66,201 research outputs found
A modular nanosystems platform for advanced cancer management
No full textAn estimated 3.2 million new cancer cases and 1.7 million deaths per year in Europe define cancer as a crucial public health problem. The SaveMe project funded under the EU's FP7 Program is addressing major urgent needs for cancer diagnosis and treatment by design and development of a novel modular nanosystems platform integrating advanced functionalized nano-core particles and active agents. The modular platform will enable the design of diverse active nanosystems for diagnostic or therapeutic applications as defined by their active agent compositions. For the early diagnosis of pancreatic cancer Somatostatin and Galectin-1 receptors (SSTR and Gal-1/tPA) will be utilized for targeting the tumor and visualization by PET, MRI or combined scanning. Similarly labeled nanoparticles containing specific antibodies or silencing RNA directed against the tumor will be used for advanced therapeutics
Long-chain surface-modified red-emitting carbon dots as fluorescent additives for 3D printing vat-photopolymerization
No full textCarbon dots have recently attracted tremendous scientific attention thanks to their enhanced luminescence properties, photostability and low toxicity. In particular, red-emitting carbon dots (RCDs) are assuming increasing importance in biomedical applications, such as bio-imaging and phototherapy. At the same time, the possibility to create functional and complex objects by means of vat-photopolymerization-based three-dimensional (3D) printing techniques is continuously growing. This work describes the synthesis of long-chain surface-modified red emitting carbon dots, L-RCDs by esterification of RCDs, obtained from green reagents with a new solvothermal synthesis, and their employment as fluorescent additives in two formulations of photopolymerizable resins. The printing process proceeded smoothly in all cases, and red-emitting objects with different mechanical properties have been successfully obtained
Organocatalytic Asymmetric Mannich Reactions in the Preparation of Enantio-enriched beta(3)-Amino Acid Derivatives
No full textOrganocatalytic, asymmetric Mannich reactions giving beta3-amino acid derivatives have been reviewed. The Mannich-type addition of an acetate anion to an imine represents in fact one of the most direct routes to this particular class of beta-amino acids. However, due to the low acidity of simple acetates, synthetic equivalents of acetate anions had to be used. These include preformed enolates (silylketeneacetals), carbonylic compounds with improved reactivity (acetophenones and their enamines/enamides), acetates equipped with a removable group enhancing their acidity (malonates, nitroacetates, sulfonylacetates, diazoacetates), acetates able to undergo decarboxylative enolate formation (malonic acid half thioesters), and finally acetaldehyde. Each of these equivalents was combined with the requisite organocatalytic strategy, giving very powerful and effective methods for the preparation of beta3
-amino acid precursors. The simple and straightforward manipulations, used to convert these products into the target beta3-amino acid compounds, are also described
Concise and stereocontrolled synthesis of pseudo-C2-symmetric diamino alcohols and triamines for use in HIV protease inhibitors
No full textA new protocol is described for the stereocontrolled synthesis of pseudo-C2-symmetric core units of interest as candidates for HIV protease inhibition. Addition of unbranched and branched organolithium reagents to cyanohydrins from L-phenylalaninal and L-isoleucinal, followed by in situ reduction of the intermediate imines and CHT deprotection under MW irradiation, led to 1,3-diamino alcohols 6a and 8a as the major products in satisfactory to good yields. The first preparation of a previously unreported pseudo-C2-symmetric triamino derivative was accomplished expeditiously via high-yielding nitro-Mannich addition of the silylnitronate, from 2-phenyl-1-nitroethane, to the PMP imine derived from L-phenylalaninal. Reduction of the nitro group in the moderately unstable nitro diamine adduct, followed by chromatographic separation of the required diastereoisomer and CHT debenzylation under MW irradiation, led to the 2-PMP-protected triamine 19 isolated as a bis(sulfonamide)
Some principles for the design of robust ligand shells for biological applications of nanoparticles
No full textQuantitative spectral electromechanical characterization of soft piezoelectric nanocomposites
No full textWe present a modular system for the quantitative characterization of the piezoelectric coefficient of piezoelectric polymers and soft polymeric nanocomposites in the compression mode. Our approach is based on an apparatus providing spectral information on the electro-mechanical response in aselected range of frequencies of compressive loads (10–1200 Hz), with high sensitivity (down to 0.5 pC/N) and automated data acquisition modalities, enabling repeatability and reproducibility of the electro-mechanical characterization in the low-force regime (0.1 N 1.5 N). The system is modular and can be developed to cover the 2 mHz-1.2 kHz frequency range in charge mode and the 2 μHz-1200 Hz in voltage mode. We calibrated and validated the apparatus functionality using a commercial PVDF piezoelectric polymer. The suitability of the system for the quantitative measurements of the piezoelectricity of soft polymeric nanocomposites was then assessed by performing measurements of a novel piezoelectric nanocomposite material. This consisted of a polydimethylsiloxane (PDMS) matrix with embedded BaTiO3 nanoparticles, engineered with functional surface coatings to favor their homogeneous dispersion into the polymer. The proposed system demonstrated to be an effective solution for the systematic characterization of the electro-mechanical conversion properties of soft piezoelectric materials in view of soft robotics and energy harvesting applications
Integrated management of Tomato yellow leaf culr in protected tomato crops in Southern Italy
No full textA New and Practical Procedure for the Bruylants Reaction. Zinc-Mediated Synthesis of Tertiary Homoallylamines and β-Aminoesters
No full textN,N-Disubstituted α-aminonitriles undergo Bruylants reaction under Barbier and Reformatsky conditions with activated halides, in the presence of zinc and 10 mol% HOAc. The high yields and the simple operational conditions make this reaction an appealing, approach to N,N-disubstituted homoallylamines and β-aminoesters
Phosphorescent bio-based resin for digital light processing (DLP) 3D-printing
No full textSince the advent of polymer-based 3D printing technology, the scientific community has directed great effort towards the development of new polymeric formulations that would allow applying this technique to various fields of application, ranging from materials science to tissue engineering. However, most of the available materials are nevertheless oil-based and cost-ineffective. This work presents a novel bio-based resin for stereolithographic DLP 3D printing formulated by mixing a photocurable polyester obtained from renewable resources (poly(1,3-propanediyl-co-glyceryl) itaconate-co-vanillate, PPGIV) with methacrylated citrate and itaconate crosslinkers (bis(HEMA) itaconate, BHI, and tris(HEMA) citrate, THC) and appropriate photopolymerization initiators, terminators and dyes. As a proof-of-concept, a photocurable ink is formulated with phosphorescent Ir(iii) cyclometalated complexes and its potential applications have been demonstrated for both rigid and flexible structures
Surface-Stabilization of Ultrathin Gold Nanowires for Capacitive Sensors in Flexible Electronics
No full textUltrathin gold nanowires (AuNWs) have shown great potential toward applications in flexible electronics. However, they suffer from high surface instability that consequently limits their applicability for solution-processed composite materials. To overcome this limitation, we show for the first time how a synthetic thiolated small-molecule ligand such as ethyl 11-(4-mercaptobenzamido) undecanoate can stabilize the AuNW surface enabling their manipulation in solution-processed composite manufacturing techniques. As a proof of concept, we show how such stabilized NWs can be formulated into a PDMS matrix and spin-coated to afford stretchable elastomeric strips capable of sensing mechanical deformation with loading as low as 0.03 wt %
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