Gallium nitride light-emitting diodes and a study of etching techniques

In the recent years Light Emitting Diodes of impressive longevity and high efficiency have been produced. Gallium Nitride in particular is used in the manufacture of Blue Light Emitting Diodes because it is a direct band gap semiconductor which can be alloyed with AlN and InN allowing band gap energies to range from 1.9eV to 6.2eV, which allows the emission of short wavelengths like that of blue light. A new structure for a GaN blue LED has been proposed. The difficulty faced in wet etching GaN resulted in the study of viable dry etching techniques. This study has looked into the Reactive Ion Etching of Gallium Nitride in Sulphur Hexafluoride. The use of Laser Ablation as an alternative method of etching GaN has been studied in detail. N-type contacts have been deposited on the etched surface and their specific contact resistivities have been measured for different samples under different conditions

Virtual Reality Exposure Therapy for Adolescents with Public Speaking Anxiety

Bakgrunn: Presentasjonsangst er en av de vanligste fryktene blant ungdom. Angsten innebærer en redsel for å bli negativt evaluert, etterfulgt av en følelse av å bli flau eller ydmyket når man snakker foran andre. Eksponeringsterapi for presentasjonsangst er utfordrende å gjennomføre, da en trenger et reelt publikum som kan fungere som det fryktede stimuli. Virtual Reality (VR) kan være løsningen, da teknologien er i stand til å skape et virtuelt publikum, som kan oppleves som ekte. For voksne med presentasjonsangt finnes det flere randomiserte kontrollerte VR-studier som viser gode kliniske effekter, men en vet lite om effekten relatert til ungdom. Ingen studier har tidligere evaluert effekten av selvveiledet, automatiserte og spillbaserte VR-intervensjoner for ungdom med presentasjonsangst. Mål: Denne oppgaven adresserte aktuelle kunnskapshull ved å kartlegge den kliniske effekten og gjennomførbarheten av to VR-intervensjoner for ungdom med presentasjonsangst: en terapeutveiledet og en selvveiledet, automatisert og spillbasert intervensjon. Målet med Artikkel I var å undersøke gjennomførbarheten og den kliniske effekten av en terapeutveiledet, enkelt-sesjons VR-intervensjon for ungdom med presentasjonsangst. Hovedmålet med Artikkel II var å undersøke den kliniske effekten av en selvveiledet, automatisert og spillbasert VR-intervensjon sammenlignet med venteliste og en selvveiledet nettbasert intervensjon. Et sekundært mål var å undersøke om VR-intervensjonen førte til en økning i påfølgende eksponeringsøvelser under det nettbaserte eksponeringsprogrammet, sammenlignet med de som mottok nettbasert psykoedukasjons- og eksponeringsprogram. Målet med Artikkel III var å undersøke om intervensjonene rettet mot presentasjonsangst også førte til en reduksjon i symptomer på perfeksjonisme og om symptomer på perfeksjonisme modererte den kliniske effekten av intervensjonene for presentasjonsangst. Metode: To kliniske studier ga data for tre studier: en ikke-randomisert gjennomførbarhet- og pilotstudie (papir I) og en to-faset, firearmet randomisert kontrollert studie (papir II og III). Begge studiene undersøkte effekter og moderatorer av behandling: symptomer på generalisert sosial angst ved baseline og tilstedeværelse i det virtuelle miljøet (artikkel I) og om perfeksjonisme modererte behandlingsresultatet (artikkel III). Selvrapporterte symptomer på presentasjonsangst ble innhentet under intervensjons- og oppfølgingsperioden i begge studiene, i tillegg til hjertefrekvensmålinger under VR-eksponeringen i Artikkel I, selvrapporterte symptomer på generalisert sosial angst i Artikkel II og III, og perfeksjonisme i Artikkel III. Gjennomførbarhets- og pilotstudien i Artikkel I inkluderte N=27 ungdommer som deltok i en terapeutveiledet, 90-minutters VR-intervensjon på én sesjon ved klinikken. To-faset, firearmede randomiserte kontrollerte studien i Artikkel II og III inkluderte N=100 ungdommer som deltok i et seks ukers digitalt selvveiledet intervensjonsprogram. Ungdommene ble randomisert i fire grupper, med følgende fase én + fase to intervensjon; 1) Kun VR, 2) VR + nettbasert eksponeringsprogram, 3) Nettbasert psykoedukasjon + eksponeringsprogram, 4) Venteliste + nettbasert psykoedukasjonsprogram. Resultater: Resultater fra Artikkel I viste en signifikant reduksjon i presentasjonsangstsymptomer fra pre til post, og symptomene holdt seg stabile ved en og tre måneders oppfølging. Basert på tilbakemeldinger fra ungdommene, ble gjennomførbarheten av intervensjonen økt i løpet av studien, noe som resulterte i ingen manglende besvarelser ved oppfølging. Symptomer på generalisert sosial angst ved baseline og tilstedeværelse modererte ikke de kliniske effektene. Det var en liten økning i hjertefrekvensen under VR-eksponeringsoppgavene. Resultater fra Artikkel II viste en signifikant større reduksjon i presentasjonsangstsymptomer blant ungdommene som mottok VR-intervensjonen sammenlignet med ventelistegruppen. Resultatene viste også at VR + nettbasert eksponeringsprogram var like effektivt sammenlignet med kun VR og nettbasert psykoedukasjon + eksponeringsprogram. I tillegg hadde alle fire grupper en signifikant reduksjon i presentasjonsangstsymptomer. I motsetning til hypotesen fullførte ikke ungdommer som mottok VR-intervensjon et høyere antall in-vivo-eksponeringsoppgaver i løpet av nettbasert eksponeringsprogram sammenlignet med de som mottok nettbasert psykoedukasjon og eksponeringsprogram. De kliniske effektene holdt seg stabile ved tre måneders oppfølging. Resultater fra Artikkel III viste at intervensjonene ikke reduserte perfeksjonisme på gruppenivå, men det var signifikante individuelle forskjeller i endringer over tid. En nedgang i perfeksjonisme var assosiert med en større reduksjon på alle utfallsmål fra post til oppfølging. Det var ingen signifikante interaksjonseffekter mellom presentasjonsangstsymptomer og nivået av perfeksjonisme før behandling. Høye nivåer av perfeksjonisme før behandling var assosiert med dårligere langsiktige resultater for begge gruppene som mottok det nettbaserte eksponeringsprogrammet. Konklusjon: Denne oppgaven bidrar til det voksende evidensgrunnlaget for VR-eksponeringsterapi, og den første som demonstrerer potensialet til både terapeutveiledet og selvveiledet VR-behandling for ungdom generelt, og spesielt for de med presentasjonsangst. Resultatene indikerer at VR-behandling kan fungere som et indisert forebyggingsprogram for ungdom med PSA. Studiene som inngår i oppgaven er gjennomført ved hjelp av et solid design. Gjennomførbarhet og pilotering var første trinn, før man for første gang med denne målgruppen evaluerte de kliniske effektene i en randomisert kontrollert studie. I tillegg har oppgaven undersøkt relevante moderatorer av behandlinger; rollen til perfeksjonisme og hvordan den kan hindre bedring. Disse resultatene kan være veiledende for hvordan optimalisere fremtidige intervensjoner for ungdom med presentasjonsangst. Fremtidige studier bør undersøke om VR-terapi har en langsiktig forebyggende effekt på utvikling av generalisert sosial angst da dette fortsatt er uklart for denne aldersgruppen.Background: Public Speaking Anxiety (PSA) is one of the most common fears reported by adolescents. PSA involves the fear of being negatively evaluated, followed by a feeling of being embarrassed or humiliated when speaking in front of others. Providing state-of-the-art in-vivo exposure therapy for PSA is difficult due to the logistics of recruiting an actual audience trained to act as the feared stimuli. An attractive way of resolving this obstacle is through Virtual Reality (VR) technology, which is capable of creating an immersive experience of being in front of a virtual audience, as if it was real. Although there are several randomized controlled trials demonstrating the clinical efficacy of VR exposure therapy for adults with PSA, little is known about its clinical effects on adolescents. Moreover, no past study has evaluated self-guided and automated VR interventions for adolescents with PSA. Aims: This thesis addressed these key knowledge gaps by exploring the clinical effects and feasibility of both therapist-guided and self-guided, and automated VR interventions for adolescents with PSA. The aim of Paper I was to investigate the feasibility and the clinical effects of a therapist-guided, single-session VR-intervention for adolescents with PSA, using low-cost consumer VR hardware. The primary aim of Paper II was to investigate the clinical efficacy of a self-guided, automated, and gamified VR intervention compared with waitlist and self-guided online programs. A secondary aim was to explore whether the VR intervention led to an increase in subsequent exposure tasks during the online exposure program compared to those receiving the online psychoeducation and exposure program. The aim of Paper III was to investigate whether interventions targeting PSA also led to a reduction in symptoms of perfectionism and whether symptoms of perfectionism moderated the clinical efficacy of self-guided interventions for PSA. Methods: Two clinical trials provided data for three studies: one non-randomized feasibility and pilot study (Paper I) and a two-phased, four-armed randomized controlled study (Paper II and III). Both trials investigated effects and moderators of treatment: baseline generalized social anxiety symptoms and presence in the virtual environment (Paper I) and whether perfectionism moderated treatment outcome (Paper III). Self-reported PSA were assessed during the intervention and follow-up period in both studies, in addition to heart rate measurements during the VR exposure in Paper I, self-reported symptoms of generalized SAD in Paper II and III, and perfectionism in Paper III. The non-randomized feasibility and pilot study in Paper I included N=27 adolescents who participated in a therapist-guided, 90-minutes single-session VR intervention at the clinic. The two-phased, four-armed randomized controlled study in Paper II and III included N=100 adolescents who participated in a six weeks digital self-guided interventions program. The adolescents were randomized into four groups, with the following phase one + phase two intervention; 1) VR only, 2) VR + online exposure program, 3) Online psychoeducation + exposure program, 4) Waitlist + online psychoeducation program. Results: Results from Paper I revealed a significant decrease in PSA symptoms from pre to post, and symptoms remained stable at one- and three-month follow-up. Based on feedback from the adolescents, the feasibility of the intervention was increased during the trial, resulting in no missing data. Baseline generalized social anxiety symptoms and presence did not moderate the clinical effects. There was a small increase in heart rate during the VR exposure tasks. Results from Paper II revealed a significantly greater reduction in PSA symptoms among the adolescents who received the VR intervention compared to the the waitlist group. The results also demonstrated that VR + online exposure program was as equally effective as compared to VR only and online psychoeducation + exposure program. Moreover, all groups had a significant reduction in PSA symptoms. Contrary to the hypothesis, adolescents who received VR training did not complete a higher number of in-vivo-exposure tasks during the online exposure program compared to those receiving online psychoeducation and exposure program. The clinical effects remained stable at three-month follow-up. Results from Paper III revealed that the interventions did not reduce perfectionism at a group level, however, there were significant individual differences in changes over time. A decrease in perfectionism was associated with a larger reduction on all outcome measures from post to follow-up. There were no significant interaction effects between PSA symptoms and the pre-treatment level of perfectionism. High pre-treatment levels of perfectionism was associated with poorer long-term outcomes for both groups receiving the online exposure program. Conclusions: In sum, this thesis contributes to the growing evidence base for VR exposure therapy, and is among the first to demonstrate the potential of both therapist-guided and self-guided, VR interventions for adolescents in general and with PSA in particular. The results indicate that VR may serve as an indicated prevention program for adolescents with PSA. The studies included in the thesis is conducted through a strong design with feasibility and piloting as a first step before evaluating, for the first time with this target group, the clinical effects in a randomized controlled trial. Moreover, the thesis has investigated relevant moderators of treatments, specifically the role of perfectionism and how it may hinder treatment improvement. These results can provide guidance on how to optimize future interventions for the large group of adolescents with PSA. Future studies should investigate whether VR interventions have a long-term preventive effect on the development of generalized social anxiety as this remains unclear for this age group.Doktorgradsavhandlin

A case report: venous sinus thrombosis in pregnancy

Venous sinus thrombosis (VST) should be considered in the differential diagnosis of all unexplained central nervous system disorders of sudden onset. Etiological factors are subclinical forms of several common thrombophilic states occurring together, rather than the typical inherited and rare causes. Diagnosis is often missed because of the heterogeneity in clinical presentation and radiological investigation is essential for the diagnosis. Prognosis depends on the early detection. By correcting the cause, the complications can be prevented

To evaluate the role of MRI in infants with suspected hypoxic ischemic encephalopathy and prognosticating neurological outcome at end of one year

Background: Hypoxic ischemic encephalopathy (HIE) is one the common causes of neonatal fatality due to perinatal asphyxia. The long-term outcomes of HIE are impaired mental and motor development, hearing loss, recurrent seizures and cerebral palsy. MRI is increasingly becoming the gold standard in diagnosis of HIE as it involves no radiation and can be performed during a neonates physiological sleep. To evaluate the role of MRI in infants with suspected hypoxic ischemic encephalopathy in prognosticating neurological outcomes at end of one year.Methods: A total of 50 patients were included in the study who underwent MRI of brain. A clinical follow up was done at the end of one year.Results: The sensitivity of MRI in prognosticating clinical outcome was 72% and specificity was 71% while PPV and NPV was 86% and 50% respectively.Conclusions: MRI is a useful modality to assess early changes in HIE and it can prognosticate clinical outcome

Socioeconomic and nutritional determinants of low birth weight babies: A hospital based study

According to the World Health Organization (WHO) definition, infants with birth weights of less than 2,500 grams are classified as low birth weight (LBW). LBW is a sensitive indicator for predicting the chances of both infant survival and healthy childhood growth and development, and it also reflects the present and past health status of the mother. LBW constitutes an important factor affecting neonatal mortality and morbidity. Objective: To find the incidence of low birth weight babies and its determinants Materials and methods: Present study was a cross sectional type. All mothers delivering live born singleton neonate in study place (Postnatal ward of Rohilkhand Medical College and hospital) were interviewed with pretested, predesigned schedule. Statistical analysis was done using SPSS version 21software and chi square test, OR etc. Results: Overall incidence of LBW was 20% and mean birth weight was 2776.85 + 383.6 gm LBW was found to be more common in the rural population and poor educational status. A higher incidence of LBW was seen in mothers with inadequate diet and those who were anaemic. Conclusion: Low birth weight still poses a fair problem in our perspective, and when we cannot control ethnic factors like height, or do a drastic socio-economic upliftment, some basic factors, like good ANC care, correcting anemia, and above all motivating the mother to follow some habits in the ANC period like adequate consumption of food and adequate rest, institutional deliveries shall take a long way forward in addressing the problem

Ultrasound evaluation of carpal tunnel syndrome in patients with bifid median nerve

Background: Patients with high division of the median nerve proximal to carpal tunnel, or bifid median nerve, may present with carpal tunnel syndrome (CTS). Ultrasound (US) measurements indicative of CTS in this subset of patients differ from those in patients with non-bifid median nerve.   The objectives were to evaluate the parameter ∆CSA [difference between the maximum cross-sectional area of bifid median nerve within carpal tunnel (CSAc) and outside tunnel (CSAp)] in the diagnosis of CTS, to compare sensitivity and specificity of ∆CSA with nerve conduction velocity studies (NCS), and to compare the cross-sectional area (CSAc, CSAp & ∆CSA) of bifid median nerve in CTS patients with that in asymptomatic controls.Methods: 20 wrists with bifid median nerves and symptoms suggestive of CTS were included in the study group. Nerve conduction velocity studies (NCS) were performed in all cases. 4 wrists of asymptomatic age-matched subjects had bifid median nerves and normal NCS and were included in the control group. High resolution ultrasonography was performed for all wrists and findings documented. Statistical Analysis: Receiver Operating Characteristics curves were used to obtain the level of significance (p-value) and assessment of correlation between ∆CSA and NCS findings.Results: There was significant correlation between ∆CSA and NCS. A cut-off value of 2.3mm2 gave the best calculated sensitivity (76.9 %) and specificity (100%).Conclusions: CSA criteria for diagnosing CTS in patients with bifid median nerves are different from those in patients with non-bifid median nerve. ∆CSA is a sensitive and specific parameter for confirming the diagnosis of CTS in patients with bifid median nerve with sensitivity approaching that of NCS

Synergistic Effect of Garcinol and Curcumin on Antiproliferative and Apoptotic Activity in Pancreatic Cancer Cells

Pancreatic cancer (PaCa) is a major health concern due to its aggressiveness and early metastasis. Current treatments for PaCa are limited by development of resistance against therapy. As an alternative strategy, we assessed the combinatorial effect of dietary compounds, garcinol and curcumin, on human PaCa cells (BxPC-3 and Panc-1). A significant (P < 0.05) dose-dependent reduction in cell viability and increase in apoptosis were observed in both cell lines as compared to untreated controls. A combination index (CI) value < 1, for a two-way comparison of curcumin and garcinol, suggests synergism. The potency (Dm) of the combination of garcinol and curcumin was 2 to 10 fold that of the individual agents. This indicates that curcumin and garcinol in combination exhibit a high level of synergism, with enhanced bioactivity, thereby reducing the required effective dose required for each individually. This combinatorial strategy may hold promise in future development of therapies against PaCa

Study of adequacy of informed consent in caesarean section in a tertiary care, teaching and research institute of Northern India

Background: Informed consent consists of availing information to the patient in an understandable manner without coercion to allow the patient to make an informed decision about their healthcare. In the case of caesarean section, information must include name, nature, proposed benefits of the procedure, risks of the procedure, alternative procedures, implications on the future reproductive health and anesthetic options. Aim and objective: To study the adequacy of informed consent in patients who undergo caesarean section at PT. B. D. Sharma, PGIMS, Rohtak.Methods: It was a cross sectional study. The study population was the group of patients who underwent emergency or elective caesarean section at PGIMS, Rohtak. A pretested questionnaire was adopted from a study carried out at School of Medicine, University of Zambia and was administered to the patients.Results: It was found that majority of the patients were in the age group of 21-30 years and most of them (71%) were from the rural areas. In 90% of the cases the outcome of caesarean section was term live births and majority of them (84%) were emergency caesarean section. The patients were asked fourteen questions regarding various aspects of informed consent based on the five point Likert scale.Conclusions: Majority of the caesarean sections were performed due to some emergency indications. It was found that overall patients were well informed about the procedure and the related consequences.

Pregnancy with third degree uterine prolapse: a rare case report

Occurrence of prolapse of uterus during pregnancy is an extremely rare event. Less than 300 cases have been reported in the literature till date. Incidence of uterine prolapse in pregnancy is 1 in 10,000-15,000 deliveries worldwide. A 35 year old G5P3L1A1 with history of five months amenorrhea was referred to our hospital in view of uterine prolapse. On enquiring she gave history of something coming out of vagina since one month. On local examination, third degree uterovaginal prolapse with cord prolapse seen. Patient went into labour spontaneously and expelled an abortus. She was discharged next day with advice regarding follow up visit after six weeks. Uterine prolapse during pregnancy is a rare occurrence which increases both maternal and fetal morbidity. There are many etiological factors which have been cited to be responsible for this condition, important ones are: Multiparity, vaginal delivery, advanced maternal age, increased body mass index. Elective caesarean section can be planned in cases with edematous and elongated cervix. Individualized approach and careful monitoring is the key to manage such patients. Uterine prolapse during pregnancy is a rare event. While managing such patients, an obstetrician should keep in mind threats of spontaneous abortion, preterm labour, cervical dystocia, etc

Study of pattern of nosocomial infections among post-operative patients following obstetrical and gynaecological surgeries in a tertiary care institute of northern India

Background: Hospital acquired infections (HAIs) are the major causes of morbidity and mortality, functional disability and financial burden among the patients admitted in hospitals. The nosocomial infection has thrown a big challenge to the health sector in both the developing and developed countries; therefore, it is important to put in place surveillance system for monitoring its incidence rate and planning early interventions for its prevention. The aim and objective of the study was to study the socio demographic profile of the patients who underwent Obstetrical and Gynecological surgeries and to identify the risk factors and causative organisms associated with the post-operative nosocomial infection and pattern of antibiotics sensitivity.Methods: It was a record based retrospective study carried out in a tertiary care referral institute. The case files of all post-operative patients from January 2015 to July 2015 were retrieved from the Medical Record department and an extensive analysis was carried out.Results: It was found that majority of the patients (75%) with nosocomial infection were in the age group of 20-35 years and all were married. Most of them (72%) were from the rural background. It was observed that around 9% patients reported nosocomial infection after emergency laparotomy procedure as compared to 8% of patients after elective procedure.Conclusions: In this study it was found that surgical site infection (SSI) was most common nosocomial infection followed by Urinary tract infection. The majority of surgical site infections can be prevented by the preoperative, intraoperative and postoperative phases of care