The Photochemical Mediated Ring Contraction of 4H-1,2,6-Thiadiazines To Afford 1,2,5-Thiadiazol-3(2H)-one 1-Oxides.

1,2,6-Thiadiazines treated with visible light and 3O2 under ambient conditions are converted into difficult-to-access 1,2,5-thiadiazole 1-oxides (35 examples, yields of 39-100%). Experimental and theoretical studies reveal that 1,2,6-thiadiazines act as triplet photosensitizers that produce 1O2 and then undergo a chemoselective [3 + 2] cycloaddition to give an endoperoxide that ring contracts with selective carbon atom excision and complete atom economy. The reaction was optimized under both batch and continuous-flow conditions and is also efficient in green solvents.

Recovery Of Zinc from Scrap Steel Using Zinc-Bromine Battery Technology.

Secondary production of steel is known to significantly decrease the CO2 emissions of steelmaking, but only 40 % of steel is produced through recycling, which is made difficult by contamination of scrap resources with nonferrous metals and nonmetal debris. These contaminants include zinc, towards which blast furnace and electric arc systems have a low tolerance (<0.02 wt %). In this work, clean and efficient recovery of zinc from the surface of steel substrates was investigated using a custom-made low-cost membrane-free non-flow zinc-bromine battery (ZBB) that enabled rapid and straightforward integration and removal of steel substrates. The electrical performance of the cell was characterized by charge-discharge profiles, and zinc removal and recovery onto electrodes was characterized by using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Upon discharging, the cell efficiently removed >99.9 wt % zinc from steel surfaces. On recharging the cell, zinc was re-electroplated onto a carbon foam electrode in an easily recoverable form and with high purity. The process was repeated over 30 cycles to demonstrate robustness. The work shows the importance of the cutoff voltage upon discharging: if less than 0.5 V, the cell co-extracted iron into the electrolyte solution, affecting cell durability and zinc purity. A two-stage process for recovering zinc from scrap steel is proposed, illustrating how ZBB technology could enable efficient and clean recovery of zinc from complex scrap steel resources in the steel industry.

Vocal cord dysfunction after pediatric cardiac surgery: A prospective implementation study.

Objective: To determine the incidence, outcomes, and evaluate diagnostic modalities for postoperative vocal cord dysfunction (VCD) following cardiothoracic surgery in children. Methods: A prospective mixed-methods study using principles of implementation science was completed. All patients undergoing surgery involving the aortic arch, ductus, or ligamentum arteriosum and vascular rings from September 2019 to December 2020 were enrolled. Patients underwent speech pathology assessment, laryngeal ultrasound, and flexible direct laryngoscopy. Results: Ninety-five patients were eligible for inclusion. The incidence of VCD ranged from 18% to 56% and varied according to procedure group. VCD occurred in 42% of neonates. Repair of hypoplastic aortic arch was associated with increased risk of VCD (57%; P = .002). There was no significant difference in duration of intubation, pediatric intensive care unit stay, or hospital stay. Forty percent children were able to achieve full oral feeding. Children with VCD were more likely to require nasogastric supplementary feeding at discharge (60% vs 36%; P = .044). Sixty-eight percent of patients demonstrated complete resolution of VCD at a median of 97 days postoperatively. Laryngeal ultrasound and speech pathology assessment combined had a sensitivity of 91% in comparison to flexible direct laryngoscopy. Conclusions: VCD occurred in one-third and resolved in two-thirds of patients at a median of 3 months following cardiac surgery. Aortic arch repair carried the highest risk of VCD. VCD adversely influenced feeding. Forty percent of patients achieved full oral feeding before discharge. VCD did not delay intensive care unit or hospital discharge. Speech pathology assessment and laryngeal ultrasound combined was reliable for diagnosis in most patients and was more patient friendly than flexible direct laryngoscopy.

COVID-19-related anosmia.

On average, 47% of patients with COVID-19 self-report an olfactory disorder, although the inaccuracy of self-reporting means this figure may be higher.

Exploring how changes to the steroidal core alter oleogelation capability in sterol: γ-oryzanol blends.

Oleogels based on sterols such as ß-sitosterol blended with the sterol ester γ-oryzanol are a very interesting class of systems, but there are aspects of their formation and structure that remain elusive. It has previously been shown that a methyl group on the C30 position of the sterol-ester plays an important role in gelation. This work explored the effect that having C30 methyl groups on both the sterol and the sterol-ester had on the gelation process and subsequent gel structure. Lanosterol and saponified γ-oryzanol (which was synthesized as part of this study) were identified as materials of interest, as both feature a methyl group on the C30 position of their steroidal cores. It was observed that both sterols formed gels when blended with γ-oryzanol, and also that lanosterol gelled sunflower oil without the addition of γ-oryzanol. All of these gels were significantly weaker than that formed by ß-sitosterol blended with γ-oryzanol. To explore why, molecular docking simulations along with AFM and SAXS were used to examine these gels on a broad range of length scales. The results suggest that saponified γ-oryzanol-γ-oryzanol gels have a very similar structure to that of ß-sitosterol-γ-oryzanol gels. Lanosterol-γ-oryzanol gels and pure lanosterol gel, however, form with a totally different structure facilitated by the head-to-tail stacking motif exhibited by lanosterol. These results give further evidence that relatively slight changes to the molecular structure of gelators can result in significant differences in subsequent gel properties.

8,8'-(Benzo[c][1,2,5]thiadiazole-4,7-diyl)bis(quinolin-4(1H)-one): a twisted photosensitizer with AIE properties.

A new benzothiadiazole (BTZ) luminogen is prepared via the Suzuki-Miyaura Pd-catalysed C-C cross-coupling of 8-iodoquinolin-4(1H)-one and a BTZ bispinacol boronic ester. The rapid reaction (5 min) affords the air-, thermo-, and photostable product in 97% yield as a yellow precipitate that can be isolated by filtration. The luminogen exhibits aggregated-induced emission (AIE) properties, which are attributed to its photoactive BTZ core and nonplanar geometry. It also behaves as a molecular heterogeneous photosensitizer for the production of singlet oxygen under continuous flow conditions.

Mechanochemical Synthesis of N-Aryl Amides from O-Protected Hydroxamic Acids.

Two robust and efficient mechanochemical protocols for the synthesis of an array of N-arylamides have been developed. This was achieved by a C-N cross-coupling between O-pivaloyl hydroxamic acids and aryl iodides or aryl boronic acids, in the presence of a stoichiometric amount of a copper mediator. The effectiveness of this method is highlighted by the high-yielding (up to 94 %), scalable (up to 8 mmol), and rapid (20 minutes) synthesis of N-aryl amides (15 examples), using a variety of deactivated and sterically encumbered substrates, whilst employing mild conditions and in the absence of solvents. In addition, it was determined that whilst the O-pivaloyl hydroxamic acid precursors can be synthesised mechanochemically, iron contamination originating from the steel jars was found to occur which can hinder the efficacy of this process. Furthermore, 3D printing was used to produce custom milling jars that could successfully accommodate a scaled-up version of the two protocols.

The management of periorbital cellulitis secondary to sinonasal infection: a multicenter prospective study in the United Kingdom.

BACKGROUND: Periorbital cellulitis is a potential sight-threatening complication of sinusitis. The majority of patients improve with medical management. Previous studies have suggested significant variations in practice and lack of evidence regarding the optimal management of this condition. METHODS: A prospective study was conducted over a 12-month period at 8 centers in the United Kingdom assessing the management of patients requiring inpatient treatment for periorbital cellulitis secondary to sinonasal infections. RESULTS: A total of 143 patients were recruited, of whom 40 were excluded. Of the remaining 103 patients, 5 (4.9%) were diagnosed with neurosurgical complications. This resulted in 98 patients admitted with periorbital cellulitis secondary to an upper respiratory tract infection/sinusitis. A total of 72 were children, of whom 12 (16.7%) required surgical intervention; and of 26 adults, 5 (19.2%) required surgery: the most common antimicrobial regimes administered were intravenous ceftriaxone (with or without metronidazole), and co-amoxiclav. The use of both ceftriaxone and metronidazole from admission was associated with the shortest duration of inpatient stay (3.8 days) in comparison to ceftriaxone alone (5.8 days) or co-amoxiclav (4.5 days) and a reduction in number of patients requiring surgical intervention. There was also an association between the early use of intranasal decongestants and steroids and reduction in requirement for surgical intervention. CONCLUSION: For a condition where swab and blood cultures are often negative, this study supports the use of ceftriaxone in combination with metronidazole. The administration of intranasal decongestants and corticosteroids correlated with a smaller percentage of those progressing to surgery in those with and without periorbital abscesses.

Systematic Review of Round Window Operations for the Treatment of Superior Semicircular Canal Dehiscence.

A review of the literature is presented to consider the role of round window (RW) operations in superior semicircular canal dehiscence (SSCD). Primary (PubMed) and secondary sources (TRIP, Cochrane database, Best Practice, and PubMed Clinical Queries) were used to identify relevant studies. Four original studies (three case series and one case report) were identified. All were retrospective reviews and used a number of subjective and objective outcome measures to assess the efficacy of a minimally invasive, transmeatal approach to perform RW surgery for SSCD. The current evidence suggesting that RW operations for SSCD are unlikely to replace more established surgical procedures as first-line treatment may be appropriate in a select group of patients. Further multicenter, randomized controlled trials are required to establish their efficacy in patients with SSCD.

Molecular Interactions behind the Self-Assembly and Microstructure of Mixed Sterol Organogels.

In this work, we have employed docking and atomistic molecular dynamics (MD) simulations supported by complementary experiments using atomic force microscopy, rheology, and spectroscopy to investigate the self-assembled structure of ß-sitosterol and γ-oryzanol molecules into cylindrical tubules in a nonaqueous solvent. Docking models of several phytosterols, including sitosterol, with oryzanol and other sterol esters demonstrate that for systems to form tubules, the phytosterol sterane group must be stacked in a wedge shape with the ester sterane group and a hydrogen bond must form between the hydroxyl group of the phytosterol and the carbonyl group of the ester. MD of the self-assembled structure were initiated with the molecules in a roughly cylindrical configuration, as suggested from previous experimental studies, and the configurations were found to be stable during 50 ns simulations. We performed MD simulations of two tubules in proximity to better understand the aggregation of these fibrils and how the fibrils interact in order to stick together. We found that an interfibril network of noncovalent bonds, in particular van der Waals and π-π contacts, which is formed between the ferulic acid groups of oryzanol through the hydroxyl, methoxy, and aromatic groups, is responsible for the surface-to-surface interactions between fibrils; an observation supported by molecular spectroscopy. We believe that these interactions are of primary importance in creating a strong organogel network.

Targetable Mechanical Properties by Switching between Self-Sorting and Co-assembly with In Situ Formed Tripodal Ketoenamine Supramolecular Hydrogels.

A new family of supramolecular hydrogelators are introduced in which self-sorting and co-assembly can be utilised in the tuneability of the mechanical properties of the materials, a property closely tied to the nanostructure of the gel network. The in situ reactivity of the components of the gelators allows for system chemistry concepts to be applied to the formation of the gels and shows that molecular properties, and not necessarily the chemical identity, determines some gel properties in these family of gels.

Mobile Delivery of Health Information for People with Mild Cognitive Impairment.

The design of a smartphone application (app) for promoting healthy lifestyle choices has been investigated for people with mild cognitive impairment. The app was designed to provide health-related messages and assist users to keep track of activities such as walking, eating and drinking water. A reward scheme with gold, silver and bronze awards was incorporated as a means of assisting user motivation. Responses to the app and user feedback were gathered for purposes of evaluation and improvement. Outcomes indicate that the approach has some potential and could have good implications for encouraging positive health-related behaviour change in this population, hence prompting further investigation and development of the concept.

Halogen effects on the solid-state packing of phenylalanine derivatives and the resultant gelation properties.

Phenylalanine is an important amino acid both biologically, essential to human health, and industrially, as a building block of artificial sweeteners. Our interest in this particular amino acid and its derivatives lies with its ability to form gels in a number of solvents. We present here the studies of the influence of halogen addition to the aromatic ring on the gelation properties and we analyse the crystal structures of a number of these materials to elucidate the trends in their behaviour based on the halogen addition to the aromatic group and the interactions that result.

Supramolecular Amino Acid Based Hydrogels: Probing the Contribution of Additive Molecules using NMR Spectroscopy.

Supramolecular hydrogels are composed of self-assembled solid networks that restrict the flow of water. l-Phenylalanine is the smallest molecule reported to date to form gel networks in water, and it is of particular interest due to its crystalline gel state. Single and multi-component hydrogels of l-phenylalanine are used herein as model materials to develop an NMR-based analytical approach to gain insight into the mechanisms of supramolecular gelation. Structure and composition of the gel fibres were probed using PXRD, solid-state NMR experiments and microscopic techniques. Solution-state NMR studies probed the properties of free gelator molecules in an equilibrium with bound molecules. The dynamics of exchange at the gel/solution interfaces was investigated further using high-resolution magic angle spinning (HR-MAS) and saturation transfer difference (STD) NMR experiments. This approach allowed the identification of which additive molecules contributed in modifying the material properties.