Dr. Nicholas M. Randell  Dr. Julia Rendon  Dr. Martine Demeunynck  Pierre-Alain Bayle  Dr. Serge Gambarelli  Dr. Vincent Artero  Dr. Jean-Marie Mouesca  Dr. Murielle Chavarot-Kerlidou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(61):13911-13920

Molecular photosensitizers that are able to store multiple reducing equivalents are of great interest in the field of solar fuel production, where most reactions involve multielectronic reduction processes. In order to increase the reducing power of a ruthenium tris-diimine charge-photoaccumulating complex, two structural modifications on its fused dipyridophenazine-pyridoquinolinone ligand were computationally investigated. Addition of an electron-donating oxime group was calculated to substantially decrease the reduction potentials of the complex, thus guiding the synthesis of a pyridoquinolinone-oxime derivative. Its spectroscopic and (spectro)electrochemical characterization experimentally confirmed the DFT predictions, with the first and second reduction processes cathodically shifted by −0.24 and −0.14 V, respectively, compared to the parent complex. Moreover, the ability of this novel artificial photosynthetic system to store two photogenerated electrons at a more reducing potential, via a proton-coupled electron-transfer mechanism, was demonstrated.  相似文献   

    

ElHadji Assane Diop  Jenna Jacquat  Nicolas Drouin  Emerson Ferreira Queiroz  Jean‐Luc Wolfender  Tahir Diop  Julie Schappler  Serge Rudaz 《Electrophoresis》2019,40(21):2820-2827

Mycobacterium tuberculosis is the causative agent of tuberculosis, an infectious bacterial disease, which most commonly affects the lungs. In the search for novel active compounds or medicines against tuberculosis, an ethnopharmacological survey combined with a host‐pathogen assay has recently highlighted the potency of an aqueous extract of Combretum aculeatum. C. aculeatum is used in traditional medicine and has demonstrated a significant in vitro antimycobacterial activity. Punicalagin, an ellagitannin, was isolated and found to be related to the biological activity of the extract. An analytical method for the evaluation of punicalagin in C. aculeatum was developed by capillary electrophoresis. After method optimization, the quantification of punicalagin was achieved for the evaluation of various plant extracts to determine the content of punicalagin related to the extraction modes and conditions, origin of the plant material, and harvesting period. The developed method demonstrated that the leaves presented the highest punicalagin content compared to the seeds and stems. A decoction of 30 min in boiling water was found to be the best extraction mode of C. aculeatum.  相似文献   

    

Małgorzata Kowalska  Magdalena Woźniak  Anna Krzton-Maziopa  Serge Tavernier  Łukasz Pazdur  Anna Żbikowska 《Journal of Dispersion Science and Technology》2019,40(2):192-205

The aim of this work was to obtain and evaluate the stability of new emulsion systems, in which diacylglycerols derived from enzymatic interesterification of mutton tallow with hemp oil were used as emulsifiers. In order to achieve a higher content of the polar fat fraction in the final fat blend, a different amount of water was added to the reaction mixtures. The modified fats with a mixture of mono and diacylglycerols served as a fat base for emulsions. Based on the results of Turbiscan test, the droplet size, emulsion texture, and studies of rheological properties, it was found that addition of water to the reaction mixture in the range of 1.00–1.25%, wt./wt., caused the formation of a sufficient amount of emulsifiers stabilizing the dispersion system.

The novelty of this work was to determine the optimal amount of water added to the interesterification of mutton tallow with vegetable oil, ensuring the synthesis of a high-efficiency emulsifying system. Another new aspect of this work was to show that the diacylglycerols obtained during such fat modification constitute effective emulsifiers for new stable emulsion systems that may find potential use as food emulsions (dressings) or cosmetic products dedicated to sensitive skin.  相似文献   

    

Sophie Bernadet  Eugnie Tavernier  Duc‐Minh Ta  Renaud A. L. Valle  Serge Ravaine  Antoine Fcant  Rnal Backov 《Advanced functional materials》2019,29(9)

Operating photo‐induced reactions exclusively on catalyst surfaces while not exploiting the full catalyst volume generates a major footprint penalty for the photocatalytic reactor and leads to an inefficient use of the catalytic material. Photonic investigations clearly show that the solid foams have a strongly multidiffusive character, with photons being significantly trapped within the sample cores while addressing a photon mean free path l_t = 20.1 ± 1.3 µm. This 3D process both greatly limits back‐reactions and promotes outstanding selectivity toward methane (around 80%) generation, and even ethane (around 18%) through C‐C coupling reaction, with residual carbon monoxide and dihydrogen contents (around 2%). Silica–titania TiO₂@Si(HIPE) self‐standing macrocellular catalysts lead to optimal efficient thicknesses up to 20 times those of powders, thereby enhancing the way for real 3D‐photodriven catalytic processes above the millimeter scale and up to a 6 mm thickness. A rather simple Langmuir–Hinshelwood based kinetic model is proposed which highlights the strong dependence of photocatalytic reaction rates on light scattering and the crucial role on oxidation back‐reactions. In addition, a strong correlation between light attenuation coefficient and photon mean free path and median pore aperture diameter is demonstrated, offering thus a tool for photocatalytic behavior prediction.  相似文献   

    

Xiaohong Chen  Lu Yin  Jian Lv  Andrew J. Gross  Minh Le  Nathaniel Georg Gutierrez  Yang Li  Itthipon Jeerapan  Fabien Giroud  Anastasiia Berezovska  Rachel K. O'Reilly  Sheng Xu  Serge Cosnier  Joseph Wang 《Advanced functional materials》2019,29(46)

This work demonstrates a stretchable and flexible lactate/O₂ biofuel cell (BFC) using buckypaper (BP) composed of multi‐walled carbon nanotubes as the electrode material. Free‐standing BP, functionalized with a pyrene‐polynorbornene homopolymer, is fabricated as the immobilization matrix for lactate oxidase (LOx) at the anode and bilirubin oxidase at the cathode. This biofuel cell delivers an open circuit voltage of 0.74 V and a high‐power density of 520 µW cm^?2. The functionalized BP electrodes are assembled onto a stretchable screen‐printed current collector with an “island–bridge” configuration, which ensures conformal contact between the wearable BFC and the human body and endows the BFC with excellent performance stability under stretching condition. When applied to the arm of the volunteer, the BFC can generate a maximum power of 450 µW. When connected with a voltage booster, the on‐body BFC is able to power a light emitting diode under both pulse discharge and continuous discharge modes during exercise. This demonstrates the promising potential of the flexible BP‐based BFC as a self‐sustained power source for next‐generation wearable electronics.  相似文献   

    

&#x;or&#x;e Tadi&#x;  Rayana Manasfi  Marine Bertrand  Andrs Sauvêtre  Serge Chiron 《Molecules (Basel, Switzerland)》2022,27(10)

Different groups of organic micropollutants including pharmaceuticals and pesticides have emerged in the environment in the last years, resulting in a rise in environmental and human health risks. In order to face up and evaluate these risks, there is an increasing need to assess their occurrence in the environment. Therefore, many studies in the past couple of decades were focused on the improvements in organic micropollutants’ extraction efficiency from the different environmental matrices, as well as their mass spectrometry detection parameters and acquisition modes. This paper presents different sampling methodologies and high-resolution mass spectrometry-based non-target screening workflows for the identification of pharmaceuticals, pesticides, and their transformation products in different kinds of water (domestic wastewater and river water). Identification confidence was increased including retention time prediction in the workflow. The applied methodology, using a passive sampling technique, allowed for the identification of 85 and 47 contaminants in the wastewater effluent and river water, respectively. Finally, contaminants’ prioritization was performed through semi-quantification in grab samples as a fundamental step for monitoring schemes.  相似文献   

    

Davi Jardim Martins;Jenny Kaur Singh;Tiya Jahjah;Alexandre Teixeira Vessoni;Giovana da Silva Leandro;Matheus Molina Silva;Denis Serge François Biard;Annabel Quinet;Carlos Frederico Martins Menck; 《Photochemistry and photobiology》2024,100(1):4-18

Xeroderma pigmentosum (XP) variant cells are deficient in the translesion synthesis (TLS) DNA polymerase Polη (eta). This protein contributes to DNA damage tolerance, bypassing unrepaired UV photoproducts and allowing S-phase progression with minimal delay. In the absence of Polη, backup polymerases perform TLS of UV lesions. However, which polymerase plays this role in human cells remains an open question. Here, we investigated the potential role of Polι (iota) in bypassing ultraviolet (UV) induced photoproducts in the absence of Polη, using NER-deficient (XP-C) cells knocked down for Polι and/or Polη genes. Our results indicate that cells lacking either Polι or Polη have increased sensitivity to UVC radiation. The lack of both TLS polymerases led to increased cell death and defects in proliferation and migration. Loss of both polymerases induces a significant replication fork arrest and G1/S-phase blockage, compared to the lack of Polη alone. In conclusion, we propose that Polι acts as a bona fide backup for Polη in the TLS of UV-photoproducts.  相似文献   

    

Serge Lamboley  Basile Vuichoud  Jean-Yves de Saint Laumer  Andreas Herrmann 《Molecules (Basel, Switzerland)》2023,28(1)

Imidazolidin-4-ones were investigated as hydrolytically cleavable profragrances to increase the long-lastingness of perfume perception in a fabric softener application. The reaction of different amino acid amides with 2-alkyl- or 2-alkenylcyclopentanones as the model fragrances to be released afforded the corresponding bi- or tricyclic imidazolidin-4-ones as mixtures of diastereoisomers, which were separated by column chromatography. In polar solution, the different stereoisomers equilibrated under thermodynamic conditions to form mixtures with constant isomeric distributions, as shown by NMR spectroscopy. Dynamic headspace analysis on dry cotton demonstrated the controlled fragrance release from the precursors in practical application. Under non-equilibrium conditions (continuous evaporation of the fragrance) and depending on the structure and stereochemistry of the profragrances, the recorded headspace concentrations of the fragrance released from the precursors increased by a factor of 2 up to 100 with respect to the unmodified reference. Prolinamide-based precursors released the highest amount of fragrance and were thus found to be particularly suitable for prolonging the evaporation of cyclopentanone-derived fragrances on a dry cotton surface.  相似文献   

    

KangJu Lee  Yumeng Xue  Junmin Lee  Han‐Jun Kim  Yaowen Liu  Peyton Tebon  Einollah Sarikhani  Wujin Sun  Shiming Zhang  Reihaneh Haghniaz  Betül elebi‐Saltik  Xingwu Zhou  Serge Ostrovidov  Samad Ahadian  Nureddin Ashammakhi  Mehmet R. Dokmeci  Ali Khademhosseini 《Advanced functional materials》2020,30(23)

Mesenchymal stem cells (MSCs) have been widely used for regenerative therapy. In most current clinical applications, MSCs are delivered by injection but face significant issues with cell viability and penetration into the target tissue due to a limited migration capacity. Some therapies have attempted to improve MSC stability by their encapsulation within biomaterials; however, these treatments still require an enormous number of cells to achieve therapeutic efficacy due to low efficiency. Additionally, while local injection allows for targeted delivery, injections with conventional syringes are highly invasive. Due to the challenges associated with stem cell delivery, a local and minimally invasive approach with high efficiency and improved cell viability is highly desired. In this study, a detachable hybrid microneedle depot (d‐HMND) for cell delivery is presented. The system consists of an array of microneedles with an outer poly(lactic‐co‐glycolic) acid shell and an internal gelatin methacryloyl (GelMA)‐MSC mixture (GMM). The GMM is characterized and optimized for cell viability and mechanical strength of the d‐HMND required to penetrate mouse skin tissue is also determined. MSC viability and function within the d‐HMND is characterized in vitro and the regenerative efficacy of the d‐HMND is demonstrated in vivo using a mouse skin wound model.  相似文献   

    

Dr. Christophe Renault  Prof. Serge G. Lemay 《ChemElectroChem》2020,7(1):69-73

We propose an analytical method based on electrochemical collisions to detect individual graphene oxide (GO) sheets in an aqueous suspension. The collision rate is found to exhibit a complex dependence on redox mediator and supporting electrolyte concentrations. The analysis of multiple collision events in conjunction with numerical simulations allows quantitative information to be extracted, such as the molar concentration of GO sheets in suspension and an estimate of the size of individual sheets. We also evidence by numerical simulation the existence of edge effects on a 2D blocking object.  相似文献