Impact of Pt(hkl) Electrode Surface Structure on the Electrical Double Layer Capacitance.

The classical theory of the electrical double layer (EDL) does not consider the effects of the electrode surface structure on the EDL properties. Moreover, the best agreement between the traditional EDL theory and experiments has been achieved so far only for a very limited number of ideal systems, such as liquid metal mercury electrodes, for which it is challenging to operate with specific surface structures. In the case of solid electrodes, the predictive power of classical theory is often not acceptable for electrochemical energy applications, e.g., in supercapacitors, due to the effects of surface structure, electrode composition, and complex electrolyte contributions. In this work, we combine ab initio molecular dynamics (AIMD) simulations and electrochemical experiments to elucidate the relationship between the structure of Pt(hkl) surfaces and the double-layer capacitance as a key property of the EDL. Flat, stepped, and kinked Pt single crystal facets in contact with acidic HClO4 media are selected as our model systems. We demonstrate that introducing specific defects, such as steps, can substantially reduce the EDL capacitances close to the potential of zero charge (PZC). Our AIMD simulations reveal that different Pt facets are characterized by different net orientations of the water dipole moment at the interface. That allows us to rationalize the experimentally measured (inverse) volcano-shaped capacitance as a function of the surface step density.

Oral Rehabilitation of a Pediatric Patient with Vitamin D-dependent Rickets II: A Rare Case Report.

Vitamin D-dependent rickets (VDDR) is a disorder of bone development characterized by softened weak bones. It is of two types-vitamin D-dependent rickets-I (VDDR-I) and vitamin D-dependent rickets type II (VDDR-II). Vitamin D-dependent rickets type II is a rare autosomal recessive disorder. The patients exhibit characteristic clinical features as well as numerous dental manifestations such as hypoplastic teeth, missing teeth, enlarged pulp chambers, and recurrent spontaneous abscesses. The case presented in this article is of vitamin D-dependent rickets type II in a pediatric dental patient who reported with multiple missing teeth and required treatment consisting of restorations and extractions. The aim of the present article is to raise awareness on the characteristics of this disorder, as well as its treatment and dental considerations. HOW TO CITE THIS ARTICLE: Chhonkar A, Gupta A, et al. Oral Rehabilitation of a Pediatric Patient with Vitamin D-dependent Rickets II: A Rare Case Report. Int J Clin Pediatr Dent 2019;12(1):73-75.

Oral health status of 5 years and 12 years old school going children in rural Gurgaon, India: an epidemiological study.

BACKGROUND AND AIMS: Oral health is an essential component of health throughout life. Hardly any information is available on the oral health status of children in Gurgaon. Thus, the present study was conducted among 5-year-old and 12-years-old children in schools in rural Gurgaon. MATERIALS AND METHODS: A total of 1003 children were examined of which 619 were in 5 years age group and 384 in 12 years group. The prevalence of dental caries was studied using dentition status and treatment needs index. For dental calculus criteria of Community Periodontal and for dental fluorosis Dean's index was used. RESULTS: In 5 years age group prevalence of dental caries was 68.5%, dental fluorosis was 22.5% and treatment needs were 63.7%. In 12 year age group prevalence of dental caries was 37.5%, dental fluorosis was 76.04%, highest community periodontal index score was 2, seen in 80.2% and overall treatment needs were 44.3%. CONCLUSION: Preventive approaches seem to be a viable alternative to tackle the overwhelming problem of dental caries and other oral diseases. Provision of oral health education in schools and school based preventive programs are important for improvement of this situation.

Retrospective study on laparoscopic management of ectopic pregnancy.

PURPOSE: To evaluate various laparoscopic methods for management of tubal ectopic pregnancy and study the incidence of ectopic pregnancy including the incidence of cornual ectopic pregnancy and conversion to laparotomy during laparoscopic procedure. METHODS: A retrospective study was conducted in North Point Hospital, Delhi, on all laparoscopies conducted in 4 years, i.e., from January 2008 to December 2011. RESULTS: Incidence of ectopic pregnancy was 4.62 % (out of all laparoscopic surgeries over 4 years) and that for cornual pregnancy was 4.65 % (out of all ectopic pregnancies); no laparotomy was done for the management of ectopic pregnancy. The site of ectopic pregnancy in the tubal pregnancy varied, with 76.75 % in the ampullary region, 16.27 % isthumic, 2.33 % fimbrial, and 4.65 % in the cornual region. Salpingectomy was done in 53.5 % cases and 46.5 % of patients underwent a conservative approach in the form of salpingostomy. CONCLUSION: The laparoscopic management of ectopic pregnancy is a safe and effective option with greatly reduced morbidity.