The photothermal response of plasmonic nanomaterials can be exploited for a number of biomedical applications in diagnostics (biosensing and optoacoustic imaging) and therapy (drug delivery and ...photothermal therapy). The most common cellular response to photothermal cancer treatment (ablation of solid tumors) using plasmonic nanomaterials is necrosis, a process that releases intracellular constituents into the extracellular milieu producing detrimental inflammatory responses. Here we report the use of laser-induced photothermal therapy employing gold nanoprisms (NPRs) to specifically induce apoptosis in mouse embryonic fibroblast cells transformed with the SV40 virus. Laser-irradiated “hot” NPRs activate the intrinsic/mitochondrial pathway of apoptosis (programmed cell death), which is mediated by the nuclear-encoded proteins Bak and Bax through the activation of the BH3-only protein Bid. We confirm that an apoptosis mechanism is responsible by showing how the NPR-mediated cell death is dependent on the presence of caspase-9 and caspase-3 proteins. The ability to selectively induce apoptotic cell death and to understand the subsequent mechanisms provides the foundations to predict and optimize NP-based photothermal therapy to treat cancer patients suffering from chemo- and radioresistance.
We present the first Ge-based constraints on sub-MeV /c2 dark matter (DM) particles interacting with electrons using a 33.4 g Ge cryogenic detector with a 0.53 electron-hole pair (rms) resolution, ...operated underground at the Laboratoire Souterrain de Modane. Competitive constraints are set on the DM-electron scattering cross section, as well as on the kinetic mixing parameter of dark photons down to 1 eV / c2. In particular, the most stringent limits are set for dark photon DM in the 6 to 9 eV / c2 range. These results demonstrate the high relevance of Ge cryogenic detectors for the search of DM-induced eV-scale electron signals.
The simultaneous removal of organic, inorganic, and microbial contaminants from water by one material offers significant advantages when fast, facile, and robust water purification is required. ...Herein, we present a supported ionic liquid phase (SILP) composite where each component targets a specific type of water contaminant: a polyoxometalate‐ionic liquid (POM‐IL) is immobilized on porous silica, giving the heterogeneous SILP. The water‐insoluble POM‐IL is composed of antimicrobial alkylammonium cations and lacunary polyoxometalate anions with heavy‐metal binding sites. The lipophilicity of the POM‐IL enables adsorption of organic contaminants. The silica support can bind radionuclides. Using the POM‐SILP in filtration columns enables one‐step multi‐contaminant water purification. The results show how multi‐functional POM‐SILPs can be designed for advanced purification applications.
Pure and simple: Multi‐functional polyoxometalate supported ionic liquid phases (POM‐SILPs) can remove organic, inorganic, and microbial contaminants from water. Each POM‐SILP component targets one specific contaminant so that toxic heavy metals, radionuclides, organic dyes, and bacteria can be removed from water simultaneously.
Natural polysaccharides are frequently used in the design of drug delivery systems due to their biocompatibility, biodegradability, and low toxicity. Moreover, they are diverse in structure, size, ...and charge, and their chemical functional groups can be easily modified to match the needs of the final application and mode of administration. This review focuses on polysaccharidic nanocarriers based on chitosan and hyaluronic acid for small interfering RNA (siRNA) delivery, which are highly positively and negatively charged, respectively. The key properties, strengths, and drawbacks of each polysaccharide are discussed. In addition, their use as efficient nanodelivery systems for gene silencing applications is put into context using the most recent examples from the literature. The latest advances in this field illustrate effectively how chitosan and hyaluronic acid can be modified or associated with other molecules in order to overcome their limitations to produce optimized siRNA delivery systems with promising
and
results.
We disclose a direct approach to the diastereoselective synthesis of phosphorus substituted N-acylaziridines based on a one-pot ZnCl2-catalyzed Joullié–Ugi three-component reaction of phosphorylated ...2H-azirines, carboxylic acids and isocyanides. Hence, this robust protocol offers rapid access to an array of N-acylaziridines in moderate-to-good yields and up to 98:2 dr for substrates over a wide scope. The relevance of this synthetic methodology was achieved via a gram-scale reaction and the further derivatization of the nitrogen-containing three-membered heterocycle. The diastereo- and regioselective ring expansion of the obtained N-acylaziridines to oxazole derivatives was accomplished in the presence of BF3·OEt2 as an efficient Lewid acid catalyst.
Reinfection by the severe acute respiratory syndrome coronavirus type 2 (SARS-COV-2) has been reported in many countries, suggesting that the virus may continue to circulate among humans despite the ...possibility of local herd immunity due to massive previous infections. The emergence of variants of concern (VOC) that are more transmissible than the previous circulating ones has raised particular concerns on the vaccines effectiveness and reinfection rates. The P.1 lineage was first identified in December 2020 in Manaus city and is now globally spread. We report the first case of reinfection of SARS-CoV-2 caused by the P.1 variant outside of Manaus. The potential of these new variants to escape naturally and vaccine- induced immunity highlights the need for a global vigilance.
Corrosion of stone by acid rain and deterioration from biofilms are global problems for industrial and residential buildings as well as cultural heritage, such as statues or historic buildings. ...Herein we show how typical building stones can be protected from corrosion (“weathering”) and biofilm formation (“biodeterioration”) by application of thin films of polyoxometalate‐based ionic liquids (POM‐ILs). Stone samples are coated with hydrophobic, acid resistant POM‐ILs featuring biocidal properties. Exposure of the samples to simulated acid rain showed negligible corrosion compared to the significant deterioration of unprotected samples; in addition the biocidal properties of the POM‐ILs suppress the formation of biofilms on coated stone slabs. A new class of modular molecular materials for protecting stones can now be developed for use in construction, environmental protection, and cultural heritage preservation.
Brush‐on protection: Polyoxometalate ionic liquids (POM‐ILs) are used as brush‐on coatings to protect natural building stones from acid corrosion and the growth of biofilms. Tuning of their physical, chemical and rheological properties opens new opportunities for deploying POM‐ILs on construction stones or outdoor cultural heritage objects.
Benzo-fused γ-lactam rings such as isoindolin-2-ones and 2-oxindoles are part of the structure of many pharmaceutically active molecules. They can be often synthesized by means of multicomponent ...approaches and recent contributions in this field are summarized in this review. Clear advantages of these methods include the efficiency in saving raw materials and working time. However, there is still a need of new catalytic systems to allow the enantioselective preparation of these heterocycles by multicomponent reactions.
Colloidal nanoparticles (NPs) have become versatile building blocks in a wide variety of fields. Here, we discuss the state-of-the-art, current hot topics, and future directions based on the ...following aspects: narrow size-distribution NPs can exhibit protein-like properties; monodispersity of NPs is not always required; assembled NPs can exhibit collective behavior; NPs can be assembled one by one; there is more to be connected with NPs; NPs can be designed to be smart; surface-modified NPs can directly reach the cytosols of living cells.
The extent to which pre-Columbian societies altered Amazonian landscapes is hotly debated. We performed a basin-wide analysis of pre-Columbian impacts on Amazonian forests by overlaying known ...archaeological sites in Amazonia with the distributions and abundances of 85 woody species domesticated by pre-Columbian peoples. Domesticated species are five times more likely than nondomesticated species to be hyperdominant. Across the basin, the relative abundance and richness of domesticated species increase in forests on and around archaeological sites. In southwestern and eastern Amazonia, distance to archaeological sites strongly influences the relative abundance and richness of domesticated species. Our analyses indicate that modern tree communities in Amazonia are structured to an important extent by a long history of plant domestication by Amazonian peoples.
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