Search

The electrochemical kinetics of the electrode material plays a crucial role in the development of various energy storage devices such as batteries, supercapacitors, and hybrid supercapacitors.

Redox-mediated interconversion of oxide to hydroxide (M4+O2− + H2O + e− ↔ M3+OH− + OH−) in aqueous media is the key reason for the high capacity of Y1−xSrxMnO3−δ electrodes.

Currently, enhancing the performance of electrochemical supercapacitors is the subject of intense research to fulfill the ever-increasing demand for grid-scale energy storage and delivery solution, thereby utilizing the full potential of renewable energy resources and decreasing our dependence on fossil fuels. Metal sulfides, such as cobalt sulfide (CoS), nickel sulfide (NiS), molybdenum sulfide (MoS), copper sulfide (CuS), and others, have recently emerged as a promising class of active electrode materials, alongside other supercapacitor electrode materials, due to their relatively high specific capacitance values and exceptional reversible redox reaction activities. The synthesis, characterizations, and electrochemical performances of single-phase nanocrystalline β-NiS are presented here and the electrode based on this material shows a specific capacitance of 1578 F g

Introduction: The fontanels are soft membrane covered gaps and the meeting of more than two cranial bones placed side by side. There are six fontanels, of which anterior fontanel is most prominent. We tried to determine the anterior fontanel dimension of the neonates of different gestational age. This in turn will help in diagnosing newborns with serious medical conditions and ensuring their prompt care. Objectives: Estimation of neonatal anterior fontanel area, for use in neonatal screening. Methods: A cross sectional study was conducted in a tertiary care hospital with 530 consecutively live born new born of 28 -41 weeks gestation. After three days of life anterior fontanel area was measured. The values were summarized using descriptive statistics, including percentile values. Results: In index study, we deducted anterior fontanel dimensions of newborns of gestational age ranging from 28 to 41 weeks. The mean anterior fontanel size was 3.20 ± 1.71. Anterior fontanel variation with gestational age showed that anterior fontanel area increases with increase in gestational age. However, another study with greater number of participants and in a community setting may be helpful. Conclusion: Anterior fontanel area can be used as a tool for identifying newborns with grave ailments. Abnormal fontanel measurement can be either large or small anterior fontanel. These are associated with many important consequences. Detecting them early will help in seeking appropriate medical guidance.

Pseudocapacitive electrochemical capacitance of SrFeO3 with Fe4+/Fe2+ redox couples.

Herein, we report ligand-centered redox controlled Zn(II)-catalyzed multicomponent approaches for synthesizing pyrimidines and triazines. Taking advantage of the ligand-centered redox events and using a well-defined Zn(II)-catalyst (1a) bearing (

La1−xKxCoO3−δ (0 ≤ x ≤ 0.5) display a remarkable pseudocapacitive charge storage capacitance in a neutral 0.5 M Na2SO4 electrolyte and superior electrocatalytic activities for the OER and ORR in a 1 M KOH electrolyte.

We report two new efficient iron-catalyzed synthetic strategies for multicomponent synthesis of tri-substituted pyrazoles using biomass-derived alcohols as the primary feedstock.

The shift in redox energy of the Cr3+/2+ couple due to bonding with (SO4)2− polyanions in the eldfellite structure makes Cr3+/2+ accessible, resulting in superior intercalative/deintercalative energy storage for NaCr(SO4)2vs. Na/Li cell.

Catalysis offers a straightforward route to prepare various value-added molecules starting from readily available raw materials. The catalytic reactions mostly involve multi-electron transformations. Hence, compared to the inexpensive and readily available 3d-metals, the 4d and 5d-transition metals get an extra advantage for performing multi-electron catalytic reactions as the heavier transition metals prefer two-electron redox events. However, for sustainable development, these expensive and scarce heavy metal-based catalysts need to be replaced by inexpensive, environmentally benign, and economically affordable 3d-metal catalysts. In this regard, a metal-ligand cooperative approach involving transition metal complexes of redox noninnocent ligands offers an attractive alternative. The synergistic participation of redox-active ligands during electron transfer events allows multi-electron transformations using 3d-metal catalysts and allows interesting chemical transformations using 4d and 5d-metals as well. Herein we summarize an up-to-date literature report on the metal-ligand cooperative approaches using transition metal complexes of redox noninnocent ligands as catalysts for a few selected types of catalytic reactions.

The green energy alternative to a fossil fuel-based economy can be provided only by coupling renewable energy solution solutions such as solar or wind energy plants with large-scale electrochemical energy storage devices. Enabling high-energy storage coupled with high-power delivery can be envisaged though high-capacitive pseudocapacitor electrodes. A pseudocapacitor electrode with multiple oxidation state accessibility can enable more than 1e- charge/transfer per molecule to facilitate superior energy storage. K-doped LaFeO3 (La1-x K x FeO3-δ) is presented here as an electrode having a high pseudocapacitance storage, equivalent to 1.32e- charge/transfer per molecule, resulting in a capacity equivalent of 662 F/g at 1 mV/s scan rate by introduction of a layered potential over the Fe-ion octahedral to utilize higher redox state energies (Fe4+→ Fe2+). La/K ordering in orthorhombic perovskite (La1-x K x FeO3-δ) made the Fe4+ oxidation state accessible, and a systematic shift in the redox energies of Fe4+/3+ and Fe3+/2+ redox couples was observed with K+ ion doping in the A site of the LaFeO3 perovskite, which resulted in a high faradic contribution to the capacitance, coupled with anionic intercalation of H2O/OH- in the host perovskite lattice. The surface capacitive and diffusion control contributions for capacitance are about 42 and 58%, respectively, at -0.6 V, with a scan rate of 1 mV/s. A high gravimetric capacitance, equivalent to 619, 347, 188, 121, and 65 F/g, respectively, at 1, 2, 3, 5, and 10 A/g constant current, was observed for the La0.5K0.5FeO3-δ electrode. Up to 88.9% capacitive retention and 97% Coulombic efficacy were obtained for continuous 5000 cycles of charge/discharge for the La0.5K0.5FeO3-δ electrode. The gravimetric capacitance values of ASCs (activated carbon//La0.5K0.5FeO3-δ) are 348, 290, 228, and 147 F/g at current densities of 1, 2, 3, and 5 A/g, respectively. A maximum specific power of ∼3594 W/kg was obtained when the specific energy reached ∼117 Wh/kg at 5 A/g of current density.

We report a sustainable and eco-friendly approach for selective

Grid-scale bulk energy storage solutions are needed to utilize the full potential of renewable energy technologies. Pseudocapacitive electrochemical energy storage can play a vital role in developing efficient energy storage solutions. The use of perovskites as anion intercalation-type pseudocapacitor electrodes has received significant attention in recent years. In this study, Sr-doped YMnO

The as-prepared La

Herein we report a ligand-centered redox-controlled strategy for the synthesis of an unusual binuclear diradical cobalt(III) complex, [Co2III(L•3-)2] (1), featuring two three-electron reduced trianionic monoradical 2,9-bis(phenyldiazo)-1,10-phenanthroline ligands (L•3-) and two intermediate-spin cobalt(III) centers having a Co-Co bond. Controlled ligand-centered oxidation of 1 afforded two mononuclear complexes, [CoII(L•-)(L0)]+([3])+and [CoII(L0)2]2+([2]2+), which upon further ligand-centered reduction yielded a di-azo-anion diradical complex, [CoII(L•-)2] (4). In complex 1, two three-electron reduced di-azo-anion monoradical ligands (L•3-) bridge two intermediate Co(III) centers at a distance of 2.387(2) Å, while upon oxidation, one of the coordinating azo-arms of L becomes pendent, and in complexes [2]2+, [3]+, and 4, two tetradentate ligands coordinate a single Co(II) center in a tridentate meridional fashion with one uncoordinated azo-arm from each of the ligands. In the presence of reducing agents, the monomers [2]2+, [3]+, and 4 undergo ligand-centered reduction to form azo-anion radicals, and the otherwise pendent azo-arms in the presence of cobalt(II)-salts like Co(ClO4)2or CoCl2bind the second Co(II)-ion; further internal electron transfer from the cobalt center to the arylazo backbone produces the binuclear complex 1. Spectroscopic analysis, DFT studies, and control experiments were performed to understand the electronic structures and the ligand-centered redox-controlled interconversion. The application of complex 1 as a molecular memory device (memristor) was also explored. Complex 1 showed encouraging results as a memristor with a current ON/OFF ratio > 104 and is highly promising for resistive RAM/ROM applications.

Recent global concerns over continuously increasing air pollution and the related health risks due to automobile exhaust have shifted our attention towards green transportation. Recent decades have witnessed a revolution in portable energy-storage systems, mainly lithium-based energy-storage devices. However, the uneven distribution of global lithium reserves and its scarcity lead to huge price differences and geopolitical imbalances, and hence the research in energy-storage materials has shifted towards the development of cost-effective, abundant electrode materials. Here, NaCr(SO

Introduction: Inflammatory demyelinating disease like combined central and peripheral demyelination (CCPD) could have varied clinical presentation depending upon the topographical distribution of neural involvement. Case presentation: A seven-year-old child had presented with fever followed by acute onset flaccid paralysis and urinary retention. Weakness in the lower limbs as reported was ascending and symmetric in nature, while no history of trauma, band-like sensation or altered sensorium were documented. Superficial and deep tendon reflexes of both the lower limbs were absent. Routine blood investigations had revealed neutrophilic leucocytosis only. Serum IgM antibody for scrub typhus was found positive. CSF study didn’t show cyto-protein dissociation. NCV had demonstrated absence of F wave and H reflex in the peripheral nerves of lower limbs. Anti-ganglioside antibody profiles were negative. Subsequent investigations including MRI brain and spinal cord had revealed acute onset CCPD. Conclusion: Acute onset combined central and peripheral demyelination in a child had presented as acute flaccid paralysis of the lower limbs and the condition was temporally association with scrub typhus.

OBJECTIVE: To assess macrophage activation syndrome (MAS) in septic shock leading to multiorgan dysfunction syndrome (MODS). METHODS: A prospective observational study was conducted at a tertiary care hospital to evaluate the MAS criteria in different stages of sepsis. Children aged 6 months to 12 years in different stages of septic shock were recruited. The Paediatric Rheumatology International Trials Organisation Collaborative Initiative (PRINTO) criteria of MAS were applied initially at the stage of septic shock and subsequently at the stage of MODS (MODS cohort) or following recovery from septic shock without going through MODS (non-MODS cohort). RESULTS: A total of 127 subjects were studied, with 53 comprising the MODS cohort and the rest 74 the non-MODS cohort. At the initial assessment, a comparable proportion of subjects in the MODS and non-MODS groups satisfied the MAS criteria (20.75% and 25.68%, respectively; p=0.529). However, by the time of progression to MODS, 81.13% of the subjects satisfied the MAS criteria in the MODS group, whereas only 16.18% subjects in the non-MODS group continued to satisfy the MAS criteria (p

To overcome the environmental challenges caused by utilization of fossil fuel based energy technologies and to utilize the full potential of renewable energy sources such as solar, wind and tidal, high power and high energy density containing large scale electrochemical energy storage devices are a matter of concern and a need of the hour. Pseudocapacitors with accessibility to multiple oxidation states for redox charge transfer can achieve a higher degree of energy storage density compared to electric double layer capacitors (EDLC) and the hybrid supercapacitor is one of the prominent electrochemical capacitors that can resolve the low energy density issues associated with EDLCs. Due to its open pore framework structure with superior structural stability and accessibility of Co2+/3+/4 redox states, porous anhydrous CoC2O4 nanorods are envisaged here as a potential energy storage electrode in a pseudo-capacitive mode. Superior specific capacitance equivalent to 2116 F g−1 at 1 A g−1 in the potential window of 0.3 V was observed for anhydrous CoC2O4 nanorods in aqueous 2 M KOH electrolyte. A predominant pseudo-capacitive mechanism seems to be operative behind the high charge storage at electrodes as intercalative (Inner) and surface (outer) charge storage contributions were found to be 75% and 25% respectively. Further, in full cell asymmetric supercapacitor (ASC) mode in which porous anhydrous CoC2O4 nanorods were used as positive electrodes and activated carbon (AC) was utilised as negative electrodes within an operating potential window of 1.3 V, a highest specific energy of W h kg−1 and specific power of ∼647 W kg−1 at 0.5 A g−1 current density were obtained with superior cycling stability. High cycling stability coupled with superior electrochemical storage properties make anhydrous CoC2O4 nanorods potential pseudo-capacitive electrodes for large scale energy storage applications.

Herein, we report the synthesis and characterization of two ruthenium-based pincer-type catalysts, [

Pseudocapacitors offer both high energy and high power, making them suitable for grid-scale electrochemical energy storage to harness renewable energy produced from sun, wind, and tides. To overcome performance degradation in terms of cycling fading and lower specific capacitance values at high charge/discharge rates of electrochemical pseudocapacitors based on transition-metal oxides, perovskite-structured SrFeO

OBJECTIVE: To delineate the pattern of joint involvement in neonatal septic arthritis, assess the prognosis, and determine significant predictors of unfavorable outcome. METHODS: Subjects were recruited through purposive sampling after obtaining parental consent. A detailed history and examination findings with perinatal data were recorded. Ultrasound and magnetic resonance imaging data of affected joints and blood culture and aspirated joint fluid culture data were recorded along with management received. Cases were followed-up every 3 months from discharge up to minimum 12 months. An unfavorable outcome indicated by permanent joint deformity or restricted range of movement of the affected joint, limb length discrepancy, and persistent joint deformity upon radio imaging at the end of the follow-up period were also included. RESULTS: The hip joint involvement (59.2%) was the commonest with predominance of the monoarticular pattern of affliction (74.4%). An overall outcome was favorable in 70.3% subjects with prompt diagnosis and management. A delay in seeking treatment was found to be an indicator of unfavorable outcome. In addition, disease detection by ultrasound at presentation predicted unfavorable outcome. CONCLUSION: Neonatal septic arthritis is a rare disease with predominant hip or knee involvement. Outcome is favorable with early detection and institution of appropriate management. A delay in treatment worsens prognosis.

Herein we report the synthesis, characterization and catalytic application of three new cobalt(ii)-complexes of redox noninnocent arylazo ligands, 2-(phenylazo)-1,10-phenanthroline (L1a), 2-(4-chlorophenylazo)-1,10-phenanthroline (L1b) and 2,9-bis(phenyldiazo)-1,10-phenanthroline (L2) respectively. The reaction of L1a with CoIICl2·6H2O produced a μ-dichloro bridged binuclear cobalt(ii)-complex [Co(L1a)2Cl2] (1a) while the same reaction when carried out with 2-(4-chlorophenyl)azo-1,10-phenanthroline (L1b) and 2,9-bis(phenyldiazo)-1,10-phenanthroline (L2) ligands produced two new mononuclear five-coordinate cobalt(ii)-complexes 1b and 2 respectively. In complex 1a and 1b, the ligands L1a and L1b are coordinated to the cobalt(ii)-center in a tridentate mode utilizing all of its nitrogen donor sites while in complex 2 one of the azo-donor sites of the ligand L2 remain pendant. All these complexes were characterized using available spectroscopic techniques and DFT studies. We further explored the potential of these complexes as catalysts for the synthesis of pharmaceutically important organic compounds via the functionalization of alcohols. A variety of substituted quinazolin-4(3H)-ones were synthesized under aerobic conditions via the coupling of alcohols and 2-aminobenzamide using 1b as the catalyst. Mechanistic investigations revealed that both cobalt and the arylazo scaffold act synergistically during catalysis.

The oxygen evolution reaction (OER) is a key half-reaction in hydrogen–oxygen electrolysers that is very important for efficient electrochemical energy generation, storage and fuel production that offers a clean alternative to fissile fuel combustion based energy systems. Several transition metal containing perovskites were recently explored for the development of superior OER catalysts, and their activity was correlated with the applied potentials at a specific current density to eg electron density present in the materials. The rock salt structure is envisaged here as a model host structure similar to perovskite to tune the eg electrons to obtain superior electro-catalytic activity. Incorporation of Ni into CoO lattices helps to stabilize the rock salt structure and modulate the eg electrons to develop superior OER and ORR electrocatalysts. Nickel doped rock salt structured CoO, NixCo1−xO (0 ≤ x ≤ 0.5), were synthesized by employing a solid state metathesis synthesis route. The compounds were characterised by powder X-ray diffraction (XRD), TGA, FT-IR and X-ray Photoelectron Spectroscopy (XPS). Ni0.3Co0.7O with 1.3 eg electrons showed superior electrocatalytic activity for the oxygen evolution reaction. The overpotential for the Ni0.3Co0.7O sample was also found to be ∼0.450 V for 1 M and about ∼0.389 V at 5 M concentration of the KOH electrolyte.

Objectives We aimed to evaluate blood pressure (BP) in Indian children who had similar demographic characteristics but hailed from different altitudes. Methods BP of school going children, aged 5 to 12 years, at five different locations varying in altitude (near sea level: n = 425; 2000 feet: n = 244; 4000 feet: n = 248; 6000 feet: n = 242 and 8000 feet: n = 250) was measured in a mountainous district in Himalaya. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded by aneroid sphygmomanometer in the sitting posture using a calibrated instrument and four trained resident doctors. The average of three readings was taken. Results Of the 1229 children whose data were analyzed, 50.4% were boys. SBP showed a progressive rise from 99.5 (4.00) mmHg [mean (standard deviation)] at near sea level to 106.7 (4.17) mmHg at 8000 feet. Similarly, DBP showed a rise from 60.1 (3.67) mmHg to 66.8 (4.58) mmHg over the same altitude range. Analysis of covariance for BP variation with altitude, with age as covariate, indicated a modest but statistically significant rise in both SBP and DBP with altitude. Higher BP values was noted among children residing at higher than at lower altitude (0.8% at sea level to 18.8% at 8000 feet). Correlations between SBP and DBP values and height and weight, though positive and significant at p Conclusions These data will help in correct interpretation of BP readings in children residing at high altitude.