Unveiling the Reaction Mechanism of Diels-Alder Cycloadditions between 2,5-Dimethylfuran and Ethylene Derivatives Using Topological Tools.

The [4+2] Diels-Alder cycloaddition reaction between 2,5-DMF (1) and ethylene derivatives (2a-h) activated by electron-withdrawing groups has been studied at the density functional theory levels using a panoply of tools to unravel the reaction mechanisms. From the analysis of the reactivity indices, 2a-h behave as electrophiles while 1 as nucleophile, and the activation of the double bond of ethylene increases its electrophilicity, which is accompanied by an enhancement of the polarity of the reaction. The activation Gibbs free energy decreases linearly as a function of this increase of polarity, as estimated by the electrophilicity difference between the reactants.

Vibronic Structure of the UV/Visible Absorption Spectra of Phenol and Phenolate: A Hybrid Density Functional Theory─Doktorov's Quantum Algorithm Approach.

The Doktorov's quantum algorithm has been enacted in combination with time-dependent density functional theory (TD-DFT) to simulate the vibronic structure of the UV/visible absorption spectra of the phenol and phenolate molecules. On the one hand, DFT and TD-DFT are employed with classical algorithms to calculate the ground and excited-state electronic structures as well as their vibrational frequencies and normal modes, whereas, on the other hand, quantum algorithms are employed for evaluating the vibrational transition intensities. In comparison to a previous study, , 128, 4369-4377, which demonstrated Doktorov's quantum algorithm as a proof of concept to predict the vibronic structure of ionization spectra, it is applied here to medium-size molecules with more than 30 vibrational normal modes, without accounting for Duschinsky rotations due to software limitations.

Solvent effects on the second harmonic responses of donor-acceptor Stenhouse adducts: from implicit to hybrid solvation models.

The effect of conformational dynamics and solvent interactions on the second-order nonlinear optical (NLO) responses of the open and closed forms of a donor-acceptor Stenhouse adduct (DASA) are investigated by a mixed quantum/classical computational approach, which couples molecular dynamics (MD) simulations and time-dependent density functional theory (TD-DFT) calculations. The latter are further combined with various solvation schemes, including polarizable continuum models, hybrid QM/MM approaches using either non polarizable or polarizable electrostatic embedding, and QM/QM' schemes with explicit treatment of a few molecules of the first solvation shell. The performances of the different solvation models are discussed in the context of comparisons with experimental data obtained from hyper-Rayleigh scattering measurements.

Quantum chemistry study on the hyper-Rayleigh scattering optical activity of -carvone and (1,5)-α-pinene.

In this work, the HRS-OA circular differential scattering ratios of medium-size chiral molecules, -carvone and (1,5)-α-pinene, has been computed by means of TD-DFT calculations. The results have been discussed as a function of the basis set size. For -carvone a conformational analysis has been taken into account.

Three-dimensional representation of the pure electric-dipole and the mixed first hyperpolarizabilities: The modified unit sphere representation.

In this work, the theory of the modified unit sphere representation (mUSR) has been proposed as a computational tool suitable for the three-dimensional representation of the pure electric-dipole [ ] as well as of the mixed electric-dipole/magnetic-dipole [ and ] or electric-dipole/electric-quadrupole [ and ] first hyperpolarizabilities. These five quantities are Cartesian tensors and they are responsible for the chiral signal in the chiroptical version of the hyper-Rayleigh scattering (HRS) spectroscopy, namely the HRS optical activity (HRS-OA) spectroscopy. For the first time, for each hyperpolarizability, alongside with the three-dimensional representation of the whole (i.

Close margin of adverse histologic factors with a negative primary tumor margin is not associated with increased locoregional recurrence in colon cancer.

Purpose: Locoregional recurrence after resection of colon cancer is increased when primary tumor margin is positive (<1 ​mm). Data is limited regarding the risk of locoregional recurrence with close margin (<1 ​mm) of histologic factors, such as intravascular tumor, intranodal tumor, tumor deposits, or extranodal extension. We hypothesized that close margin of these factors doesn't affect locoregional recurrence.

Assessment of embedded versus remote pharmacist versus remote student pharmacist outreach on statin prescribing.

Background: The Statin Use in Persons with Diabetes (SUPD) measure is a Star measure by the Center for Medicare & Medicaid Services. The Duke Population Health Management Office has a team of pharmacists and pharmacy students who conduct targeted outreach to patients at risk of failing statin quality measures. Pharmacy services are embedded in select primary care clinics and other clinics are supported remotely.

Reactivity and Steric Parameters from 2D to 3D Bulky Pyridines: Increasing Steric Demand at Nitrogen with Chiral Azatriptycenes.

Sterically hindered pyridines embedded in a three-dimensional triptycene framework have been synthesized, and their resolution by chiral HPLC enabled access to unprecedented enantiopure pyridines exceeding the known steric limits. The design principles for new axially chiral pyridine derivatives are then described. To rationalize their associations with Lewis acids and transition metals, a comprehensive determination of the steric and electronic parameters for this new class of pyridines was performed.

Simulating Vibronic Spectra by Direct Application of Doktorov Formulas on a Superconducting Quantum Simulator.

In this work, a direct quantum implementation of the Doktorov formulas for calculating the vibronic spectrum of molecules under the harmonic approximation is presented. It is applied to the three-atom molecules HO, SO, ClO, HS, and ZnOH. The method solves the classically hard problem of estimating the Franck-Condon (FC) factors by using the Duschinsky matrices as the only input via the Doktorov quantum circuit.

On the third-order nonlinear optical responses of and stilbenes - a quantum chemistry investigation.

The second hyperpolarizabilities () of the stilbene molecular switch in its and forms have been calculated using quantum chemistry methods to address their third-order nonlinear optical contrasts, to assess the reliability of lower-cost DFT methods, and to make comparisons with experiments. First, the reference CCSD(T) method shows that -stilbene presents a value twice larger than its isomer (its value is 2.7 times larger).

More People, More Active, More Often for Heart Health - Taking Action on Physical Activity.

Physical inactivity is a leading contributor to increased cardiovascular morbidity and mortality. Almost 500 million new cases of preventable noncommunicable diseases (NCDs) will occur globally between 2020 and 2030 due to physical inactivity, costing just over US$300 billion, or around US$ 27 billion annually (WHO 2022). Active adults can achieve a reduction of up to 35% in risk of death from cardiovascular disease.

Disentangling the molecular polarizability and first hyperpolarizability of methanol-air interfaces.

Liquid-air interfaces have extensive implications in different areas of interest because the dynamical processes at the interface can be different from those in bulk. Thus, its characterization, understanding, and control may be pivotal in advancing discoveries. However, characterizing the interface requires special and selective tools to avoid signals from the bulk region.

Earth Mover's Charge Transfer Distance: A General and Robust Approach for Describing Excited State Locality.

A novel approach for assessing the extent of electron displacement in optical transitions is proposed by implementing the Earth Mover's Distance (EMD) method, which quantifies the spatial dissimilarity between ground and excited state electron density distributions. In contrast to previous descriptors, this index provides a representative and intuitively understandable distance under a robust and computationally efficient scheme for all possible forms of locality, even in the most difficult to dissect topological cases. The theoretical differences among the existing indices and our method are first illustrated with the help of a simplified model system, followed by a benchmarking of several partial atomic charge models using experimentally relevant push-pull compounds with diverse symmetries.

Bridge improvement work: maximising non-linear optical performance in polyoxometalate derivatives.

New phenyl and stilbene-bridged polyoxometalate (POM) charge-transfer chromophores with diphenylamino donor groups produce, respectively, the highest intrinsic and absolute quadratic hyperpolarisabilities measured for such species. The obtained for the phenyl bridge - at 180 × 10 esu - is remarkable for a short conjugated system while changing to the stilbene (260 × 10 esu) produces a substantial increase in non-linearity for a minimal red-shift in the absorption profile. Together with TD-DFT calculations, the results show that maximising conjugation in the π-bridge is vital to high performance in such "POMophores".

Diverticular Abscess Complicating Pregnancy at 18 Weeks' Gestation in a 30-Year-Old Female: A Case Report.

The co-occurrence of diverticulitis with pregnancy is incredibly rare and the management of recurrent complicated diverticulitis may not be feasible in a pregnant patient. Adding cases to the incredibly sparse literature may highlight similarities and create potential recommendations for at-risk populations. We present a case of a female at 18 weeks' gestation who presented with left lower quadrant pain.

Impact of neoadjuvant therapy on nodal harvest in clinical stage III rectal cancer: Establishing optimum cut-offs by disease response.

Introduction: A minimum lymph node harvest (LNH) of 12 is the current standard for appropriate nodal staging in resectable rectal cancer. However, the rise of neoadjuvant chemoradiation (NCRT) and total neoadjuvant therapy (TNT) has been associated with decreasing number of LNH. We hypothesize that as tumor response to neoadjuvant therapy increases, the optimum for LNH to achieve appropriate nodal staging should decrease.

Multimillion Atom Simulations of Di-8-ANEPPS Chromophores Embedded in a Model Plasma Membrane: Toward the Investigation of Realistic Dyed Cell Membranes.

A multistep computational approach has been employed to study a multimillion all-atom dyed plasma membrane, with no less than 42 different lipid species spanning the major head groups and a variety of fatty acids, as well as cholesterol, with the objective of investigating its structure and dynamics, as well as its impact on the embedded di-8-ANEPPS dyes. The latter are commonly used as bioimaging probes and serve as local microscopes. So, they provide information on membrane morphology via their second harmonic nonlinear optical (NLO) responses, which have the advantage of being specific to interface regions and sensitive to the chromophore environment.

Second-order nonlinear optical properties of X-shaped pyrazine derivatives.

This work reports an investigation of the second-order NLO properties of two isomer series of X-shaped pyrazine derivatives, by means of HRS measurements and DFT calculations. The systems differ in the relative position of the donor and acceptor substituents with respect to the axis formed by the nitrogen atoms of the central pyrazine ring. Although the magnitude of the second harmonic signal is similar, HRS measurements revealed that the anisotropy of the NLO response strongly differs in the two chromophore series, the one of the 2,3-isomers being strikingly dipolar, while the one of the 2,6-isomers is mostly octupolar.

Fact or fiction? Does the position of the end-to-end (EEA) stapler spike matter for colorectal anastomoses using a double-stapled technique?

Aim: Surgeons often have strong opinions about how to perform colorectal anastomoses with little data to support variations in technique. The aim of this study was to determine if location of the end-to-end (EEA) stapler spike relative to the rectal transection line is associated with anastomotic integrity.

Method: This study was a retrospective analysis of a quality collaborative database at a quaternary centre and regional hospitals.

First hyperpolarizability of the di-8-ANEPPS and DR1 nonlinear optical chromophores in solution. An experimental and multi-scale theoretical chemistry study.

The solvent effects on the linear and second-order nonlinear optical properties of an aminonaphtylethenylpyridinium (ANEP) dye are investigated by combining experimental and theoretical chemistry methods. On the one hand, deep near infrared (NIR) hyper-Rayleigh scattering (HRS) measurements (1840-1950 nm) are performed on solutions of di-8-ANEPPS in deuterated chloroform, dimethylformamide, and dimethylsulfoxide to determine their first hyperpolarizablity (βHRS). For the first time, these HRS experiments are carried out in the picosecond regime in the deep NIR with very moderate (≤3 mW) average input power, providing a good signal-to-noise ratio and avoiding solvent thermal effects.

Intramolecular locking and coumarin insertion: a stepwise approach for TADF design.

Three novel TADF (thermally activated delayed fluorescence) emitters based on the well-studied Qx-Ph-DMAC fluorophore are designed and synthesized. The photophysical properties of these materials are studied from a theoretical and experimental point of view, demonstrating the cumulative effects of multiple small modifications that combine to afford significantly improved TADF performance. First, an extra phenyl ring is added to the acceptor part of Qx-Ph-DMAC to increase the conjugation length, resulting in BQx-Ph-DMAC, which acts as an intermediate molecular structure.

Three-Dimensional Rotational Averaging Using Irreducible Sets of Linearly Independent Fundamental Isotropic Cartesian Tensors: A Computational Approach.

The theoretical formulation of linear and nonlinear molecular spectroscopies applied to isotropic samples (e.g., liquid or gas solutions) goes through a fundamental step known as the rotational averaging of Cartesian tensors.

Improving Hypertension Control in the Black Patient Population: A Quality Improvement Study of Workflow Redesign Using the Electronic Health Record to Integrate Self-Monitoring, Education, and Reporting.

Background: Nearly half of American adults have hypertension (HTN), and non-Hispanic Black patients are diagnosed at a higher rate than others.

Local Problem: Our local clinic population reflected disproportionate rates of uncontrolled HTN among Black patients.

Methods: A quality improvement pre-/postintervention design was used to evaluate an educational intervention to reduce blood pressure (BP) and improve self-monitoring of BP in Black patients using the Chronic Care Model.