ZnO thin film-nanowire array homo-structures with tunable photoluminescence and optical band gap

The growth and optical behavior of ZnO thin film-nanowire array homo-structures is reported. The ZnO films are deposited on glass substrates by thermal evaporation and subjected to heat treatment at 400 °C for 2 h to achieve crystallinity and stoichiometry. The surface comprises spherical grains or elongated flakes depending on thickness of films. These films are introduced in to a hydrothermal reactor in a medium of zinc acetate and HMTA to realize the nanostructures. The process results in the formation of ZnO nanowires with dimensions that are strongly dependent on the surface microstructure of the ZnO films. The role of temperature (90–180 °C) and duration (10 min to 10 h) of hydrothermal processing is investigated in detail. It is demonstrated that low temperature and short duration are ideal for producing nanowires with diameter < 100 nm, while longer durations and higher temperatures lead to large diameter and long length nanowires. Interestingly, all wires converge to a hexagonal shape with increase in duration or temperature. The lowest diameter of the vertically aligned nanowires is 50 nm and length upto 10 μm is achieved. Optical band gap of the homo-structures is of the order of 3.4–3.5 eV. Raman and photoluminescence spectra indicate the presence of defects in the films. The thin films exhibit a strong defect related photoluminescence peak centred around 550 nm. The nanowires grown on the films display both the UV-near band edge peak as well as the defect related peak. However, the intensity of the defect peak decreases with increase in length of the nanowires indicating that the photoluminescence of the homo-structures can be tuned by changing the surface microstructure of the films and also the aspect ratio of the nanowires.

ZnO homo-structures with tunable photoluminescence and band gap.     

Research letters

Patients with transfusion-dependent thalassemia are expected to have an unfavorable quality of life due to multiple factors. We studied the quality of life in 72 patients (age 5-39 y) with transfusion-dependent thalassemia in the era of improved care, and assessed different parameters affecting it.     

One stage slide cricotracheoplasty and repair of complete atrioventricular septal defect

Successful single stage repair of complete atrioventricular septal defect and cricotracheal stenosis in an 8-month-old baby with Trisomy 21 is described. The case is notable for rarity of cricoid stenosis being managed together with the long segment tracheal narrowing using the technique of slide cricotracheoplasty.     

Uncontrolled haemorrhage in pelvic fracturesdCan the inevitable be avoided?

Pelvic fractures carry a considerable risk for morbidity and mortality. Half or more of the early deaths in these patients have been attributed directly to haemorrhage. The transfusional requirements are four times higher for open pelvic fractures compared with a similar group of closed pelvic fractures. The loss of the tamponade effect by disruption of the pelvic soft tissues and the energy imparted play a central role in this potentially life threatening situation. We reported a case of open pelvic fracture in which persistent haemorrhage was stopped by giving recombinant activated coagulation factor VIIa as our last resort.     

Significance of p53 expression in ovarian tumors and its correlation to the morphological differentiation

Cancer of breast and cervix reign supreme among the fatal diseases in women globally. Interestingly the ovarian cancer has the highest mortality rate. This is attributed to its late clinical presentation and delayed diagnosis. The expression of p53 throws light on the prognosis of ovarian tumors. The surface epithelial tumors, especially the serous cystadenocarcinoma and non Hodgkin lymphoma of ovary where in the expression p53 was high compared to the benign and borderline tumors. Further the expression of p53 in tumors arising from germinal cells, sex-cord stromal cells are observed to be very low. The expression of p53 and its correlation to the morphology enhances the prognostic significance.     

Predicting negligence in female sterilization failure using time interval to sterilization failure: analysis of 131 cases

BACKGROUND: Sterilization failure due to 'tubal non-occlusion' or 'wrong structure sterilization' is considered negligent, whereas 'spontaneous tubal recanalization' or 'fistula formation' is considered non-negligent. We examined whether interval to pregnancy failure was predictive of a negligent rather non-negligent failure mechanism. We aim to test this hypothesis in a selected population series of known mechanisms of sterilization failure and their time interval to failure. METHODS: Analyses of 131 failed sterilizations pooled from UK (NHS Litigation Authority, Medical Protection Society and our hospital), Australia and a qualitative systematic review. RESULTS: We identified 88 negligent and 43 non-negligent sterilization failures. Filshie and ring methods failed earlier than diathermy and Pomeroy methods. Sterilization failure occurred significantly earlier in negligent than non-negligent failure mechanisms [median failure intervals 7.0 versus 12.0 months; Hazard ratio (2.35 95% CI 1.31-4.21)]. Knowing that sterilization failure occurred early, increased the probability that the failure mechanism was likely to be negligent rather than non-negligent. CONCLUSIONS: A short interval to failure is suggestive of a negligent failure mechanism. There is less certainty in the predictive value of longer time intervals on the mechanism of failure due to a paucity of cases. A national register of failed sterilizations that have been systematically investigated is needed to improve our understanding of negligent and non-negligent failure mechanisms.     

A case report of children of the same family presenting with congenital cataract- as part of a rare genetic disorder—Sengers Syndrome

Sengers syndrome is a rare autosomal recessive mitochondrial disorder characterized by congenital cataract, hypertrophic cardiomyopathy, and mitochondrial myopathy. We report two siblings with known mutation for Sengers Syndrome (AGK gene mutation) who presented to us with cataract and hypertrophic cardiomyopathy. They have a deceased elder sibling who was operated for cataract earlier.