18 research outputs found

    Relationship between the Clinical Frailty Scale and short-term mortality in patients ≥ 80 years old acutely admitted to the ICU: a prospective cohort study.

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    BACKGROUND: The Clinical Frailty Scale (CFS) is frequently used to measure frailty in critically ill adults. There is wide variation in the approach to analysing the relationship between the CFS score and mortality after admission to the ICU. This study aimed to evaluate the influence of modelling approach on the association between the CFS score and short-term mortality and quantify the prognostic value of frailty in this context. METHODS: We analysed data from two multicentre prospective cohort studies which enrolled intensive care unit patients ≥ 80 years old in 26 countries. The primary outcome was mortality within 30-days from admission to the ICU. Logistic regression models for both ICU and 30-day mortality included the CFS score as either a categorical, continuous or dichotomous variable and were adjusted for patient's age, sex, reason for admission to the ICU, and admission Sequential Organ Failure Assessment score. RESULTS: The median age in the sample of 7487 consecutive patients was 84 years (IQR 81-87). The highest fraction of new prognostic information from frailty in the context of 30-day mortality was observed when the CFS score was treated as either a categorical variable using all original levels of frailty or a nonlinear continuous variable and was equal to 9% using these modelling approaches (p < 0.001). The relationship between the CFS score and mortality was nonlinear (p < 0.01). CONCLUSION: Knowledge about a patient's frailty status adds a substantial amount of new prognostic information at the moment of admission to the ICU. Arbitrary simplification of the CFS score into fewer groups than originally intended leads to a loss of information and should be avoided. Trial registration NCT03134807 (VIP1), NCT03370692 (VIP2)

    Designing Quinone-based Organic Batteries

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    The demand for secondary energy storage is ever increasing, being at the forefront of the transformation to a sustainable society. Conventional batteries, whose electrode materials require mining and high temperature refining, generate substantial carbon dioxide emissions during production. Furthermore, the process for recycling of these batteries is difficult and still at in its infancy. On the contrary, organic batteries could be a sustainable and alternative energy storage solution and is therefore gaining increased attention. While there are several promising organic battery concepts, the focus in of this thesis has been towards batteries using quinones as capacity carrying units. Furthermore, a special emphasis was put on conducting polymers for providing conductivity within the electrode material, predominately in the form of conducting redox polymers. Several battery designs have been explored. All-organic batteries, cycling protons both with an ionic liquid and with a readily available aqueous electrolyte, have been evaluated with promising results concerning rate capabilities and low temperature operation. Hybrid-organic battery designs have shown that quinones easily cycle Lithium ions and act in a dual ion battery with a Manganese oxide cathode. This thesis therefore gives a broad overview on how quinone organic batteries can be designed and provides an outlook on how future development can be focused

    Designing Quinone-based Organic Batteries

    No full text
    The demand for secondary energy storage is ever increasing, being at the forefront of the transformation to a sustainable society. Conventional batteries, whose electrode materials require mining and high temperature refining, generate substantial carbon dioxide emissions during production. Furthermore, the process for recycling of these batteries is difficult and still at in its infancy. On the contrary, organic batteries could be a sustainable and alternative energy storage solution and is therefore gaining increased attention. While there are several promising organic battery concepts, the focus in of this thesis has been towards batteries using quinones as capacity carrying units. Furthermore, a special emphasis was put on conducting polymers for providing conductivity within the electrode material, predominately in the form of conducting redox polymers. Several battery designs have been explored. All-organic batteries, cycling protons both with an ionic liquid and with a readily available aqueous electrolyte, have been evaluated with promising results concerning rate capabilities and low temperature operation. Hybrid-organic battery designs have shown that quinones easily cycle Lithium ions and act in a dual ion battery with a Manganese oxide cathode. This thesis therefore gives a broad overview on how quinone organic batteries can be designed and provides an outlook on how future development can be focused

    Nonstoichiometric triazolium protic ionic liquids for all-organic batteries

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    Non stoichiometric protic ionic liquids (NSPILs) are efficient electrolytes for protic electrochemical devices such as the all-organic proton battery, which has been suggested as a sustainable approach to energy storage. NSPILs contain a mixture of proton donors and acceptors and are ideal for this purpose due to their high proton conductivity, high electrochemical stability, low cost and ease of synthesis. The electrolyte proton activity must be controlled carefully in these devices since it greatly influences the kinetics and energetics of the electrode redox reactions, and hence also impacts battery device performance. In this study, specific NSPILs were designed and evaluated as electrolytes for the all-organic proton battery. The NSPILs were based on either 1,2,4-triazole or 1-methyl-1,2,4-triazole partially protonated with bis(trifluoromethylsulfonyl)imide (TFSI) to produce a range of NSPILs with different degrees of protonation. Both types of NSPIL investigated here exhibit a maximum observed conductivity of 1.2 S/cm (at 120 and 70 °C, respectively), and the eutectic composition of 1-methyl-1,2,4-triazolium TFSI also has high conductivity at 25 °C (24.9 mS/cm), superior to e.g. imidazolium TFSI NSPILs. Pulsed field gradient NMR in conjunction with electrochemical impedance spectroscopy showed that the conductivity originated mainly from vehicle diffusion and proton hopping. Quinone functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes exhibited reversible, fast and stable redox conversion in these electrolytes, and a model is suggested to determine proton activities of NSPILs based on the quinone formal potential. An all-organic proton battery cell was assembled to demonstrate the usefulness of these electrolytes in devices. Fast and complete redox conversion with a cell potential of 0.45 V was demonstrated, even up to scan rates corresponding to 140 C. Compared to the pyridine based electrolytes used for the all-organic proton battery up until now, the present electrolytes display several advantages including lower melting point, lower toxicity, and compatibility with plastic materials

    An Alternative to Carbon Additives : The Fabrication of Conductive Layers Enabled by Soluble Conducting Polymer Precursors – A Case Study for Organic Batteries

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    Utilizing organic redox-active materials as electrodes is a promising strategy to enable innovative battery designs with low environmental footprint during production, which can be hard to achieve with traditional inorganic materials. Most electrode compositions, organic or inorganic, require binders for adhesion and conducting additives to enable charge transfer through the electrode, in addition to the redox-active material. Depending on the redox-active material, many types and combinations of binders and conducting additives have been considered. We designed a conducting polymer (CP), with a soluble, trimeric unit based on 3,4-ethylenedioxythiophene (E) and 3,4-propylenedioxythiophene (P) as the repeat unit, acting as a combined binder and conducting additive. While CPs as additives have been explored earlier, in the current work, the use of a trimeric precursor enables solution processing together with the organic redox-active material. To evaluate this concept, the CP was blended with a redox polymer (RP), which contained a naphthoquinone (NQ) redox group at different ratios. The highest capacity for the total weight of the CP/RP electrode was 77 mAh/g at 1 C in the case of 30% EPE and 70% naphthoquinone-substituted poly(allylamine) (PNQ), which is 70% of the theoretical capacity given by the RP in the electrode. We further used this electrode in an aqueous battery, with a MnSO4 cathode. The battery displayed a voltage of 0.95 V, retaining 93% of the initial capacity even after 500 cycles at 1 C. The strategy of using a solution-processable CP precursor opens up for new organic battery designs and facile evaluation of RPs in such

    An Aqueous Conducting Redox-Polymer-Based Proton Battery that Can Withstand Rapid Constant-Voltage Charging and Sub-Zero Temperatures

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    Electrodes based on organic matter operating in aqueous electrolytes enable new approaches and technologies for assembling and utilizing batteries that are difficult to achieve with traditional electrode materials. Here, we report how thiophene‐based trimeric structures with naphthoquinone or hydroquinone redox‐active pendent groups can be processed in solution, deposited, dried and subsequently polymerized in solid state to form conductive (redox) polymer layers without any additives. Such post‐deposition polymerization offers efficient use of material, high mass loading (up to 10 mg cm−2) and good flexibility in the choice of substrate and coating method. By employing these materials as anode and cathode in an acidic aqueous electrolyte a rocking‐chair proton battery is built. The battery shows good cycling stability (85 % after 500 cycles), withstands rapid charging, with full capacity (60 mAh g−1) reached within 100 seconds, allows for direct integration with photovoltaics, and retains its favorable characteristics even at −24 °C

    Characterization of PEDOT-Quinone conducting redox polymers in water-in-salt electrolytes for safe and high-energy Li-ion batteries

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    Li-ion batteries (LIBs) raise safety and environmental concerns, which mostly arise from their toxic and flammable electrolytes and the extraction of limited material resources by mining. Recently, water-in-salt electrolytes (WiSEs), in which a large amount of lithium salt is dissolved in water, have been proposed to allow for assembling safe and high-voltage (&gt;3.0 V) aqueous LIBs. In addition, organic materials derived from abundant building blocks and their tunable properties could provide safe and sustainable replacements for inorganic cathode materials. In the current work, the electrochemical properties of a conducting redox polymer based on poly(3,4-ethylenedioxythiophene) (PEDOT) with hydroquinone (HQ) pendant groups have been characterized in WiSEs. The quinone redox reaction occurs within the potential region where the polymer is conducting, and fast redox conversion that involves lithium cycling during pendant group redox conversion was observed. These properties make conducting redox polymers promising candidates as cathode-active materials for safe and high-energy aqueous LIBs. An organic-based aqueous LIB, with a HQ-PEDOT as a cathode, Li4Ti5O12 (LTO) as an anode, and ca. 15 m lithium bis(trifluoromethanesulfonyl)imide water/dimethyl carbonate (DMC) as electrolyte, yielded an output voltage of 1.35 V and high rate capabilities up to 500C

    The impact of frailty on survival in elderly intensive care patients with COVID-19: the COVIP study

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    Auteurs : COVIP study groupInternational audienceBackground The COVID-19 pandemic has led highly developed healthcare systems to the brink of collapse due to the large numbers of patients being admitted into hospitals. One of the potential prognostic indicators in patients with COVID-19 is frailty. The degree of frailty could be used to assist both the triage into intensive care, and decisions regarding treatment limitations. Our study sought to determine the interaction of frailty and age in elderly COVID-19 ICU patients. Methods A prospective multicentre study of COVID-19 patients ≥ 70 years admitted to intensive care in 138 ICUs from 28 countries was conducted. The primary endpoint was 30-day mortality. Frailty was assessed using the clinical frailty scale. Additionally, comorbidities, management strategies and treatment limitations were recorded. Results The study included 1346 patients (28% female) with a median age of 75 years (IQR 72–78, range 70–96), 16.3% were older than 80 years, and 21% of the patients were frail. The overall survival at 30 days was 59% (95% CI 56–62), with 66% (63–69) in fit, 53% (47–61) in vulnerable and 41% (35–47) in frail patients ( p < 0.001). In frail patients, there was no difference in 30-day survival between different age categories. Frailty was linked to an increased use of treatment limitations and less use of mechanical ventilation. In a model controlling for age, disease severity, sex, treatment limitations and comorbidities, frailty was independently associated with lower survival. Conclusion Frailty provides relevant prognostic information in elderly COVID-19 patients in addition to age and comorbidities. Trial registration Clinicaltrials.gov: NCT04321265 , registered 19 March 2020

    The association of the Activities of Daily Living and the outcome of old intensive care patients suffering from COVID-19

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    Purpose: Critically ill old intensive care unit (ICU) patients suffering from Sars-CoV-2 disease (COVID-19) are at increased risk for adverse outcomes. This post hoc analysis investigates the association of the Activities of Daily Living (ADL) with the outcome in this vulnerable patient group. Methods: The COVIP study is a prospective international observational study that recruited ICU patients >= 70 years admitted with COVID-19 (NCT04321265). Several parameters including ADL (ADL; 0 = disability, 6 = no disability), Clinical Frailty Scale (CFS), SOFA score, intensive care treatment, ICU- and 3-month survival were recorded. A mixed-effects Weibull proportional hazard regression analyses for 3-month mortality adjusted for multiple confounders. Results: This pre-specified analysis included 2359 patients with a documented ADL and CFS. Most patients evidenced independence in their daily living before hospital admission (80% with ADL = 6). Patients with no frailty and no disability showed the lowest, patients with frailty (CFS >= 5) and disability (ADL < 6) the highest 3-month mortality (52 vs. 78%, p < 0.001). ADL was independently associated with 3-month mortality (ADL as a continuous variable: aHR 0.88 (95% CI 0.82-0.94, p < 0.001). Being "disable" resulted in a significant increased risk for 3-month mortality (aHR 1.53 (95% CI 1.19-1.97, p 0.001) even after adjustment for multiple confounders. Conclusion: Baseline Activities of Daily Living (ADL) on admission provides additional information for outcome prediction, although most critically ill old intensive care patients suffering from COVID-19 had no restriction in their ADL prior to ICU admission. Combining frailty and disability identifies a subgroup with particularly high mortality
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