Breast Cancer Screening and Prophylactic Mastectomy for High-Risk Women in Romania.

Breast cancer remains a significant contributor to morbidity and mortality within oncology. Risk factors, encompassing genetic and environmental influences, significantly contribute to its prevalence. While germline mutations, notably within the BRCA genes, are commonly associated with heightened breast cancer risk, a spectrum of other variants exists among affected individuals.

What Is Wrong with Hyaluronic Acid Chemistry? A N/C Solid-State NMR Re-Evaluation of Its Dopamine Conjugates.

In this work, a systematic N/C solid-state NMR investigation is performed on three dopamine (DA) conjugates of hyaluronic acid, considered in both its native (HA) and NaIO-oxidized (HA) forms. Two of them, here named HA-DA and HA-DA, have been previously introduced as covalent conjugates involving DA amine nitrogen: the former by EDC-mediated amide bond formation, and the latter by reaction of the Schiff base with the aldehyde moieties presumed to exist in HA. The third conjugate, HA-DA, is reported here for the first time; it is obtained by simply mixing hyaluronan with DA∙HCl at pH 5.

The effect of 1H offset and flip-angle on heteronuclear decoupling efficiency in ROSPAC pulsed sequence: A Floquet description.

A new heteronuclear decoupling sequence for solid-state NMR and magic angle spinning faster than 60 kHz was recently introduced [Simion et al., J. Chem.

Oxidative Polymerization of 3,4-Dihydroxybenzylamine─The Lower Homolog of Dopamine.

Polydopamine (PDA) formed by oxidative polymerization of dopamine has attracted wide interest because of its unique properties, in particular its strong adhesion to almost all types of surfaces. 3,4-Dihydroxybenzylamine (DHBA) as the lower homolog of PDA also contains a catechol unit and an amino group and thus can be expected to exhibit a similar adhesion and reaction behavior. In fact, autoxidation of DHBA with air in 2-amino-2-hydroxymethyl-propane-1,3-diol (Tris) buffer gives rise to deeply colored oligomer/polymer products (poly(3,4-dihydroxybenzylamine) (PDHBA)) that strongly adhere to several surfaces.

Surgical management of massive penoscrotal lymphedema. Case report and literature review.

Introduction: Giant lymphedema of the penis and scrotum is a rare and peculiar condition that carries many challanges for both the patient and the physician. The etiology of the disease is often difficult to trace, especially in geographical areas where filariasis is not endemic.

Case Presentation: We reported an advanced case of massive penoscrotal lymphedema presented to our plastic surgery department.

Heteronuclear decoupling with rotor-synchronized phase-alternated cycles.

A new heteronuclear decoupling pulse sequence is introduced, dubbed ROtor-Synchronized Phase-Alternated Cycles (ROSPAC). It is based on a partial refocusing of the coherences (spin operator products or cross-terms) [Filip et al., J.

Co-Crystals of Etravirine by Mechanochemical Activation.

The co-crystals formation of etravirine with three carboxylic acids was investigated. New co-crystals of etravirine with adipic acid, benzoic acid, and 4-hydroxybenzoic acid have been synthesized by wet milling of ingredients for 120 min. The novelty of these solid forms was first evidenced by powder X-ray diffraction.

Comprehensive mineralogical and physicochemical characterization of recent sapropels from Romanian saline lakes for potential use in pelotherapy.

In this study we aimed to compare the mineralogical, thermal, physicochemical, and biological characteristics of recent organic carbon-rich sediments ('sapropels') from three geographically distant Romanian lakes (Tekirghiol and Amara, SE Romania, and Ursu, Central Romania) with distinct hydrogeochemical origins, presently used for pelotherapy. The investigated lakes were classified as inland brackish Na-Cl-sulfated type (Amara), coastal moderately saline and inland hypersaline Na-Cl types (Tekirghiol and Ursu, respectively). The settled organic matter is largely composed of photosynthetic pigments derived from autochthonous phytoplankton.

Hydrogen-Mediated Noncovalent Interactions in Solids: What Can NMR Crystallography Tell About?

Hydrogen atoms play a crucial role in the aggregation of organic (bio)molecules through diverse number of noncovalent interactions that they mediate, such as electrostatic in proton transfer systems, hydrogen bonding, and CH-π interactions, to mention only the most prominent. To identify and adequately describe such low-energy interactions, increasingly sensitive methods have been developed over time, among which quantum chemical computations have witnessed impressive advances in recent years. For reaching the present state-of-the-art, computations had to rely on a pool of relevant experimental data, needed at least for validation, if not also for other purposes.

Optimized multi-step NMR-crystallography approach for structural characterization of a stable quercetin solvate.

Herein we report the preparation and solid state structural investigation of the 1,4-dioxane-quercetin solvate. NMR crystallography methods were employed for crystal structure determination of the solvate from microcrystalline powder. The stability of the compound relative to other reported quercetin solvates is discussed and found to be in perfect agreement with the hydrogen bonding networks/supra-molecular architectures formed in each case.

Highly sensitive solid forms discrimination on the whole tablet of the active ingredients in quercetin dietary supplements by NMR crystallography approaches.

Similarly to synthetic drugs, the exact crystalline form of active ingredients in solid formulations of dietary supplements may directly influence the dissolution rate, bioavailability, and stability of the final product, but this information is usually not provided by manufacturers. Working on the examples of two commercial quercetin dietary supplements a quick, reliable, and sensitive method is introduced for quercetin solid forms discrimination directly on the marketed products, without the need for prior sample preparation. It exploits the complementarity between solid-state Nuclear Magnetic Resonance (ss-NMR) and Powder X-Ray Diffraction (PXRD), which proved essential for performing a complete and accurate solid-state characterization of the two commercial products, and for obtaining new insights into the complex quercetin solid-forms landscape.

Crystal Structure and Desolvation Behaviour of the Tadalafil Monosolvates with Acetone and Methyl Ethyl Ketone.

Crystal structures of Tadalafil (TDF) monosolvated forms with acetone (ACE) and methyl ethyl ketone (MEK) were determined by single-crystal X-ray diffraction in which same persistent chains of TDF molecules are present as in the reported structures. The solvates crystallize in a higher orthorhombic symmetry than the known forms with monoclinic structures. Weak interactions between TDF and solvent molecules are present in both solvates, leading to slight conformational distortions of TDF molecules.

Can the conformation of flexible hydroxyl groups be constrained by simple NMR crystallography approaches? The case of the quercetin solid forms.

Hydrogen atoms in systems with many flexible hydroxyl side-groups are difficult to be exactly located from experimental X-Ray diffraction and/or solid-state NMR data, thus often leading to wrong conclusions with respect to the hydrogen bonding network established in crystal lattice. A simple computational method is proposed in the present work to tackle this problem, which may be readily incorporated in conventional NMR crystallography protocols. The method is based on ranking all possible conformations of the flexible hydroxyls according to their lattice energy in crystalline environments.

Structure of polydopamine: a never-ending story?

Polydopamine (PDA) formed by the oxidation of dopamine is an important polymer, in particular, for coating various surfaces. It is composed of dihydroxyindole, indoledione, and dopamine units, which are assumed to be covalently linked. Although PDA has been applied in a manifold way, its structure is still under discussion.

Testing the limits of sensitivity in a solid-state structural investigation by combined X-ray powder diffraction, solid-state NMR, and molecular modelling.

A solid state structural investigation of ethoxzolamide is performed on microcrystalline powder by using a multi-technique approach that combines X-ray powder diffraction (XRPD) data analysis based on direct space methods with information from (13)C((15)N) solid-state Nuclear Magnetic Resonance (SS-NMR) and molecular modeling. Quantum chemical computations of the crystal were employed for geometry optimization and chemical shift calculations based on the Gauge Including Projector Augmented-Wave (GIPAW) method, whereas a systematic search in the conformational space was performed on the isolated molecule using a molecular mechanics (MM) approach. The applied methodology proved useful for: (i) removing ambiguities in the XRPD crystal structure determination process and further refining the derived structure solutions, and (ii) getting important insights into the relationship between the complex network of non-covalent interactions and the induced supra-molecular architectures/crystal packing patterns.

Structure of N-(5-ethyl-[1,3,4]-thiadiazole-2-yl)toluenesulfonamide by combined X-ray powder diffraction, 13C solid-state NMR and molecular modelling.

The crystal structure solution of the title compound is determined from microcrystalline powder using a multi-technique approach that combines X-ray powder diffraction (XRPD) data analysis based on direct-space methods with information from (13)C solid-state NMR (SSNMR), and molecular modelling using the GIPAW (gauge including projector augmented-wave) method. The space group is Pbca with one molecule in the asymmetric unit. The proposed methodology proves very useful for unambiguously characterizing the supramolecular arrangement adopted by the N-(5-ethyl-[1,3,4]-thiadiazole-2-yl)toluenesulfonamide molecules in the crystal, which consists of extended double strands held together by C-H···π non-covalent interactions.

SD-CAS: Spin Dynamics by Computer Algebra System.

A computer algebra tool for describing the Liouville-space quantum evolution of nuclear 1/2-spins is introduced and implemented within a computational framework named Spin Dynamics by Computer Algebra System (SD-CAS). A distinctive feature compared with numerical and previous computer algebra approaches to solving spin dynamics problems results from the fact that no matrix representation for spin operators is used in SD-CAS, which determines a full symbolic character to the performed computations. Spin correlations are stored in SD-CAS as four-entry nested lists of which size increases linearly with the number of spins into the system and are easily mapped into analytical expressions in terms of spin operator products.

Determining relative proton-proton proximities from the build-up of two-dimensional correlation peaks in 1H double-quantum MAS NMR: insight from multi-spin density-matrix simulations.

The build-up of intensity-as a function of the number, n(rcpl), of POST-C7 elements used for the excitation and reconversion of double-quantum (DQ) coherence (DQC)-is analysed for the fifteen distinct DQ correlation peaks that are observed experimentally for the eight separate (1)H resonances in a (1)H (500 MHz) DQ CRAMPS solid-state (12.5 kHz MAS) NMR spectrum of the dipeptide beta-AspAla (S. P.

CHHC and (1)H-(1)H magnetization exchange: analysis by experimental solid-state NMR and 11-spin density-matrix simulations.

A protocol is presented for correcting the effect of non-specific cross-polarization in CHHC solid-state MAS NMR experiments, thus allowing the recovery of the (1)H-(1)H magnetization exchange functions from the mixing-time dependent buildup of experimental CHHC peak intensity. The presented protocol also incorporates a scaling procedure to take into account the effect of multiplicity of a CH(2) or CH(3) moiety. Experimental CHHC buildup curves are presented for l-tyrosine.

WITHDRAWN: CHHC and (1)H-(1)H magnetization exchange: Analysis by experimental solid-state NMR and 11-spin density-matrix simulations.

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.

Low-load rotor-synchronised Hahn-echo pulse train (RS-HEPT) 1H decoupling in solid-state NMR: factors affecting MAS spin-echo dephasing times.

Transverse dephasing times T(2)' in spin-echo MAS NMR using rotor-synchronised Hahn-echo pulse-train (RS-HEPT) low-load (1)H decoupling are evaluated. Experiments were performed at 300 and 600 MHz for (13)CH-labelled L-alanine and (15)NH(delta)-labelled L-histidine.HCl.

Quantifying hydrogen-bonding strength: the measurement of 2hJNN couplings in self-assembled guanosines by solid-state 15N spin-echo MAS NMR.

(2h)J(NN) hydrogen-bond mediated J couplings are measured in the solid state for two synthetic deoxyguanosine derivatives by (15)N MAS NMR spin-echo experiments. The use of rotor-synchronised Hahn-echo pulse train (RS-HEPT) (1)H decoupling, with a duty cycle of 6%, allows spin-echo durations out to 200 ms, hence enabling the accurate determination of J couplings as small as 3.8 Hz.

Polarization transfer from remote protons in 13C CP/MAS.

An experimental procedure for CP/MAS polarization transfer from remote 1H nuclear spins is introduced, which is applicable to protonated carbons in organic solids. It is based on preparing a state of non-uniform polarization, where directly bonded 13C-1H nuclei are de-polarized prior to recording the CP buildup curve. This curve is then expected to quantify the polarization transfer from remote protons only.

Heteronuclear decoupling under fast MAS by a rotor-synchronized Hahn-echo pulse train.

A new heteronuclear decoupling mechanism under fast magic-angle spinning MAS is introduced. It is based on refocusing the coherences responsible for the dephase of low-gamma nuclei ((13)C, (15)N) transverse spin-polarization in the presence of strongly dipolar-coupled protons, and has the advantage that can be implemented by pulsed techniques, with all the benefits resulting from a reduced duty cycle compared with conventional decoupling by continuous rf irradiation. The decoupling efficiency of a simple rotor-synchronized Hahn-echo pulse train is analyzed both theoretically and experimentally.