Search results for "molekyylit"
showing 10 items of 69 documents
Encapsulation and solid state sequestration of gases by calix[6]arene-based molecular containers
2017
Two calix[6]arene-based molecular containers were synthesized in high yields. These containers can encapsulate small guests through a unique "rotating door" complexation process. The sequestration of greenhouse gases is clearly demonstrated. They can be stored in the solid state for long periods and released via dissolution of the inclusion complex.
Electron Accumulative Molecules.
2018
With the goal to produce molecules with high electron accepting capacity and low reorganization energy upon gaining one or more electrons, a synthesis procedure leading to the formation of a B–N(aromatic) bond in a cluster has been developed. The research was focused on the development of a molecular structure able to accept and release a specific number of electrons without decomposing or change in its structural arrangement. The synthetic procedure consists of a parallel decomposition reaction to generate a reactive electrophile and a synthesis reaction to generate the B–N(aromatic) bond. This procedure has paved the way to produce the metallacarboranylviologen [M(C2B9H11)(C2B9H10)-NC5H4-…
The expression and prognostic relevance of programmed cell death protein 1 in tongue squamous cell carcinoma
2020
Background Programmed cell death protein 1 (PD‐1) is an immune checkpoint receptor which plays an important role in a patient´s immune responses to microbial and cancer antigens. It is expressed in tumor infiltrating lymphocytes (TILs) with many different malignancies. The aim of the study was to evaluate PD‐1 expression and its prognostic value in tongue cancer. Methods The data of tongue squamous cell carcinoma (TSCC) patients (N=81) treated in Tampere University Hospital between 1999‐2013 was used. Control data consisted of patients with non‐malignant tongue mucous membrane lesions (N=48). The formalin‐fixed paraffin‐embedded samples were stained immunohistochemically and scanned via dig…
Molecular Mechanism of ATP Hydrolysis in an ABC Transporter
2018
Hydrolysis of nucleoside triphosphate (NTP) plays a key role for the function of many biomolecular systems. However, the chemistry of the catalytic reaction in terms of an atomic-level understanding of the structural, dynamic, and free energy changes associated with it often remains unknown. Here, we report the molecular mechanism of adenosine triphosphate (ATP) hydrolysis in the ATP-binding cassette (ABC) transporter BtuCD-F. Free energy profiles obtained from hybrid quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) simulations show that the hydrolysis reaction proceeds in a stepwise manner. First, nucleophilic attack of an activated lytic water molecule at the ATP γ-…
Supramolecular systems based on gold(I) derivatives : molecular recognition of L-glutamine and polyQ
2017
L-glutamiinin ja polyglutamiinin molekyylintunnistuksessa käytettyjen uusien organometallikompleksien mielenkiintoiset luminesoivat ominaisuudet ovat peräisin 4-etynyylianiliiniligandista ja fosfaaniyksiköstä sekä molekyylien välisistä Au⋯Au vuorovaikutuksista. Heikkojen intermolekulaaristen vuorovaikutusten on havaittu johtavan kuitu- ja pallomaisten muotojen morfologisiin muutoksiin vierasmolekyylien läsnä ollessa. Muodostunut isäntä-vieras -kompleksi tuottaa erilaisen emission vierasmolekyylistä riippuen. Lisäksi [Au(4-etynyylianiliini)(PTA)]:n itsejärjestäytymisen termodynaamisia funktioita tutkittiin eri pitoisuuksissa ja lämpötiloissa NMR mittausten avulla. Nämä lineaariset kulta(I) -…
Plasmonic Resonant Nanoantennas Induce Changes in the Shape and the Intensity of Infrared Spectra of Phospholipids.
2021
Surface enhanced infrared absorption spectroscopic studies (SEIRAS) as a technique to study biological molecules in extremely low concentrations is greatly evolving. In order to use the technique for identification of the structure and interactions of such biological molecules, it is necessary to identify the effects of the plasmonic electric-field enhancement on the spectral signature. In this study the spectral properties of 1,2-Dipalmitoyl-sn-glycero-3 phosphothioethanol (DPPTE) phospholipid immobilized on gold nanoantennas, specifically designed to enhance the vibrational fingerprints of lipid molecules were studied. An AFM study demonstrates an organization of the DPPTE phospholipid in…
GROMEX: A Scalable and Versatile Fast Multipole Method for Biomolecular Simulation
2020
Atomistic simulations of large biomolecular systems with chemical variability such as constant pH dynamic protonation offer multiple challenges in high performance computing. One of them is the correct treatment of the involved electrostatics in an efficient and highly scalable way. Here we review and assess two of the main building blocks that will permit such simulations: (1) An electrostatics library based on the Fast Multipole Method (FMM) that treats local alternative charge distributions with minimal overhead, and (2) A $λ$-dynamics module working in tandem with the FMM that enables various types of chemical transitions during the simulation. Our $λ$-dynamics and FMM implementations d…
Control of Molecular Orbital Ordering Using a van der Waals Monolayer Ferroelectric
2022
Two-dimensional (2D) ferroelectric materials provide a promising platform for the electrical control of quantum states. In particular, due to their 2D nature, they are suitable for influencing the quantum states of deposited molecules via the proximity effect. Here, we report electrically controllable molecular states in phthalocyanine molecules adsorbed on monolayer ferroelectric material SnTe. In particular, we demonstrate that the strain and ferroelectric order in SnTe creates a transition between two distinct orbital orders in the adsorbed phthalocyanine molecules. By controlling the polarization of the ferroelectric domain using scanning tunneling microscopy (STM), we have successfully…
Inverse Conformational Selection in Lipid–Protein Binding
2021
International audience; Interest in lipid interactions with proteins and other biomolecules is emerging not only in fundamental biochemistry but also in the field of nanobiotechnology where lipids are commonly used, for example, in carriers of mRNA vaccines. The outward-facing components of cellular membranes and lipid nanoparticles, the lipid headgroups, regulate membrane interactions with approaching substances, such as proteins, drugs, RNA, or viruses. Because lipid headgroup conformational ensembles have not been experimentally determined in physiologically relevant conditions, an essential question about their interactions with other biomolecules remains unanswered: Do headgroups excha…
Enhanced Surface Ligands Reactivity of Metal Clusters by Bulky Ligands for Controlling Optical and Chiral Properties.
2021
Surface ligands play critical roles in determining the surface properties of metal clusters. However, modulating the properties and controlling the surface structure of clusters through surface‐capping agent displacement remain a challenge. In this work, a silver cluster, [Ag 14 (SPh(CF 3 ) 2 ) 12 (PPh 3 ) 4 (DMF) 4 ] ( Ag 14 ‐DMF , where HSPh(CF 3 ) 2 is 3,5‐bis(trifluoromethyl)benzenethiol, PPh 3 is triphenylphosphine and DMF is N,N‐Dimethylformamide), with weakly coordinated DMF ligands on the surface silver sites, was synthesized by using a mixed ligands strategy (bulky thiolates, phosphines and small solvents). The as‐prepared Ag 14 ‐DMF is a racemic mixture of chiral molecules. Owing …