Inverting the Solvatochromism of Pyridinium-N-phenolate Dyes by the Addition of a Second Pyridinium Unit.

Three bipyridinium phenolates were synthesized, and their spectral behavior was recorded at various solvent polarities and compared to a classic pyridinium phenolate dye possessing only one pyridinium acceptor ring in its structure. The addition of a second pyridinium unit to the classic solvatochromic core results in an unexpected change in the spectral behavior from negative solvatochromism (displacement of the absorption band to shorter wavelengths) to inverted solvatochromism, characterized by the transition from negative to positive solvatochromism (displacement of the absorption band to longer wavelengths) at moderate solvent polarities.

Artificial Intelligence and Virtual Reality in Headache Disorder Diagnosis, Classification, and Management.

PURPOSE OF REVIEW: This review provides an overview of the current and future role of artificial intelligence (AI) and virtual reality (VR) in addressing the complexities inherent to the diagnosis, classification, and management of headache disorders. RECENT FINDINGS: Through machine learning and natural language processing approaches, AI offers unprecedented opportunities to identify patterns within complex and voluminous datasets, including brain imaging data. This technology has demonstrated promise in optimizing diagnostic approaches to headache disorders and automating their classification, an attribute particularly beneficial for non-specialist providers. Furthermore, AI can enhance headache disorder management by enabling the forecasting of acute events of interest, such as migraine headaches or medication overuse, and by guiding treatment selection based on insights from predictive modeling. Additionally, AI may facilitate the streamlining of treatment efficacy monitoring and enable the automation of real-time treatment parameter adjustments. VR technology, on the other hand, offers controllable and immersive experiences, thus providing a unique avenue for the investigation of the sensory-perceptual symptomatology associated with certain headache disorders. Moreover, recent studies suggest that VR, combined with biofeedback, may serve as a viable adjunct to conventional treatment. Addressing challenges to the widespread adoption of AI and VR in headache medicine, including reimbursement policies and data privacy concerns, mandates collaborative efforts from stakeholders to enable the equitable, safe, and effective utilization of these technologies in advancing headache disorder care. This review highlights the potential of AI and VR to support precise diagnostics, automate classification, and enhance management strategies for headache disorders.

Four Decades of Occipital Nerve Stimulation for Headache Disorders: A Systematic Review.

PURPOSE OF REVIEW: Chronic headaches are a significant source of disability worldwide. Despite the development of conventional strategies, a subset of patients remain refractory and/or experience side effects following these treatments. Hence, occipital nerve stimulation (ONS) should be considered as an alternative strategy for intractable chronic headaches. This review aims to provide a comprehensive overview of the effectiveness, safety, mechanisms and practical application of ONS for the treatment of headache disorders. RECENT FINDINGS: Overall response rate of ONS is 35.7-100%, 17-100%, and 63-100% in patients with cluster headache, chronic migraine and occipital neuralgia respectively. Regarding the long-term effectivity in all groups, 41.6-88.0% of patients remain responders after ≥ 18.3 months. The most frequently reported adverse events include lead migration/fracture (13%) and local pain (7.3%). Based on our results, ONS can be considered a safe and effective treatment for chronic intractable headache disorders. To support more widespread application of ONS, additional research with larger sample sizes should be conducted.

Pain Scales: What Are They and What Do They Mean.

PURPOSE OF REVIEW: It is essential to have validated and reliable pain measurement tools that cover a wide range of areas and are tailored to individual patients to ensure effective pain management. The main objective of this review is to provide comprehensive information on commonly used pain scales and questionnaires, including their usefulness, intended purpose, applicability to different patient populations, and associated advantages and disadvantages. RECENT FINDINGS: Acute pain questionnaires typically focus on measuring the severity of pain and the extent of relief achieved through interventions. Chronic pain questionnaires evaluate additional aspects such as pain-related functional limitations, psychological distress, and psychological well-being. The selection of an appropriate pain scale depends on the specific assessment objectives. Additionally, each pain scale has its strengths and limitations. Understanding the differences among these pain scales is essential for selecting the most appropriate tool tailored to individual patient needs in different settings. CONCLUSION: Medical professionals encounter challenges in accurately assessing pain. Physicians must be familiar with the different pain scales and their applicability to specific patient population.

Educational initiatives in headache medicine: A 20-year scoping review.

BACKGROUND: Headache disorders are among the most common and disabling medical conditions worldwide, have a great societal impact and are a common reason to seek medical care. Headache disorders are often misdiagnosed and undertreated, and the number of headache fellowship-trained physicians cannot meet patient demand. Educational initiatives for non-headache-specialist clinicians may be an avenue to increase clinician competency and patient access to appropriate management. OBJECTIVE: To undertake a scoping review of the educational initiatives in headache medicine for medical students, trainees, general practitioners/primary care physicians, and neurologists. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for scoping reviews, an author (M.D.), with the help of a medical librarian, conducted a search of the Embase, Ovid Medline, and PsychInfo databases for articles related to medical educational initiatives on headache medicine in medical students, residents, and physicians over the last 20 years. RESULTS: A total of 17 articles met the inclusion criteria for this scoping review. Six articles were identified for medical students, seven for general practitioners/primary care physicians, one for emergency medicine residents, two for neurology residents, and one for neurologists. Certain educational initiatives were headache-focused while others had headaches as one of the educational topics. Educational content was delivered and assessed via diverse and innovative means, such as flipped classroom, simulation, theatrical performance, repeated quizzing and study, and a formalized headache elective. CONCLUSION: Education initiatives in headache medicine are important to improve competency and patient access to appropriate management of various headache disorders. Future research should focus on using innovative and evidence-based methods of content delivery, knowledge, and procedural assessment, and evaluating changes in practice behaviors.

Computational Quantification of the Zwitterionic/Quinoid Ratio of Phenolate Dyes for Their Solvatochromic Prediction.

Solvatochromic dyes are utilized in various chemical and biological media as chemical sensors. Unfortunately, there is no simple way to predict the type of solvatochromism based on the structure of the dye alone, which restricts their design and synthesis. The most important family of solvatochromic sensors, pyridinium phenolate dyes, has the strongest solvatochromism. Using a natural population analysis (NPA) of the natural bond orbitals (NBO) of the phenolate group in the frontier molecular orbitals, it is possible to calculate the relative polarity of the ground state and excited state and, thus to develop a model that can predict the three types of solvatochromism observed for this family: negative, positive, and inverted. This methodology has been applied to thirteen representative examples from the literature. Our results demonstrate that the difference in the electron density of the phenolate moiety in the frontier molecular orbitals is a simple and inexpensive theoretical indicator for calculating the relative polarity of the ground and excited states of a representative library of pyridinium phenolate sensors, and thus predicting their solvatochromism. Comparing the results with the bond length alternation (BLA) and bond order alternation (BOA) indices showed that the NPA/NBO method is a better way to predict solvatochromic behavior.

Stroke-Like Migraine Attacks After Radiation Therapy (SMART) Syndrome: A Comprehensive Review.

PURPOSE OF REVIEW: SMART syndrome is a delayed complication of cranial irradiation that can be misconstrued as tumor recurrence or some other intracranial neurological disease. Recognition of this clinical syndrome is imperative as it can obviate the need for invasive diagnostic testing and can provide reassurance to both the patient and their loved ones. RECENT FINDINGS: SMART syndrome is generally considered a reversible clinical syndrome; however, neurological deficits may become permanent. Pathophysiology of SMART syndrome may involve cerebrovascular autoregulation impairment, neuronal dysfunction leading to trigeminovascular system impairment and/or cortical spreading depression, and seizures. In addition to MRI brain with gadolinium, other imaging modalities, such as CT perfusion, MR perfusion, MR spectroscopy, and FDG PET/CT, aid in arriving to the diagnosis sooner. Patients should also undergo electroencephalogram in order to promptly identify and treat seizures. There are currently no clear guidelines on how to effectively treat SMART syndrome, but treatment may involve anti-seizure medication, anti-hypertensives, anti-platelet, and steroid therapy. This review provides a comprehensive understanding of the clinical characteristics of SMART syndrome from presentation to diagnostic evaluation. We also discuss radiographic features and treatment strategies for this rare disease. With increased radiotherapy utilization, prompt clinical recognition of SMART syndrome and further development of a comprehensive diagnostic approach to SMART syndrome utilizing newer radiographic modalities as well as treatment algorithms to effectively treat this clinical condition will be imperative.

The Future of the Lecture in Neurology Education.

The lecture has been a core pedagogical method since the early days of formal medical education. Although approaches to formal lectures have evolved over the years, there has been ongoing debate about the role that lectures should play in modern medical education. Arguably, traditional lectures do not align well with modern learning theory, and do not take full advantage of our current knowledge of how people learn. In many modern medical curricula, lectures have been replaced by self-study activities, including video-based lectures, computer-based learning modules, and other self-directed learning. We argue that scheduled "together time" is still important, particularly in neurology education, where there is a strong emphasis on clinical reasoning. We outline alternative teaching methods that effectively use this time, including the flipped classroom, just-in-time teaching, problem-based learning, and team-based learning. We discuss ways in which these approaches may be particularly conducive to components of neurology education.

A computationally-derived model for the solvatochromism of p-phenolates with high predictive power.

We report that the positive, reverse or negative solvatochromism of p-phenolate-based dyes is highly correlated with the multireferential (MR) character of their ground-state wave function, with negative compounds presenting the highest degeneracy. CASSCF/NEVPT2 calculations show that the high MR character of the wave-function in negative dyes allows those systems to increase the dipole moment of the ground state by breaking the degeneracy as a response to the field of a polar solvent. The resulting stabilization of the ground-state with increasing solvent polarity leads to the observed negative solvatochromic behavior. A computational indicator based on our results has been successfully used for determining the direction of the solvatochromic shift of 24 dyes. Thus, our work sheds light on the physical-chemical basis for solvatochromism while providing experimental chemists with a practical tool for the design of novel negative, positive or reverse solvatochromic dyes.

The Flögel-three-component reaction with dicarboxylic acids - an approach to bis(ß-alkoxy-ß-ketoenamides) for the synthesis of complex pyridine and pyrimidine derivatives.

An extension of the substrate scope of the Flögel-three-component reaction of lithiated alkoxyallenes, nitriles and carboxylic acids is presented. The use of dicarboxylic acids allowed the preparation of symmetrical bis(ß-ketoenamides) from simple starting materials in moderate yields. Cyclocondensations of these enamides to 4-hydroxypyridine derivatives or to functionalized pyrimidines efficiently provided symmetrically and unsymmetrically substituted fairly complex (hetero)aromatic compounds containing up to six conjugated aryl and hetaryl groups. In addition, subsequent functionalizations of the obtained heterocycles by palladium-catalyzed couplings or by oxidations are reported. We also describe the simple synthesis of a structurally interesting macrocyclic bispyrimidine derivative incorporating a 17-membered ring, whose configuration was elucidated by DFT calculations and by subsequent reactions.

Bartender: Martini 3 Bonded Terms via Quantum Mechanics-Based Molecular Dynamics.

Coarse-grained (CG) molecular dynamics (MD) simulations have grown in applicability over the years. The recently released version of the Martini CG force field (Martini 3) has been successfully applied to simulate many processes, including protein-ligand binding. However, the current ligand parametrization scheme is manual and requires an a priori reference all-atom (AA) simulation for benchmarking. For systems with suboptimal AA parameters, which are often unknown, this translates into a CG model that does not reproduce the true dynamical behavior of the underlying molecule. Here, we present Bartender, a quantum mechanics (QM)/MD-based parametrization tool written in Go. Bartender harnesses the power of QM simulations and produces reasonable bonded terms for Martini 3 CG models of small molecules in an efficient and user-friendly manner. For small, ring-like molecules, Bartender generates models whose properties are indistinguishable from the human-made models. For more complex, drug-like ligands, it is able to fit functional forms beyond simple harmonic dihedrals and thus better captures their dynamical behavior. Bartender has the power to both increase the efficiency and the accuracy of Martini 3-based high-throughput applications by producing numerically stable and physically realistic CG models.

Governing the emissive properties of 4-aminobiphenyl-2-pyrimidine push-pull systems via the restricted torsion of N,N-disubstituted amino groups.

Donor-acceptor-substituted biphenyl derivatives are particularly interesting model compounds, which exhibit intramolecular charge transfer because of the extent of charge transfer between both substituents. The connection of a 4-[1,1'-biphenyl]-4-yl-2-pyrimidinyl) moiety to differently disubstituted amino groups at the biphenyl terminal can offer push-pull compounds with distinctive photophysical properties. Herein, we report a comprehensive study of the influence of the torsion angle of the disubstituted amino group on the emissive properties of two pull-push systems: 4-[4-(4-N,N-dimethylaminophenyl)phenyl]-2,6-diphenylpyrimidine (D1) and 4-[4-(4-N,N-diphenylaminophenyl)phenyl]-2,6-diphenylpyrimidine (D2). The torsion angle of the disubstituted amino group, either N,N-dimethyl-amine or N,N-diphenyl-amine, at the biphenyl end governs their emissive properties. A drastic fluorescence quenching occurs in D1 as the solvent polarity increases, whereas D2 maintains its emission independently of the solvent polarity. Theoretical calculations on D1 support the presence of a twisted geometry for the lowest energy, charge-transfer excited state (S1,90), which corresponds to the minimum energy structure in polar solvents and presents a small energy barrier to move from the excited to the ground state, thereby favoring the non-radiative pathway and reducing the fluorescence efficiency. In contrast, this twisted structure is absent in D2 due to the steric hindrance of the phenyl groups attached to the amine group, making the non-radiative decay less favorable. Our findings provide insights into the crucial role of the substituent in the donor moiety of donor-acceptor systems on both the singlet excited state and the intramolecular charge-transfer process.

On the physical-chemical nature of solvent polarizability and dipolarity.

The positive solvatochromism of three dyes, with a spectral behavior strongly dependents on the medium dipolarity/polarizability, was studied theoretically. Both a polarizable continuum-solvent model (CSM) and explicit solvent molecules were employed to model solvent effects. The CSM approach, coupled with ten different TDDFT methods, yielded unsatisfactory results in eleven solvents. The explicit-solvation calculations, thought of much higher computational cost, yielded excellent results. As CSM schemes are known correctly model non-specific electrostatic effects, our results indicate that the traditionally considered non-specific nature of solvent dipolarity needs to be reconsidered, requiring the explicit consideration of the solute-solvent interactions for their accurate theoretical description.

Education Research: Online Alzheimer education for high school and college students: A randomized controlled trial.

OBJECTIVE: Alzheimer disease (AD) risk factors are present throughout the lifespan. This randomized controlled trial evaluated the effectiveness of various online education strategies concerning AD risk reduction and brain health in younger populations. METHOD: High school and college students were recruited via social media (Facebook and Instagram) to join AlzU.org, an evidence-based education portal, and were randomized to 1 of 4 courses: highly interactive webinar lessons narrated by actor Seth Rogen (celebrity webinar) or a physician (doctor webinar), minimally interactive video lessons with Seth Rogen (celebrity video), or minimally interactive video lessons (control). Surveys were administered at baseline and postcourse. The primary outcome was change in knowledge of AD risk reduction assessed by pre vs post lesson quiz scores. Secondary outcomes included change in awareness of AD research, hopefulness about AD, interest in pursuing health care, willingness to volunteer, and likelihood of recommending AlzU.org. RESULT: A total of 721 participants joined. A total of 281 (38.9%) completed the course. Among college students, quiz score improvements were greater in celebrity webinar and celebrity video vs doctor webinar and control. Among high school students, no differences were found in quiz scores. In both groups, celebrity webinar, celebrity video, and doctor webinar resulted in greater improvements in awareness that nutrition and exercise may reduce AD risk vs controls. Among college students, celebrity webinar and celebrity video group participants felt more hopeful about the future of AD and more likely to recommend AlzU.org vs doctor webinar and control participants. Among college students, celebrity webinar, celebrity video, and doctor webinar participants were more willing to volunteer for AD causes and pursue health care careers vs controls. CONCLUSION: Online education involving a celebrity may be an effective strategy for educating college students about AD risk reduction strategies. Further studies are warranted in high school students.

Insights into the halochromism of a bithiophene π* probe.

The positive halochromism of the solvatochromic 4-nitro-4'-(N,N-dimethylamino)-2,2'-bithiophene in acetone and 1-butanol was investigated by molecular dynamics simulations and quantum mechanics calculations. Interactions of the dye with the solvated sodium cation were found to have only a minor effect on the observed halochromism, which was ultimately ascribed to a predominant interaction between iodide anions and the N,N-dimethylamino group of the dye.

A benchmark for the size of the QM system required for accurate hybrid QM/MM calculations on the metal site of the protein copper, zinc superoxide dismutase.

The protein superoxide dismutase 1 (SOD1) is a copper and zinc-binding protein that has been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). The Zn(II) binding to SOD1 is critical for the stability of the protein, and has been by itself implicated in ALS pathogenesis. Hence, the quantum mechanical (QM) study of the Zn(II)-site of SOD1 is relevant for understanding ALS. The hybrid QM-molecular mechanics (QM/MM) approach commonly employed for the QM study of proteins is highly dependent on the size of the sub-system treated quantum-mechanically. The size of the QM system also determines the computational feasibility of a given method. In the present work, we compare optimized geometries for the metal site and Zn(II) dissociation energies obtained with a QM/MM methodology employing different sizes for the QM sub-system. We find that geometries converge rapidly to RMSDs of around 0.3 Å, and fails to converge further, while a QM system of 480 atoms was required for converging the Zn(II) interaction energy of SOD1 to within 5 kcal*mol-1, and a 611-atoms QM system for a 1 kcal*mol-1 convergence with respect to our reference, 1280 QM-atoms system. Graphical Abstract The size of the QM system is critical for both the accuracy and the computational cost of a QM/MM calculation. We have identified a optimum balance for the study of the active site of the coppper, zinc superoxide dismutase.

The Solvatofluorochromism of 2,4,6-Triarylpyrimidine Derivatives.

Seven new 2,4,6-triarylpyrimidines were synthesized and their solvatofluorochromism investigated in 12 solvents and in an aqueous micellar solution of reduced Triton X-100. A multiparametric analysis of their emission band showed that the solvent dipolarity and basicity were mainly responsible for their solvatofluorochromism, which arose from an internal charge-transfer from a donor fragment to the pyrimidine acceptor, confirmed by theoretical calculations. In the micellar system, quenching of their fluorescence by addition of derivatives of 2,2,6,6-tetramethylpiperidinoxyl (TEMPO) radical was investigated and the results were consistent with the spectral changes brought about by the micro-heterogeneous system.

A Neurology Clerkship Curriculum Using Video-Based Lectures and Just-in-Time Teaching (JiTT).

Introduction: Just-in-time teaching is an educational strategy that involves tailoring in-session learning activities based on student performance in presession assessments. We implemented this strategy in a third-year neurology clerkship. Methods: Linked to core neurology clerkship lectures, eight brief video-based lectures and knowledge assessments were developed. Students watched videos and completed multiple-choice questions, and results were provided to faculty, who were given the opportunity to adjust the in-person lecture accordingly. Feedback was obtained by surveys of students and faculty lecturers and from student focus groups and faculty. Student performance on the end-of-clerkship examination was analyzed. Results: Between October 2016 and April 2017, 135 students participated in the curriculum, and 56 students (41.5%) responded to the surveys. Most students agreed or strongly agreed that the new curriculum enhanced their learning and promoted their sense of responsibility in learning the content. Faculty agreed that this pedagogy helped prepare students for class. Most students watched the entire video-based lecture, although there was a trend toward decreased audience retention with longer lectures. There were no significant changes in performance on the end-of-clerkship examination after implementation of just-in-time teaching. In focus groups, students emphasized the importance of tying just-in-time teaching activities to the lecture and providing video-based lectures well in advance of the lectures. Discussion: Just-in-time teaching using video-based lectures is an acceptable and feasible method to augment learning during a neurology clinical clerkship. We believe this method could be used in other neurology clerkships with similar success.

A Video-Based Introductory EEG Curriculum for Neurology Residents and Other EEG Learners.

INTRODUCTION: It is difficult to provide standardized formal education in EEG because of time limitations and the availability of expert teachers. Video-based miniature lectures are a useful way to standardize the foundational principles of EEG and support learning during EEG/epilepsy rotations. METHODS: A curriculum of 10 EEG teaching videos was developed based on concepts outlined in the Accreditation Council for Graduate Medical Education Neurology Milestones. The videos were short (6-17 minutes) and made available to residents rotating through an EEG/epilepsy rotation in two neurology residency programs. Residents were instructed to review the videos and then apply their newly learned skills during EEG reading sessions. A survey about the process was completed at the end of the year. RESULTS: Twenty-one residents participated in the curriculum, and 15 (71%) responded to the survey. Two-thirds of respondents (10/15) said that they watched all of the videos, and 87% (13/15) watched at least half of the videos. All of the respondents used the videos as introductions to EEG concepts, and approximately half of respondents returned to the videos as a refresher after the rotation was over. Nearly all respondents either agreed or strongly agreed that the curriculum was a useful component of the rotation and helped them to understand difficult concepts. All strongly agreed that they would recommend the curriculum to other residents. DISCUSSION: A video-based approach to EEG teaching could complement existing curricula and ensure that learners have access to foundational miniature lectures when and where they need them.