Drill turn technique for enhanced visualization of wide-neck bifurcation aneurysms in Y-stent-assisted coiling with LVIS EVO stents: technical considerations and mid-term results.

BACKGROUND: Crossing Y-stent-assisted coiling (CYSAC) is a feasible yet technically challenging technique for the treatment of wide-neck bifurcation aneurysms (WNBAs). OBJECTIVE: To present mid-term results of Y-stent-assisted coiling (YSAC) using the LVIS EVO stent and to describe our "drill turn" technique for stent crossing. METHODS: This retrospective, observational study included 37 consecutive patients treated with YSAC using LVIS EVO stents at five centres between September 2020 and March 2023. RESULTS: Immediately after treatment, 31 of the 37 patients (83.8%) achieved Raymond-Roy occlusion classification (RROC) Class I occlusion, while 5 patients (13.5%) had Class II and 1 patient (2.7%) had Class III occlusion. The mean follow-up period was 32.8 months (range: 11-41 months), and all patients underwent follow-up imaging after ≥ 6 months. On follow-up imaging, 34 patients (92%), including all those with immediate RROC Class I occlusion, 2 with Class II, and 1 with Class III, showed Class I occlusion. One patient with RROC Class II occlusion demonstrated a gradual decrease in residual filling, while one large partially thrombosed middle cerebral artery aneurysm and one large basilar tip aneurysm (8%) with residual neck filling remained unchanged on the 6-month digital subtraction angiograph. CONCLUSION: Utilizing the described drill turn technique, CYSAC with LVIS EVO stents was found to be feasible and safe for WNBA treatment, with high and stable occlusion rates observed during mid-term follow-up.

Revisiting the Most Stable Structures of the Benzene Dimer.

The benzene dimer (BD) is an archetypal model of π∙∙∙π and C-H∙∙∙π noncovalent interactions as they occur in its cofacial and perpendicular arrangements, respectively. The enthalpic stabilization of the related BD structures has been debated for a long time and is revisited here. The revisit is based on results of computations that apply the coupled-cluster theory with singles, doubles and perturbative triples [CCSD(T)] together with large basis sets and extrapolate results to the complete basis set (CBS) limit in order to accurately characterize the three most important stationary points of the intermolecular interaction energy (ΔE) surface of the BD, which correspond to the tilted T-shaped (TT), fully symmetric T-shaped (FT) and slipped-parallel (SP) structures. In the optimal geometries obtained by searching extensive sets of the CCSD(T)/CBS ΔE data of the TT, FT and SP arrangements, the resulting ΔE values were -11.84, -11.34 and -11.21 kJ/mol, respectively. The intrinsic strength of the intermolecular bonding in these configurations was evaluated by analyzing the distance dependence of the CCSD(T)/CBS ΔE data over wide ranges of intermonomer separations. In this way, regions of the relative distances that favor BD structures with either π∙∙∙π or C-H∙∙∙π interactions were found and discussed in a broader context.

Flow diversion for unruptured MCA bifurcation aneurysms: comparison of p64 classic, p64 MW HPC, and p48 MW HPC flow diverter stents.

Background: MCA bifurcation aneurysms pose treatment challenges because of the complex hemodynamics at the bifurcation and the risk of rupture. FDS implantation has been controversial and there are only limited reports. Therefore, the aim of this study was to assess the efficacy and safety of this treatment strategy using p64 MW HPC and p48 MW HPC FDSs for MCA bifurcation aneurysms, compared with the p64 classic FDS. Materials and methods: We retrospectively analyzed our institutional database and identified all patients with saccular, non-ruptured MCA bifurcation aneurysms treated with p64 MW HPC, p48 MW HPC, or p64 classic FDS implantation alone. Aneurysms with implantation of additional devices in the same session, previous treatments, and acutely ruptured and fusiform aneurysms were excluded. Results: A total of 79 aneurysms met the inclusion criteria: 23 receiving a p64 MW HPC, 34 receiving a p48 MW HPC, and 22 receiving a p64 classic FDS. The occlusion rate was highest for the p48 MW HPC 2 mm FDS, at 88.9% at FU2, compared with 72.2% for the p64 MW HPC and 70.6% for the p64 classic. The time to aneurysm occlusion was shortest with the p64 MW HPC, at 178.31 days. The highest retreatment rate was observed with the p48 MW HPC 3 mm. Conclusion: Treatment of MCA bifurcation aneurysms with a p48 MW HPC 2 mm or p64 MW HPC FDS is a safe and reliable strategy achieving high aneurysm occlusion rates - attributable to their lower porosity in relation to the parent vessel diameter as compared to the p48 MW HPC 3 mm FDS-, with reasonable morbidity and mortality.

Feasibility of single antiplatelet therapy after stent assisted coiling for ruptured intracranial aneurysms.

Object: We retrospectively analyzed clinical data to evaluate the safety and efficacy of single antiplatelet therapy (SAPT) after stent-assisted coil embolization (SAC) for ruptured cerebral aneurysms. Methods: In total, 176 stent-assisted coil embolization procedures were investigated. Among them, 77 ruptured and 99 unruptured aneurysms were grouped and compared respectively. In the ruptured group, only SAPT (aspirin) was administered after the procedure. Meanwhile, in the unruptured group, dual antiplatelet therapy (DAPT) (aspirin and clopidogrel) was administered before and after the procedure following standard guidelines. We compared both groups in regards to thromboembolic complications by analyzing post procedural diffusion-weighted images (DWI), hyperacute thrombosis during the procedure, and post-procedural symptoms. Results: The single antiplatelet therapy ruptured intracranial aneurysm (SAPT-RIA) group had 77 saccular aneurysms (62 ICA, 3 MCA, 4 ACA, 8 posterior circulation) with a mean diameter of 8.07 mm. The dual antiplatelet therapy unruptured intracranial aneurysm (DAPT-UIA) group had 99 aneurysms (81 ICA, 5 MCA, 3 ACA, 10 posterior circulation) with a mean diameter of 6.32 mm. DWI positivity rates were similar between groups, but hyperacute thrombosis was higher in the SAPT-RIA group (10.4%) compared to none in the DAPT-UIA group. Each group had one symptomatic complication. Conclusions: SAPT could be a viable option for the peri-procedural management of SAC in acutely ruptured cases.

Quantum Mechanics Characterization of Non-Covalent Interaction in Nucleotide Fragments.

Accurate calculation of non-covalent interaction energies in nucleotides is crucial for understanding the driving forces governing nucleic acid structure and function, as well as developing advanced molecular mechanics forcefields or machine learning potentials tailored to nucleic acids. Here, we dissect the nucleotides' structure into three main constituents: nucleobases (A, G, C, T, and U), sugar moieties (ribose and deoxyribose), and phosphate group. The interactions among these fragments and between fragments and water were analyzed. Different quantum mechanical methods were compared for their accuracy in capturing the interaction energy. The non-covalent interaction energy was decomposed into electrostatics, exchange-repulsion, dispersion, and induction using two ab initio methods: Symmetry-Adapted Perturbation Theory (SAPT) and Absolutely Localized Molecular Orbitals (ALMO). These calculations provide a benchmark for different QM methods, in addition to providing a valuable understanding of the roles of various intermolecular forces in hydrogen bonding and aromatic stacking. With SAPT, a higher theory level and/or larger basis set did not necessarily give more accuracy. It is hard to know which combination would be best for a given system. In contrast, ALMO EDA2 did not show dependence on theory level or basis set; additionally, it is faster.

Anions as Lewis Acids in Noncovalent Bonds.

The ability of an anion to serve as electron-accepting Lewis acid in a noncovalent bond is assessed via DFT calculations. NH3 is taken as the common base, and is paired with a host of ACln - anions, with central atom A=Ca, Sr, Mg, Te, Sb, Hg, Zn, Ag, Ga, Ti, Sn, I, and B. Each anion reacts through its σ or π-hole although the electrostatic potential of this hole is quite negative in most cases. Despite the contact between this negative hole and the negative region of the approaching nucleophile, the electrostatic component of the interaction energy of each bond is highly favorable, and accounts for more than half of the total attractive energy. The double negative charge of dianions precludes a stable complex with NH3.

Chemistry of Cyclo[18]Carbon (C18): A Review.

Carbon-based allotropes are propelling a technological revolution in communication, sensing, and computing, concurrently challenging fundamental theories of the previous century. Nevertheless, the demand for advanced carbon-based materials remains substantial. The crux lies in the efficient and reliable engineering of novel carbon allotrope. Although C18 has undergone theoretical and experimental investigation for an extended period, its preparation and direct observation in the condensed phase occurred only recently through STM/AFM techniques. The distinctive cyclic ring structure and the dual 18-center π delocalization character introduce various uncommon properties to C18, rendering it a subject worthy of in-depth exploration. In this context, this review delves into past developments contributing to the state-of-the-art understanding of C18 and provides insights into how future endeavours can expedite practical applications. Encompassing a broad spectrum, this review comprehensively investigates almost all facets of C18, including geometric characteristics, electron delocalization, bonding nature, aromaticity, reactivity, electronic excitation, UV/Vis spectrum, intermolecular interaction, response to external fields, electron affinity, ionization, and other molecular properties. Moreover, the review also outlines representative strategies for the direct synthesis and characterization of C18 using atom manipulation techniques. Following this, C18-based complexes are summarized, and potential applications in catalysis, electrochemical devices, optoelectronics, and sensing are discussed.

Intermolecular interaction energies with AROFRAG-A systematic approach for fragmentation of aromatic molecules.

Intermolecular interactions with polycyclic aromatic hydrocarbons (PAHs) represent an important area of physisorption studies. These investigations are often hampered by a size of interacting PAHs, which makes the calculation prohibitively expensive. Therefore, methods designed to deal with large molecules could be helpful to reduce the computational costs of such studies. Recently we have introduced a new systematic approach for the molecular fragmentation of PAHs, denoted as AROFRAG, which decomposes a large PAH molecule into a set of predefined small PAHs with a benzene ring being the smallest unbreakable unit, and which in conjunction with the Molecules-in-Molecules (MIM) approach provides an accurate description of total molecular energies. In this contribution we propose an extension of the AROFRAG, which provides a description of intermolecular interactions for complexes composed of PAH molecules. The examination of interaction energy partitioning for various test cases shows that the AROFRAG3 model connected with the MIM approach accurately reproduces all important components of the interaction energy. An additional important finding in our study is that the computationally expensive long-range electron-correlation part of the interaction energy, that is, the dispersion component, is well described at lower AROFRAG levels even without MIM, which makes the latter models interesting alternatives to existing methods for an accurate description of the electron-correlated part of the interaction energy.

Halogen Bond via an Electrophilic π-Hole on Halogen in Molecules: Does It Exist?

This study reveals a new non-covalent interaction called a π-hole halogen bond, which is directional and potentially non-linear compared to its sister analog (σ-hole halogen bond). A π-hole is shown here to be observed on the surface of halogen in halogenated molecules, which can be tempered to display the aptness to form a π-hole halogen bond with a series of electron density-rich sites (Lewis bases) hosted individually by 32 other partner molecules. The [MP2/aug-cc-pVTZ] level characteristics of the π-hole halogen bonds in 33 binary complexes obtained from the charge density approaches (quantum theory of intramolecular atoms, molecular electrostatic surface potential, independent gradient model (IGM-δginter)), intermolecular geometries and energies, and second-order hyperconjugative charge transfer analyses are discussed, which are similar to other non-covalent interactions. That a π-hole can be observed on halogen in halogenated molecules is substantiated by experimentally reported crystals documented in the Cambridge Crystal Structure Database. The importance of the π-hole halogen bond in the design and growth of chemical systems in synthetic chemistry, crystallography, and crystal engineering is yet to be fully explicated.

An efficient method by combining different basis sets and SAPT levels.

In symmetry-adapted perturbation theory (SAPT), accurate calculations on non-covalent interaction (NCI) for large complexes with more than 50 atoms are time-consuming using large basis sets. More efficient ones with smaller basis sets usually result in poor prediction in terms of dispersion and overall energies. In this study, we propose two composite methods with baseline calculated at SAPT2/aug-cc-pVDZ and SAPT2/aug-cc-pVTZ with dispersion term corrected at SAPT2+ level using bond functions and smaller basis set with δ MP2 corrections respectively. Benchmark results on representative NCI data sets, such as S22, S66, and so forth, show significant improvements on the accuracy compared to the original SAPT Silver standard and comparable to SAPT Gold standard in some cases with much less computational cost.

Similarities and Differences of Hydridic and Protonic Hydrogen Bonding.

Ab initio calculations were employed to investigate the interactions between selected electron-donating groups, characterized by M-H bonds (where M represents a transition metal and H denotes a hydridic hydrogen), and electron-accepting groups featuring both σ- and π-holes. The study utilized the ωB97X-D3BJ/def2-TZVPPD level of theory. Hydridic hydrogen complexes were found in all complexes with σ- and π-holes. A comparative analysis was conducted on the properties hydridic H-bond complexes, presented here and those studied previously, alongside an extended set of protonic H-bonds complexes. While the stabilization energies changes in M-H bond lengths, vibrational frequencies, intensities of the spectral bands, and charge transfer for these complexes are comparable, the nature of hydridic and protonic H-bonds fundamentally differ. In protonic H-bond complexes, the main stabilization forces arise from electrostatic contributions, while in hydridic H-bond complexes, dispersion energy, is the primary stabilization factor due to the excess of electrons and thus larger polarizability at hydridic H. The finding represents an important characteristic that distinguishes hydridic H-bonding from protonic H-bonds.

Short duration of dual antiplatelet therapy following complex percutaneous coronary intervention: A systematic review and meta-analysis.

INTRODUCTION AND AIM: The optimal composition and duration of antiplatelet therapy after complex percutaneous coronary intervention (PCI) remains unclear. We conducted a meta-analysis to compare 1-3 months of dual antiplatelet therapy (DAPT) followed by monotherapy vs. 12 months of DAPT. METHOD: MEDLINE/PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were queried for studies comparing 1-3 months of DAPT followed by monotherapy vs. 12 months of DAPT in the outcomes of complex PCI from inception through January 2023. Outcomes of interest included major bleeding, all-cause mortality, cardiovascular mortality, myocardial infarction (MI), stent thrombosis, target vessel revascularization, and stroke. RESULTS: Compared to 12 months, 1-3 months of dual antiplatelet therapy had a weak association with less major bleeding (OR 0.67; 95 % CI, 0.44-1.00; p = 0.05; I2 = 28 %). There were no significant differences between the shorter and longer antiplatelet therapy in terms of all-cause mortality (OR 0.83; 95 % CI, 0.59-1.16; p = 0.21; I2 = 17 %), cardiovascular mortality (OR 0.87; 95 % CI, 0.53-0.42; p = 0.50; I2 = 0), MI (OR 0.97; 95 % CI, 0.69-1.35; p = 0.82; I2 = 32 %), stent thrombosis (OR 1.17, 95 % CI, 0.77-1.76; p = 0.38; I2 = 0 %), target vessel revascularization (OR 1.05, 95 % CI, 0.58-1.89; p = 0.82; I2 = 64 %), or stroke (OR 1.10, 95 % CI, 0.55-2.17; p = 0.37; I2 = 7 %);. CONCLUSION: Among patients undergoing complex PCI, DAPT for 1-3 months may be associated with less major bleeding but similar rates of cardiovascular events (death, MI, stroke, stent thrombosis, and revascularization) compared to DAPT for 12 months.

Ab initio Modeling of Hydrogen Bonding of Remdesivir and Adenosine with Uridine.

Remdesivir (RDV) emerged as an effective drug against the SARS-CoV-2 virus pandemic. One of the crucial steps in the mechanism of action of RDV is its incorporation into the growing RNA strand. RDV, an adenosine analogue, forms Watson-Crick (WC) type hydrogen bonds with uridine in the complementary strand and the strength of this interaction will control efficacy of RDV. While there is a plethora of structural and energetic information available about WC H-bonds in natural base pairs, the interaction of RDV with uridine has not been studied yet at the atomic level. In this article, we aim to bridge this gap, to understand RDV and its hydrogen bonding interactions, by employing density functional theory (DFT) at the M06-2X/cc-pVDZ level. The interaction energy, QTAIM analysis, NBO and SAPT2 are performed for RDV, adenosine, and their complex with uridine to gain insights into the nature of hydrogen bonding. The computations show that RDV has similar geometry, energetic, molecular orbitals, and aromaticity as adenosine, suggesting that RDV is an effective adenosine analogue. The important geometrical parameters, such as bond distances and red-shift in the stretching vibrational modes of adenosine, RDV and uridine identify two WC-type H-bonds. The relative strength of these two H-bonds is computed using QTAIM parameters and the computed hydrogen bond energy. Finally, the SAPT2 study is performed at the minima and at non-equilibrium base pair distances to understand the dominant intermolecular physical force. This study, based on a thorough analysis of a variety of computations, suggests that both adenosine and RDV have similar structure, energetic, and hydrogen bonding behaviour.

Pretreatment antithrombotic strategies in non-ST elevation acute coronary syndromes in contemporaneous clinical practice.

BACKGROUND: Pretreatment antithrombotic strategies in non-ST elevation acute coronary syndromes (NSTE-ACS) during hospitalization is still a matter of contention within the cardiology community. Our aim was to analyze in-hospital and one-year follow-up outcomes of patients with NSTE-ACS pretreated with dual antiplatelet therapy (DAPT) versus single antiplatelet therapy (SAPT). METHODS: A retrospective study was carried out with NSTE-ACS patients planned to undergo an invasive strategy and were included in the Portuguese Registry of ACS between 2018-2021. A composite primary outcome (in-hospital re-infarction, stroke, heart failure, hemorrhage, death) was compared regarding antiplatelet strategy (DAPT versus SAPT). Secondary outcomes were defined as one-year all-cause mortality and one-year cardiovascular rehospitalization. RESULTS: A total of 1469 patients were included, with a mean age of 66±12 years and 73.9% were male. DAPT regime was used in 38.2% and SAPT in 61.8% of patients. NSTE myocardial infarction was the most frequent presentation (88.5%). Revascularization after 24h occurred in 44.8% patients (63% of these after 48h). Enoxaparin was the anticoagulant more frequently used (45.1%). The primary outcome was more frequently observed in the SAPT group (10.4%, p=0.033), mainly driven by more ischemic events. Time until revascularization > 48h and SAPT regime were independent predictors of the primary outcome (OR 1.66, p=0.036 and OR 2.03, p=0.008, respectively). CONCLUSION: NSTE-ACS patients pretreated with SAPT had worse in-hospital outcomes. This difference can be probably explained by a delay in time until revascularization. Pretreatment DAPT strategy and crossover between heparins is still frequently used in clinical practice.

Halogen Bonding Involving Isomeric Isocyanide/Nitrile Groups.

2,3,5,6-Tetramethyl-1,4-diisocyanobenzene (1), 1,4-diisocyanobenzene (2), and 1,4-dicyanobenzene (3) were co-crystallized with 1,3,5-triiodotrifluorobenzene (1,3,5-FIB) to give three cocrystals, 1·1,3,5-FIB, 2·2(1,3,5-FIB), and 3·2(1,3,5-FIB), which were studied by X-ray diffraction. A common feature of the three structures is the presence of I···Cisocyanide or I···Nnitrile halogen bonds (HaBs), which occurs between an iodine σ-hole and the isocyanide C-(or the nitrile N-) atom. The diisocyanide and dinitrile cocrystals 2·2(1,3,5-FIB) and 3·2(1,3,5-FIB) are isostructural, thus providing a basis for accurate comparison of the two types of noncovalent linkages of C≡N/N≡C groups in the composition of structurally similar entities and in one crystal environment. The bonding situation was studied by a set of theoretical methods. Diisocyanides are more nucleophilic than the dinitrile and they exhibit stronger binding to 1,3,5-FIB. In all structures, the HaBs are mostly determined by the electrostatic interactions, but the dispersion and induction components also provide a noticeable contribution and make the HaBs attractive. Charge transfer has a small contribution (<5%) to the HaB and it is higher for the diisocyanide than for the dinitrile systems. At the same time, diisocyanide and dinitrile structures exhibit typical electron-donor and π-acceptor properties in relation to the HaB donor.

Unveiling the Noncovalent Interaction of Thiazol-2-ylidene and Its Derivatives as N-heterocyclic Carbene with Different Proton Donor Molecules.

The importance of noncovalent interaction has gained attention in various domains covering drug and novel catalyst design. The present study mainly characterizes the role of hydrogen bond (H-bond) and other intermolecular interactions in different (1 : 1) complex analogues formed between the N-aryl-thiazol-2-ylidene (YR) and five proton donor (HX) molecules. The analysis of the singlet-triplet energy gap ( Δ E S - T ${{\rm{\Delta }}E_{\left( {S - T} \right)} }$ ) confirmed the stability of the singlet state for this class of N-aryl-thiazol-2-ylidenes than the triplet state. The interaction energy values of the YR-HX complexes follow the order: YR-NH3

Elucidating the adsorption of 2-Mercaptopyridine drug on the aluminum phosphide (Al12P12) nanocage: A DFT study.

Adsorption amplitude of the aluminum phosphide (Al12P12) nanocage toward the 2-Mercaptopyridine (MCP) drug was herein monitored based on density functional theory (DFT) calculations. The adsorption process through MCP⋅⋅⋅Al12P12 complex in various configurations was elucidated by means of adsorption (Eads) energies. According to the energetic affirmations, the Al12P12 nanocage demonstrated potential versatility toward adsorbing the MCP drug within the investigated configurations and exhibited significant negative adsorption energies up to -27.71 kcal/mol. Upon the results of SAPT analysis, the electrostatic forces showed the highest contributions to the overall adsorption process with energetic values up to -74.36 kcal/mol. Concurrently, variations of molecular orbitals distribution along with alterations in the energy gap (Egap) and Fermi level (EFL) of the studied nanocage were denoted after adsorbing the MCP drug. The favorable impact of water solvent within the MCP⋅⋅⋅Al12P12 complexes was unveiled and confirmed by negative solvation energy (ΔEsolv) values up to -17.75 kcal/mol. According to thermodynamic parameters, the spontaneous and exothermic natures of the considered adsorption process were proclaimed by negative values of ΔG and ΔH parameters. Significant changes in the IR and Raman peaks, along with the appearance of new peaks, were noticed, confirming the occurrence of the targeted adsorption process. Furthermore, the adsorption features of the MCP drug on the Al12N12 nanocage were elucidated and compared to the Al12P12 analog. The obtained results demonstrated the higher preferability of Al12P12 nanocage than the Al12N12 candidate towards adsorbing the MCP drug without structural distortion.

Complexes of HXeY with HX (Y, X = F, Cl, Br, I): Symmetry-Adapted Perturbation Theory Study and Anharmonic Vibrational Analysis.

A comprehensive analysis of the intermolecular interaction energy and anharmonic vibrations of 41 structures of the HXeY⋯HX (X, Y = F, Cl, Br, I) family of noble-gas-compound complexes for all possible combinations of Y and X was conducted. New structures were identified, and their interaction energies were studied by means of symmetry-adapted perturbation theory, up to second-order corrections: this provided insight into the physical nature of the interaction in the complexes. The energy components were discussed, in connection to anharmonic frequency analysis. The results show that the induction and dispersion corrections were the main driving forces of the interaction, and that their relative contributions correlated with the complexation effects seen in the vibrational stretching modes of Xe-H and H-X. Reasonably clear patterns of interaction were found for different structures. Our findings corroborate previous findings with better methods, and provide new data. These results suggest that the entire group of the studied complexes can be labelled as "naturally blueshifting", except for the complexes with HI.

Quantifying the Intrinsic Strength of C-H⋯O Intermolecular Interactions.

It has been recognized that the C-H⋯O structural motif can be present in destabilizing as well as highly stabilizing intermolecular environments. Thus, it should be of interest to describe the strength of the C-H⋯O hydrogen bond for constant structural factors so that this intrinsic strength can be quantified and compared to other types of interactions. This description is provided here for C2h-symmetric dimers of acrylic acid by means of the calculations that employ the coupled-cluster theory with singles, doubles, and perturbative triples [CCSD(T)] together with an extrapolation to the complete basis set (CBS) limit. Dimers featuring the C-H⋯O and O-H⋯O hydrogens bonds are carefully investigated in a wide range of intermolecular separations by the CCSD(T)/CBS approach, and also by the symmetry-adapted perturbation theory (SAPT) method, which is based on the density-functional theory (DFT) treatment of monomers. While the nature of these two types of hydrogen bonding is very similar according to the SAPT-DFT/CBS calculations and on the basis of a comparison of the intermolecular potential curves, the intrinsic strength of the C-H⋯O interaction is found to be about a quarter of its O-H⋯O counterpart that is less than one might anticipate.