Investigations of surface related electronic properties in SmB6 and LaAlO3SrTiO3 heterostructures

This dissertation reports research performed on two types of two-dimensional systems: SmB6 and LaAlO3/SrTiO3 (LAO/STO). SmB6 has been proposed to be a topological Kondo insulator at low temperature. In order to understand carriers/ lattice dynamics and their interactions, femtosecond pump-probe spectroscopy is performed in SmB6 single crystals and thin lms at variable temperatures. The collective oscillation modes in GHz - THz and the change of carrier relaxations is observed as a function of temperature. From the temperature dependent results for d hybridization, opening of the hybridization gap, \phonon bottleneck , and th possible topological surface state formation is revealed. The topological surface state should support helical Dirac dispersion with momentum-spin lockage. This dissertation reports on current injection in SmB6 thin lm with circularly polarized light at oblique incidence. This spin polarized photocurrent is concluded to be a direct result of spin momentum lockage in SmB6. LAO/STO interface shows 2-dimensional electron gas (2DEG) at the interface when the thickness of LAO is more than 3 unit cell. Carrier properties at the LAO/STO interfaces are highly sensitive to the top surface termination of LAO. The spontaneous dissociation of water on LAO surface is systematically studied by density functional theory and experimental surface characterizations. Extrinsic effects from surface adsorbates were often ignored in the previous studies of the 2DEG. From the experiments, it is found that the dissociated water molecules, especially the surface protons, strongly aect the interface density of states, electron distributions and lattice distortions. The investigations also reveal the importance of additional molecular water layers. These additional water layers, through hydrogen bonds, provide an energetically feasible pathway for manipulating the surface-bonded protons and thus, the interface electrical characteristics

Vision screening among hearing-impaired school children in Biratnagar, Nepal

Background: The prevalence of hearing impairment in Nepal is 16.5%, affecting approximately 2.71 million people. Deaf children are visually dependent, and even a mild refractive error may cause visual discomfort. The goal of this study was to determine the need for vision screenings in schools for the hearing impaired in Biratnagar, Nepal. Methods: A cross-sectional study was conducted with permission from Birat Deaf Secondary School, Biratnagar, Nepal. A total of 130 hearing-impaired students were examined. Non-invasive, comprehensive optometric examinations were performed to detect visual disorders. When a more detailed evaluation was needed, the students were referred to the Pediatric Ophthalmology Department, Biratnagar Eye Hospital Biratnagar, Nepal. Results: Of the 130 hearing-impaired students, 58 (44.6%) were male and 72 (55.4%) were female. The mean ± standard deviation of age was 16.03 ± 3.8 years (range 6–25 years). Twenty-one (16.1%) students had refractive errors: 13 (10%) had myopia, 7 (5.4%) had hyperopia, and 1 (0.8%) had anisometropia. In the cover test, 88 (67.7%) had orthophoria, 19 (14.6%) had exophoria, 11 (8.5%) had esophoria, 5 (3.85%) had exotropia, and 3 (2.3%) had esotropia. Cover tests were not performed in 4 (3.1%) students, as they were unable to fixate due to nystagmus or decreased vision. On ocular examination, 20 (15.3%) students had anterior segment abnormalities, including lid abnormality, conjunctivitis, Bitot’s spots, pterygium, corneal opacity, and lenticular opacity. Posterior segment or retinal abnormalities were found in four students with one having Usher syndrome. Color vision defects, nystagmus, and amblyopia were found in 8 (6.1%), 2 (1.5 %), and 1 (0.8%), respectively. Conclusions: The findings of the present study reflect the need of periodic vision screenings in schools for the hearing impaired in Nepal. These children are at a high risk of vision impairment. How to cite this article: Sah SK, Thakur R, Adhikari PR. Vision screening among hearing-impaired school children in Biratnagar, Nepal. Med Hypothesis Discov Innov Optom. 2021 Spring; 2(1): 36-40. DOI: https://doi.org/10.51329/mehdioptometry123 &nbsp

Development of Cost Optimized Horizontal Gel Electrophoresis Running Unit for Developing Countries (Nepal)

The use of expensive lab techniques has left many high schools and even university students unacquainted with the basic experimental procedures and protocols in developing country including Nepal. Horizontal gel electrophoresis is one of the expensive protocols, which every student in the laboratory may not get an equal chance to access individually. However, this technique, being indispensable and inevitable in molecular biology principles, is of abounding importance for students to be familiar with. Thus, realizing its importance, we present an extremely simple and inexpensive design of gel-electrophoresis unit, which emulates electrophoresis analysis with the use of nichrome and aluminum wires as a substitute for platinum wires, together with daily used plastic materials. Because of these factors, the approximate cost of unit design is significantly reduced to an amount of 10 USD. The efficiency of the substitute wires was confirmed and it resulted in satisfactory data characterized by good resolution of the DNA fragments. The inexpensive nature, good results and simplicity of the device make it an ideal unit for teaching and learning in developing countries

Adult Wilms’ Tumor: A Rare Case Report

Wilms’ tumor is one of the most common intraabdominal malignancies among children and treatment protocols have been well studied in this population. The clinical presentation differs between the pediatric and adult populations with adults presenting similar to patients with renal cell carcinoma. Diagnosis is usually made by surgical pathology as imaging cannot differentiate between Wilms’ tumor and other kidney pathologies. In addition to surgical excision, treatment includes systemic chemotherapy and/or radiation. In this case report, we present a patient who underwent successful surgical resection of a 29x24x25 cm right-sided Wilms’ tumor with subsequent chemotherapy and radiation

Neutrophil to lymphocyte ratio predicts short- and long-term mortality following revascularization therapy for ST elevation myocardial infarction

Background: Several inflammation biomarkers have been implicated in the pathogenesis and prognosis of acute coronary syndromes. However, the prognostic role of the neutrophil-lymphocyte white cell interactive response to myocardial injury in predicting short- and long-term mortality after ST elevation myocardial infarction (STEMI) remains poorly defined.Methods: We evaluated 250 consecutive STEMI patients presenting acutely for revascularization to our tertiary care center over 1 year. Patients with acute sepsis, trauma, recent surgery, autoimmune diseases, or underlying malignancy were excluded. Data gathered included demographics, clinical presentation, leukocyte markers, electrocardiograms, evaluations, therapy,major adverse cardiac events, and all-cause mortality.Results: Mean age was 62 ± 15 years, 70.4% of subjects were males while majority (49.4%) were Caucasians. Mean duration of follow-up was 571 ± 291 days (median 730 days). Univariate analysis of several inflammatory biomarkers including C-reactive protein, revealed white cell count (OR = 1.09, p < 0.001) and neutrophil to lymphocyte ratio (NLR) (OR = 1.05, p = 0.011) as predictors of short- and long-term mortality; but not mean neutrophil count (OR = 1.04, p = 0.055) or lymphocyte count alone (OR = 0.96, p = 0.551). Multivariate analysis using backward stepwise regression revealed NLR (OR = 2.64, p = 0.026), female gender (OR = 5.35, p < 0.001), cerebrovascular accident history (OR = 3.36, p = 0.023), low glomerular filtration rate (OR = 0.98, p = 0.012) and cardiac arrest on admission (OR = 17.43, p < 0.001) as robust independent predictors of long-term mortality. NLR was divided into two sub-groups based on an optimal cut off value of 7.4. This provided the best discriminatory cut off point for predicting adverse mortality outcome. Both short-term (≤ 30 days) and long-term (≤ 2 years) mortality were predicted with Kaplan-Meier survival curve separation best stratified by a NLR cut off value of 7.4.Conclusions: NLR based on an optimal cut off value of 7.4, was an excellent predictor of short- and long-term survival in patients with revascularized STEMI and warrants larger scale multi-center prospective evaluation, as a prognostic indicator. NLR offers improved prognostic capacity when combined with conventional clinical scoring systems, such as the Thrombolysis In Myocardial Infarction risk score.

A REVIEW ON THE MEDICINAL PLANT PSIDIUM GUAJAVA LINN. (MYRTACEAE)

Psidium guajava is an important food crop and medicinal plant available in tropical and subtropical countries, widely used in food and folk medicines around the world. It contains important phytoconstituents such as tannins, triterpenes, flavonoid: quercetin, pentacyclic triterpenoid: guajanoic acid, saponins, carotenoids, lectins, leucocyanidin, ellagic acid, amritoside, beta-sitosterol, uvaol, oleanolic acid and ursolic acid. In view of the immense medicinal importance of the plant, this review is an effort to compile all the information reported on its ethanobotanical, phytochemical and pharmacological activities. The present work attempts to generate interest among the masses regarding its potential in preventing and treating several common diseases. Many pharmacological studies have demonstrated the ability of this plant to exhibit antioxidant, hepatoprotective, anti-allergy, antimicrobial, antigenotoxic, antiplasmodial, cytotoxic, antispasmodic, cardioactive, anticough, antidiabetic, antiinflamatory and antinociceptive activities, supporting its traditional uses. Suggesting a wide range of clinical applications for the treatment of infantile rotaviral enteritis, diarrhoea and diabetes. Key words: ethanobotany, myrtaceae, pharmacology, physicochemical, phytochemical, Psidium guajav

Awareness regarding radiation knowledge among clinicians practicing in Bharatpur, Nepal

Missed lung lesions are one of the most frequent causes of malpractice issues, caused by several reasons; among them suboptimal radiography. When radiographers interpret acquired images of a patient, an acceptance or rejection must be decided. When a retake is required, radiographers need to know how to improve the image quality. Improvements in image quality properties as contrast, sharpness and noise often lead to improved perception, which in turn should enable more information to the observer and also allow computer-assisted detection (CAD) to be more successful

Outcome analysis of Cohen’s cross trigonal ureteric reimplantation in paediatric age group

Introduction: Cohen’s cross trigonal ureteric reimplantation is the gold standard for surgical management of vesicoureteric reflux (VUR) in children with high success rate. The objective of this study was to evaluate and assess the outcome of open Cohen’s procedure in children with VUR.  Methods: A retrospective review of all patients with VUR who underwent Cohen’s procedure between March 2010 and February 2020 was done. The following were recorded for each patient: age, sex, grade of reflux, operative time, outcome and complications.  Results: The series consisted of 40 patients (25 girls and 15 boys) who underwent Cohen’s procedure with a mean age of 32 months (6 months to 8 years). Bilateral repairs were performed in 16 patients (40%) in the same setting and unilateral repair in 24 patients (60%). Twenty-two patients (55%) had grade IV VUR, 13 patients (32.5%) had grade V VUR and 05 patients (12.5%) had grade III VUR. Mean operative time for bilateral repairs was 249.4(200-290) minutes and 158.3(130-180) minutes for unilateral repair respectively. The mean length of hospital stay was 10.55 (7-15) days. Major complications included two persistent VURs, and one case of bladder hematoma. Postoperative ultrasound abdomen in all patients and micturating cystourethrogram in few patients was obtained, in which 38 patients (95%) had normal study. Conclusion: Cohen’s uretric reimplantation is a standard procedure in paediatric VUR. For better outcome, patient selection and refinement of operative technique should be pursued

Outcome analysis of Cohen’s cross trigonal ureteric reimplantation in paediatric age group

Introduction: Cohen’s cross trigonal ureteric reimplantation is the gold standard for surgical management of vesicoureteric reflux (VUR) in children with high success rate. The objective of this study was to evaluate and assess the outcome of open Cohen’s procedure in children with VUR.  Methods: A retrospective review of all patients with VUR who underwent Cohen’s procedure between March 2010 and February 2020 was done. The following were recorded for each patient: age, sex, grade of reflux, operative time, outcome and complications.  Results: The series consisted of 40 patients (25 girls and 15 boys) who underwent Cohen’s procedure with a mean age of 32 months (6 months to 8 years). Bilateral repairs were performed in 16 patients (40%) in the same setting and unilateral repair in 24 patients (60%). Twenty-two patients (55%) had grade IV VUR, 13 patients (32.5%) had grade V VUR and 05 patients (12.5%) had grade III VUR. Mean operative time for bilateral repairs was 249.4(200-290) minutes and 158.3(130-180) minutes for unilateral repair respectively. The mean length of hospital stay was 10.55 (7-15) days. Major complications included two persistent VURs, and one case of bladder hematoma. Postoperative ultrasound abdomen in all patients and micturating cystourethrogram in few patients was obtained, in which 38 patients (95%) had normal study. Conclusion: Cohen’s uretric reimplantation is a standard procedure in paediatric VUR. For better outcome, patient selection and refinement of operative technique should be pursued