Tailoring Metal-Organic Frameworks and Derived Materials for High-Performance Zinc-Air and Alkaline Batteries.

Developing multifunctional materials from earth-abundant elements is urgently needed to satisfy the demand for sustainable energy. Herein, we demonstrate a facile approach for the preparation of a metal-organic framework (MOF)-derived Fe2O3/C, composited with N-doped reduced graphene oxide (MO-rGO). MO-rGO exhibits excellent bifunctional electrocatalytic activities toward the oxygen evolution reaction (ηj=10 = 273 mV) and the oxygen reduction reaction (half-wave potential = 0.77 V vs reversible hydrogen electrode) with a low ΔEOER-ORR of 0.88 V in alkaline solutions. A Zn-air battery based on the MO-rGO cathode displays a high specific energy of over 903 W h kgZn-1 (∼290 mW h cm-2), an excellent power density of 148 mW cm-2, and an open-circuit voltage of 1.430 V, outperforming the benchmark Pt/C + RuO2 catalyst. We also hydrothermally synthesized a Ni-MOF that was partially transformed into a Ni-Co-layered double hydroxide (MOF-LDH). A MO-rGO||MOF-LDH alkaline battery exhibits a specific energy of 42.6 W h kgtotal mass-1 (106.5 µW h cm-2) and an outstanding specific power of 9.8 kW kgtotal mass-1 (24.5 mW cm-2). This work demonstrates the potential of MOFs and MOF-derived compounds for designing innovative multifunctional materials for catalysis, electrochemical energy storage, and beyond.

Phase-Dependent Energy Storage Performance of the NixSey Polymorphs for Supercapacitor-Battery Hybrid Devices.

Transition-metal chalcogenides have emerged as a promising class of materials for energy storage applications due to their earth abundance, high theoretical capacity, and high electrical conductivity. Herein, we introduce a facile and one-pot electrodeposition method to prepare high-performance nickel selenide NixSey (0.5 ≤ x/y ≤ 1.5) nanostructures (specific capacity = 180.3 mA h g-1 at 1 A g-1). The as-synthesized nickel selenide (NS) nanostructure is however converted to other polymorphs of nickel selenide including orthorhombic NiSe2, trigonal Ni3Se2, hexagonal NiSe, and orthorhombic Ni6Se5 over cycling. Interestingly, NiSe2 and Ni3Se2 polymorphs that display a more metallic character and superior energy storage performance are the predominant phases after a few hundred cycles. We fabricated a hybrid device using activated carbon (AC) as a supercapacitor-type negative electrode and NS as a high-rate battery-type positive electrode (AC||NS). This hybrid device provides a high specific energy of 71 W h kg-1, an excellent specific power of up to 31 400 W kg-1, and exceptional cycling stability (80% retention of the initial capacity after 20 000 cycles). The higher energy storage performance of the device is a result of the development of high-performance NiSe2 and Ni3Se2 polymorphs. Moreover, the reduction of the critical dimension of the NS particles to the nanoscale partially induces an extrinsic pseudocapacitive behavior that improves the rate capability and durability of the device. We also explored the origin of the superior energy storage performance of the NS polymorphs using density functional theory calculations in terms of the computed density of states around the Fermi level, electrical conductivity, and quantum capacitance that follows the trend NiSe2 > Ni3Se2 > NiSe > Ni6Se5. The present study thus provides an appealing approach for tailoring the phase composition of NS as an alternative to the commonly used templated synthesis methods.

Analysis of a national difficult airway database.

Difficult airway management continues to adversely affect patient care and clinical outcomes and is poorly predicted. Previous difficult airway management is the most accurate predictor of future difficulty. The Difficult Airway Society initiated a national airway database to allow clinicians to access details of previous difficult airway episodes in patients issued with a difficult airway alert card. We aimed to analyse this database, reporting patient characteristics, airway management and patient outcomes. We included all living adult patients reported in the first 5 years of the database (n = 675). Clinical airway assessment was reported in 634 (94%) patients, with three or more parameters assessed in 488 (72%). A history of difficult airway was known in 136 (20%) patients and difficult airway management was anticipated in 391 (58%). In all, 75 (11%) patients had an airway-related critical incident, with 1 in 29 being awoken from anaesthesia, 1 in 34 requiring unplanned or prolonged stay in the intensive care unit and 1 in 225 needing an emergency front-of-neck airway or had a cardiac arrest/peri-arrest episode. Airway-related critical incidents were associated with out-of-hours airway management, but no other associations were apparent. Our data report the first analysis of a national difficult airway database, finding that unanticipated difficult airway management continues to occur despite airway assessment, and the rate of critical incidents in this cohort of patients is high. This database has the potential to improve airway management for patients in the future.

Recent Advances in Carbon Anodes for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have gained tremendous attention for large-scale energy storage applications due to the natural abundance, low cost, and even geographic distribution of sodium resources as well as a similar working mechanism to lithium-ion batteries (LIBs). One of the critical bottlenecks, however, is the design of high-performance and low-cost anode materials. Graphite anode that has dominated the market share of LIBs does not properly intercalate sodium ions. However, other carbonaceous materials are still considered as one of the most promising anode materials for SIBs in virtue of their high electronic conductivity, abundant active sites, hierarchical porosity, and excellent mechanical stability. In this review, we have tried to summarize the latest progresses made on the development of carbon-based negative electrodes (including hard carbons, soft carbons, and synthetic carbon allotropes) for SIBs. We also have provided a comprehensive understanding of their physical properties, the sodium ions storage mechanisms, and the improvement measures to cope with the current challenges. In addition, we have proposed future research directions for SIBs that will provide important insights into further development of carbon-based materials for SIBs.

Trilayer Metal-Organic Frameworks as Multifunctional Electrocatalysts for Energy Conversion and Storage Applications.

The need for enhanced energy storage and improved catalysts has led researchers to explore advanced functional materials for sustainable energy production and storage. Herein, we demonstrate a reductive electrosynthesis approach to prepare a layer-by-layer (LbL) assembled trimetallic Fe-Co-Ni metal-organic framework (MOF) in which the metal cations within each layer or at the interface of the two layers are linked to one another by bridging 2-amino-1,4-benzenedicarboxylic acid linkers. Tailoring catalytically active sites in an LbL fashion affords a highly porous material that exhibits excellent trifunctional electrocatalytic activities toward the hydrogen evolution reaction (ηj=10 = 116 mV), oxygen evolution reaction (ηj=10 = 254 mV), as well as oxygen reduction reaction (half-wave potential = 0.75 V vs reference hydrogen electrode) in alkaline solutions. The dispersion-corrected density functional theory calculations suggest that the prominent catalytic activity of the LbL MOF toward the HER, OER, and ORR is due to the initial negative adsorption energy of water on the metal nodes and the elongated O-H bond length of the H2O molecule. The Fe-Co-Ni MOF-based Zn-air battery exhibits a remarkable energy storage performance and excellent cycling stability of over 700 cycles that outperform the commercial noble metal benchmarks. When assembled in an asymmetric device configuration, the activated carbon||Fe-Co-Ni MOF supercapacitor provides a superb specific energy and a power of up to 56.2 W h kg-1 and 42.2 kW kg-1, respectively. This work offers not only a novel approach to prepare an LbL assembled multimetallic MOF but also provides a benchmark for a multifunctional electrocatalyst for water splitting and Zn-air batteries.

Radiologic Predictors of Increased Number of Necrosectomies During Endoscopic Management of Walled-off Pancreatic Necrosis.

GOALS: No established methods exist to predict who will require a higher number of endoscopic necrosectomy sessions for walled-off necrosis (WON). We aim to identify radiologic predictors for requiring a greater number of necrosectomy sessions. This may help to identify patients who benefit from aggressive endoscopic management. MATERIALS AND METHODS: This is a multicenter retrospective study of patients with WON at 3 tertiary care centers. WON characteristics on preintervention computed tomography imaging were evaluated to determine if they were predictive of requiring more endoscopic necrosectomy. RESULTS: A total of 104 patients were included. Seventy patients (67.3%) underwent endoscopic necrosectomy, with median of 2 necrosectomies. WON largest transverse diameters (P=0.02), largest coronal diameters (P=0.01), necrosis pattern [likelihood ratio (LR)=17.85, P<0.001], spread (LR=11.02, P=0.01), hemorrhage (LR=8.64, P=0.003), and presence of disconnected pancreatic duct (LR=6.80, P=0.01) were associated with undergoing ≥2 necrosectomies. Patients with septations/loculations were significantly less likely to undergo ≥2 necrosectomies (LR=4.86, P=0.03). CONCLUSIONS: Several computed tomography radiologic features were significantly associated with undergoing ≥2 necrosectomies. These could help identify patients who will undergo a higher number of endoscopic necrosectomy sessions.

Polyaniline-Lignin Interpenetrating Network for Supercapacitive Energy Storage.

Because of increasing interest in environmentally benign supercapacitors, earth-abundant biopolymers have found their way into value-added applications. Herein, a promising nanocomposite based on an interpenetrating network of polyaniline and sulfonated lignin (lignosulfonate, LS) is presented. On the basis of an appropriate regulation of the nucleation kinetics and growth behavior via applying a series of rationally designed potential pulse patterns, a uniform PANI-LS film is achieved. On the basis of the fast rate of H+ insertion-deinsertion kinetics, rather than the slow SO42- doping-dedoping process, the PANI-LS nanocomposite delivers specific capacitance of 1200 F g-1 at 1 A g-1 surpassing the best conducting polymer-lignin supercapacitors known. A symmetric PANI-LS||PANI-LS device delivers a high specific energy of 21.2 W h kg-1, an outstanding specific power of 26.0 kW kg-1, along with superb flexibility and excellent cycling stability. Thus, combining charge storage attributes of polyaniline and lignosulfonate enables a waste-to-wealth approach to improve the supercapacitive performance of polyaniline.

Hyperosmolarity-induced vasopressin expression and intrinsic excitability of supraoptic neurons of adult offspring are changed by early maternal separation.

Adverse early life experiences can produce long-lasting changes in neurocircuits. The aim of this study was to investigate the programming effects of early maternal separation on the adult offspring vasopressin system. We hypothesized that subjecting adult rats to 4.5 h of daily maternal separation between postnatal days 1 - 21 will have altered hyperosmolarity-induced Avp expression and the response of supraoptic (SON) neurons to electrical and osmotic stimulation. We measured Avp mRNA and hn-RNA in the SON and in the paraventricular nucleus (PVN) by quantitative PCR, and assessed the intrinsic excitability of magnocellular SON neurons as well as their osmotic responses by the patch-clamp technique. In maternally-separated rats we found that basal and osmolarity-induced Avp mRNA gene expression was upregulated in the SON, whereas osmolarity-induced Avp hn-RNA gene expression was abolished. Similarly, in the PVN of maternally-separated rats the osmolarity-induced Avp mRNA gene expression was blunted. The supraoptic neurons of separated rats also had greater excitability than those of non-separated rats. Our results indicate that early maternal separation has long-term consequences on basal and hyperosmolarity-induced Avp hypothalamic expression as well as on the intrinsic excitability of magnocellular supraoptic neurons.

Re-infection of SARS-CoV-2: A case in a young dental healthcare worker.

Reinfection with SARS-CoV-2 is a rare phenomenon. To date, there has been some cases reported from countries such as United States, Ecuador, Hong Kong, the Netherlands and Belgium. This case report presents the first case of reinfection from Saudi Arabia, and probably the first dental student to have been re-infected with COVID-19. A 24-year-old male dental student presents with reinfection after a period of three months since he was first infected with COVID-19. The signs and symptoms reported by the patient were similar in both instances, except that he developed fever only at the time of reinfection. The infection and reinfection were confirmed with a RT-PCR test reports. This report highlights how it is necessary to continue to observe all the prescriptions recently indicated in the literature in order to avoid new contagion for all health workers after healed from covid-19 or asymptomatic positive, since as seen sometimes the infection does not ensures complete immunity in 100% of cases.

Exploration of Advanced Electrode Materials for Approaching High-Performance Nickel-Based Superbatteries.

The surging interest in high performance, low-cost, and safe energy storage devices has spurred tremendous research efforts in the development of advanced electrode active materials. Herein, the in situ growth of zinc-iron layered double hydroxide (Zn-Fe LDH) on graphene aerogel (GA) substrates through a facile, one-pot hydrothermal method is reported. The strong interaction and efficient electronic coupling between LDH and graphene substantially improve interfacial charge transport properties of the resulting nanocomposite and provide more available redox active sites for faradaic reactions. An LDH-GA||Ni(OH)2 device is also fabricated that results in greatly enhanced specific capacity (187 mAh g-1 at 0.1 A g-1 ), outstanding specific energy (147 Wh kg-1 ), excellent specific power (16.7 kW kg-1 ), along with 88% capacity retention after >10 000 cycles. This approach is further extended to Ni-MH and Ni-Cd batteries to demonstrate the feasibility of compositing with graphene for boosting the energy storage performance of other well-known Ni-based batteries. In contrast to conventional Ni-based batteries, the nearly flat voltage plateau followed by a sloping potential profile of the integrated supercapacitor-battery enables it to be discharged down to 0 V without being damaged. These findings provide new prospects for the design of high-performance and affordable superbatteries based on earth-abundant elements.

Novel corona virus disease (COVID-19) awareness among the dental interns, dental auxiliaries and dental specialists in Saudi Arabia: A nationwide study.

BACKGROUND: Dental health care workers (DHCW's) are invariably at a higher risk of contracting COVID-19. The objectives were; to investigate the current knowledge on COVID-19 among the DHCW's; and to conduct quasi-experiment among the DHCW's who were unaware of the disseminated COVID-19 information. METHODS: A nationwide cross-sectional study targeting dental interns, auxiliaries, and specialists with a two-staged cluster sampling technique was performed. A 17-item questionnaire was subjected to reliability and validity tests before being administered. The participants for quasi-experiment were separated from the original sample after their initial response. Chi-square test assessed responses to knowledge statements between the participants. Difference in mean knowledge scores between the categories of DHCW's and sources of COVID-19 information was assessed using ANOVA. Data from the quasi experiment (pre vs post knowledge intervention) was subjected to paired t-test. Percentage of DHCWs providing correct or wrong responses to each knowledge statement at baseline and after 7 days were compared using McNemar test. RESULTS: The overall sample consisted of 706 (N) participants, and the DHCW's with no prior knowledge on COVID-19 (N=206) were part of the quasi experiment. Findings from cross-sectional study revealed that knowledge was significantly (p<0.05) related to the qualification level (interns vs auxiliaries vs specialists). However, the difference in the source of information (WHO/CDC vs Journal articles vs MoH) did not demonstrate any effect. Number of participants with correct responses to knowledge questions had significantly (p<0.05) increased after intervention. Also, the overall mean knowledge score (10.74±2.32 vs 12.47±1.68; p<0.001) had increased significantly after the intervention. CONCLUSION: In conclusion, the basic knowledge on COVID-19 among the DHCW's in Saudi Arabia is acceptable. Timely dissemination of information by the Ministry of Health, Saudi Arabia had a positive impact on the COVID-19 knowledge score of the DHCW's.

Difficult Airway Society guidelines for awake tracheal intubation (ATI) in adults.

Awake tracheal intubation has a high success rate and a favourable safety profile but is underused in cases of anticipated difficult airway management. These guidelines are a comprehensive document to support decision making, preparation and practical performance of awake tracheal intubation. We performed a systematic review of the literature seeking all of the available evidence for each element of awake tracheal intubation in order to make recommendations. In the absence of high-quality evidence, expert consensus and a Delphi study were used to formulate recommendations. We highlight key areas of awake tracheal intubation in which specific recommendations were made, which included: indications; procedural setup; checklists; oxygenation; airway topicalisation; sedation; verification of tracheal tube position; complications; management of unsuccessful awake tracheal intubation; post-tracheal intubation management; consent; and training. We recognise that there are a range of techniques and regimens that may be effective and one such example technique is included. Breaking down the key practical elements of awake tracheal intubation into sedation, topicalisation, oxygenation and performance might help practitioners to plan, perform and address complications. These guidelines aim to support clinical practice and help lower the threshold for performing awake tracheal intubation when indicated.

Nile Blue Functionalized Graphene Aerogel as a Pseudocapacitive Negative Electrode Material across the Full pH Range.

The pursuit of new negative electrode materials for redox supercapacitors with a high capacitance, boosted energy, and high rate capability is still a tremendous challenge. Herein, we report a Nile Blue conjugated graphene aerogel (NB-GA) as a negative electrode material with excellent pseudocapacitive performance (with specific capacitance of up to 483 F g-1 at 1 A g-1) in all acidic, neutral, and alkaline aqueous electrolytes. The contribution from capacitive charge storage represents 93.4% of the total charge, surpassing the best pseudocapacitors known. To assess the feasibility of NB-GA as a negative electrode material across the full pH range, we fabricated three devices, namely, a symmetric NB-GA||NB-GA device in an acidic (1.0 M H2SO4) electrolyte, an NB-GA||MnO2 device in a pH-neutral (1.0 M Na2SO4) electrolyte, and an NB-GA||LDH (LDH = Ni-Co-Fe layered double hydroxide) device in an alkaline (1.0 M KOH) electrolyte. The NB-GA||NB-GA device exhibits a maximum specific energy of 22.1 Wh kg-1 and a specific power of up to 8.1 kW kg-1; the NB-GA||MnO2 device displays a maximum specific energy of 55.5 Wh kg-1 and a specific power of up to 14.9 kW kg-1, and the NB-GA||LDH device shows a maximum specific energy of 108.5 Wh kg-1 and a specific power of up to 25.1 kW kg-1. All the devices maintain excellent stability over 5000 charge-discharge cycles. The outstanding pseudocapacitive performances of the NB-GA nanocomposites render them a highly promising negative electrode material across the entire pH range.

Towards establishing standard performance metrics for batteries, supercapacitors and beyond.

Over the past decade, electrochemical energy storage (EES) devices have greatly improved, as a wide variety of advanced electrode active materials and new device architectures have been developed. These new materials and devices should be evaluated against clear and rigorous metrics, primarily based on the evidence of real performances. A series of criteria are commonly used to characterize and report performance of EES systems in the literature. However, as advanced EES systems are becoming more and more sophisticated, the methodologies to reliably evaluate the performance of the electrode active materials and EES devices need to be refined to realize the true promise as well as the limitations of these fast-moving technologies, and target areas for further development. In the absence of a commonly accepted core group of metrics, inconsistencies may arise between the values attributed to the materials or devices and their real performances. Herein, we provide an overview of the energy storage devices from conventional capacitors to supercapacitors to hybrid systems and ultimately to batteries. The metrics for evaluation of energy storage systems are described, although the focus is kept on capacitive and hybrid energy storage systems. In addition, we discuss the challenges that still need to be addressed for establishing more sophisticated criteria for evaluating EES systems. We hope this effort will foster ongoing dialog and promote greater understanding of these metrics to develop an international protocol for accurate assessment of EES systems.

Saffron carotenoids (crocin and crocetin) binding to human serum albumin as investigated by different spectroscopic methods and molecular docking.

Therapeutic effects of saffron ingredients were studied in some diseases. The pharmacokinetics and pharmacodynamics of these ingredients were also studied, but their transport mechanism is not clearly known. Serum albumin has been known as the most important transporter of many drugs in the body that affects their disposition, transportation, and bioavailability. Here, we investigated the interaction of crocin (Cro) with HSA, for the first time, and compared with the crocetin (Crt)-HSA interaction. UV and fluorescence spectroscopy, circular dichroism (CD), and molecular docking was applied to investigate the possibility and mechanism of binding of HSA with these natural carotenoids. The gradually addition of Cro increased HSA absorbency at 278 nm, while Crt decreased it. Both of these changes induced HSA unfolding that was confirmed by the decreased α-helix content, as determined by the CD. Both carotenoids quenched HSA fluorescence emission, but with different mechanisms. The Stern-Volmer plots indicated a dynamic quenching of intrinsic emission of HSA due to Cro addition, while Crt quenching followed both static and dynamic quenching mechanisms. Docking results indicated binding of Cro/Crt in sub-domain IIA, Sudlow site I of HSA, which accompanied with the hydrogen bonding of Cro/Crt with Tyr138. The interaction of these ligands (Cro/Crt) caused HSA unfolding and affects the hydrophobic environment of Trp241, which result in the quenching of Trp fluorescence. The UV spectroscopy and fluorescence quenching data indicated the differences in the mechanisms of interaction of Cro/Crt with HSA, which is due to the differences in the structure and hydrophobicity of these ligands.

Secular trends of Streptococcus pyogenes sepsis in Pakistan and analysis of clinical features in a hospitalized cohort.

Streptococcus pyogenes or Group A Streptococcus (GAS) is a re-emerging pathogen of significant public health importance. We present trends in GAS blood cultures over a 10 year period in Pakistan and characteristics of hospitalized patients with GAS sepsis over three years at a tertiary care hospital in Karachi, Pakistan. Blood cultures positive for GAS from 2004 -2014 were recorded at the clinical microbiology laboratory of the Aga Khan University and studied for trends in positivity rates. Medical records of patients hospitalized at the Aga Khan University hospital from 2012-2014 were also examined for clinical features and outcomes. GAS trends show a steady rate of blood culture positivity over 11 years, with higher rates in those >50 years, and seasonality favouring winter months. Case fatality rate in the hospitalized cohort was 34.1% (n= 14; of 41 patients). Malignancy predominated as the underlying predisposing factor among the 15-49 age group. Presence of sepsis was an independent predictor of mortality in GAS bacteremia. Studies of GAS trends in developing regions are important to inform changing epidemiology. GAS septic shock continues to have high case fatality despite antibiotic treatment. Early recognition, aggressive, goal-directed therapy for sepsis and prevention are possible control measures to prevent high mortality.

Thrombospondin-derived peptide attenuates Sjögren's syndrome-associated ocular surface inflammation in mice.

Sjögren's syndrome is the second most common rheumatic disease in which autoimmune response targets exocrine glands (salivary and lacrimal glands) result in clinical symptoms of dry mouth and dry eye. Inflammation of the lacrimal gland induces tear abnormalities that contribute to the inflammation of the ocular surface, which includes ocular mucosa. Thrombospondin-1 (TSP-1) plays a critical regulatory role in the ocular mucosa and as such TSP-1-/- mice develop spontaneously chronic ocular surface inflammation associated with Sjögren's syndrome. The autoimmune pathology is also accompanied by a peripheral imbalance in regulatory (Treg ) and inflammatory Th17 effectors. In this study, we demonstrate an in-vitro effect of a CD47-binding TSP-derived peptide in the induction of transforming growth factor (TGF)-ß1-secreting forkhead box protein 2 (Foxp3+ ) Tregs from activated CD4+ CD25- T cells and the inhibition of pathogenic T helper type 17 (Th17)-promoting interleukin (IL)-23 derived from antigen-presenting cells. The in-vivo administration of this peptide promotes Foxp3+ Treg induction and inhibition of Th17 development. Consistent with these results, topical administration of CD47-binding TSP peptide, both before and after the onset of the disease, attenuates clinical symptoms of SS-associated dry eye in TSP-1-/- mice. Augmented expression of Foxp3 detected in the draining lymph nodes of TSP peptide -treated mice compared to those treated with control peptide suggests the ability of TSP peptide to restore peripheral immune imbalance. Thus, our results suggest that TSP-derived peptide attenuates Sjögren's syndrome-associated dry eye and autoimmune inflammation by preventing Th17 development while promoting the induction of Tregs . Collectively, our data identify TSP-derived peptide as a novel therapeutic option to treat autoimmune diseases.