Photoswitchable nonlinear optical properties of azobenzene-based supramolecular complexes: insights from density functional theory.

Density functional theory (DFT) calculations were performed for a series of supramolecular assemblies containing azobenzene (Azo-X where X = I, Br and H) and alkoxystilbazole subunits to evaluate their electronic, linear and nonlinear optical properties. These assemblies are derivatives of azobenzene, obtained by the substitution of electron-withdrawing and electron-donating groups onto the molecular skeleton. The interaction energies (Eint) of all the designed supramolecular complexes (IA-IF, IIA-IIF and IIIA-IIIF) range from -1.0 kcal mol-1 to -7.7 kcal mol-1. The electronic properties of these hydrogen/halogen bond driven supramolecular assemblies such as vertical ionization energies (VIE), HOMO-LUMO energy gap (GH-L), excitation energies, density of states (DOS) and natural population (NPA) analyses were also computed. The non-covalent interaction index (NCI) and quantum theory of atoms in molecules (QTAIM) analyses were also performed to validate the nature of inter- and intra-molecular interactions in these complexes. A substantial enhancement in the first hyperpolarizability (ß0) values of the designed supramolecular complexes was observed, which is driven by the charge transfer from the pyridyl moiety of alkoxystilbazole to Azo-X. The highest ß0 value of 1.3 × 104 au was observed for the supramolecular complex of p-nitro substituted azobenzene with alkoxystilbazole (ID complex). Moreover, the results show that the substitution of electron-withdrawing groups on Azo-X can also bring larger ß0 values for such complexes. It was confirmed on a purely theoretical basis that both the types of noncovalent interactions present and the substituent group incorporated influence the nonlinear optical (NLO) response of the systems. Furthermore, the ß0 values of the E (trans) and Z (cis) forms were compared to demonstrate the two-way photoinduced switching mechanism.

A Case of acute Myocardial Infarction in a Patient with Essential Thrombocythaemia Treated with Anagrelide.

Anagrelide is a medication primarily used to manage thrombocytosis, an abnormal increase in platelet levels in the blood. It is often prescribed for patients with myeloproliferative disorders, such as essential thrombocythaemia (ET). Given the heightened susceptibility to thromboembolism associated with this condition, the primary emphasis in treatment revolves around reducing the risk of thrombotic events through the administration of cytotoxic agents. While anagrelide is generally effective in reducing platelet counts, it comes with potential side effects, including an increased risk of certain thrombotic events. Anagrelide acts by inhibiting megakaryocyte maturation and platelet release, thereby reducing platelet production. However, this platelet-lowering effect may be accompanied by an increase in platelet activation and reactivity, which could contribute to a prothrombotic state. We present a case of a 60-year-old female with a history of ET, managed with anagrelide and hydroxyurea therapy, who experienced an acute ST-elevation myocardial infarction. LEARNING POINTS: The dual role of anagrelide: although anagrelide is effective in lowering platelet levels in essential thrombocythaemia, it can increase platelet activation, raising thrombotic risk. Clinicians need to monitor patients closely for thrombotic events.Balancing efficacy and side effects: the risk of severe side effects such as myocardial infarction, as seen in this case report, necessitates a balanced approach in using anagrelide, weighing its benefits against potential risks.

Hantavirus-Induced Cardiac Tamponade: A Diagnostic Dilemma.

Herein we describe a case of a 60-year-old white male from New York City who was admitted to hospital due to worsening dyspnea. He presented with an acute onset of fever, night sweats, and progressively worsening non-productive cough and orthopnea over the preceding week. Electrocardiogram findings revealed atrial fibrillation. Manifesting signs of hypoperfusion, a trans-esophageal echocardiography was performed, which demonstrated the presence of a cardiac tamponade. An emergency pericardiocentesis was performed, draining 750 cc of serosanguinous content. Laboratory investigations depicted an inflammatory milieu marked by lymphocytic leukocytosis, cardiac function impairment, and remarkably elevated d-dimer and brain natriuretic peptide levels. Notably, high-sensitivity troponin T remained within normal limits. Comprehensive viral panel assays, including COVID-19, Influenza A+B, Respiratory Syncytial Virus, Hepatitis C, HIV, Cytomegalovirus, Coxsackie A+B, and Herpes Simplex Virus, returned negative results. Furthermore, anti-nuclear factor and rheumatoid factor titers were negative. Blood and fungal cultures, as well as assessments for Mycobacterium tuberculosis, yielded negative findings. On further history-taking, he reported that he had occupational exposure to rat droppings and urine two weeks ago. Serological analysis demonstrated positive hantavirus IgG and IgM antibodies. Supportive management was initiated. Consequently, the patient was discharged asymptomatic, without pericardial effusion. Evaluation after two weeks revealed no recurrence of symptoms.