Porphyrin‐Based Metal–Organic Frameworks
A major challenge in studying Zr‐porphyrin‐based metal–organic frameworks (MOFs) is the poor reproducibility of reported syntheses. Article number 2210613 by ...Bettina V. Lotsch and co‐workers investigates the formation of Zr‐MOF particles step‐by‐step to understand and ultimately control the critical stages during nucleation and growth. Notably, water is essential to the formation of Zr‐oxo clusters and influences both the formation kinetics and phase purity of the product.
Nanocatalytic medicine has been developed recently to trigger intratumoral generation of highly toxic reactive oxygen species (ROS) for cancer therapy, which, unfortunately, suffers from compromised ...therapeutic efficacy due to a self‐protective mechanism, autophagy, of cancer cells to mitigate oxidative damage. In this work, during the efforts of ROS generation by nanocatalytic medicine, a pharmacological autophagy inhibition strategy is implemented for augmenting ROS‐induced oxidative damage for synergetic cancer therapy. An iron‐containing metal‐organic framework MOF(Fe) nanocatalyst as a peroxidase mimic is used to catalyze the generation of highly oxidizing •OH radicals specifically within cancer cells, while chloroquine is applied to deacidify lysosomes and inhibit autophagy, cutting off the self‐protection pathway under severe oxidative stress. Cancer cells fail to extract their components to detoxicate and strengthen themselves, finally succumbing to the ROS‐induced oxidative damage during nanocatalytic therapy. Both in vitro and in vivo results demonstrate the synergy between nanocatalytic therapy and autophagy inhibition, suggesting that such a combined strategy is applicable to amplify tumor‐specific oxidative damage and may be informative to future design of therapeutic regimen.
The antitumor effect of nanocatalytic medicine is demonstrated to be largely elevated by inhibition of a self‐protective mechanism known as autophagy. In this work, during the efforts of catalytic reactive oxygen species generation by NH2‐MIL‐88B (Fe) nanocatalyst, chloroquine is also applied to deacidify lysosomes and inhibit autophagy, which significantly augments oxidative damage on tumors.
Seawater electrolysis is a sustainable technology for producing hydrogen that would neither cause global freshwater shortages nor create carbon emissions. However, this technology is severely ...hampered by the insufficient stability and the competition from the chlorine evolution reaction (ClER) in actual application. Herein, a metal–organic framework (MOF)‐on‐MOF heterojunction (Ni‐BDC/NH2‐MIL‐88B(Fe)) denoted as (Ni‐BDC/NM88B(Fe)) is synthesized as an effective oxygen evolution reaction (OER) electrocatalyst for high‐performance seawater electrolysis, which exhibits a long stability of 200 h and low overpotentials of 232 and 299 mV at 100 mA cm−2 in alkaline freshwater and seawater solution, respectively. The exceptional performance is attributed to the rapid self‐reconstruction of Ni‐BDC/NM88B(Fe) to produce NiFeOOH protective layer, thereby avoiding ClER‐induced dissolution. Moreover, the interface interaction between Ni‐BDC and NM88B(Fe) could form the Ni─O─Fe bonds in Ni‐BDC/NM88B(Fe) to promote the electron transfer and lower the energy barrier of the rate‐determining step, thereby accelerating the OER. These electrochemical properties make it intriguing candidate as an efficient electrocatalyst for practical alkaline seawater electrolysis.
A hetero‐structured Ni‐BDC/NM88B(Fe) metal–organic framework is synthesized to be as an outstanding electrocatalyst for seawater oxidation. The unique electronic channel (Ni─O─Fe) in this heterostructure not only enables the rapid reconstruction to generate the protective layer of NiFeOOH, thereby avoiding the effects of CER, but also optimizes the adsorption energy of the intermediates, leading to superior seawater oxidation performance.
Metal–organic framework (MOF) and covalent organic framework (COF) nanosheets are a new type of two‐dimensional (2D) materials with unique design principles and various synthesis methods. They are ...considered ideal electrochemical devices due to the ultrathin thickness, easily tunable molecular structure, large porosity and other unique properties. There are two common methods to synthesize 2D MOF/COF nanosheets: bottom‐up and top‐down. The top‐down strategy mainly includes ultrasonic assisted exfoliation, electrochemical exfoliation and mechanical exfoliation. Another strategy mainly includes interface synthesis, modulation synthesis, surfactant‐assisted synthesis. In this Review, the development of ultrathin 2D nanosheets in the field of electrochemistry (supercapacitors, batteries, oxygen reduction, and hydrogen evolution) is introduced, and their unique dimensional advantages are highlighted.
Materials for electrochemistry: Metal–organic framework and covalent organic framework nanosheets represent one promising kind of power materials for electrochemical. Synthesis strategies, tailored material properties and different electrochemical performances are prominent features of supercapacitors, batteries, OER and HER. Metal–organic framework and covalent organic framework nanosheets comprehensively summarized and evaluations are given in this Review.
Metal–organic framework (MOF) is highly desirable as a functional material owing to its low density, tunable pore size, and diversity of coordination formation, but limited by the poor dielectric ...properties. Herein, by controlling the solvent and mole ratio of cobalt/linker, multidimension‐controllable MOF‐derived nitrogen‐doped carbon materials exhibit tunable morphology from sheet‐, flower‐, cube‐, dodecahedron‐ to octahedron‐like. Tunable electromagnetic parameters of Co@N‐doped carbon composites (Co@NC) can be obtained and the initial MOF precursor determines the distribution of carbon framework and magnetic cobalt nanoparticles. Carbonized Co@NC composites possess the following advantages: i) controllable dimension and morphology to balance the electromagnetic properties with evenly charged density distribution; ii) magnetic‐carbon composites offer plenty of interfacial polarization and strong magnetic coupling network; iii) a MOF‐derived dielectric carbon skeleton provides electronic transportation paths and enhances conductive dissipation. Surface‐mediated magnetic coupling reflects the stray magnetic flux field, which is corroborated by the off‐axis electron holography and micro‐magnetic simulation. Optimized octadecahedral Co@NC sample exhibits the best microwave absorption (MA) of −53.0 dB at the thickness of 1.8 mm and broad effective frequency from 11.4 to 17.6 GHz (Ku‐band). These results pave the way to fabricate high‐performance MA materials with balanced electromagnetic distribution and controlled morphology.
A series of magnetic‐dielectric composites with homogeneous Co NPs embedded into the metal–organic framework‐derived carbon framework are fabricated by a self‐template and confined conversion strategy. Benefiting from the precise dimension regulation and perfect magnetic‐electric balance, the multi‐morphology Co@NC absorbers endow the composite with optimal and efficient microwave absorption performance.
Precise design of low‐cost, efficient and definite electrocatalysts is the key to sustainable renewable energy. Herein, this work develops a targeted‐anchored and subsequent spontaneous‐redox ...strategy to synthesize nickel‐iron layered double hydroxide (LDH) nanosheets anchored with monodispersed platinum (Pt) sites (Pt@LDH). Intermediate metal‐organic frameworks (MOF)/LDH heterostructure not only provides numerous confine points to guarantee the stability of Pt sites, but also excites the spontaneous reduction for PtII. Electronic structure, charge transfer ability and reaction kinetics of Pt@LDH can be effectively facilitated by the monodispersed Pt moieties. As a result, the optimized Pt@LDH that with the 5% ultra‐low content Pt exhibits the significant increment in electrochemical water splitting performance in alkaline media, which only afford low overpotentials of 58 mV at 10 mA cm−2 for hydrogen evolution reaction (HER) and 239 mV at 10 mA cm−2 for oxygen evolution reaction (OER), respectively. In a real device, Pt@LDH can drive an overall water‐splitting at low cell voltage of 1.49 V at 10 mA cm−2, which can be superior to most reported similar LDH‐based catalysts. Moreover, the versatility of the method is extended to other MOF precursors and noble metals for the design of ultrathin LDH supported monodispersed noble metal electrocatalysts promoting research interest in material design.
A targeted‐anchored and subsequent spontaneous‐redox strategy is developed to synthesize nickel‐iron layered double hydroxide (LDH) nanosheets anchored with monodispersed platinum (Pt) sites (Pt@LDH). As‐prepared Pt@LDH‐4h can drive an overall water‐splitting at low cell voltage of 1.49 V at 10 mA cm−2, which can be superior to most reported similar LDH‐based catalysts.
•Sustainable Development Goals have been drafted and endorsed recently.•The SDGs and their targets have laid an overall policy framework; however, the conceptual one for indicator development is ...missing.•We stress the need to conceptualise and operationalise the targets with focus on the indicators’ relevance.
At the UN in New York the Open Working Group created by the UN General Assembly proposed a set of global Sustainable Development Goals (SDGs) which comprises 17 goals and 169 targets. Further to that, a preliminary set of 330 indicators was introduced in March 2015. Some SDGs build on preceding Millennium Development Goals while others incorporate new ideas. A critical review has revealed that indicators of varied quality (in terms of the fulfilment certain criteria) have been proposed to assess sustainable development. Despite the fact that there is plenty of theoretical work on quality standards for indicators, in practice users cannot often be sure how adequately the indicators measure the monitored phenomena. Therefore we stress the need to operationalise the Sustainable Development Goals’ targets and evaluate the indicators’ relevance, the characteristic of utmost importance among the indicators’ quality traits. The current format of the proposed SDGs and their targets has laid a policy framework; however, without thorough expert and scientific follow up on their operationalisation the indicators may be ambiguous. Therefore we argue for the foundation of a conceptual framework for selecting appropriate indicators for targets from existing sets or formulating new ones. Experts should focus on the “indicator-indicated fact” relation to ensure the indicators’ relevance in order for clear, unambiguous messages to be conveyed to users (decision- and policy-makers and also the lay public). Finally we offer some recommendations for indicators providers in order to contribute to the tremendous amount of conceptual work needed to lay a strong foundation for the development of the final indicators framework.
Metal–organic framework cathodes usually exhibit low capacity and poor electrochemical performance for Li‐ion storage owing to intrinsic low conductivity and inferior redox activity. Now a ...redox‐active 2D copper–benzoquinoid (Cu‐THQ) MOF has been synthesized by a simple solvothermal method. The abundant porosity and intrinsic redox character endow the 2D Cu‐THQ MOF with promising electrochemical activity. Superior performance is achieved as a Li‐ion battery cathode with a high reversible capacity (387 mA h g−1), large specific energy density (775 Wh kg−1), and good cycling stability. The reaction mechanism is unveiled by comprehensive spectroscopic techniques: a three‐electron redox reaction per coordination unit and one‐electron redox reaction per copper ion mechanism is demonstrated. This elucidatory understanding sheds new light on future rational design of high‐performance MOF‐based cathode materials for efficient energy storage and conversion.
A high‐performance MOF: A conductive and redox‐active copper–benzoquinoid 2D metal–organic framework (MOF) with high capacity was designed for Li‐ion batterie. A new Li‐ion storage mechanism was unveiled by comprehensive spectroscopic methods.
Lithium metal batteries (LMBs) with high energy density have received widespread attention; however, there are usually issues with lithium dendrite growth and safety. Therefore, there is a demand for ...solid electrolytes with high mechanical strength, room‐temperature ionic conductivity, and good interface performance. Herein, a 3D cross‐linked metal‐organic framework (MOF)‐derived polymer solid electrolyte exhibits good mechanical and ionic conductive properties simultaneously, in which the MOF with optimized pore size and strong imidazole cation sites can restrict the migration of anions, resulting in a uniform Li+ flux and a high lithium‐ion transference number (0.54). Moreover, the MOF‐derived polymer solid electrolytes with the 3D cross‐linked network can promote the rapid movement of Li+ and inhibit the growth of lithium dendrites. Lithium symmetric batteries assembled with the 3D MOF‐derived polymer solid electrolytes are subjected to lithium plating/stripping and cycled over 2000 h at a current density of 0.1 mA cm−2 and over 800 h at a current density of 0.2 mA cm−2. The Li/P‐PETEA‐MOF/LiFePO4 batteries exhibit excellent long‐cycle stability and cycle reversibility.
A novel 3D cross‐linked metal‐organic framework (MOF)‐derived polymer solid electrolyte with good mechanical, ionic conductive properties, and interfacial compatibility is achieved by cross‐linking vinyl‐functionalized MOFs (Vinyl‐ZIF‐8) to polyethylene glycol diacrylate (PEGDA) through pentaerythritol tetraacrylate (PETEA). The unique structure of the MOFs‐derived hybrids electrolytes adsorb anions and only allow Li+ to pass through, resulting in uniform Li+ flux distribution, high t+, and dendrite‐free.
Image guided radiotherapy (IGRT) in head and neck cancer treatment can be challenging due to complexities presented by variable target and organ at risk (OAR) position. In the authors department an ...audit of 178 consecutive patients found primary target baseline shifts occurred in 17% of patients (30/178). When baseline shifts are detected by radiographers (RTTs) initial referral online is to departmental IGRT advanced practitioner radiographers (IGRT APRTT). Decision making by IGRT APRTTs can be subjective, introducing a level of uncertainty during the online IGRT process. It also increases the time taken for treatment to take place.
Departmental protocol is to image first three days and then weekly (eNAL). Audit data demonstrated that 54.3% of all head and neck fractions were imaged, a significant increase upon the expected 24% for an eNAL protocol. This imaging workload provided an impetus to consider daily imaging for head and neck treatment. The clinical head and neck team within the authors department acknowledged this and wanted to provide robust protocols that would aid decision making and establish a clinician approved scope of practice for both RTTs and IGRT APRTTs. The aim of this report is to detail the project pathway and evaluate the effectiveness of the developed framework.
The intent was to apply principles of project management planning and develop the framework within a systematic framework. The project pathway steps are illustrated in figure 1. A timeframe of 6 months was established for completion. Using the 178 patients included within the audit, relevant CBCT images with primary target baseline shifts were reviewed by an interdisciplinary team. The members consisted of the head and neck consultant group (5 clinicians), head of treatment planning, radiotherapy technical lead, pre-treatment RTT, IGRT APRTT team representative, and two RTTS. Images were discussed and consideration for optimising online and offline interventions was made. Based on consensus judgements thematic trends were categorised. A decision making framework was constructed to cover various scenarios with recommended actions dependent on thresholds. Established actions levels were based on severity: •Green - proceed to treat•• Amber- proceed to treat with required intervention online/offline•Red - do not treat
Prior to implementation a dual registration methodology for glottis treatments was validated (described in a supporting abstract), training materials were developed and a pilot timing study was carried out to determine if implementation would lead to improvements in efficiency. 20 glottic, hypopharyngeal and tongue base patients were included in the timing study. Two RTTs involved in the development of the project employed the scope of practice outlined by the framework to online image reviews. In order to capture the complete IGRT process timing began at the start of CBCT acquisition and was recorded when the first treatment VMAT arc was initiated. Although no further changes within the department were made that might have influenced IGRT review the timing study included timing for online image review from other RTTs without use of the framework scope of practice. This allowed comparison for scenarios where escalation to IGRT APRTTs was needed and where no escalation was required. Display omitted
The head and neck IGRT framework (figure 2) project pathway was completed in 146 days and within the projected 6 months (153 days). The process began 18th May 2023 (audit results completed and disseminated/project outcome established) and was finalised 11th October 2023 (dissemination of project results). Display omitted
20 patients and 60 images were included within the pilot timing study. Images that required no escalation resulted in a mean time of 3:08 minutes calculated as from start of CBCT acquisition until the first treatment VMAT arc was initiated. For image reviews which required escalation to an IGRT APRTT the mean time taken was 7:08 minutes. For a subset of twenty images reviewed by RTTs under the decision-making framework, which would have otherwise been escalated to IGRT ARPTTs, the mean image review time was 4:08 minutes. This represents a 42% reduction in image workflow time compared to the department's standard method of escalation to IGRT ARPTTs.
Employing a collaborative interdisciplinary approach using project management principles in the development of an IGRT decision making framework for head and neck radiotherapy lead to a successful and efficient outcome. It encouraged the establishment of a consensus approach and has allowed scope and opportunity to develop creative solutions in managing primary target displacement, such as the use of dual registration. Furthermore it has augmented and expanded the RTT IGRT scope of practice, helped standardise actions and reduce uncertainty, and improved on-treatment efficiency in preparation for adoption of daily imaging.
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