Mechanically interlocked host systems for ion-pair recognition.

The ever-increasing interest directed towards the construction of host architectures capable of the strong and selective recognition of various ionic species of biological, medical and environmental importance has identified mechanically interlocked molecules (MIMs), such as rotaxanes and catenanes, as potent host systems, owing to their unique three-dimensional topologically preorganised cavity recognition environments. Ion-pair receptors are steadily gaining prominence over monotopic receptor analogues due to their enhanced binding strength and selectivity, demonstrated primarily through acyclic and macrocyclic heteroditopic host systems. Exploiting the mechanical bond for ion-pair recognition through the strategic design of neutral heteroditopic MIMs offers exciting opportunities to accomplish potent and effective binding while mitigating competing interactions from the bulk solvent and counter-ions.

Bis-Squaramide-Based [2]Rotaxane Hosts for Anion Recognition.

The first examples of bis-squaramide axle containing [2]rotaxanes linked via rigid aryl and flexible alkyl spacers synthesised using copper(I) catalysed active metal template methodology are reported. The halide and oxoanion binding properties of the [2]rotaxanes in aqueous-organic solvent media are examined through extensive H-NMR titration experiments to investigate the impact of integrating multiple squaramide motifs on the anion binding capabilities of the interlocked receptors. These studies reveal that the bis-squaramide rotaxane host systems exhibit enhanced halide anion binding capabilities relative to a mono-squaramide axle functionalised rotaxane, demonstrating a rare anti-Hofmeister bias halide anion selectivity trend in aqueous-organic mixtures and highlighting the efficacy of the potent solvent shielded hydrophobic interlocked binding pocket created upon mechanical bond formation.

Squaramide-Based Heteroditopic [2]Rotaxanes for Sodium Halide Ion-Pair Recognition.

A series of squaramide-based heteroditopic [2]rotaxanes consisting of isophthalamide macrocycle and squaramide axle components are synthesized using an alkali metal cation template-directed stoppering methodology. This work highlights the unprecedented sodium cation template coordination of the Lewis basic squaramide carbonyls for interlocked structure synthesis. Extensive quantitative H NMR spectroscopic anion and ion-pair recognition studies reveal the [2]rotaxane hosts are capable of cooperative sodium halide ion-pair mechanical bond axle-macrocycle component recognition, eliciting up to 20-fold enhancements in binding strengths for bromide and iodide, wherein the Lewis basic carbonyls and Lewis acidic NH hydrogen bond donors of the squaramide axle motif operate as cation and anion receptive sites simultaneously in an ambidentate fashion.

ABO Blood Group in Relation to COVID-19 Susceptibility and Clinical Outcomes: A Retrospective Observational Study in the United Arab Emirates.

(1) Background: The association between ABO blood groups and COVID-19 outcomes was investigated in several studies. The results were controversial. This study aimed to explore the association between ABO blood groups and COVID-19 outcomes.

The significance of antiglobulin (Coombs) test reactivity in patients with COVID-19.

Previous case reports have described patients with COVID-19-associated autoimmune hemolytic anemia (AIHA), and cold agglutinin disease (CAD) which is characterized by a positive direct antiglobulin (DAT) or "Coombs" test, yet the mechanism is not well understood. To investigate the significance of Coombs test reactivity among COVID-19 patients, we conducted a retrospective study on hospitalized COVID-19 patients treated at NMC Royal Hospital between 15 April and 30 May 2020. There were 27 (20%) patients in the Coombs-positive group and 108 (80%) in the Coombs-negative group.

Vitamin D Status in Relation to the Clinical Outcome of Hospitalized COVID-19 Patients.

Coronavirus Disease (COVID-19) is a newly emerged infectious disease that first appeared in China. Vitamin D is a steroid hormone with an anti-inflammatory protective role during viral infections, including SARS-CoV-2 infection, via regulating the innate and adaptive immune responses. The study aimed to investigate the correlation between serum 25-hydroxyvitamin D (25[OH]D) levels and clinical outcomes of COVID-19.

Treatment Outcomes of Tocilizumab in Critically-Ill COVID-19 Patients, Single-Centre Retrospective Study.

(1) Background: Severe COVID-19 outcomes are associated with cytokine release syndrome, characterized by the release of several immune modulators, including Interleukin-6 (IL-6). Tocilizumab (TCZ) is an IL-6 receptor antagonist used to treat rheumatic arthritis. The study aimed to evaluate the efficacy and safety of TCZ against COVID-19.

Reduced ADAMTS13 Activity in Correlation with Pathophysiology, Severity, and Outcome of COVID-19: A Retrospective Observational Study.

Background: Low ADAMTS13 activity has been suggested to be an interplaying factor in the pathogenesis of COVID-19, considering that it is a thromboinflammatory disease with high risk of microthrombosis.

Objectives: The study aimed to explore the correlation between ADAMTS13 activity and the pathophysiological pathway of COVID-19.

Methods: We carried out a retrospective observational study of 87 patients with COVID-19 in NMC Royal Hospital, Abu Dhabi, UAE.

Pharmaceutical evaluation and dynamic vapor sorption studies of fast dissolving intraoral films of Loratadine.

The aim of the study was to develop intraoral films (IOFs) of loratadine and to assess the storage conditions by dynamic vapour sorption studies. The excipient selection was guided by drug excipient compatibility studies and the incompatibility of loratadine with dibutylphathalate and Tween20 was confirmed by Electro-spray Ionization Mass Spectrometry. Thus intaroral films were developed using HPMC E-15 LV and polyvinyl alcohol (PVA) as lone and mixed film formers to get eighteen formulations (F1- F18) that varied in the type and amount of plasticizer used.