physical and theoretical chemistry

Structure and dynamics of propylammonium nitrate-acetonitrile mixtures: An intricate multi-scale system probed with experimental and theoretical techniques

In this article, we report the study of structural and dynamical properties for a series of acetonitrile/propylammonium nitrate mixtures as a function of their composition. These systems display an unusual increase in intensity in their X-ray diffraction patterns in the low-q regime, and their H-1-NMR diffusion-ordered NMR spectroscopy (DOSY) spectra display unusual diffusivities.

Inherently chiral cone-calix[4]arenes via a subsequent upper rim ring-closing/opening methodology

Access to chiral calix[4]arenes can unlock novel supramolecular architectures for enantioselective catalysis and molecular recognition. However, accessibility to these structures has been significantly hindered so far. We report herein the synthesis and characterization of di- and trifunctionalized cone-calix[4]arenes featuring a lactone moiety spanning the distal positions at the upper rim. The lactones force the whole skeleton to assume pinched-cone conformations. The ring-closure is favored by the high conformational flexibility of the calixarene scaffold.

An X-ray and computational study of liquid pentylammonium nitrate

In this article we report the study of liquid pentylammonium nitrate with Wide Angle X-ray scattering and AIMD simulations. Static and dynamical features were characterized by comparing the experimental X-ray pattern with ab initio molecular dynamics simulation trajectories. From the analysis, we were able to focus our attention on the nature and time duration of the hydrogen bond network established between cation and anion.

Taurine grafting and collagen adsorption on PLLA films improve human primary chondrocyte adhesion and growth

Biocompatible and degradable poly(?-hydroxy acids) are one of the most widely used materials in scaffolds for tissue engineering. Nevertheless, they often need surface modification to improve interaction with cells. Aminolysis is a common method to increase the polymer hydrophilicity and to introduce surface functional groups, able to covalently link or absorb, through electrostatic interaction, bioactive molecules or macromolecules. For this purpose, multi-functional amines, such as diethylenediamine or hexamethylenediamine are used.

Adenosine monophosphate recognition by zinc-salophen complexes: IRMPD spectroscopy and quantum modeling study

Zn-salophen complexes are a promising class of fluorescent chemosensors for nucleotides and nucleic acids. We have investigated, by means of IRMPD spectroscopy experiments and quantum chemical calculations, the structure of the host-guest complexes formed by two efficient Zn-salophen receptors and dihydrogen phosphate or adenosine 5'-monophosphate (AMP) anions. In the host-guest complexes the phosphate group is bound with a Zn. O(phosphate) bond. In addition, a hydrogen bond can be formed between the PO. H group and one of the oxygen atoms of the salophen structure.

Assembly and functional analysis of an S/MAR based episome with the cystic fibrosis transmembrane conductance regulator gene

Improving the efficacy of gene therapy vectors is still an important goal toward the development of safe and efficient gene therapy treatments. S/MAR (scaffold/matrix attached region)-based vectors are maintained extra-chromosomally in numerous cell types, which is similar to viral-based vectors. Additionally, when established as an episome, they show a very high mitotic stability.

Loss of miR-107, miR-181c and miR-29a-3p promote activation of Notch2 signaling in pediatric high-grade gliomas (pHGGs)

The mechanisms by which microRNAs control pediatric high-grade gliomas (pHGGs) have
yet to be fully elucidated. Our studies of patient-derived pHGG tissues and of the pHGG cell line
KNS42 revealed down-regulation in these tumors of three microRNAs, specifically miR-107, miR-181c,
and miR-29a-3p. This down-regulation increases the proliferation of KNS42 cells by de-repressing
expression of the Notch2 receptor (Notch2), a validated target of miR-107 and miR-181c and a

Disruptor of telomeric silencing 1-like (DOT1L): disclosing a new class of non-nucleoside inhibitors by means of ligand-based and structure-based approaches

Chemical inhibition of chromatin-mediated signaling involved proteins is an established strategy to drive expression net-works and alter disease progression. Protein methyltransferases are among the most studied proteins in epigenetics and, in particular, disruptor of telomeric silencing 1-like (DOT1L) lysine methyltransferase plays a key role in MLL-rearranged acute leukemia Selective inhibition of DOT1L is an established attractive strategy to breakdown aberrant H3K79 methylation and thus overexpression of leukemia genes, and leukemogenesis.

Stereo- and regioselective gold(i)-catalyzed hydroamination of 2-(arylethynyl)pyridines with anilines

The gold-catalyzed hydroamination of 2-(arylethynyl)pyridines with anilines affords stereoselectively Z-enamine products with excellent regioselectivity. The reaction proceeds with moderate to excellent yields and accommodates a diverse range of functional groups on alkynes (ether, bromo, trifluoromethyl, acetyl, and carbomethoxy) and anilines (ether, bromo, chloro, and carbethoxy). The stereochemistry of the obtained enamines is complementary to that reported in previous studies. A plausible explanation for the observed selectivity was attained by means of NMR experiments.

High potency of melaleuca alternifolia essential oil against multi-drug resistant gram-negative bacteria and methicillin-resistant staphylococcus aureus

Purpose: Herein, an extended investigation of Tea tree oil (TTO) against a number of multi-drug resistant (MDR) microorganisms in liquid and vapor phases is reported. Methods: The activity of TTO was tested against methicillin-sensitive Staphylococcus aureus (MSSA), Escherichia coli, and clinical strains of methicillin-resistant S. aureus (MRSA), extended-spectrum beta lactamases producer carbapenem-sensitive Klebsiella pneumoniae (ESBL-CS-Kp), carbapenem-resistant K. pneumoniae (CR-Kp), Acinetobacter baumannii (CR-Ab), and Pseudomonas aeruginosa (CR-Pa).

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