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In this study, a library of phthalimide Schiff base linked to 1,4-disubstituted-1,2,3-triazoles was designed, synthesised, and characterised by different spectral analyses. All analogues have been introduced for in vitro assay of their antiviral activity against COVID-19 virus using Vero cell as incubator with different concentrations. The data revealed most of these derivatives showed potent cellular anti-COVID-19 activity and prevent viral growth by more than 90% at two different concentrations with no or weak cytotoxic effect on Vero cells. Furthermore, in vitro assay was done against this enzyme for all analogues and the results showed two of them have IC50 data by 90 µM inhibitory activity. An extensive molecular docking simulation was run to analyse their antiviral mechanism that found the proper non-covalent interaction within the Mpro protease enzyme. Finally, we profiled two reversible inhibitors, COOH and F substituted analogues that might be promising drug candidates for further development have been discovered.

Twelve novel chalcones were synthesized using 2-alkyloxy-naphthaldehydes and Mannich bases of 4-hydroxyacetophenone. The chalcones were characterized using FTIR, 1D and 2D NMR and HRMS spectroscopy. Comparative docking analysis was carried out to screen their affinity towards the AChE enzyme (PDB 1EVE). All chalcones showed lower binding energy (−13.06 to −10.43 kcal/mol) against AChE better than donepezil (−10.52 kcal/mol). All chalcones were potent inhibitors towards AChE, with IC50 values ranging between 0.11 and 5.34 nM better than donepezil (IC50 33.4 nM) and selectivity indexes (0.66–23.83), despite the fact that chalcones 10 and 13 were inactive. The structure activity relationship indicated that introducing diethyl amine in ring A of the chalcone skeleton and the propargyl moiety at ring B was affirmed to be a prospective drug against AChE. The multifunctional properties of chalcone 15 were all advantages that demonstrate an excellent candidate for the development of an effective drug against AChE.

An efficient microwave-assisted one-step synthetic route toward Mannich bases is developed from 4-hydroxyacetophenone and different secondary amines in quantitative yields, via a regioselective substitution reaction. The reaction takes a short time and is non-catalyzed and reproducible on a gram scale. The environmentally benign methodology provides a novel alternative, to the conventional methodologies, for the synthesis of mono- and disubstituted Mannich bases of 4-hydroxyacetophenone. All compounds were well-characterized by FT-IR, 1H NMR, 13C NMR, and mass spectrometry. The structures of 1-{4-hydroxy-3-[(morpholin-4-yl)methyl]phenyl}ethan-1-one (2a) and 1-{4-hydroxy-3-[(pyrrolidin-1-yl)methyl]phenyl}ethan-1-one (3a) were determined by single crystal X-ray crystallography. Compound 2a and 3a crystallize in monoclinic, P21/n, and orthorhombic, Pbca, respectively. The most characteristic features of the molecular structure of 2a is that the morpholine fragment adopts a chair conformation with strong intramolecular hydrogen bonding. Compound 3a exhibits intermolecular hydrogen bonding, too. Furthermore, the computed Hirshfeld surface analysis confirms H-bonds and π⁻π stack interactions obtained by XRD packing analyses.

The syntheses of a novel 1,4,8,11,15,18,22,25-octahexyloxy-2,3,9,10,16,17,23,24-octa-(4-trifluoromethoxyphenyl) phthalocyanine (3a) and its zinc(II) phthalocyanine derivative (3b) have been described and characterized by elemental analysis,1H NMR, 13C NMR, 19F NMR, mass, UV-Vis and FT-IR. The newly prepared metal-free phthalocyanine and its zinc(II) counterpart are soluble in most organic solvents. The photophysical and photochemical properties such as aggregation, fluorescence, singlet oxygen generation and photodegradation under light irradiation of these phthalocyanines have been investigated in DMF. The hexadeca-substituted phthalocyanines (3a and 3b) showed longer absorption and emission wavelength values when compared to that of reported phthalocyanine derivatives due to substitution of the all possible positions in the phthalocyanine framework. The zinc(II) phthalocyanine derivative does not only have a good singlet oxygen generation but also has other photophysicochemical properties that enables this phthalocyanine to be useful as a photosensitizer for cancer treatment using photodynamic therapy.

Background: Previous studies have been conducted to assess pneumothorax. However, few studies were done to assess pneumothorax in COVID-19 patients in the intensive care unit (ICU). Objective: Our aim is to describe and analyze the prevalence, clinical characteristics, risk factors, and outcomes of COVID-19 pneumothorax patients in the intensive care unit. Methods: We performed a retrospective review of the medical records of 418 patients, who tested positive for COVID-19 by polymerase chain reaction test and required ICU admission in King Fahad Hospital of The University from 02/01/2020 to 01/09/2021. A total number of 36 pneumothorax patients were included in the study. Results: Of 418 patients who were followed up in the intensive care unit as COVID-19 cases, 36 patients developed a pneumothorax (8.61%). The mean age of the patients was 55.6 ± 15.06 years, 23 patients were male, and 13 were female. Seventeen patients were obese, and only one patient was an active smoker. Twenty-four patients had at least one comorbidity; hypertension was the most common. Thirty-two patients were intubated, and the duration of intubation was 23.23 ± 15.9 days. The time from intubation to pneumothorax development was 8.8 ± 9.3 days. Six patients were on bilevel positive airway pressure ventilation (BIPAP), 2 patients on continuous positive airway pressure ventilation (CPAP), 3 patients on High-Flow Nasal Cannula ventilation (HFNC), 9 patients on pressure-control ventilation (PC), and 16 patients on pressure regulated volume control ventilation (PRVC). Of 36 patients, 26 died, and the mortality rate was 72.2%. Conclusion: Our study showed that risk factors of pneumothorax occurrence in COVID-19 critically ill patients include male patients, hypertension, diabetes mellitus, endotracheal intubation and mechanical ventilation. More efforts should be made to determine the risk factors and assess the outcomes of those patients to develop preventive measures and management guidelines. [ABSTRACT FROM AUTHOR]

In this current study, the novel bis[4,5-(pyrene-2-yl)-3,6-(hexyloxy)] phthalonitrile (SPN) fluorophore has been successfully synthesized. Structural characterization of this novel compound was performed by different spectroscopic methods such as FT-IR, MALDI-TOF, 1H-NMR, 13C-NMR and elemental analyses as well. In addition, the photophysical properties were determined using UV–vis absorption, steady-state fluorescence, time-resolved fluorescence spectroscopic methods and quantum chemical calculations. The metal sensing behavior of the SPN was determined in the presence of various metals (Li+, Na+, K+, Mg2+, Ca2+, Ba2+, Mn2+, Fe3+, Cr3+, Co2+, Ni2+, Ag+, Cd2+, Al3+, Hg+ and Zn2+) using fluorescence spectroscopy. The novel pyrene based phthalonitrile (SPN) showed high sensitivity and selectivity towards Fe3+ ion over other examined metal ions. In order to perform the determination of Fe3+ ion in environmental samples, experimental conditions such as selectivity, stability, precision, sensitivity, accuracy and recovery were optimized. Also, the complex stoichiometry of the novel pyrene based phthalonitrile (SPN) and Fe3+ ions was determined by a Job's plot. The compound was also studied via density functional theory calculations revealing the interaction mechanism of the molecule with Fe3+ ions. [ABSTRACT FROM AUTHOR]

aimoni,1 Latifah I AlMusailet,1 Shaya Y AlQahtani,2 Mohammed S Alshahrani31College of Medicine, Imam Abdulrahman bin Faisal University, Dammam, Eastern Province, Saudi Arabia; 2Department of Internal Medicine and Critical Care Medicine, King Fahd Hospital of the University, Imam Abdulrahman bin Faisal University, Khobar, Eastern Province, Saudi Arabia; 3Emergency and Critical Care Departments, King Fahd Hospital of the University, Imam Abdulrahman bin Faisal University, Khobar, Eastern Province, Saudi ArabiaCorrespondence: Mohammed S Alshahrani, Emergency and Critical Care Departments, King Fahd Hospital of the University, Imam Abdulrahman bin Faisal University, Khobar, Eastern Province, 34219, Saudi Arabia, Tel +966556966663, Fax +966138966770, Email [email protected] Purpose: Secondary infections have been observed among coronavirus disease 2019 (COVID-19) patients, especially in the intensive care unit (ICU) setting, which is associated with worse clinical outcomes. The current study aimed to investigate the incidence, common pathogens, and outcome of bacterial and fungal secondary infections among ICU patients with COVID-19. Methods: A retrospective chart review of all patients admitted to the ICU at King Fahd Hospital of the University in Saudi Arabia. All adult patients aged ≥ 18 admitted in the ICU for ≥ 48 hours with positive COVID-19 reverse transcription-polymerase chain reaction test during the period between March 2020 till September 2021 were included. Results: Out of 314 critically ill patients, 133 (42.4%) developed secondary infections. The incidence of secondary bacterial infection was 32.5% with Pseudomonas aeruginosa (n = 34), Acinetobacter baumannii (n = 33), and Klebsiella pneumoniae (n = 17) being the predominant pathogens, while secondary fungal infection was 25.2% mainly caused by Candida albicans (n = 43). Invasive mechanical ventilation was significantly associated with the development of secondary bacterial infections (odds ratio [OR] = 17.702, 95% confidence interval [CI] 7.842– 39.961, p < 0.001) and secondary fungal infections (OR = 12.914, 95% CI 5.406– 30.849, p < 0.001). Mortality among patients with secondary infections was 69.2% (n = 92). Secondary infections were associated with longer hospital and ICU stays with a median of 25 days (interquartile range [IQR] 17– 42) and 19 days (IQR 13– 32), respectively. Conclusion: Bacterial and fungal secondary infections are common among COVID-19 patients admitted to the ICU with a predominance of gram-negative bacteria and Candida species. The development of secondary infections was significantly associated with invasive mechanical ventilation. Poor clinical outcomes have been observed, demonstrated with a prolonged hospital and ICU stays and higher mortality. [ABSTRACT FROM AUTHOR]

Twelve novel chalcones were synthesized using 2-alkyloxy-naphthaldehydes and Mannich bases of 4-hydroxyacetophenone. The chalcones were characterized using FTIR, 1D and 2D NMR and HRMS spectroscopy. Comparative docking analysis was carried out to screen their affinity towards the AChE enzyme (PDB 1EVE). All chalcones showed lower binding energy (−13.06 to −10.43 kcal/mol) against AChE better than donepezil (−10.52 kcal/mol). All chalcones were potent inhibitors towards AChE, with IC50 values ranging between 0.11 and 5.34 nM better than donepezil (IC50 33.4 nM) and selectivity indexes (0.66–23.83), despite the fact that chalcones 10 and 13 were inactive. The structure activity relationship indicated that introducing diethyl amine in ring A of the chalcone skeleton and the propargyl moiety at ring B was affirmed to be a prospective drug against AChE. The multifunctional properties of chalcone 15 were all advantages that demonstrate an excellent candidate for the development of an effective drug against AChE. [ABSTRACT FROM AUTHOR]

This article is focused on the design and photophysical properties of a series of novel porphyrin and metalloporphyrin dendrimers containing cationic η6-chloroarene-η5-cyclopentadienyliron(II) complexes functionalized with naphthalene and capped with ferrocene. The incorporation of cationic η6-chloroarene-η5-cyclopentadienyliron moieties into the dendrimer structures enhances solubility, and facilitates nucleophilic aromatic substitution and addition reactions due to the intense electron-withdrawing ability of the iron center. Divergent approaches were employed to yield highly symmetrical branched materials, with interesting and potentially useful properties. The preparation of these dendrimers was achieved via metal-mediated nucleophilic aromatic substitutions and Steglich esterifications. These dendrimers and their precursors were characterized through nuclear magnetic resonance spectroscopy, infrared spectroscopy, and UV-Visible and fluorescence spectroscopy. Substitution on the porphyrin core with various side chains and terminal functional groups and chromophores had little impact on the porphyrin emission properties, allowing for a wide variety of fluorescent macromolecules to be prepared which retain this characteristic emission. Also, the presence or absence of the organopyrene moieties also had little effect on the emission from these compounds. Complexation of a metal cation, such as Zn2+, by these compounds, did however result in a significant blue shift in the observed fluorescence; this interesting result has the potential for applications in the development of fluorescent-based cation sensors. [ABSTRACT FROM AUTHOR]

In this study, the novel 4-( N,N′ -dimethylamino)phenyl substituted lutetium(III) acetate phthalocyanine ( 2 ) and its quaternized derivative ( 3 ) were synthesized via a Suzuki-Miyaura coupling reaction between tetrakis(iodo) lutetium(III)acetate phthalocyanine ( 1 ) and 4-( N,N -dimethylamino)phenylboronic acid, and subsequent quaternization using dimethyl sulfate, respectively. The obtained phthalocyanine 3 exhibited excellent solubility in water which is important for photodynamic therapy applications. Photophysical properties such as fluorescence quantum yield and fluorescence lifetime, and photochemical properties such as singlet oxygen generation and photostability were investigated to determine their suitability for photodynamic therapy. The lutetium(III) phthalocyanines, especially quaternized derivative 3 , showed promising properties as potential photosensitizers for the treatment of cancer, producing higher singlet oxygen (Φ Δ = 0.59) than motexafin lutetium (Φ Δ = 0.31) which is a clinically used lutetium texaphyrin photosensitizer. [ABSTRACT FROM AUTHOR]

Background: Subarachnoid hemorrhage is one of high morbidity in vascular neurology and neurosurgery and one of the clipart for this is symptomatic vasospasm that can leads to delayed cerebral ischemia. Other common complication is electrolytes and fluid homeostasis disturbance and among these, is Sodium disequilibrium, either hypo- or hypernatremia. In our institution we observed that hyponatremia is common, and it is more evident in patient with symptomatic vasospasm. For that we retrospectively looked at the association of hyponatremia and the occurrence of symptomatic vasospasm or delayed cerebral ischemia in aSAH. Methods: Retrospective chart review with daily monitoring of sodium level from day 1to day 21 from the ictus, aSAH. We include all adult patients (Age > 18 years) who were admitted to intensive care with diagnosis of aSAH and undergone aneurysm securing procedures within 48 h. Results: Among 45 patients 24 (43%) developed symptomatic vasospasm and delayed cerebral ischemia and it was most common in males (13/22: 59%). Sodium level especially hyponatremia in period between days (1–4) with median of 134 in vasospasm group (50%). Conclusions: Delayed cerebral ischemia/symptomatic vasospasm occurs more commonly in males and associated with hyponatremia (Na+

Breast cancer is common among females worldwide and is most commonly reported in women aged 30–40 years and less commonly in those aged

Photochromic dihydroindolizines (DHIs) 4a,5-dihydropyrrolo[1,2-b]pyridazine based tripodal-linker systems with adamantane core and ethyl benzoate tripods as anchoring groups have been successfully synthesized. In addition, new spirocyclopropene precursors have been prepared through both chemical and photochemical processes. The photochromic properties of the newly synthesized DHIs derivatives have been optimized and fine-tuned by the incorporation of various substituents on the fluorene (region A) and pyridazine (region C) moieties. Several alternative routes for the synthesis of the DHIs under investigation have been established. The Sonogashira crosscoupling reaction was utilized for fragment coupling between DHIs and the phenylacetylene tether of the adamantane core. Several reaction conditions of this key reaction were surveyed to obtain optimal yields of a new series of coupling products targeted for anchoring to semiconductor nanoparticles. The chemical structures of the newly synthesized materials were elucidated by both analytical and spectroscopic tools. Irradiation of the photochromic DHIs with polychromatic light resulted in ring opened colored betaines which underwent cycloreversion reactions via thermal 1,5-electrocyclization processes. The kinetic of the thermal 1,5-electrocyclization was studied by using a UV/VIS/NIR spectrophotometer. The kinetic measurements showed the half-lives of the colored betaines to be in the second domain. A pronounced increase in the half-lives of betaines bearing dimethyl-substituted pyridazine was noted compared with non-substituted pyridazine betaines. A strong effect of solvent polarity on the λ and half-lives of the betaines was observed. The further adjustment of the absorption maxima and the kinetic properties via the manipulation of substituents on the fluorene (region A) and pyridazine moieties (region C) should yield more refined systems for application as supports onto metal-oxide surfaces which remains an active area of our ongoing research. Copyright © 2010 John Wiley & Sons, Ltd. Photochromic DHI-tripodal linker towards anchoring on the metal-oxide nanoparticles have been synthesized. Tuning of the photochromic behavior by structure changes was recorded. [ABSTRACT FROM AUTHOR]

Multi-addressable photophysical properties of new synthesized photochromic materials based on photochromic dihydroindolizine system (DHI) covalently linked to N-acyl-11 aminoundecanoic acid (AUDA) or to its sodium salt or to its ester, through an amidic or urethane linkage have been studied. The DHI skeleton in these compounds is substituted in both the fluorene part (region A) or in the heterocyclic base (region B) with the gelling moieties. These molecules have been designed to respond to their environment. Interestingly, they are shown to act as efficient gelators for polar organic fluids, water and obviously they exhibit a thermosensitive answer as low molecular mass organogelators. In these fluids, the aggregative properties are totally suppressed upon conversion to neutral carboxylic species. The gels of these carboxylate sodium salts are shown to be markedly affected by light irradiation. Supramolecular gelating assemblies can be disrupted by the photoinduced ring opening of the DHI subunit, so that the macroscopic flowing property is recovered. Upon a further thermal treatment, the system is reversibly converted back to the supramolecular network. Controlled gelation could be achieved using temperature, light, or acidity as external stimuli. These new synthesized photochromic gels with their multi-addressable properties will find their applications as super photoresponsive materials. Developing and tuning of the photophysical properties of the synthesized compounds by the amide and urethane substituents in the 4-position of the fluorene and pyridazine regions have been achieved. The absorption maxima (λmax) and the half-lives (t1/2) of the colored betaines were detected in all cases using UV/VIS spectrophotometric measurements. Irradiation of DHI 12-20 in CH2Cl2 or in acetonitrile solutions at ambient temperature with polychromatic light leads to the formation of red to red-violet colored betaines 12′-20′. The kinetics of the bleaching process of betaines 12′-20′ to DHIs 12-20 were found to take place in the second range (96-218 s) and fit well the first order thermal back reaction. Some of these DHIs showed a photostability higher than that of the standard one. These interesting photophysical properties will help this family of compounds to find useful applications. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The phase change in metal-free 1,4,8,11,15,18,22,25-octahexylphthalocyanine compound with eight non-peripheral hexyl chains was investigated under non-isothermal conditions by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Two endothermic changes were reported. The first one between 332 and 350 K relates to the transition from the hexagonal columnar mesophase to a less ordered crystalline phase, P1. The second endothermic transition from 408 to 417 K is due to the transition to the discotic columnar mesophase, P2. The isoconversional methods of Friedman, and Kissinger, Akahira and Sunose (KAS) were used to determine the variation of the activation energy for crystallisation with temperature, E α(T). Using the Friedman method the average values of E α(T) were 121.31 and 352.77 kJ mol-1 for the first and second peaks, respectively. The KAS method gave higher values of E α(T) with averages of 173.25 and 411.44 kJ mol-1, respectively. The specific heat was measured and found to vary with temperature. [ABSTRACT FROM AUTHOR]

Atrial fibrillation is a common cardiac arrhythmia worldwide. In patients with hyperthyroidism, atrial fibrillation is the most common comorbid cardiac condition. Here, the authors report a case of a 47-year-old female with no significant medical history who presented with heart failure symptoms. Further analysis confirmed atrial fibrillation with a dilated atria and severe mitral regurgitation. In addition, she was found to be hyperthyroid. Accordingly, electrical cardioversion treatment was initiated, and her hyperthyroidism was managed. This resulted in her normal sinus rhythm being restored and subsequently being maintained. A repeat echocardiography 6 months later showed resolution of mitral regurgitation, improvement of atrial size and normalization of the left ventricular systolic function. Therefore, based on this case report, the authors suggest that atrial remodeling and functional mitral regurgitation secondary to atrial dilatation can be reversed by restoring and maintaining the sinus rhythm.