Demographic and Clinical Profile of Women Attending Genetic Clinic for Prenatal Invasive Testing at a Tertiary Referral Center, India.

Background The Prenatal Invasive Tests (PIT) are used during pregnancy for the detection of genetic anomalies. Studies addressing the profile of women who come to seek prenatal invasive testing are scarce. Objective To assess the socio-demographic characteristics and clinical profile of women who are referred for prenatal invasive testing in a tertiary referral center in India. Method A descriptive, cross-sectional study was undertaken in 60 women who came to the genetic clinic at a tertiary referral center, New Delhi, India following counseling regarding prenatal invasive testing. Data was collected using a self-developed and validated semi-structured questionnaire, administered after the counseling for the test by the counselor. Data were analyzed using mean, percentage, standard deviation and range. Result The majority of the women were from urban residences and all of them were literate. Nearly half of the women were in the age group 21-30 years. Mean gestational age was 19.24 ± 2.63 weeks and most were pregnant for the second time. The main reasons for referral were advanced maternal age and abnormal obstetric ultrasonography. The participant's understanding of the test was still incomplete despite the counseling and there was a need for additional counseling/information. One-third of them preferred additional counseling whereas, the remaining twothirds preferred booklets and pamphlets. Conclusion The profiles of pregnant women referred to genetic clinic provide better insight about their background for the health personnel and this study emphasizes rechecking the understanding regarding invasive tests following counseling; which eventually helps for appropriate decision making regarding the tests.

Outcome of Uretero Renoscopic Lithotripsy (URSL) with Holmium LASER Vs Pneumatic Lithotripter for Lower Ureteric Stones, Experience from University Hospital of Nepal.

Background There are various methods of endoluminal ureteral stone fragmentation. Among various modalities Laser lithotripsy and Pneumatic lithotripsy are commonly used and have shown comparable outcomes. Objective To compare the efficacy and outcome of laser and pneumatic lithotripsy in a patient with lower ureteric calculi. The comparison will be done in stone free rate, migration of stone and complication of the procedure. Method This is a prospective comparative study in a cohort of patients at University Hospital with Lower Ureteric stone. Ninety patients were randomized in to two groups (Laser Lithotripsy Vs Pneumatic Lithotripsy) during the study period. The purpose of this study was to measure the immediate stone free rate, intra-operative complications, mean operative time, post-operative complication and if any stone retention after six weeks follow up. Result Both the groups were similar in Age and Gender. Immediate stone free rate was slightly higher in Laser lithotripsy group (97.77%) in comparison to Pneumatic lithotripter group (84.44%) with p=0.507 which is not statistically significant. There was statistical difference in terms of stone migration rate, mean operation time in favor of Laser Lithotripsy group (p<0.01, in both parameters). There were no immediate complications in both the group however there were three cases of short segment ureteric strictures (6.66%) in case of Pneumatic lithotripsy on six weeks follow up which was managed conservatively. Conclusion Both LASER lithotripter and Pneumatic lithotripter are equally efficacious modality of endoluminal URSL in lower ureteric stone with similar Stone Free Rate. Laser lithotripsy showed lower frequency of stone migration and had shorter procedure time.

Quantized Faraday and Kerr rotation and axion electrodynamics of a 3D topological insulator.

Topological insulators have been proposed to be best characterized as bulk magnetoelectric materials that show response functions quantized in terms of fundamental physical constants. Here, we lower the chemical potential of three-dimensional (3D) Bi2Se3 films to ~30 meV above the Dirac point and probe their low-energy electrodynamic response in the presence of magnetic fields with high-precision time-domain terahertz polarimetry. For fields higher than 5 tesla, we observed quantized Faraday and Kerr rotations, whereas the dc transport is still semiclassical. A nontrivial Berry's phase offset to these values gives evidence for axion electrodynamics and the topological magnetoelectric effect. The time structure used in these measurements allows a direct measure of the fine-structure constant based on a topological invariant of a solid-state system.

Network effects and pathways in Deep brain stimulation in Parkinson's disease.

Deep brain stimulation of subthalamic nucleus (STN-DBS) became a standard therapeutic option in Parkinson's disease (PD), even though the underlying modulated network of STN-DBS is still poorly described. Probabilistic tractography and connectivity analysis as derived from diffusion tensor imaging (DTI) were performed together with modelling of implanted electrode positions and linked postoperative clinical outcome. Fifteen patients with idiopathic PD without dementia were selected for DBS treatment. After pre-processing, probabilistic tractography was run from cortical and subcortical seeds of the hypothesized network to targets represented by the positions of the active DBS contacts. The performed analysis showed that the projections of the stimulation site to supplementary motor area (SMA) and primary motor cortex (M1) are mainly involved in the network effects of STN-DBS. An involvement of the "hyperdirected pathway" and a clear delimitation of the cortico-spinal tract were demonstrated. This study shows the effects of STN-DBS in PD distinctly rely on the network connections of the stimulated region to M1 and SMA, motor and premotor regions.

High-Resolution Faraday Rotation and Electron-Phonon Coupling in Surface States of the Bulk-Insulating Topological Insulator Cu_{0.02}Bi_{2}Se_{3}.

We have utilized time-domain magnetoterahertz spectroscopy to investigate the low-frequency optical response of the topological insulator Cu_{0.02}Bi_{2}Se_{3} and Bi_{2}Se_{3} films. With both field and frequency dependence, such experiments give sufficient information to measure the mobility and carrier density of multiple conduction channels simultaneously. We observe sharp cyclotron resonances (CRs) in both materials. The small amount of Cu incorporated into the Cu_{0.02}Bi_{2}Se_{3} induces a true bulk insulator with only a single type of conduction with a total sheet carrier density of ~4.9×10^{12}/cm^{2} and mobility as high as 4000 cm^{2}/V·s. This is consistent with conduction from two virtually identical topological surface states (TSSs) on the top and bottom of the film with a chemical potential ~145 meV above the Dirac point and in the bulk gap. The CR broadens at high fields, an effect that we attribute to an electron-phonon interaction. This assignment is supported by an extended Drude model analysis of the zero-field Drude conductance. In contrast, in normal Bi_{2}Se_{3} films, two conduction channels were observed, and we developed a self-consistent analysis method to distinguish the dominant TSSs and coexisting trivial bulk or two-dimensional electron gas states. Our high-resolution Faraday rotation spectroscopy on Cu_{0.02}Bi_{2}Se_{3} paves the way for the observation of quantized Faraday rotation under experimentally achievable conditions to push the chemical potential in the lowest Landau level.

Testing the effects of pre-processing on voxel based morphometry analysis.

Voxel based morphometry (VBM) is an automated analysis technique which allows voxel-wise comparison of mainly grey-matter volumes between two magnetic resonance images (MRI). Two main analysis processes in VBM are possible. One is cross-sectional data analysis, where one group is compared with another to depict see the regions in the brain, which show changes in their grey-matter volume. Second is longitudinal data analysis, where MRIs, taken at different time points, are compared to see the regions in the brain that show changes in their grey matter volume for one time point with respect to another time point. Both types of analyses require pre-processing steps before performing the statistical analysis. In this study, we examined grey matter differences for patients with blepharospasmus (BFS) before and after treatment, at two different time points. The main evidence base therapy for this condition is the "botulinum toxin" injection in the respective muscles. The main aim of this study was to look at the effects of different pre-processing steps, namely, normalization and smoothing on the results of the longitudinal data analysis. A second aim was to analyze structural grey-matter differences before and after the treatment. Our results showed that the DARTEL normalization and the lower width for smoothing as preprocessing steps delivered pathophysiological plausible results. The longitudinal analysis revealed significant temporal differences after the injection of the botulinum toxin injection mainly in patients with BFS.

Differentiating tremor patients using spiral analyses.

Essential tremor follows an autosomal dominant type of inheritance in the majority of patients, yet its genetic basis has not been identified. The age of onset in this tremor is bimodal, one in young age and another when they are old. The old onset is referred to as senile tremor in this study. The precise pathology is still not completely understood for both these tremors. We wanted to develop an easy diagnostic tool to differentiate these two tremors clinically. In this study, the spirals were asked to be drawn by 30 patients, 15 from each group. The spirals were recorded digitally from each hand, with and without the spiral template, using a Wacom intuos version 4 tablets. The aim of the study was to look at the easy diagnostic measures from these spirals to distinguish the two cohorts of patients. The first measure was to use the well-known clinical scores like the number of complete circles without the template, width, height, axis, and degree of severity. The second measure was to estimate the peak frequency and the peak amplitude for the position, velocity, and acceleration data, in the frequency domain. The well-known clinical scores, most of them, did not show any significant difference between the two patient cohorts except the degree of severity which showed significant difference. The peak frequency and the peak amplitude in most of the data were not significantly different between the two cohorts of patients, only the peak amplitude from the acceleration data showed significant difference. Thus, we could use these two parameters to differentiate between the two tremors patient groups, which would be an easy clinical diagnostic tool without the need for any complicated analyses.

Observation of Dirac plasmons in a topological insulator.

Plasmons are quantized collective oscillations of electrons and have been observed in metals and doped semiconductors. The plasmons of ordinary, massive electrons have been the basic ingredients of research in plasmonics and in optical metamaterials for a long time. However, plasmons of massless Dirac electrons have only recently been observed in graphene, a purely two-dimensional electron system. Their properties are promising for novel tunable plasmonic metamaterials in the terahertz and mid-infrared frequency range. Dirac fermions also occur in the two-dimensional electron gas that forms at the surface of topological insulators as a result of the strong spin-orbit interaction existing in the insulating bulk phase. One may therefore look for their collective excitations using infrared spectroscopy. Here we report the first experimental evidence of plasmonic excitations in a topological insulator (Bi2Se3). The material was prepared in thin micro-ribbon arrays of different widths W and periods 2W to select suitable values of the plasmon wavevector k. The linewidth of the plasmon was found to remain nearly constant at temperatures between 6 K and 300 K, as expected when exciting topological carriers. Moreover, by changing W and measuring the plasmon frequency in the terahertz range versus k we show, without using any fitting parameter, that the dispersion curve agrees quantitatively with that predicted for Dirac plasmons.

An open, randomized, comparative study of efficacy and safety of risperidone and haloperidol in schizophrenia.

OBJECTIVES: In the last decade there have been numerous randomized controlled trials comparing the efficacy and safety of second generation antipsychotics and conventional antipsychotics in the treatment of schizophrenia, but most of them have been conducted in the western population. This study compared the efficacy and safety of risperidone versus haloperidol in the Nepalese context, in order to add on to the very few literatures available on this topic in the South East Asia region and compare them. METHODS: Patients with the diagnosis of schizophrenia were randomly assigned to receive risperidone 4-6 milligrams (mg) per day and haloperidol 10-20 mg per day, and were followed up for 6 weeks. Assessment were done on the day of the diagnostic interview and days 7, 14, 28 and 42 (end point). During the assessment periods Positive and Negative Syndrome Scale (PANSS) was administered to monitor the progress in psychopathology and Udvalg for Kliniske Undersogelser (UKU) side effects rating scale was applied to rate the treatment emergent adverse effects. RESULTS: Both risperidone and haloperidol were associated with substantial baseline- to- endpoint reduction in symptom severity. After one week of treatment, the improvement in schizophrenia with risperidone was significantly better than haloperidol in terms of PANSS- total Score (-45.4 versus -29.5), negative subscale score (-14.3 versus -6.68) and general psychopathology subscale score (-20.9 versus -13.7). At the end point of the study, the benefit was maintained in total score (-52.1 versus -43.1), though the negative subscale score still showed tendency for greater improvement in psychopathology with risperidone. The side effects profile did not show significant differences except in extrapyramidal symptoms. Thirty-eight percent of risperidone treated patients had to resort to anti-parkinsonian treatment compared to 78% in haloperidol treatment group. CONCLUSION: Similar to the studies in the western countries, Asia and Indian subcontinent, both risperidone and haloperidol were effective in the reduction of psychopathological symptoms in this group of Nepalese population with the diagnosis of schizophrenia. However, risperidone was quicker and better then haloperidol and risperidone had a better safety profile. This is important, because extrapyramidal side effects of neuroleptics are responsible for non-compliance and increased cost in terms of us of anti-parkinsonian medication.