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Iron-based enzymes efficiently activate molecular oxygen to perform the oxidation of methane to methanol (MTM), a reaction central to the contemporary chemical industry. Conversely, a very limited number of artificial catalysts have been devised to mimic this process. Herein, we employ the MIL-100(Fe) metal-organic framework (MOF), a material that exhibits isolated Fe sites, to accomplish the MTM conversion using O2 as the oxidant under mild conditions. We apply a diverse set of advanced operando X-ray techniques to unveil how MIL-100(Fe) can act as a catalyst for direct MTM conversion. Single-phase crystallinity and stability of the MOF under reaction conditions (200 or 100 °C, CH4 + O2) are confirmed by X-ray diffraction measurements. X-ray absorption, emission, and resonant inelastic scattering measurements show that thermal treatment above 200 °C generates Fe(II) sites that interact with O2 and CH4 to produce methanol. Experimental evidence-driven density functional theory (DFT) calculations illustrate that the MTM reaction involves the oxidation of the Fe(II) sites to Fe(III) via a high-spin Fe(IV)âO intermediate. Catalyst deactivation is proposed to be caused by the escape of CH3⢠radicals from the relatively large MOF pore cages, ultimately resulting in the formation of hydroxylated triiron units, as proven by valence-to-core X-ray emission spectroscopy. The O2-based MTM catalytic activity of MIL-100(Fe) in the investigated conditions is demonstrated for two consecutive reaction cycles, proving the MOF potential toward active site regeneration. These findings will desirably lay the groundwork for the design of improved MOF catalysts for the MTM conversion.
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Herein, we report the synthesis and characterization of several chiral (cyclopentadienone)iron complexes (CICs) featuring either two (R)-BINOL-derived stereoaxes or a combination of one (R)-BINOL-derived stereoaxis and a stereogenic plane. The stereoplane-containing CICs were obtained as epimer mixtures, which were separated by flash column chromatography and assigned an absolute configuration based on XRD analysis, NMR and order of elution. The library was tested in the asymmetric hydrogenation of ketones showing good catalytic activity and a moderate stereoselectivity which, notably, is mostly imparted by the stereogenic plane. Indeed, the two epimers of each CIC possessing a stereoplane show opposite and equally strong stereochemical preference.
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BACKGROUND: Intracranial hematomas (IHs) occur commonly after severe traumatic brain injury, but their effects on outcomes in patients with prolonged disorders of consciousness (DoC) following coma (i.e., unresponsive wakefulness syndrome and minimally conscious state) are unknown. METHODS: In this multicenter longitudinal study, we compared clinical outcomes and serum neurofilament light chain (NFL) levels of 52 patients with traumatic DoC with (n = 35) and without (n = 17) IH in the acute phase. Patients were evaluated with the Coma Recovery Scale-Revised (CRS-R) at enrollment (1-3 months post-injury) and with the CRS-R, extended Glasgow Outcome Scale (GOSE), and Functional Independence Measure (FIM) at 6 months post-injury. At the same timepoints, serum NFL levels were compared between patients with and without IHs and with those of 52 sex- and age-matched healthy controls. RESULTS: Patients with and without IH did not differ in terms of DoC or CRS-R scores at admission, or clinical outcomes (death, unresponsive wakefulness syndrome, minimally conscious state, or emergence from minimally conscious state) or CRS-R, GOSE, or FIM scores 6 months post-injury. NFL levels were significantly higher in patients than in controls at admission and 6 months post-injury (both p < 0.0001), but they did not differ between patients with and without IH. CONCLUSIONS: This study showed that IHs do not affect clinical outcomes or markers of axonal degeneration in patients with traumatic DoC.
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Estado de Consciência , Estado Vegetativo Persistente , Humanos , Estado de Consciência/fisiologia , Estado Vegetativo Persistente/etiologia , Transtornos da Consciência/etiologia , Coma , Estudos Longitudinais , HemorragiaRESUMO
Atherosclerosis is a chronic and progressive inflammatory process beginning early in life with late clinical manifestation. This slow pathological trend underlines the importance to early identify high-risk patients and to treat intensively risk factors to prevent the onset and/or the progression of atherosclerotic lesions. In addition to the common Cardiovascular (CV) risk factors, new markers able to increase the risk of CV disease have been identified. Among them, high levels of Lipoprotein(a)-Lp(a)-lead to very high risk of future CV diseases; this relationship has been well demonstrated in epidemiological, mendelian randomization and genome-wide association studies as well as in meta-analyses. Recently, new aspects have been identified, such as its association with aortic stenosis. Although till recent years it has been considered an unmodifiable risk factor, specific drugs have been developed with a strong efficacy in reducing the circulating levels of Lp(a) and their capacity to reduce subsequent CV events is under testing in ongoing trials. In this paper we will review all these aspects: from the synthesis, clearance and measurement of Lp(a), through the findings that examine its association with CV diseases and aortic stenosis to the new therapeutic options that will be available in the next years.
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Estenose da Valva Aórtica , Aterosclerose , Doenças Cardiovasculares , Humanos , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/prevenção & controle , Lipoproteína(a)/genética , Estudo de Associação Genômica Ampla , Estenose da Valva Aórtica/epidemiologia , Estenose da Valva Aórtica/genética , Estenose da Valva Aórtica/tratamento farmacológico , Fatores de Risco , Aterosclerose/tratamento farmacológico , Aterosclerose/genéticaRESUMO
Industrial processes prominently feature π-acidic gases, and an adsorbent capable of selectively interacting with these molecules could enable important chemical separations1-4. Biological systems use accessible, reducing metal centres to bind and activate weakly π-acidic species, such as N2, through backbonding interactions5-7, and incorporating analogous moieties into a porous material should give rise to a similar adsorption mechanism for these gaseous substrates8. Here, we report a metal-organic framework featuring exposed vanadium(II) centres capable of back-donating electron density to weak π acids to successfully target π acidity for separation applications. This adsorption mechanism, together with a high concentration of available adsorption sites, results in record N2 capacities and selectivities for the removal of N2 from mixtures with CH4, while further enabling olefin/paraffin separations at elevated temperatures. Ultimately, incorporating such π-basic metal centres into porous materials offers a handle for capturing and activating key molecular species within next-generation adsorbents.
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C2 H2 /CO2 separation is a highly challenging process as a consequence of their similar physicochemical properties. In this work we have explored, by static and dynamic gas sorption techniques and computational modelling, the suitability of a series of two isoreticular robust Ni(II)pyrazolate-based MOFs, bearing alkyne moieties on the ligand backbones, for C2 H2 /CO2 separation. The results are consistent with high adsorption capacity and selectivity of the essayed systems towards C2 H2 molecules. Furthermore, a post-synthetic treatment with KOH ethanolic solution gives rise to linker vacancy defects and incorporation of extraframework potassium ions. Creation of defects is responsible for increased adsorption capacity for both gases, however, strong interactions of the cluster basic sites and extraframework potassium cations with CO2 molecules are responsible for a lowering of C2 H2 over CO2 selectivity.
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CONTEXT: A reduction in the use of opioids by older adult patients could reduce unpleasant side effects for them. During general anesthesia, binaural beat (BB) listening has been found to reduce intraoperative fentanyl consumption as well as postoperative pain scores and discharge time. Auditory BBs are a perceptual phenomenon occurring when tones of 2 slightly different frequencies are presented simultaneously and separately to each ear. OBJECTIVE: The study intended to evaluate the ability of BBs, as a nonpharmacological premedication, to reduce postoperative morphine consumption in older adults undergoing total knee replacement surgery and to modify the levels of anxiety and feelings of pain that patients experience. DESIGN: The research team designed a prospective, single-center, randomized controlled study. SETTING: The study was conducted in the Orthopedic Department of the Santa Maria Maddalena Hospital (Volterra [Pisa], Italy). PARTICIPANTS: Forty older adults at the hospital who were undergoing total knee joint replacement with spinal anesthesia participated in the study. INTERVENTION: The study included 2 groups (n = 20 each), one receiving BBs stimulation with frequencies of 256 Hz in one ear and 260 Hz in the opposite ear producing a BB of 4 Hz (intervention group), and the other receiving acoustical stimulation at 256 Hz in both ears (control group). BBs, or acoustical stimulation, were administered before the surgical procedure. Both acoustical stimuli, generated with the Gnaural program, were delivered through stereo headphones connected to a laptop in the preoperative holding area. OUTCOME MEASURES: The study measured postoperative, cumulative, self-administered morphine consumption, in mg, through a patient-controlled analgesia device. Feelings of anxiety were also assessed using the State-Trait Anxiety Inventory, and feelings of pain were measured every 8 h during the first postoperative day using a numerical rating scale. RESULTS: Patients who received the intervention, consumed almost half of the dosage of morphine during the first postoperative day when compared with the control group's consumption, 5.75 mg ± 5.25 vs 11.85 mg ± 7.71, respectively. The consumption did not correlate to anxiety measures. Regarding pain perception, no differences between the groups were captured. CONCLUSIONS: BB stimulation before surgery can be successfully used as a nonpharmacological treatment to reduce morphine consumption in older adults who undergo knee replacement. The use of a noninvasive, safe, and inexpensive BB intervention can result in a positive effect on patients' postoperative recovery.
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Artroplastia do Joelho , Morfina , Idoso , Método Duplo-Cego , Humanos , Itália , Morfina/uso terapêutico , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/prevenção & controle , Estudos ProspectivosRESUMO
The solvatomorphism of the anthelmintic drug moxidectin is investigated, and a new solvatomorph with nitromethane is reported. Moreover, the hitherto unknown crystal structures of the solvatomorphs with ethanol and 2-propanol are reported and discussed. The thermal characterization of these solvatomorphs through variable-temperature powder X-ray diffraction analysis (VT-PXRD) is also described, providing new insights into the crystallochemistry of this active pharmaceutical ingredient.
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Macrolídeos/química , Solventes/química , Cristalografia por Raios X , Ligação de Hidrogênio , Conformação Molecular , Difração de Pó , TemperaturaRESUMO
Two isostructural coordination polymers with coinage metal(I) cations were compressed with the purpose of testing interactions between chains, which may trigger metallophilic interactions or otherwise expand the metal coordination. DFT calculations and X-ray diffraction studies reveal an extraordinary difference between Ag(I) and Cu(I) in homologous compounds. Argentophilic interactions are favored by a mild compression, and at P = 7.94 GPa, the Ag-Ag distance matches the value of metallic silver. On the other hand, no cuprophilic interaction is activated even by compression up to 8 GPa, and Cu-Cu distances remain outside the van der Waals spheres.
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Two structurally constrained chelators based on a fused bicyclic scaffold, 4-amino-4-methylperhydro-pyrido[1,2-a][1,4]diazepin-N,N',N'-triacetic acids [(4R*,10aS*)-PIDAZTA (L1) and (4R*,10aR*)-PIDAZTA (L2)], were designed for the preparation of GaIII -based radiopharmaceuticals. The stereochemistry of the ligand scaffold has a deep impact on the properties of the complexes, with unexpected [Ga(L2)OH] species being superior in terms of both thermodynamic stability and inertness. This peculiar behavior was rationalized on the basis of molecular modeling and appears to be related to a better fit in size of GaIII into the cavity of L2. Fast and efficient formation of the GaIII chelates at room temperature was observed at pH values between 7 and 8, which enables 68 Ga radiolabeling under truly physiological conditions (pHâ 7.4).
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Compostos Bicíclicos com Pontes/química , Quelantes/química , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Complexos de Coordenação/metabolismo , Cristalografia por Raios X , Teoria da Densidade Funcional , Radioisótopos de Gálio/química , Meia-Vida , Humanos , Concentração de Íons de Hidrogênio , Cinética , Conformação Molecular , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/metabolismo , Transferrina/químicaRESUMO
The role of substrate topography in phenotype expression of in vitro cultured cells has been widely assessed. However, the production of the nanostructured interface via the deposition of sol-gel synthesized nanoparticles (NPs) has not yet been fully exploited. This is also evidenced by the limited number of studies correlating the morphological, structural and chemical properties of the grown thin films with those of the sol-gel 'brick' within the framework of the bottom-up approach. Our work intends to go beyond this drawback presenting an accurate investigation of sol-gel TiO2 NPs shaped as spheres and rods. They have been fully characterized by complementary analytical techniques both suspended in apolar solvents, by dynamic light scattering (DLS) and nuclear magnetic resonance (NMR) and after deposition on substrates (solid state configuration) by transmission electron microscopy (TEM) and powder x-ray diffraction (PXRD). In the case of suspended anisotropic rods, the experimental DLS data, analyzed by the Tirado-Garcia de la Torre model, present the following ranges of dimensions: 4-5 nm diameter (∅) and 11-15 nm length (L). These results are in good agreement with that obtained by the two solid state techniques, namely 3.8(9) nm ∅ and 13.8(2.5) nm L from TEM and 5.6(1) ∅ and 13.3(1) nm L from PXRD data. To prove the suitability of the supported sol-gel NPs for biological issues, spheres and rods have been separately deposited on coverslips. The cell response has been ascertained by evaluating the adhesion of the epithelial cell line Madin-Darby canine kidney. The cellular analysis showed that titania films promote cell adhesion as well clustering organization, which is a distinguishing feature of this type of cell line. Thus, the use of nanostructured substrates via sol-gel could be considered a good candidate for cell culture with the further advantages of likely scalability and interfaceability with many different materials usable as supports.
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Coloides/química , Nanoestruturas/química , Transição de Fase , Titânio/química , Animais , Proliferação de Células , Cães , Células Madin Darby de Rim Canino , Nanosferas/química , Nanosferas/ultraestrutura , Nanoestruturas/ultraestrutura , Nanotubos/química , Nanotubos/ultraestrutura , Ácido Oleico/química , Tamanho da Partícula , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier , Água/químicaRESUMO
Stormwater wetlands are engineered to accumulate sediment and pollutants from stormwater and provide environmental value to urban environments. Therefore, contaminated sediment risks causing toxicity to aquatic fauna. This research identifies contaminants of concern in urban wetland sediments by assessing sediment toxicity using the amphipod Austrochiltonia subtenuis. Sediments from 98 wetlands were analyzed for contaminants, and laboratory bioassays were performed with A. subtenuis. Wild Austrochiltonia spp. were also collected from wetlands to assess field populations. Random forest modeling was used to identify the most important variables predicting survival, growth, and field absence of Austrochiltonia spp. Bifenthrin was the most frequently detected pesticide and also the most important predictor of Austrochiltonia spp. responses. Copper, permethrin, chromium, triclosan, and lead were also important. The median lethal effect concentration (LC50) of bifenthrin to laboratory-based A. subtenuis (1.09 (±0.08) µg/gOC) exposed to wetland sediments was supported by a bifenthrin-spiked sediment experiment, indicating A. subtenuis is a suitable test species. Furthermore, Austrochiltonia spp. were absent from all sites that exceeded the calculated bifenthrin LC50, demonstrating the impact of this contaminant on wild populations. This research demonstrates the sensitivity of Austrochiltonia spp. to urban sediment contamination and identifies bifenthrin as a contaminant of concern in urban wetlands.
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Anfípodes , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Cidades , Sedimentos Geológicos , Abastecimento de Água , Áreas AlagadasRESUMO
The antiproliferative response to anticancer treatment is the result of concurrent responses in all cell cycle phases, extending over several cell generations, whose complexity is not captured by current methods. In the proposed experimental/computational approach, the contemporary use of time-lapse live cell microscopy and flow cytometric data supported the computer rendering of the proliferative process through the cell cycle and subsequent generations during/after treatment. The effects of treatments were modelled with modules describing the functional activity of the main pathways causing arrest, repair and cell death in each phase. A framework modelling environment was created, enabling us to apply different types of modules in each phase and test models at the complexity level justified by the available data. We challenged the method with time-course measures taken in parallel with flow cytometry and time-lapse live cell microscopy in X-ray-treated human ovarian cancer cells, spanning a wide range of doses. The most suitable model of the treatment, including the dose-response of each effect, was progressively built, combining modules with a rational strategy and fitting simultaneously all data of different doses and platforms. The final model gave for the first time the complete rendering in silico of the cycling process following X-ray exposure, providing separate and quantitative measures of the dose-dependence of G1, S and G2M checkpoint activities in subsequent generations, reconciling known effects of ionizing radiations and new insights in a unique scenario.
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Ciclo Celular/efeitos da radiação , Proliferação de Células/efeitos da radiação , Modelos Biológicos , Neoplasias Ovarianas/radioterapia , Linhagem Celular Tumoral , Simulação por Computador , Relação Dose-Resposta à Radiação , Feminino , Humanos , Microscopia de Vídeo , Imagem com Lapso de TempoRESUMO
The hydrogen bond network of three polymorphs (1α, 1ß, and 1γ) and one solvate form (1·H2O) arising from the hydration-dehydration process of the Ru(II) complex [(p-cymene)Ru(κN-INA)Cl2] (where INA is isonicotinic acid), has been ascertained by means of one-dimensional (1D) and two-dimensional (2D) double quantum (1)H CRAMPS (Combined Rotation and Multiple Pulses Sequences) and (13)C CPMAS solid-state NMR experiments. The resolution improvement provided by homonuclear decoupling pulse sequences, with respect to fast MAS experiments, has been highlighted. The solid-state structure of 1γ has been fully characterized by combining X-ray powder diffraction (XRPD), solid-state NMR, and periodic plane-wave first-principles calculations. None of the forms show the expected supramolecular cyclic dimerization of the carboxylic functions of INA, because of the presence of Cl atoms as strong hydrogen bond (HB) acceptors. The hydration-dehydration process of the complex has been discussed in terms of structure and HB rearrangements.
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Environmental stimuli can induce plastic changes in life history traits, and stimuli experienced by parents can be transmitted to the next generation ("transgenerational") through the inheritance of factors unrelated to changes in DNA sequences. Transgenerational effects are common in species living in habitats subjected to recurrent stressful events, such as fluctuating resource availability. In a previous study, the nutritional status of the midge Chironomus tepperi has been reported to influence life history traits of the offspring. In this study we investigated whether they also alter sensitivity of offspring to zinc. Offspring of parents reared under low food conditions had a shorter development time and lower reproductive output compared to offspring of parents raised under excess food. While zinc exposure decreased the survival of offspring generally, the interaction between parental food level and zinc exposure did not influence the relative sensitivity of offspring toward zinc. Parental nutritional stress therefore triggered transgenerational effects, potentially acting as confounding factors in ecotoxicological studies, but they did not directly affect the susceptibility of offspring to zinc.
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Chironomidae/efeitos dos fármacos , Zinco/toxicidade , Fenômenos Fisiológicos da Nutrição Animal , Animais , Chironomidae/crescimento & desenvolvimento , Chironomidae/fisiologia , Fertilidade/efeitos dos fármacosRESUMO
An unexpected nitro group displacement during a nitro-Mannich reaction led to the one-pot formation of the octahydro-2H-pyrazino[1,2-a]pyrazine core, representing the shortest access to date to this pharmacologically relevant heterobicyclic system. A mechanistic hypothesis is suggested and supported by specific experiments and HRMS analysis of reaction mixtures.
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BACKGROUND: Blood flow restriction training (BFR-t) data are heterogeneous. It is unclear whether rehabilitation with BFR-t after an anterior cruciate ligament (ACL) injury is more effective in improving muscle strength and muscle size than standard rehabilitation. PURPOSE: To review outcomes after an ACL injury and subsequent reconstruction in studies comparing rehabilitation with and without BFR-t. STUDY DESIGN: Systematic review. Level of evidence, 3. METHODS: A search of English-language human clinical studies published in the past 20 years (2002-2022) was carried out in 5 health sciences databases, involving participants aged 18-65 undergoing rehabilitation for an ACL injury. Outcomes associated with muscle strength, muscle size, and knee-specific patient-reported outcome measures (PROMs) were extracted from studies meeting inclusion criteria and compared. RESULTS: The literature search identified 279 studies, of which 5 met the selection criteria. Two studies suggested that BFR-t rehabilitation after an ACL injury improved knee or thigh muscle strength and muscle size compared with rehabilitation consisting of comparable and higher load resistance training, with two studies suggesting the opposite. The single study measuring PROMs showed improvement compared to traditional rehabilitation, with no difference in muscle strength or size. CONCLUSION: BFR-t after an ACL injury seems to benefit muscle strength, muscle size, and PROM scores compared with standard rehabilitation alone. However, only 1 large study included all these outcomes, which has yet to be replicated in other settings. Further studies utilizing similar methods with a common set of outcome measures are required to confirm the effects of BFR-t on ACL rehabilitation.
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Healthcare-associated infections (HAIa) and antimicrobial resistance are expected to be the next threat to human health and are most frequent in people with severe acquired brain injury (SABI), who can be more easily colonized by multidrug-resistant organisms (MDROs). The study's aim is to investigate the impact of MDRO colonizations and infections on SABI rehabilitation outcomes. This retrospective observational study was performed in a tertiary referral specialized rehabilitation hospital. The main outcomes were the presence of carbapenemase-producing Enterobacteriaceae (CPE) colonization, type and timing of HAI and MDRO HAI, and the number of CPE transmissions. We included 48 patients, 31% carrying CPE on admission and 33% colonized during the hospitalization. A total of 101 HAI were identified in 40 patients, with an overall incidence of 10.5/1000 patient days. Some 37% of patients had at least one MDRO infection, with a MDRO infection incidence of 2.8/1000 patient days. The number of HAIs was significantly correlated with the length of stay (LOS) (r = 0.453, p = 0.001). A significant correlation was found between colonization and type of hospital room (p = 0.013). Complications and HAI significantly affected LOS. We suggest that CPE carriers might be at risk of HAI and worse outcomes compared with non-CPE carriers.
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Understanding adsorption processes at the molecular level, with multi-technique approaches, is nowadays at the frontier of porous materials research. In this work it is shown that with a proper data treatment, in situ high-resolution powder X-ray diffraction (HR-PXRD) at variable temperature and gas pressure can reveal atomic details of the accommodation sites, the framework dynamics as well as thermodynamic information (isosteric heat of adsorption) of the CO2 adsorption process in the robust iron(III) pyrazolate-based MOF Fe2(BDP)3 [H2BDP = 1,4-bis(1H-pyrazol-4-yl)benzene]. Highly reliable "HR-PXRD adsorption isotherms" can be constructed from occupancy values of CO2 molecules. The "HR-PXRD adsorption isotherms" accurately match the results of conventional static and dynamic gas sorption experiments and Monte Carlo simulations. These results are indicative of the impact of the molecular-level behavior on the bulk properties of the system under study and of the potential of the presented multi-technique approach to understand adsorption processes in metal-organic frameworks.
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Supplementary Table S3 in our recent publication [...].