Dual metal ion (Fe3+ and As3+) sensing and cell bioimaging using fluorescent carbon quantum dots synthesised from Cynodon dactylon

In this study, water dispersible fluorescent carbon quantum dot (CQD) has been synthesised, having an average size of 8.6 ± 0.4 nm using Cynodon dactylon (CD) following microwave assisted green synthetic one-step method. As-prepared CQD fluoresces strongly at 444 nm having a quantum yield of 1% in water when excited at 350 nm. This fluorescence of CQD is sensitive toward As3+ and Fe3+ metal ions. These CQD are utilized for dual metal ion fluorescence sensing; turn-on fluorescence sensing for As3+ and turn-off fluorescence sensing for Fe3+ ions. Limit of detection for As3+ and Fe3+ ions has been found to be 19 nM and 0.10 μM respectively, which is the lowest value reported for As3+ without any functionalization. The adsorption kinetics of As3+ and Fe3+ ions on CQD have been examined using pseudo-first-order-kinetic model revealing that physical adsorption is dominant over chemical processes in this work. For 0.41 g/L and 1.90 g/L dose of CQD, the equilibrium adsorption capacity was found to be 1.57 × 10-6 mg/g, 2.91 × 10-7 mg/g, and 1.01 × 10-5 mg/g, 1.69 × 10-6 mg/g respectively for As3+ and Fe3+ ions. Despite having low quantum yield in water, as-prepared CQD showed low cytotoxicity and good tolerance against photodegradation of biological cells at concentrations lower than 62.5 μg/mL and when the cells are illuminated up to 12 h. Owing to this, the synthesised CQD have been utilized as fluorescent probes for in itro cell imaging.

Chromium (VI) induced oxidative stress in halotolerant alga Dunaliella salina and D. tertiolecta isolated from sambhar salt lake of Rajasthan (India)

Chromium (Cr) is one of the most serious pollutants in aquatic systems. This study was performed to understand the effect of Cr (VI) on halophilic algal strains of D. salina and D. tertiolecta. The results revealed good tolerance of D. salina towards chromium (VI) up to 8 ppm concentration, whereas tolerance level in D. tertiolecta was up to 2 ppm concentration. Cr (VI) not only inhibited the growth of D. tertiolecta, but also showed increased inhibition in the level of photosynthetic pigments, protein and carbohydrate. Results have revealed that chromium (VI) induced higher increase in lipid peroxidation and H2O2 production in D. tertiolecta than the D. salina, particularly at higher concentration of chromium (VI). Chromium (VI) induced increase in the rate of RNO bleaching, loss of pigments and thiol (-SH) group was relatively higher in D. tertiolecta than the D. salina, which is indicating that D. tertiolecta was prone to Cr (VI) induced oxidative stress. Results on RNO bleaching in the presence of radical quenchers suggested that OH° radical played an important role in the chromium (VI)-induced general oxidative stress in D. tertiolecta.

Electric-field-induced patterns in soft viscoelastic films: from long waves of viscous liquids to short waves of elastic solids

We show that the electric field driven surface instability of viscoelastic films has two distinct regimes: (1) The viscoelastic films behaving like a liquid display long wavelengths governed by applied voltage and surface tension, independent of its elastic storage and viscous loss moduli, and (2) the films behaving like a solid require a threshold voltage for the instability whose wavelength always scales as approximately 4xfilm thickness, independent of its surface tension, applied voltage, loss and storage moduli. Wavelength in a narrow transition zone between these regimes depends on the storage modulus.

Deformation of metallic liquid drop by electric field for contacts in molecular–organic electronics

We study and use the behaviour of a metallic liquid drop in the presence of an external electric field (EF). The droplet profile is governed by the stabilizing surface energy and the destabilizing electrostatic energy, with a critical voltage beyond which the droplet becomes unstable. We explore the EF-induced behaviour of low melting temperature alloy in the liquid state and observe that the droplet modifications in the linear response regime can be retained upon cooling the drop to the solid state. We demonstrate that this procedure can be used as an electrode with precise dimensions for applications in molecular and polymer electronics.

Urinary bladder paraganglioma in a case of von Hippel-Lindau disease

Pheochromocytoma is a well-known association in patients with von Hippel-Lindau disease. However, extra-adrenal pheochromocytoma or paraganglioma with this association is rare. We describe a patient with von Hippel-Lindau disease who presented with haematuria and was diagnosed to have a urinary bladder paraganglioma, which is an extremely rare tumour. Herein we report this case which, to the best of our knowledge, represents the first case highlighting the association of urinary bladder paraganglioma with von Hippel-Lindau disease.

Rigid nasendoscope with video camera system for intubation in infants with Pierre-Robin sequence

We describe an alternative intubation technique using a rigid nasendoscope and a video camera monitor system in two infants with Pierre-Robin sequence presenting for palatoplasty. After induction with an inhalational anaesthetic technique, the tracheas of the infants could not be intubated with direct laryngoscopy using a Wisconsin blade. In the absence of a flexible paediatric fibrescope, a rigid endoscope (2.7 mm, 70 degrees lateral illumination) was passed orally to provide a view of the glottis on the monitor screen. A tracheal tube, bent into a J-shape using a stylet, was inserted orally and manipulated into the trachea, under video guidance. This technique proved to be simple, permitting a favourable view of the glottis. It should be considered for passing a tracheal tube through the vocal cords in infants who present with a difficult airway.

Efficacy of turmeric on blood sugar and polyol pathway in diabetic albino rats

In the traditional system of medicine, Ayurveda, several spices and herbs are thought to possess medicinal properties. Among the spices, turmeric rhizomes (Curcuma longa. Linn.) are used as flavoring and coloring agents in the Indian diet everyday. In this research, we studied the effect of turmeric and its active principle, curcumin, on diabetes mellitus in a rat model. Alloxan was used to induce diabetes. Administration of turmeric or curcumin to diabetic rats reduced the blood sugar, Hb and glycosylated hemoglobin levels significantly. Turmeric and curcumin supplementation also reduced the oxidative stress encountered by the diabetic rats. This was demonstrated by the lower levels of TBARS (thiobarbituric acid reactive substances), which may have been due to the decreased influx of glucose into the polyol pathway leading to an increased NADPH/NADP ratio and elevated activity of the potent antioxdiant enzyme GPx. Moreover, the activity of SDH (sorbitol dehydrogenase), which catalyzes the conversion of sorbitol to fructose, was lowered significantly on treatment with turmeric or curcumin. These results also appeared to reveal that curcumin was more effective in attenuating diabetes mellitus related changes than turmeric.

Is open pyeloplasty still justified?

OBJECTIVE

To determine the success rate, complications and morbidity from open pyeloplasty.

PATIENTS AND METHODS

The study included 63 patients with confirmed pelvi-ureteric junction (PUJ) obstruction who underwent 66 pyeloplasties. Their records were analysed retrospectively for age, clinical presentation, serum creatinine level, presence of infection, surgical technique, and pre- and post-operative isotopic renography. The mean (range) follow-up was 15.5 (3-60) months.

RESULTS

Pain was the most common presenting symptom; most pyeloplasties were dismembered and 77% of the procedures were performed by urological trainees. Retrograde pyelography did not alter the management in any patient. The complications were persisting PUJ obstruction in four, urinary leakage in two, transient vesico-ureteric obstruction in two and meatal stenosis in one. There were no complications in non-intubated pyeloplasties. Pain was successfully relieved in 98% of patients, renal function improved or remained stable in 92% and deteriorated in 7.7%. One patient underwent a revision pyeloplasty and another required nephrectomy. A younger patient, absence of urinary tract infection and absence of palpable mass were favourable factors.

CONCLUSION

Pyeloplasty is the most effective and permanent treatment for PUJ obstruction. Newer endoscopic procedures currently used must be carefully assessed against this 'gold standard' before becoming widespread.