 infection. With regard to these 13 patients, the median age at coronavirus disease (COVID-19) diagnosis was 68 years (range 28–76 years) and 8 (61.5%) were female. Five patients had rheumatoid arthritis, three had systemic vasculitis, two had Sjögren syndrome, and two had systemic lupus erythematosus. Additionally, seven patients (53.8%) had pulmonary involvement secondary to RMD. Eight patients (61.5%) developed severe disease leading to hospitalization, and seven developed bilateral pneumonia and respiratory insufficiency. Of the eight hospitalized patients, five (62.5%) fulfilled the acute respiratory distress syndrome criteria and three developed a critical disease and died. Our cohort had a high rate of severe disease requiring hospitalization (61.5%), with bilateral pneumonia and hyperinflammation leading to a high mortality rate (23.1%). Treatment with rituximab should be considered a possible risk factor for unfavorable outcomes in COVID-19 patients with RMD. However, further study is required to confirm this association.
High‐performance flexible strain sensors are key components for the next generation of wearable health monitoring devices. Here, the authors have fabricated a novel strain sensor based on gold ...nanoparticles (AuNPs) interconnected by flexible and responsive molecular linkers. The combination of conductive AuNPs (25 nm in diameter) with tetra(ethylene glycol) dithiol (SH‐TEG‐SH) linkers yields a covalent 3D network which can be directly deposited onto prepatterned flexible supports exposing interdigitated Au electrodes. The electrically insulating nature of the linkers effectively defines the tunneling modulated charge transfer through the AuNPs network. When compressive/tensile strain is applied, the molecular linkers adopt a compressed/stretched conformation thus decreasing/increasing the interparticle distance, ultimately yielding an exponential increase/decrease of the tunneling current when voltage is applied. The strain sensor displays state‐of‐the‐art performances including a highly sensitive response to both tensile and compressive strain, as quantified by a high gauge factor (GF≈126) combined with other superior sensing properties like high flexibility, short response time (16.1 ms), and good robustness (>2000 cycles). Finally, the applicability of the device for health monitoring is demonstrated: high‐resolution artery pulse waves are acquired by placing the strain sensor onto the skin allowing the extraction of important physical parameters for human‐health assessment.
Highly sensitive and flexible strain sensor based on molecules–gold nanoparticles network has been designed and fabricated. Featuring superior sensing properties, the strain sensor is employed for human‐health monitoring by analyzing the high‐resolution radial/carotid artery pulse wave acquired by simply placing the device onto the skin.
Ageing is a complex process, induced by multifaceted interaction of genetic, epigenetic, and environmental factors. It is manifested by a decline in the physiological functions of organisms and ...associated to the development of age-related chronic diseases and cancer development. It is considered that ageing follows a strictly-regulated program, in which some signaling pathways critically contribute to the establishment and maintenance of the aged state. Chronic inflammation is a major mechanism that promotes the biological ageing process and comorbidity, with the transcription factor NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) as a crucial mediator of inflammatory responses. This, together with the finding that the activation or inhibition of NF-κB can induce or reverse respectively the main features of aged organisms, has brought it under consideration as a key transcription factor that acts as a driver of ageing. In this review, we focused on the data obtained entirely through the generation of knockout and transgenic mouse models of either protein involved in the NF-κB signaling pathway that have provided relevant information about the intricate processes or molecular mechanisms that control ageing. We have reviewed the relationship of NF-κB and premature ageing; the development of cancer associated with ageing and the implication of NF-κB activation in the development of age-related diseases, some of which greatly increase the risk of developing cancer.
Health monitoring is experiencing a radical shift from clinic‐based to point‐of‐care and wearable technologies, and a variety of nanomaterials and transducers have been employed for this purpose. 2D ...materials (2DMs) hold enormous potential for novel electronics, yet they struggle to meet the requirements of wearable technologies. Here, aiming to foster the development of 2DM‐based wearable technologies, reduced graphene oxide (rGO)‐based liquid‐gated transistors (LGTs) for cation sensing in artificial sweat endowed with distinguished performance and great potential for scalable manufacturing is reported. Laser micromachining is employed to produce flexible transistor test patterns employing rGO as the electronic transducer. Analyte selectivity is achieved by functionalizing the transistor channel with ion‐selective membranes (ISMs) via a simple casting method. Real‐time monitoring of K+ and Na+ in artificial sweat is carried out employing a gate voltage pulsed stimulus to take advantage of the fast responsivity of rGO. The sensors show excellent selectivity toward the target analyte, low working voltages (<0.5 V), fast (5–15 s), linear response at a wide range of concentrations (10 µm to 100 mm), and sensitivities of 1 µA/decade. The reported strategy is an important step forward toward the development of wearable sensors based on 2DMs for future health monitoring technologies.
A low‐cost and scalable fabrication of plastic liquid‐gated transistors (LGTs) based on reduced graphene oxide (rGO) for ion sensing in artificial sweat is presented. Laser micromachining is utilized to produce flexible transistors employing rGO as the electronic transducer. Ion‐selective membranes (ISMs) engineered on the device surface provide K+ and Na+ selectivity, pushing forward the development of wearable chemical sensing technologies.
The unique electrochemical properties of polyoxometalates (POMs) render them ideal components for the fabrication of next‐generation high‐performance energy storage systems. However, their practical ...applications have been hindered by their high solubility in common electrolytes. This problem can be overcome by the effective hybridization of POMs with other materials. Here we present the design and synthesis of two novel polyoxometalate‐covalent organic frameworks (POCOF) via one‐pot solvothermal strategy between an amino‐functionalized Anderson‐type POM and a trialdehyde‐based building unit. We show that structural and functional complexity can be enriched by adding hydroxyl groups in the 2,4,6 position to the benzene‐1,3,5‐tricarbaldehyde allowing to exploit for the first time in POCOFs the keto‐enol tautomerization as additional feature to impart greater chemical stability to the COFs and enhanced properties leading to large specific surface area (347 m2/g) and superior electrochemical performance of the POCOF‐1 electrodes, when compared with POCOF‐2 electrodes that possess only imine‐type linkage and with pristine POM electrodes. Specifically, POCOF‐1 electrodes display remarkable specific, areal, and volumetric capacitance (125 F/g, 248 mF/cm2 and 41.9 mF/cm3, respectively) at a current density of 0.5 A/g, a maximum energy density (56.2 Wh/kg), a maximum power density (3.7 kW/kg) and an outstanding cyclability (90 % capacitance retention after 5000 cycles).
The engineering of novel nanostructured electrode materials represents a viable strategy to obtain devices with high energy and power density. We present the synthesis of two novel polyoxometalate‐covalent organic frameworks (POCOF) with superior electrochemical performance in terms of specific capacitance (125 F/g), energy and power density (56.2 Wh/kg and 3.7 kW/kg, respectively) and high cyclability (5000 cycles).
There is an increasing interest in the production of chemicals and fuels from renewable resources due to the continuing price increase of fossil resources, the insecurity of the availability of ...fossil resources in the future, and additionally environmental concerns and legislations. Biobutanol may be produced by the acetone–butanol–ethanol (ABE) fermentation.
This paper reviews the biobutanol production bringing up the problems and challenges to overcome. The aim of the paper is to help in finding opportunities to make the process feasible in the near future. The analysis stresses the idea of improving the efficiency of the fermentation stage by altering the up (pretreatment of the raw material) and downstream (product recovery and purification) processes. The paper also explores the biobutanol production from the biorefinery perspective. Finally the review brings up the important role of research in developing and implementing the production of biobutanol by the ABE fermentation.
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