Spatially selective narrow band and broadband absorption in Ag/SiO2/Ag based trilayer thin films by oblique angle deposition of SiO2layer

We have experimentally demonstrated spatially selective absorption in Ag-SiO2-Ag based trilayer thin films by tuning the deposition angle of SiO2layer. These structures generate cavity resonance which can be tuned across the substrate locations due to spatially selective thickness and refractive index of silicon oxide (SiO2) film sandwiched between metallic silver (Ag) mirrors. Spatially selective property of SiO2film is obtained by oblique angle deposition technique using an electron beam evaporation system. The resonance wavelength of absorption in this trilayer structure shifts across the substrate locations along the direction of oblique deposition. The extent of shift in resonance increases with increase in angle of deposition of SiO2layer. 4.14 nm mm-1average shift of resonance wavelength is observed when SiO2is deposited at 40° whereas 4.76 nm mm-1average shift is observed when SiO2is deposited at 60°. We observed that the width of resonance increases with angle of deposition of the cavity layer and ultimately the resonant absorption disappears and becomes broadband when SiO2is deposited at glancing angle deposition (GLAD) configuration. Our study reveals that there is a suitable range of oblique angle of deposition from 40° to 60° for higher spatial tunability and resonant absorption whereas the absorption becomes broadband for glancing angle deposition.

Treatment of Infrabony Defects by Open Flap Debridement with or without Diode Laser

Background Periodontitis is the common oral condition which affects the periodontium of the teeth that leads to destruction of periodontal ligaments and alveolar bone. Open flap debridement is the surgical procedure which provides access and visibility of the site, application of laser as an adjunct has various advantanges. Objective To compare clinical outcomes after open flap debridement with or without diode laser. Method Patients aged 25-45 years diagnosed with infrabony defect ≥ 5 mm visiting Department of Dental Surgery, Bir Hospital. Control group sites were treated with open flap debridement alone, whereas test-groups were treated with Open flap debridement with diode laser. Various parameters like Plaque index, Gingival index, Pocket depth and Clinical attachment level were assessed and compared between groups at baseline, 3 and 6 months. Result The mean plaque and gingival scores improved in both the control and test groups at 3 and 6 months follow up as compared to baseline and was statistically nonsignificant between two groups. Open flap debridement with or without diode laser in the treatment of periodontal intrabony defects did not produce significant reduction in pocket depth and gain in clinical attachment level. Conclusion There was no significant differences in the clinical parameters were seen in the surgical flap debridement of infrabony pocket with and without diode laser. Diode laser can be used safely as an adjunct. However, long-term, multicentric, histologic and microbial studies are required.

Prevalence of Gingivitis in Second Trimester of Pregnancy

Background Gingivitis simply means the inflammation of gingiva. It is a reversible state but can lead to periodontitis. The final result could be the exfoliation of the tooth causing decreased masticatory function leading to a compromised quality of life. Gingivitis in the pregnant woman should be carefully assessed and treated and given special attention. There is rare documentation on the prevalence of gingivitis in pregnancy in the least developed countries. Objective To evaluate the prevalence of gingivitis in the second trimester of pregnancy and assess its relationship with age, parity, education, occupation, gravidity, oral hygiene habit and frequency of brushing. Method An observational descriptive study was conducted among 384 pregnant females in their second trimester in Kathmandu, Nepal. Demographic variables and general information including those related to oral hygiene practices and habits were collected during an interview. Plaque index and Gingival Index was recorded among the patients through full mouth examination at four sites. Result The prevalence of gingivitis in the second trimester of pregnancy was 76.3%. Statistically significant relationship was found between gingivitis and gravida and parity. A relation could not be established between gingivitis with age, education, occupation, oral hygiene habit and frequency of brushing. Conclusion The prevalence of gingivitis is found to be high in Nepalese pregnant women. Special strategies should be introduced targeting the pregnant women of least developed countries to uplift their periodontal health.

Polyglutamine Expansion in Huntingtin and Mechanism of DNA Damage Repair Defects in Huntington’s Disease

Emerging evidence suggests that DNA repair deficiency and genome instability may be the impending signs of many neurological diseases. Genome-wide association (GWAS) studies have established a strong correlation between genes that play a role in DNA damage repair and many neurodegenerative diseases, including Huntington’s disease (HD), and several other trinucleotides repeat expansion-related hereditary ataxias. Recently, many reports have documented a significant role played by the DNA repair processes in aging and in modifying many neurodegenerative diseases, early during their progression. Studies from our lab and others have now begun to understand the mechanisms that cause defective DNA repair in HD and surprisingly, many proteins that have a strong link to known neurodegenerative diseases seem to be important players in these cellular pathways. Mutations in huntingtin (HTT) gene that lead to polyglutamine repeat expansion at the N-terminal of HTT protein has been shown to disrupt transcription-coupled DNA repair process, a specialized DNA repair process associated with transcription. Due to the recent progress made in understanding the mechanisms of DNA repair in relation to HD, in this review, we will mainly focus on the mechanisms by which the wild-type huntingtin (HTT) protein helps in DNA repair during transcription, and the how polyglutamine expansions in HTT impedes this process in HD. Further studies that identify new players in DNA repair will help in our understanding of this process in neurons. Furthermore, it should help us understand how various DNA repair mechanism(s) coordinate to maintain the normal physiology of neurons, and provide insights for the development of novel drugs at prodromal stages of these neurodegenerative diseases.

Regional Differences in Gamma-Aminobutyric Acid and Glutamate Concentrations in the Healthy Newborn Brain

BACKGROUND AND PURPOSE

Gamma-aminobutyric acid and glutamate system disruptions may underlie neonatal brain injury. However, in vivo investigations are challenged by the need for special ¹H-MR spectroscopy sequences for the reliable measurement of the neurotransmitters in this population. We used J-edited ¹H-MR spectroscopy (Mescher-Garwood point-resolved spectroscopy) to quantify regional in vivo gamma-aminobutyric acid and glutamate concentrations during the early postnatal period in healthy neonates.

MATERIALS AND METHODS

We prospectively enrolled healthy neonates and acquired Mescher-Garwood point-resolved spectroscopy spectra on a 3T MR imaging scanner from voxels located in the cerebellum, the right basal ganglia, and the right frontal lobe. CSF-corrected metabolite concentrations were compared for regional variations and cross-sectional temporal trends with advancing age.

RESULTS

Fifty-eight neonates with acceptable spectra acquired at postmenstrual age of 39.1 (SD, 1.3) weeks were included for analysis. Gamma-aminobutyric acid (+ macromolecule) (2.56 [SD, 0.1]) i.u., glutamate (3.80 [SD, 0.2]), Cho, and mIns concentrations were highest in the cerebellum, whereas NAA (6.72 [SD, 0.2]), NAA/Cho, Cr/Cho, and Glx/Cho were highest in the basal ganglia. Frontal gamma-aminobutyric acid (1.63 [SD, 0.1]), Glx (4.33 [SD, 0.3]), Cr (3.64 [SD, 0.2]), and Cho concentrations were the lowest among the ROIs. Glx, NAA, and Cr demonstrated a significant adjusted increase with postmenstrual age (β = 0.2-0.35), whereas gamma-aminobutyric acid and Cho did not.

CONCLUSIONS

We report normative regional variations and temporal trends of in vivo gamma-aminobutyric acid and glutamate concentrations reflecting the functional and maturational status of 3 distinct brain regions of the neonate. These measures will serve as important normative values to allow early detection of subtle neurometabolic alterations in high-risk neonates.

The Fontan Pathway: Change in Dimension and Catheter-Based Intervention over Time

An unobstructed Fontan pathway is essential for optimal hemodynamics. We hypothesize that more extracardiac conduit (ECC) Fontan pathways develop obstruction compared to lateral tunnel (LT) Fontans and that the dilation typically observed in LTs results in similar mid-term clinical outcomes. A single-center, retrospective study was done including all Fontan cardiac catheterizations from 2006 to 2019. Angiography and medical records were reviewed to define Fontan pathway dimensions, interventions, and clinical outcomes. 232 patients underwent cardiac catheterization, where 60% were ECCs and 30% LTs. The minimum cross-sectional area (CSA) of ECCs was significantly smaller than LTs and LTs dilated over time. 13% of patients had Fontan pathway stenting at a median age of 16.2 years. The minimum CSA for patients who underwent intervention was significantly smaller than patients who did not. Lower weight at Fontan surgery was associated with intervention on the Fontan pathway, with a threshold weight of 15 kg for patients with an ECC. The median follow-up was 3.3 years. Patients who had Fontan pathway intervention were not more likely to experience the composite adverse clinical outcome. LTs were more likely than ECCs to have worse clinical outcome, when liver fibrosis was included. This is the first study to describe angiographic dimensions of the Fontan pathway in a large number of patients over time. ECCs tend to become stenotic. Lower weight at Fontan surgery is a potential risk for Fontan pathway intervention. LTs may experience worse clinical outcomes in follow-up. This information can help inform the optimal timing and method of post-Fontan surveillance.

Treatment options for leishmaniasis

Leishmaniasis is broadly classified into three types: cutaneous, mucocutaneous and visceral. The visceral form is most dangerous and can result in death. Although leishmaniasis is an ancient disease, its treatment is still challenging. Several drugs, differing in their cost, toxicity, treatment duration and emergence of drug resistance, are used for different types of leishmaniasis. To overcome these limitations, the search for newer drugs and other treatments continues. In this article, we discuss conventional drugs, other treatments, including newer options such as immunotherapy and immunochemotherapy, and future prospects for leishmaniasis treatment.

Application of Modified Regression Techniques to a Quantitative Assessment for the Motor Signs of Parkinson's Disease

Effective clinical trials for neuroprotective interventions for Parkinson's disease (PD) require a way to quantify an individual's motor symptoms and analyze the change in these symptoms over time. Clinical scales provide a global picture of function but cannot precisely measure specific aspects of motor control. We have used commercially available sensors to create a protocol called ASAP (Advanced Sensing for Assessment of Parkinson's disease) to obtain a quantitative and reliable measure of motor impairment in early to moderate PD. The ASAP protocol measures grip force as an individual tracks a sinusoidal or pseudorandom target force under three conditions of increasing cognitive load. Thirty individuals with PD have completed the ASAP protocol. The ASAP data for 26 of these individuals were summarized in terms of 36 variables, and modified regression techniques were used to predict an individual's score on the Unified Parkinson Disease Rating Scale based on ASAP data. We observed a mean prediction error of approximately 3.5 UPDRS points, and the predicted score accounted for approximately 76% of the variability of the UPDRS. These results demonstrate that the ASAP protocol can measure differences for individuals who are clinically different. This indicates that the ASAP protocol may be able to measure changes with time in the motor signs of an individual with PD.

Self-confidence Level among Intern Dentists in Performing Endodontic Treatment Procedures in Nepal

Background Endodontics is considered as one of the most difficult and stressful disciplines in dentistry. This might be due to the complex anatomical variations, recent advances in equipment, technology, materials and lack of self-confidence. Objective To determine the self-confidence level among the intern dentists in performing endodontic procedures from six different colleges of Kathmandu University, Nepal. Method A descriptive cross-sectional study was conducted among 145 intern dentists. The online questionnaire regarding confidence level (5 point Likert scale) in different endodontic procedures and difficulty level (easy, ok and difficult) with respect to teeth was distributed. For descriptive purpose, frequency and percentage for each response were calculated. Result Dental interns were confident in performing majority of the normal endodontic procedures, however, they showed less confidence in performing difficult steps like rubber dam application for anterior (74, 51%) and posterior tooth (91, 62.7%), use of electronic apex locator (89, 61.4%), using rotary files (114, 78.6%), management of flare-ups (86, 59.4%), assessment of quality of post-endodontic treatment (85, 58.5%), recall periods (75, 51.6%) and performing post and core (82, 56.6%). Likewise, upper first molars (84, 57.9%) and second molars (104, 71.7%) were found to be the most difficult teeth to treat. Conclusion It can be concluded that majority of the dental interns were confident in performing basic endodontic procedures, however, they were found to have low confidence in performing difficult steps. Further training and exposure should be incorporated to increase their confidence level.

PIAS1 modulates striatal transcription, DNA damage repair, and SUMOylation with relevance to Huntington's disease

DNA damage repair genes are modifiers of disease onset in Huntington's disease (HD), but how this process intersects with associated disease pathways remains unclear. Here we evaluated the mechanistic contributions of protein inhibitor of activated STAT-1 (PIAS1) in HD mice and HD patient-derived induced pluripotent stem cells (iPSCs) and find a link between PIAS1 and DNA damage repair pathways. We show that PIAS1 is a component of the transcription-coupled repair complex, that includes the DNA damage end processing enzyme polynucleotide kinase-phosphatase (PNKP), and that PIAS1 is a SUMO E3 ligase for PNKP. Pias1 knockdown (KD) in HD mice had a normalizing effect on HD transcriptional dysregulation associated with synaptic function and disease-associated transcriptional coexpression modules enriched for DNA damage repair mechanisms as did reduction of PIAS1 in HD iPSC-derived neurons. KD also restored mutant HTT-perturbed enzymatic activity of PNKP and modulated genomic integrity of several transcriptionally normalized genes. The findings here now link SUMO modifying machinery to DNA damage repair responses and transcriptional modulation in neurodegenerative disease.

Adrenal Ganglioneuroma

Adrenal ganglioneuromas are rare sympathetic differentiated tumors which originate from neural crest cells. These lesions are usually discovered incidentally on imaging and tend to be hormonally silent. Preoperative diagnosis of adrenal ganglioneuroma remains extremely challenging and the gold standard treatment is adrenalectomy. There is good prognosis after surgery without recurrence. We herein report a case of adrenal ganglioneuroma in a 15 year old female who presented with complaint of abdominal discomfort. Contrast Enhanced Computed Tomography abdomen showed a large septated hypodense right suprarenal mass which was echogenic on Ultrasonography. It showed T1 hypointense and T2 hyperintense signal on Magnetic Resonance Imaging of abdomen and pelvis. Excisional biopsy and histological examination of the mass was suggestive of adrenal ganglioneuroma. This report presents the clinical and radiological data for the rare tumor which would share some experience to facililate the diagnosis of adrenal ganglioneuroma.

Nature-derived materials for the fabrication of functional biodevices

Nature provides an incredible source of inspiration, structural concepts, and materials toward applications to improve the lives of people around the world, while preserving ecosystems, and addressing environmental sustainability. In particular, materials derived from animal and plant sources can provide low-cost, renewable building blocks for such applications. Nature-derived materials are of interest for their properties of biodegradability, bioconformability, biorecognition, self-repair, and stimuli response. While long used in tissue engineering and regenerative medicine, their use in functional devices such as (bio)electronics, sensors, and optical systems for healthcare and biomonitoring is finding increasing attention. The objective of this review is to cover the varied nature derived and sourced materials currently used in active biodevices and components that possess electrical or electronic behavior. We discuss materials ranging from proteins and polypeptides such as silk and collagen, polysaccharides including chitin and cellulose, to seaweed derived biomaterials, and DNA. These materials may be used as passive substrates or support architectures and often, as the functional elements either by themselves or as biocomposites. We further discuss natural pigments such as melanin and indigo that serve as active elements in devices. Increasingly, combinations of different biomaterials are being used to address the challenges of fabrication and performance in human monitoring or medicine. Finally, this review gives perspectives on the sourcing, processing, degradation, and biocompatibility of these materials. This rapidly growing multidisciplinary area of research will be advanced by a systematic understanding of nature-inspired materials and design concepts in (bio)electronic devices.

0254 The Effects of Chronic Sleep Restriction on Multiple Object Tracking

Introduction

The ability to simultaneously track numerous moving objects in the presence of irrelevant stimuli is essential for successfully carrying out a variety of tasks. Sleep loss impairs neurocognitive functioning and, as a result, attentional processing capacity is reduced. The objective of the current study was to determine if performance on the multiple object tracking (MOT) task was adversely impacted by a week of chronic sleep restriction (CSR).

Methods

Twelve healthy participants (6 males, 6 females) kept a fixed sleep-wake schedule, with a constant waketime, at home for four weeks (actigraphy confirmed compliance). During weeks one and three, participants maintained 9 hours in bed. During weeks two and four, participants were randomly assigned to 5 and 9 hours of sleep. Following weeks two and four, participants completed a 13-hour laboratory visit under dim light (< 15 lux), where they maintained a constant posture and were provided with hourly isocaloric snacks. MOT was presented at approximately 6 and 8 hours after waking. Participants were required to track four, five, or six moving targets in the presence of identical distractors (always 12 total objects).

Results

Participants slept significantly less when assigned to 5 (M = 4.43 hours, SD = 0.33 hours), compared to 9 hours of sleep (M = 7.42 hours, SD = 0.42 hours; F (1, 22) = 206.89, p = 0.00). The proportion of correct MOT responses was significantly lower following 5 (M = 0.70, SD = 0.15) compared to 9 hours of sleep (M = 0.77, SD = 0.12; F (1, 22) = 10.29, p < .05).

Conclusion

A week of CSR adversely impacted MOT performance compared to a week of sleep satiation. These findings have implications for individuals, such as air traffic controllers and truck drivers, who must visually track multiple moving objects, often while chronically sleep deprived.

Support

Supported by the Force Health Protection Program of the Office of Naval Research (SAA2402925-1, Contract Award no. N0001418IP00050).

0174 Examining Circadian Disadvantages in the National Basketball Association’s Playoffs

Introduction

Prior research on travel in the National Basketball Association’s (NBA) regular season has shown that teams journeying west relative to their home base face circadian disadvantages for evening games, while those traveling east have advantages. The current study extends previous research by examining these effects within the NBA playoffs. We hypothesized that teams would have a greater circadian advantage during eastward compared to westward travel.

Methods

In 2013, the NBA implemented a 7-game series playoff structure, in which teams play an alternating home/away 2-2-1-1-1 format. Data for all 499 postseason games played during the 2013–14 to 2018–2019 seasons were collected from Basketball-Reference and FiveThirtyEight. We investigated the impact of direction of travel based on home base city (same time zone, westward, eastward) and time zones traveled on game outcomes, Elo rating differences (i.e., a team quality metric based on wins and losses), win probability, and team scoring.

Results

Teams had lower win probabilities following 3-hour westward than same time zone and all eastward travel, while 3-hour eastward travel related to higher probabilities of winning compared to same time and all westward travel (p < .001, d > .95). Teams travelling westward with 2-hour time changes lost significantly more games than those experiencing 1-hour westward (p = .04, OR = 2.45), 1-hour eastward (p = .05, OR = 2.34), and 3-hour eastward changes (p = .02, OR = 4.68). Scoring was significantly higher following eastward travel compared to both westward (p = .001, d = 0.60) and same time zone travel (p = .003, d = 0.44). There were no differences in team quality based on direction of travel or number of time zones traveled, and game outcomes based on overall direction of travel (p > .05).

Conclusion

Direction and magnitude of travel were related to win probability, team scoring, and game outcomes, whereby teams travelling eastward and within the same time zone gained an advantage over those travelling westward. Adjustment to travel and time changes appear to influence in-game performances and outcomes in the NBA playoffs.

Support

None

Multi-drug Resistant and Extended Spectrum β-lactamase Producing Salmonella Species Isolated from Fresh Chicken Liver Samples

Background Ductus arteriosus is a vascular structure which connects the roof of main pulmonary artery near the origin of the left branch pulmonary artery to the proximal descending aorta. Patent ductus arteriosus (PDA) closure is indicated for any patient who is symptomatic from left to right shunting. Objective To investigate the hospital outcomes of surgical closure of patent ductus arteriosus over last 19 years starting from the very first case of our center. Method This is a retrospective analysis of all patent ductus arteriosus treated surgically from August 2001 to July 2019. Patients who underwent isolated surgical closure of patent ductus arteriosus were included. Data have been presented in three different eras (Era 1: 2001-2007, Era 2: 2008-2013, and Era 3: 2014-2019) to see the trend of evolution of this surgery. Result A total of 901 patients aged 8.67±8.76 years under went patent ductus arteriosus surgical closure over last 19 years. Patients in the initial era 2001-2007 were significantly older compared with other 2 eras (p=0.000). Males accounted for 35.5% of all cases. Twenty percent had severe pulmonary artery hypertension.Duration of mechanical ventilation was 3.57±9.64 hours with ICU stay of 1.55±1.53 days, and hospital stay of 3.9±2.3 days. Overall in hospital mortality was 0.8%; for isolated patent ductus arteriosus diagnosis, mortality was 0.2%. Chylothorax was noted in 0.4%. Conclusion This is the first report to analyze surgical outcomes of patent ductus arteriosus ligation in our center. We have discussed the evolution of patent ductus arteriosus surgery in our center, and have shown favorable outcomes in terms of morbidity and mortality.

Factors Affecting the Uptake of Institutional Delivery, Antenatal and Postnatal Care in Nawalparasi District, Nepal

Background Maternal deaths and complications are highly preventable with good antenatal, postnatal and skilled care during childbirth. Inadequate information on the factors affecting these services could be barrier to a reduction of maternal deaths in lowincome countries. Objective To assess the uptake of antenatal, postnatal and skilled care during childbirth. Method A cross-sectional study was conducted in eight villages of Nawalparasi district in southern Nepal. A total of 447 women who had given birth within the preceding 24 months were recruited using multistage random sampling. Data were collected using a pre-tested semi-structured questionnaire. Chi-square tests were used to assess association between variables. Result Over 70% of women had gone for at least four antenatal care check-ups while only 14.3% had at least three postnatal check-ups in their last pregnancies. The proportion of institution delivery was 54%. Women's literacy was associated with the uptake of antenatal services (p=< 0.001), postnatal care (p=0.04) and institutional delivery (p=< 0.001). Knowledge of antenatal (p=< 0.001) and postnatal care was also associated with uptake of respective services (p=< 0.001). Conclusion The uptake and knowledge of antenatal care was much better than of postnatal care. Home delivery rates were still very high. A scaling-up of education and awarenessraising interventions in this community could help improve the uptake of maternal health services.

Comprehensive case management of malaria: Operational research informing policy

In 2013, the Odisha state Vector Borne Disease Control Programme led a five year operational research project, under programmatic conditions, in close collaboration with several partners. This Comprehensive Case Management Project covered a population of 900,000 across paired control and intervention blocks in four districts, each with different transmission intensities. Key gaps in access to malaria services were identified through household surveys and a detailed situation analysis. The interventions included ensuring adequate stocks of rapid diagnostic tests and antimalarial drugs at the village level, the capacity building of health workers and ASHAs, setting up microscopy centres at the primary health care level, and conducting mass screening and treatment in poorly accessible areas. The programme strengthened the routine health system, and improved malaria surveillance as well as the access to and quality of care. Initially, the programme led to increased case reporting due to improved detection, followed by a decline in malaria incidence. Lessons from the project were then scaled up statewide in the form of a new initiative-Durgama Anchalare Malaria Nirakaran (DAMaN).

Mutant huntingtin impairs PNKP and ATXN3, disrupting DNA repair and transcription

How huntingtin (HTT) triggers neurotoxicity in Huntington's disease (HD) remains unclear. We report that HTT forms a transcription-coupled DNA repair (TCR) complex with RNA polymerase II subunit A (POLR2A), ataxin-3, the DNA repair enzyme polynucleotide-kinase-3'-phosphatase (PNKP), and cyclic AMP-response element-binding (CREB) protein (CBP). This complex senses and facilitates DNA damage repair during transcriptional elongation, but its functional integrity is impaired by mutant HTT. Abrogated PNKP activity results in persistent DNA break accumulation, preferentially in actively transcribed genes, and aberrant activation of DNA damage-response ataxia telangiectasia-mutated (ATM) signaling in HD transgenic mouse and cell models. A concomitant decrease in Ataxin-3 activity facilitates CBP ubiquitination and degradation, adversely impacting transcription and DNA repair. Increasing PNKP activity in mutant cells improves genome integrity and cell survival. These findings suggest a potential molecular mechanism of how mutant HTT activates DNA damage-response pro-degenerative pathways and impairs transcription, triggering neurotoxicity and functional decline in HD.

Monte Carlo Study of Unflattened Photon Beams Shaped by Multileaf Collimator

INTRODUCTION

This study investigates basic dosimetric properties of unflattened 6 MV photon beam shaped by multileaf collimator and compares them with those of flattened beams.

MATERIALS AND METHODS

Monte Carlo simulation model using BEAM code was developed for a 6MV photon beam based on Varian Clinic 600 unique performance linac operated with and without a flattening filter in beam line. Dosimetric features including lateral profiles, central axis depth dose, photon and electron spectra were calculated for flattened and unflattened cases, separately.

RESULTS

An increase in absolute depth dose with a factor of more than 2.4 was observed for unflattened beam which was dependent on depth. PDDs values were found to be lower for unflattened beam for all field sizes. Significant decrease in calculated mlc leakage was observed when the flattening filter was removed from the beam line. The total scatter factor, S_CP was found to show less variation with field sizes for unflattened beam indicating a decrease in head scatter. The beam profiles for unflattened case are found to have lower relative dose value in comparison with flattened beam near the field edge, and it falls off faster with distance.

CONCLUSION

Our study showed that increase in the dose rate and lower peripheral dose could be considered as realistic advantages for unflattened 6MV photon beams.

Retrospective study on outcome of macular hole surgery

INTRODUCTION

Macular hole is a common and treatable cause of central visual loss. Classic macular hole surgery consists of vitrectomy, posterior vitreous cortex removal and intraocular gas tamponade, but during the past decade focus has especially been on internal limiting membrane (ILM) peeling as adjuvant therapy for increasing closure rates.

OBJECTIVE

To determine and evaluate anatomical and visual outcome of macular hole surgery.

MATERIALS AND METHODS

Retrospective analysis of all cases of macular hole surgery done by single surgeon between 2014 -2015.

RESULTS

16 eyes were analysed with follow up of 3 months. Macular hole closure after vitrectomy was 75% with visual improvement of two or more line in 62.5%.Post surgical complication included cataract 18.8%, Increased IOP 12.5% and retinal detachment 6.2%.

CONCLUSION

Vitrectomy along with ILM peeling and Gas Tamponade with effective positioning improves in visual acuity and achieve hole closure in people with macular hole.

Phytostimulatory effect of silver nanoparticles (AgNPs) on rice seedling growth: An insight from antioxidative enzyme activities and gene expression patterns

The knowledge on the mode of action, biocompatibility and ecological tolerance of silver nanoparticles (AgNPs) is gradually accumulating over the years with contradictory findings. Most of the studies indicated the toxic impact of AgNPs on plant growth and development, where induction of oxidative stress was considered to be one of the causal factors. The present study demonstrates the phytostimulatory effect of bio-synthesized silver nanoparticles (AgNPs) during seed germination and seedling growth of rice (Oryza sativa L., cv. Swarna) under in vitro condition. All the tested concentrations of AgNPs (10, 20, 40 ppm) promote both the shoot and root growth which was evident from the increased length and biomass of the seedlings. Exposure to AgNPs also significantly increased the chlorophyll a and carotenoid contents. The content and the pattern of distribution of phenolic metabolites among the different treatments are indicative of non-toxic impact of AgNP mimicking mild or no stress to the seedlings. Growth stimulation of rice seedlings by AgNPs was further supported by a low level of reactive oxygen species (ROS) concomitant with decreased amount of lipid peroxidation and H₂O₂ content, compared to control. In order to unravel the stimulatory impact of AgNPs on rice seedling growth, the present study also describes the AgNPs induced changes in antioxidative enzyme activity and related gene expression levels. Elevated levels of catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) activities were recorded in all the AgNPs treated seedlings with improved growth. The activity of superoxide dismutase (SOD) was not significantly altered at low concentration of AgNPs. It appears that enzymes of ascorbate cycle, APX and GR are more active in ensuring protection against oxidative damage than SOD. There was significant up-regulation of CAT and APX gene expressions in seedlings exposed to AgNPs, whereas the expression level of CuZnSOD gene was decreased gradually with an increase in the concentration of AgNPs. The antioxidant enzyme activities and gene expression patterns coupled with the levels of H₂O₂ and lipid peroxidation indicates that the efficiency of redox reactions was increased in the presence of AgNPs and that accelerates the seedling growth.

Spin-Resolved Spectroscopy of the Yu-Shiba-Rusinov States of Individual Atoms

A magnetic atom in a superconducting host induces so-called Yu-Shiba-Rusinov (YSR) bound states inside the superconducting energy gap. By combining spin-resolved scanning tunneling spectroscopy with simulations we demonstrate that the pair of peaks associated with the YSR states of an individual Fe atom coupled to an oxygen-reconstructed Ta surface gets spin polarized in an external magnetic field. As theoretically predicted, the electron and hole parts of the YSR states have opposite signs of spin polarizations which keep their spin character when crossing the Fermi level through the quantum phase transition. The simulation of a YSR state right at the Fermi level reveals zero spin polarization which can be used to distinguish such states from Majorana zero modes in chains of YSR atoms.