Fabrication of Diamond Based Sensors for Use in Extreme Environments

Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This method can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. We demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.     

Management of neonatal cholestasis: Consensus statement of the pediatric gastroenterology chapter of Indian academy of pediatrics

Justification

Neonatal cholestasis is an important cause of chronic liver disease in young children. Late referral and lack of precise etiological diagnosis are reasons for poor outcome in substantial number of cases in India. There is a need to create better awareness among the pediatricians, obstetricians and primary care physicians on early recognition, prompt evaluation and referral to regional centers.

Process

Eminent national faculty members were invited to participate in the process of forming a consensus statement. Selected members were requested to prepare guidelines on specific issues, which were reviewed by two other members. These guidelines were then incorporated into a draft statement, which was circulated to all members. A round table conference was organized; presentations, ensuing discussions, and opinions expressed by the participants were incorporated into the final draft.

Objectives

To review available published data on the subject from India and the West, to discuss current diagnostic and management practices in major centers in India, and to identify various problems in effective diagnosis and ways to improve the overall outcome. Current problems faced in different areas were discussed and possible remedial measures were identified. The ultimate aim would be to achieve results comparable to the West.

Recommendations

Early recognition, prompt evaluation and algorithm-based management will improve outcome in neonatal cholestasis. Inclusion of stool/urine color charts in well baby cards and sensitizing pediatricians about differentiating conjugated from the more common unconjugated hyperbilirubinemia are possible effective steps. Considering the need for specific expertise and the poor outcome in suboptimally managed cases, referral to regional centers is warranted.     

Granular cell — Peripheral ameloblastoma: a rare variant

Ameloblastoma is an epithelial odontogenic tumour of the jaw and exhibits diverse microscopic patterns which occurs either singly or in combination with other patterns. Peripheral ameloblastoma is a rare odontogenic soft tissue tumor, derived from epithelial and/or mesenchymal elements being part of the tooth-forming apparatus. The lesions responsible for approximately 1% to 5% of all cases of ameloblastoma affecting alveolar mucosa and gingiva occurring mainly, in the middle age. This article describes a case of peripheral ameloblastoma affecting a 35-year-old female. The lesion was located in the right buccal space. The occurrence and pathogenesis of peripheral ameloblastomas in general, are reviewed. The tumour was excised and no recurrence has been observed after twenty four months of surgery.     

In vitro evaluation of antimicrobial property of silver nanoparticles and chlorhexidine against five different oral pathogenic bacteria

Introduction

Numerous antimicrobial agents are used to eliminate oral biofilm. However due to emergence of multi drug resistant microorganisms, the quest to find out biologically safe and naturally available antimicrobial agents continues.

Corticospinal tract modeling for neurosurgical planning by tracking through regions of peritumoral edema and crossing fibers using two-tensor unscented Kalman filter tractography

Purpose

The aim of this study was to present a tractography algorithm using a two-tensor unscented Kalman filter (UKF) to improve the modeling of the corticospinal tract (CST) by tracking through regions of peritumoral edema and crossing fibers.

Methods

Ten patients with brain tumors in the vicinity of motor cortex and evidence of significant peritumoral edema were retrospectively selected for the study. All patients underwent 3-T magnetic resonance imaging (MRI) including functional MRI (fMRI) and a diffusion-weighted data set with 31 directions. Fiber tracking was performed using both single-tensor streamline and two-tensor UKF tractography methods. A two-region-of-interest approach was used to delineate the CST. Results from the two tractography methods were compared visually and quantitatively. fMRI was applied to identify the functional fiber tracts.

Results

Single-tensor streamline tractography underestimated the extent of tracts running through the edematous areas and could only track the medial projections of the CST. In contrast, two-tensor UKF tractography tracked fanning projections of the CST despite peritumoral edema and crossing fibers. Based on visual inspection, the two-tensor UKF tractography delineated tracts that were closer to motor fMRI activations, and it was apparently more sensitive than single-tensor streamline tractography to define the tracts directed to the motor sites. The volume of the CST was significantly larger on two-tensor UKF than on single-tensor streamline tractography (\(p < 0.001\)).

Conclusion

Two-tensor UKF tractography tracks a larger volume CST than single-tensor streamline tractography in the setting of peritumoral edema and crossing fibers in brain tumor patients.