Temperature dependent photoreflectance study of Cu2SnS3 thin films produced by pulsed laser deposition

The energy band structure of Cu2SnS3 (CTS) thin films fabricated by pulsed laser deposition was studied by photoreflectance spectroscopy (PR). The temperature-dependent PR spectra were measured in the range of T = 10–150 K. According to the Raman scattering analysis, the monoclinic crystal structure (C1c1) prevails in the studied CTS thin film; however, a weak contribution from cubic CTS (F-43m) was also detected. The PR spectra revealed the valence band splitting of CTS. Optical transitions at EA = 0.92 eV, EB = 1.04 eV, and EC = 1.08 eV were found for monoclinic CTS at low-temperature (T = 10 K). Additional optical transition was detected at EAC = 0.94 eV, and it was attributed to the low-temperature band gap of cubic CTS. All the identified optical transition energies showed a blueshift with increasing temperature, and the temperature coefficient dE/dT was about 0.1 meV/K

Angularly resolved characterization of ion beams from laser-ultrathin foil interactions

Methods and techniques used to capture and analyze beam profiles produced from the interaction of intense, ultrashort laser pulses and ultrathin foil targets using stacks of Radiochromic Film (RCF) and Columbia Resin #39 (CR-39) are presented. The identification of structure in the beam is particularly important in this regime, as it may be indicative of the dominance of specific acceleration mechanisms. Additionally, RCF can be used to deconvolve proton spectra with coarse energy resolution while mantaining angular information across the whole beam

In situ single-crystal x-ray diffraction studies of an anomalous nitric oxide adsorption in a partially activated metal–organic framework

Funding: The authors gratefully acknowledge the assistance of Diamond Light Source for access to beamline I19-2 under proposals CY32865-1 and CY35900. The authors are also grateful for financial assistance from the ERC under advanced grant 787073, the EPSRC (EP/X014436/1 and EP/V008498/1), and the Slovenian Research and Innovation agency (Research programs P1-0021).Metal–organic frameworks (MOFs), with their high porosities and surface areas, show great utility in the field of gas adsorption. To unlock this porosity, MOFs are generally fully activated by removing all adsorbed guests using high temperatures and low pressures. However, this is energy intensive and can be unfeasible if the MOF is part of a composite, where the maximum temperature of the composite is below the activation temperature. To investigate the effect of activation temperature on adsorption, a series of in situ single-crystal X-ray diffraction (scXRD) studies were performed on Ni-MOF-74 loaded with the gas nitric oxide (NO) under different conditions. These experiments uncovered anomalous adsorption results where partially activated samples adsorb ∼14% more NO per framework material than did the fully activated sample. The scXRD experiments revealed a new NO binding site that is only present if the open metal sites are partially occupied by water molecules. To shed more light on the respective binding of the two different NO sites in Ni-MOF-74, these were studied in situ under different treatment conditions, such as the exposure to vacuum at different temperatures. This study yields insights into the nature of binding sites in MOFs, how these are affected by activation, and helps to pave the way for the improved design of processing conditions.Peer reviewe

Biomedical metal–organic framework materials : perspectives and challenges

The authors gratefully acknowledge financial support from the German Research Foundation (DFG: LA2937/4-1; SH1223/1-1; SFB 1066; GRK/RTG 2735 (project number 331065168)), the German Federal Ministry of Research and Education (BMBF: Gezielter Wirkstofftransport, PP-TNBC, Project No. 16GW0319K) and the European Research Council (ERC: Meta-Targeting (864121)). The financial support from Welch Foundation (AT-1989-20220331) and from the Human Frontier Science Program (HFSP, within the project RGP0047/2022) are also acknowledged. The authors thank the European Union (European Cooperation in Science and Technology) for the COST Action EU4MOFs (CA22147). Figures were created using BioRender.com.Metal–organic framework (MOF) materials are gaining significant interest in biomedical research, owing to their high porosity, crystallinity, and structural and compositional diversity. Their versatile hybrid organic/inorganic chemistry endows MOFs with the capacity to retain organic (drug) molecules, metals, and gases, to effectively channel electrons and photons, to survive harsh physiological conditions such as low pH, and even to protect sensitive biomolecules. Extensive preclinical research has been carried out with MOFs to treat several pathologies and, recently, their integration with other biomedical materials such as stents and implants has demonstrated promising performance in regenerative medicine. However, there remains a significant gap between MOF preclinical research and translation into clinically and societally relevant medicinal products. Here, the intrinsic features of MOFs are outlined and their suitability to specific biomedical applications such as detoxification, drug and gas delivery, or as (combination) therapy platforms is discussed. Furthermore, relevant examples of how MOFs have been engineered and evaluated in different medical indications, including cancer, microbial, and inflammatory diseases is described. Finally, the challenges facing their translation into the clinic are critically examined, with the goal of establishing promising research directions and more realistic approaches that can bridge the translational gap of MOFs and MOF‐containing (nano)materials.Publisher PDFPeer reviewe

Mixed metal-organic framework mixed-matrix membranes : insights into simultaneous moisture-triggered and catalytic delivery of nitric oxide using cryo-scanning electron microscopy

Funding: This work was supported by the European Research Council grant ADOR (Advanced Grant 787073). The authors acknowledge the EPSRC Light Element Analysis Facility Grant (EP/T019298/1) and the EPSRC Strategic Equipment Resource Grant (EP/R023751/1).The fundamental chemical and structural diversity of metal–organic frameworks (MOFs) is vast, but there is a lack of industrial adoption of these extremely versatile compounds. To bridge the gap between basic research and industry, MOF powders must be formulated into more application-relevant shapes and/or composites. Successful incorporation of varying ratios of two different MOFs, CPO-27-Ni and CuBTTri, in a thin polymer film represents an important step toward the development of mixed MOF mixed-matrix membranes. To gain insight into the distribution of the two different MOFs in the polymer, we report their investigation by Cryo-scanning electron microscopy (Cryo-SEM) tomography, which minimizes surface charging and electron beam-induced damage. Because the MOFs are based on two different metal ions, Ni and Cu, the elemental maps of the MOF composite cross sections clearly identify the size and location of each MOF in the reconstructed 3D model. The tomography run was about six times faster than conventional focused ion beam (FIB)-SEM and the first insights to image segmentation combined with machine learning could be achieved. To verify that the MOF composites combined the benefits of rapid moisture-triggered release of nitric oxide (NO) from CPO-27-Ni with the continuous catalytic generation of NO from CuBTTri, we characterized their ability to deliver NO individually and simultaneously. These MOF composites show great promise to achieve optimal dual NO delivery in real-world medical applications.Publisher PDFPeer reviewe

The laser-hybrid accelerator for radiobiological applications

The `Laser-hybrid Accelerator for Radiobiological Applications', LhARA, is conceived as a novel, uniquely-flexible facility dedicated to the study of radiobiology. The technologies demonstrated in LhARA, which have wide application, will be developed to allow particle-beam therapy to be delivered in a completely new regime, combining a variety of ion species in a single treatment fraction and exploiting ultra-high dose rates. LhARA will be a hybrid accelerator system in which laser interactions drive the creation of a large flux of protons or light ions that are captured using a plasma (Gabor) lens and formed into a beam. The laser-driven source allows protons and ions to be captured at energies significantly above those that pertain in conventional facilities, thus evading the current space-charge limit on the instantaneous dose rate that can be delivered. The laser-hybrid approach, therefore, will allow the vast ``terra incognita'' of the radiobiology that determines the response of tissue to ionising radiation to be studied with protons and light ions using a wide variety of time structures, spectral distributions, and spatial configurations at instantaneous dose rates up to and significantly beyond the ultra-high dose-rate `FLASH' regime. It is proposed that LhARA be developed in two stages. In the first stage, a programme of in vitro radiobiology will be served with proton beams with energies between 10MeV and 15MeV. In stage two, the beam will be accelerated using a fixed-field accelerator (FFA). This will allow experiments to be carried out in vitro and in vivo with proton beam energies of up to 127MeV. In addition, ion beams with energies up to 33.4MeV per nucleon will be available for in vitro and in vivo experiments. This paper presents the conceptual design for LhARA and the R&D programme by which the LhARA consortium seeks to establish the facility

Feminist geographies of digital work

Feminist thought challenges essentialist and normative categorizations of ‘work’. Therefore, feminism provides a critical lens on ‘working space’ as a theoretical and empirical focus for digital geographies. Digital technologies extend and intensify working activity, rendering the boundaries of the workplace emergent. Such emergence heightens the ambivalence of working experience: the possibilities for affirmation and/or negation through work. A digital geography is put forward through feminist theorizations of the ambivalence of intimacy. The emergent properties of working with digital technologies create space through the intimacies of postwork places where bodies and machines feel the possibilities of being ‘at’ work