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1.
Commun Chem ; 7(1): 29, 2024 Feb 13.
Article in English | MEDLINE | ID: mdl-38351167

ABSTRACT

Poorly selective mixed-metal cluster synthesis and separation yield reaction solutions of inseparable intermetalloid cluster mixtures, which are often discarded. High-resolution mass spectrometry, however, can provide precise compositional data of such product mixtures. Structure assignments can be achieved by advanced computational screening and consideration of the complete structural space. Here, we experimentally verify structure and composition of a whole cluster ensemble by combining a set of spectroscopic techniques. Our study case are the very similar nickel/gallium clusters of M12, M13 and M14 core composition Ni6+xGa6+y (x + y ≤ 2). The rationalization of structure, bonding and reactivity is built upon the organometallic superatom cluster [Ni6Ga6](Cp*)6 = [Ga6](NiCp*)6 (1; Cp* = C5Me5). The structural conclusions are validated by reactivity tests using carbon monoxide, which selectively binds to Ni sites, whereas (triisopropylsilyl)acetylene selectively binds to Ga sites.

2.
Sci Total Environ ; 886: 163882, 2023 Aug 15.
Article in English | MEDLINE | ID: mdl-37160185

ABSTRACT

Decentralized energy systems enable a higher integration of electricity generation by renewable energy sources supported by electric storage and may significantly reduce greenhouse gas emissions for electricity generation. While the environmental impact of single technologies has received great attention in recent years, the environmental impacts of decentralized energy generation and storage technologies remain unaddressed. This study presents a cradle-to-grave life cycle assessment of those technologies in Belgium for 2030 and 2050. The system technologies comprise single-Si photovoltaic installations combined with lithium-ion and second-life batteries. To compile the life cycle inventory (LCI), energy balances are built based on a Belgian impact energy model. The flexibility of the energy system is introduced by different EV charging strategies and distinct modes of stationary battery storage with the Belgium electricity grid, represented by four different scenarios: i) low flexibility, ii) medium flexibility, iii) high flexibility, and iv) high flexibility with high prosumer potential (PPH). The midpoint impact categories climate change, land use, mineral resource scarcity and terrestrial ecotoxicity of ReCiPe life cycle impact assessment method are analyzed. The decentralized energy generation and storage technologies in Belgium in 2050 result in 64.51 gCO2eq/kWh of consumed electricity for the medium flexibility scenario, representing a 72 % decrease compared to 2014. However, these reductions are driven by changes in the national electricity mix. Land use impacts are also reduced, up to 72 % for the high flexibility PPH scenario. In contrast, mineral resource scarcity and terrestrial ecotoxicity rise over time in the high flexibility PPH scenario in 2050 to 46 % and 66 %, respectively. A perturbation analysis is conducted to assess the sensitivity of the results, showing solar irradiation as the most sensitive parameter. One way to further reduce the environmental impacts of decentralized energy systems could be to investigate new strategies for the end-of-life of photovoltaic installations and batteries.


Subject(s)
Environment , Lithium , Animals , Belgium , Climate Change , Electricity , Life Cycle Stages
3.
Nat Commun ; 13(1): 1758, 2022 04 01.
Article in English | MEDLINE | ID: mdl-35365619

ABSTRACT

Fluorescence techniques dominate the field of live-cell microscopy, but bleaching and motion blur from too long integration times limit dynamic investigations of small objects. High contrast, label-free life-cell imaging of thousands of acquisitions at 160 nm resolution and 100 Hz is possible by Rotating Coherent Scattering (ROCS) microscopy, where intensity speckle patterns from all azimuthal illumination directions are added up within 10 ms. In combination with fluorescence, we demonstrate the performance of improved Total Internal Reflection (TIR)-ROCS with variable illumination including timescale decomposition and activity mapping at five different examples: millisecond reorganization of macrophage actin cortex structures, fast degranulation and pore opening in mast cells, nanotube dynamics between cardiomyocytes and fibroblasts, thermal noise driven binding behavior of virus-sized particles at cells, and, bacterial lectin dynamics at the cortex of lung cells. Using analysis methods we present here, we decipher how motion blur hides cellular structures and how slow structure motions cover decisive fast motions.


Subject(s)
Actins , Lighting , Fibroblasts , Microscopy, Fluorescence/methods
4.
Angew Chem Int Ed Engl ; 61(8): e202115100, 2022 02 14.
Article in English | MEDLINE | ID: mdl-34825766

ABSTRACT

Vectorial catalysis-controlling multi-step reactions in a programmed sequence and by defined spatial localization in a microscale device-is an enticing goal in bio-inspired catalysis research. However, translating concepts from natural cascade biocatalysis into artificial hierarchical chemical systems remains a challenge. Herein, we demonstrate integration of two different surface-anchored nanometer-sized metal-organic frameworks (MOFs) in a microfluidic device for modelling vectorial catalysis. Catalyst immobilization at defined sections along the microchannel and a two-step cascade reaction was conducted with full conversion after 30 seconds and high turnover frequencies (TOF≈105  h-1 ).

5.
Sports (Basel) ; 9(9)2021 Aug 27.
Article in English | MEDLINE | ID: mdl-34564323

ABSTRACT

The goal of this study was to assess the validity, reliability and accuracy of a smartwatch-based workout analysis application in exercise recognition, repetition count and One Repetition Maximum (1RM) prediction in the strength training-specific setting. Thirty recreationally trained athletes performed four consecutive sets of barbell deadlift, barbell bench press and barbell back squat exercises with increasing loads from 60% to 80% of their estimated 1RM with maximum lift velocity. Data was measured using an Apple Watch Sport and instantaneously analyzed using an iOS workout analysis application called StrengthControl. The accuracies in exercise recognition and repetition count, as well as the reliability in predicting 1RM, were statistically analyzed and compared. The correct strength exercise was recognised in 88.4% of all the performed sets (N = 363) with accurate repetition count for the barbell back squat (p = 0.68) and the barbell deadlift (p = 0.09); however, repetition count for the barbell bench press was poor (p = 0.01). Only 8.9% of attempts to predict 1RM using the StrengthControl app were successful, with failed attempts being due to technical difficulties and time lag in data transfer. Using data from a linear position transducer instead, significantly different 1RM estimates were obtained when analysing repetition to failure versus load-velocity relationships. The present results provide new perspectives on the applicability of smartwatch-based strength training monitoring to improve athlete performance.

6.
Micromachines (Basel) ; 12(2)2021 Feb 05.
Article in English | MEDLINE | ID: mdl-33562822

ABSTRACT

This paper presents a universal point-of-care system for fully automated quantification of human T-cell lymphotropic virus type 1 (HTLV-1) proviral load, including genomic RNA, based on digital reverse RNA transcription and c-DNA amplification by MD LAMP (mediator displacement loop-mediated isothermal amplification). A disposable microfluidic LabDisk with pre-stored reagents performs automated nucleic acid extraction, reaction setup, emulsification, reverse transcription, digital DNA amplification, and quantitative fluorogenic endpoint detection with universal reporter molecules. Automated nucleic acid extraction from a suspension of HTLV-1-infected CD4+ T-lymphocytes (MT-2 cells) yielded 8 ± 7 viral nucleic acid copies per MT-2 cell, very similar to the manual reference extraction (7 ± 2 nucleic acid copies). Fully automated sample processing from whole blood spiked with MT-2 cells showed a comparable result of 7 ± 3 copies per MT-2 cell after a run time of two hours and 10 min.

7.
Z Orthop Unfall ; 157(2): 188-193, 2019 Apr.
Article in English, German | MEDLINE | ID: mdl-30986878

ABSTRACT

INTRODUCTION: In hip arthroplasty a trend towards short stem prostheses is observed. The aim of this study is to investigate the finite element analysis and biomechanical fatigue performance of a new short stem prosthesis. METHODS: A finite element analysis was used to simulate the stresses during neck and stem loading according to the ISO standards. Numerical analysis with applied forces of up to 6 kN were performed in the vertical direction on a femoral neck-preserving stem (MiniMIS). During experimental testing, 10 million cycles with a maximum load of 5.34 kN using the worst case of a XL ceramic head (36 mm) were applied. This was followed by a Locati test, where the load was increased until failure of the stem. RESULTS: For all stems, stress values below the limits according to the ISO 5832-3 standard (yield strength of 800 N/mm2) were calculated by the finite element analysis. In the biomechanical tests, the total number of 10 million cycles with a maximum load of 5.34 kN was reached in all cases without any visible signs of implant damage. The estimated load to failure after stem testing was 2.16 kN (required by ISO 7206-4: 1.2 kN) and after neck testing > 9.35 kN (required by ISO 7206-6: 5.4 kN). SUMMARY: The presented finite element calculation and subsequent biomechanical testing show that the design of this stem meets the essential mechanical requirements given by the ISO and a material failure is not expected in all variants tested under the applied boundary conditions.


Subject(s)
Hip Prosthesis , Biomechanical Phenomena , Ceramics , Finite Element Analysis , Prosthesis Design , Stress, Mechanical
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