The impact of metal-to-ligand charge transfer towards the redox noninnocence of 2,2'-azobis(benzothiazole) (abbt) has been highlighted on coordination to {Ru II (acac) 2 } (acac = 2,4-pentanedionato). It led to the authentication of a series of mononuclear and dinuclear complexes incorporating variable oxidation states of abbt (abbt 0/ C À/2À ). Mononuclear 1 was identified as [Ru III (abbtC À )], a MLCT excited state of [Ru II (abbt)]. Dinuclear 2 was however recognized as two discrete redox isomers: (i) radical bridged mixed-valent meso-[Ru 2.5 (m-abbtC À )Ru 2.5 ] (2a) and (ii) dianionic ligand bridged isovalent meso-[Ru III (m-abbt 2À )Ru III ] (2b), demonstrating unprecedented structural confirmation of valence tautomerism in azo-based ligand systems. A crystal structure of [2]ClO 4 validated the formation of [Ru III (m-abbtC À ) Ru III ]ClO 4 . Analysis of electronic structural forms of 1 and 2 in accessible redox states via spectroelectrochemistry and DFT revealed their electron reservoir feature.

The paper deals with the electronic impact of ancillary ligands on the varying redox features of azobis(benzothiazole) (abbt) in the newly introduced mononuclear ruthenium complexes [Ru(pap) 2 (abbt)] n (1 n ) and [Ru(bpy) 2 (abbt)] n (2 n ), where pap = 2phenylazopyridine and bpy = 2,2′-bipyridine. In this regard, the complexes [Ru II (pap) 2 (abbt •− )]ClO 4 ([1]ClO 4 ), [Ru II (pap) 2 (abbt 0 )](ClO 4 ) 2 ([1](ClO 4 ) 2 ), [Ru II (bpy) 2 (abbt 0 )](ClO 4 ) 2 ([2](ClO 4 ) 2 ), and [Ru II (bpy) 2 (abbt •− )]ClO 4 ([2]ClO 4 ) were structurally and spectroscopically characterized. Unambiguous assignments of the aforestated radical and nonradical forms of abbt in 1 + /2 + and 1 2+ /2 2+ , respectively, were made primarily based on their redox-sensitive azo (NN) bond distances as well as by their characteristic electron paramagnetic resonance (EPR)/NMR signatures. Although the radical form of abbt •− was isolated as an exclusive product in the case of strongly π-acidic pap-derived 1 + , the corresponding moderately π-acidic bpy ancillary ligand primarily delivered an oxidized form of abbt 0 in 2 2+ , along with the radical form in 2 + as a minor (<10%) component. The oxidized abbt 0 -derived [1](ClO 4 ) 2 was, however, obtained via the chemical oxidation of [1]ClO 4 . Both 1 + and 2 2+ displayed multiple closed by reversible redox processes (one oxidation O1 and four successive reductions R1−R4) within the potential window of ±2.0 V versus saturated calomel electrode. The involvement of metal-, ligand-, or metal/ligand-based frontier molecular orbitals along the redox chain was assigned based on the combined experimental (structure, EPR, and spectroelectrochemisry) and theoretical [density functional theory (DFT): molecular orbitals, Mulliken spin densities/time-dependent DFT] investigations. It revealed primarily ligand (abbt/pap or bpy)-based redox activities, keeping the metal ion as a simple spectator. Moreover, frontier molecular orbital analysis corroborated the initial isolation of the radical and nonradical species for the pap-derived 1 + and bpy-derived 2 2+ as well as facile reduction of pap and abbt in 1 + and 2 + , respectively.

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In this study, a compact (15 mm × 12 mm) uniplanar multi‐band antenna is proposed for laptops and tablets application with a near omni‐directional coverage. The main structure of the antenna implements meander design for compactness and multi‐band operation. A staircase‐type arm and an F‐shaped arm are added for achieving resonances at exact frequencies and for good impedance matching, respectively. The antenna is designed such that it operates in all the global positioning system/wireless local area network/worldwide interoperability for microwave access bands and is easy to fabricate and integrate inside laptops/tablets. A prototype of the proposed antenna is fabricated, and its performance is validated for multi‐band operation and omni‐directional radiation.

Background:Portable ultrasound machines are highly valuable in ICUs, where a patient's condition might not permit shifting the patient to the USG department for imaging. Traditionally central lines are put blindly using anatomical landmarks, which often result in complications such as difficulty in access, misplaced lines, pneumothorax, bleeding from inadvertent arterial punctures, etc. Ultrasonography provides “real time” imaging, i.e., the needle can be visualized entering the vein.Aims:We performed a study to compare USG guided central venous cannulation (CVC) and conventional anatomical landmark approach to CVC, in terms of ease of cannulation, time consumed, and associated complications.Settings and Design:The study was performed in a 16-bed open ICU. Eighty patients were randomly divided in two groups.Materials and Methods:The right internal jugular vein (IJV) was cannulated in all. In Group I, a portable ultrasound machine was used during cannulation. The vessels were visualized in the transverse section with the internal carotid artery (ICA) identified as a circular pulsatile structure, while the IJV as a lateral, oval nonpulsatile structure). The needle was inserted perpendicular to the skin under visualization on the US screen. Central venous line was then inserted by the Seldinger technique. In Group II, CVC was performed by the conventional landmark approach. The parameters studied included time for insertion, attempts required, and complications encountered.Statistical Analysis:The database of all parameters was analyzed using SPSS software version 10.5.Results:The mean time to successful insertion was 145 and 176.4 sec in groups I and II, respectively (p = 0.00). An average of 1.2 attempts per cannulation was required for group I, while 1.53 for group II (p = 0.03): 10% witnessed arterial puncture and 2.5% pneumothorax in group I and none in group II.Conclusion:USG-guided CVC is thus easier, quicker, and safer than landmark approach.

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Background and Aim:Intravenous (IV) route for fentanyl administration is the gold standard for post-operative pain relief, but complications such as respiratory depression, bradycardia and hypotension have limited this route. The aim of this randomised controlled trial was to compare the efficacy of nebulised fentanyl with IV fentanyl for post-operative pain relief after lower abdominal surgery.Methods:In the post-operative care unit, at the time of first onset of pain (visual analogue scale- VAS score > 4) patients were randomised into three groups and fentanyl was administered either IV 2 μg/kg or by nebulisation of solution containing 3 or 4 μg/kg fentanyl over 8 min in 90 patients divided into three groups of 30 each. Observation were made for pain relief by visual analogue scale score 0-10. Adverse effects such as respiratory depression, bradycardia and hypotension were also recoded. Statistical analysis was performed using Medcalc software version 12, 2012. (MedCalc Software, Ostend, Belgium).Results:In the nebulisation group, it was observed that the analgesic efficacy of fentanyl was dose dependent with a delayed onset of analgesia (10 min vs. 5 min). Nebulisation with 4 μg/kg fentanyl produced analgesia at par to 2 μg/kg IV fentanyl with prolonged duration (90 min vs. 30 min) and with significantly less adverse effects.Conclusions:This study shows that nebulisation with 4 μg/kg fentanyl may be used as an alternative to IV 2 μg/kg fentanyl for adequate post-operative pain relief.