Optimized polar-azimuthal orientations for polarized light illumination of different Superconducting Nanowire Single-Photon Detector designs

The optimal orientations are determined for polarized substrate side illumination of three superconducting nanowire single-photon detector (SNSPD) designs: (1) periodic niobium-nitride (NbN) stripes standing in air with dimensions according to conventional SNSPDs, (2) same NbN patterns below ~quarter-wavelength hydrogensilsesquioxane-filled nano-cavity, (3) analogous NbN patterns in HSQ nano-cavity closed by a thin gold reflector. Numerical computation results have shown that the optical response and near-field distribution vary significantly with polar-angle, fi, and these variations are analogous across all azimuthal-angles, gamma, but are fundamentally different in various device designs. Larger absorptance is available due to p-polarized illumination of NbN patterns in P-structure configuration, while s-polarized illumination results in higher absorptance in S-structure arrangement. As a result of p-polarized illumination a global maximum appears on absorptance of bare NbN pattern at polar angle corresponding to NbN-related ATIR; integration with HSQ nano-cavity results in a global absorptance maximum at polar angle corresponding to TIR at sapphire-air interface; while the highest absorptance is observable at perpendicular incidence on P-structures aligned below gold reflector covered HSQ nano-cavity. S-polarized light illumination results in a global absorptance maximum at TIR on bare NbN patterns; the highest absorptance is available below HSQ nano-cavity at polar angle corresponding to ATIR phenomenon; while the benefit of gold reflector is large and polar angle independent absorptance.Comment: 24 pages, 7 figure

Precursor lymphoblastic lymphoma in the extramedullary tissue: A rare manifestation of chronic myeloid leukemia in blast crisis

Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by immature granulocytes in peripheral blood and bone marrow. In 95% of cases, it is always due to the presence of Philadelphia chromosome characterized by the presence of reciprocal translocation between chromosome 9 and 22. However, in 7% -17% of individuals, extramedullary proliferation also occurs, either in skin, lymph nodes, bone or central nervous system (CNS), which could be either myeloid, lymphoid or mixed progenitor in origin. The present case is of a 23-year-old male who presented with lower limb weakness, bowel and urinary incontinence. His complete blood count (CBC) findings showed a raised white blood count (WBC) of 408 X 10E9/L. Peripheral film, bone marrow biopsy and immunohistochemistry showed findings consistent with CML in chronic phase. Bone marrow cytogenetic revealed the presence of Philadelphia chromosome. Simultaneously, magnetic resonance imaging (MRI) was done which revealed extradural mass at L1-L3 level; histopathological and immunohistochemistry findings showed features compatible with precursor B cell lymphoblastic lymphoma. His cerebrospinal fluid (CSF) cytology revealed similar blast cells. This extramedullary presence of lymphoid blast cells in the CNS put the patient in the rare entity of CML in blast crisis. He was started on tablet nilotinib and also received multiple cycles of intrathecal chemotherapy with cytosar, methotrexate and hydrocortisone. He also underwent radiotherapy of extradural mass. His lower limb weakness improved dramatically. However, after receiving the fourth cycle of intrathecal therapy, the patient died consequent to neutropenic sepsis. Extramedullary blast crisis in CML has a poor prognosis. Any patient with CML, presenting with CNS symptoms or lymph node enlargement should be thoroughly investigated for extramedullary blast crisis, as there is a considerable change in management and prognosis from the prototype CML in chronic phase

Microdiscectomy for lumbosacral disc herniation and frequency of failed disc surgery

Background: Microdiscectomy for lumbosacral disc herniations is one of the most commonly performed neurosurgical procedures. The Patient demographics, symptomatology, and recovery are highly variable, and surgical outcomes depend on several factors, including Patient demographics. Failed disc surgery refers to failure of improvement in Patient\u27s symptoms following microdiscectomy, and has been observed to occur in up to 12% of Patients. To date, no study form Pakistan has looked into Patient demographics and failed disc surgery rates within the local context.Objective:The aim of this study was to review the demographics of the Patient population presenting for surgical treatment of lumbosacral disc herniations and to review our results of lumbosacral microdiscectomy at a university hospital in Pakistan.Methods: This is a retrospective analysis of all adult Patients admitted from January 2003 to January 2008 for symptomatic lumbosacral disc herniation requiring microdiscectomy, at the Aga Khan University Hospital, Karachi. Data were collected through our medical records, on a standardized form. Basic information about the Patient population, disease process, modes of nonsurgical treatment, and details on surgery and postoperative course were recorded and analyzed using SPSS.Results: Five hundred one Patients were studied, based on inclusion criteria. The mean age was 41.2 years, 347 (69%) Patients were male and 154 (31%) female. Mean body mass index of the population was 26 and was higher in females. All Patients primarily presented with radiculopathy, and the mean duration of these symptoms was 438 days. Mean duration of nonoperative management was 53 weeks. Fifty-one Patients (10.2%) had previously undergone spine surgery. A total of 442 (88%) Patients were operated at single disc level, and the rest at two levels. Sixty-six (13%) Patients were operated for upper lumbar disc herniations. Mean operative time was 94 minutes, and the most common complication was dural tear. Mean length of hospital stay was 5 days (2-12 days). Mean follow-up was 48.3 weeks (4 weeks to 14 years). Complete resolution of symptoms was seen in 360 (71.9%) Patients and failed disc surgery was diagnosed in 42 (8.4%) Patients. Twenty-six Patients (5.2%) were reoperated upon, with gradual improvement. The authors report an overall failed back surgery rate of 8.38%.Conclusions: Overall our results were comparable to published international literature. However, the authors observed significant differences in demographics, especially in terms of age, gender distribution, and mean BMI of Patient population as well as frequency of involvement of upper lumbar discs

An Insight into the Lynch Syndrome: Retrospective Study of the Pattern of Presentation and Management of Lynch Syndrome in Pakistan

Introduction: The primary objective of this study was to evaluate the baseline characteristics of Lynch syndrome (LS). Furthermore, the study aimed to evaluate overall survival (OS) among patients with LS. Materials and Methods: This was a retrospective study of colorectal cancer patients registered from January 2010 to August 2020 with an immunohistochemical diagnosis of LS. Results: A total of 42 patients were assessed. The mean age at presentation was 44 years, with male predominance (78%). Demographic preponderance was from the North of Pakistan (52.4%). The family history was positive in 32 (76.2%) patients. The colonic cancer distribution was 32 (76.2%) on the right side. Most of the patients presented with Stage II disease (52.4%), and the common mutations were MLH1 + PMS2 16 (38.1%) followed by MSH2 + MSH6 9 (21.4%). The 10-year OS was found to be 88.1%. However, the OS was 100% post pancolectomy. Conclusion: LS is prevalent in the Pakistan population, especially in the North of Pakistan. Clinical presentation and survivals are similar to the Western population

Assessing the efficiency of sub-national units in making progress towards universal health coverage: Evidence from Pakistan

The World Health Report 2010 encourages countries to reduce wastage and increase efficiency to achieve Universal Health Coverage (UHC). This research examines the efficiency of divisions (sub-provincial geographic units) in Pakistan in moving towards UHC using Data Envelop Analysis. We have used data from the Pakistan National Accounts 2011-12 and the Pakistan Social Living and Measurement Survey 2012-13 to measure per capita pooled public health spending in the divisions as inputs, and a set of UHC indicators (health service coverage and financial protection) as outputs. Sensitivity analysis for factors outside the health sector influencing health outcomes was conducted to refine the main model specification. Spider radar graphs were generated to illustrate differences between divisions with similar public spending but different performances for UHC. Pearson product-moment correlation was used to explore the strength and direction of the associations between proxy health systems organization variables and efficiency scores.The results showed a large variation in performance of divisions for selected UHC outputs. The results of the sensitivity analysis were also similar. Overall, divisions in Sindh province were better performing and divisions in Balochistan province were the least performing. Access to health care, the responsiveness of health systems, and patients\u27 satisfaction were found to be correlated with efficiency scores.This research suggests that progress towards UHC is possible even at relatively low levels of public spending. Given the devolution of health system responsibilities to the provinces, this analysis will be a timely reference for provinces to gauge the performance of their divisions and plan the ongoing reforms to achieve UHC

Computer Aided Design of a Low-Cost Painting Robot

The application of robots or robotic systems for painting parts is becoming increasingly conventional; to improve reliability, productivity, consistency and to decrease waste. However, in Pakistan only highend Industries are able to afford the luxury of a robotic system for various purposes. In this study we propose an economical Painting Robot that a small-scale industry can install in their plant with ease. The importance of this robot is that being cost effective, it can easily be replaced in small manufacturing industries and therefore, eliminate health problems occurring to the individual in charge of painting parts on an everyday basis. To achieve this aim, the robot is made with local parts with only few exceptions, to cut costs; and the programming language is kept at a mediocre level. Image processing is used to establish object recognition and it can be programmed to paint various simple geometries. The robot is placed on a conveyer belt to maximize productivity. A four DoF (Degree of Freedom) arm increases the working envelope and accessibility of painting different shaped parts with ease. This robot is capable of painting up, front, back, left and right sides of the part with a single colour. Initially CAD (Computer Aided Design) models of the robot were developed which were analyzed, modified and improved to withstand loading condition and perform its task efficiently. After design selection, appropriate motors and materials were selected and the robot was developed. Throughout the development phase, minor problems and errors were fixed accordingly as they arose. Lastly the robot was integrated with the computer and image processing for autonomous control. The final results demonstrated that the robot is economical and reduces paint wastage

Forecasting of Bitcoin Illiquidity Using High-Dimensional and Textual Features

Liquidity is the ease of converting an asset (physical/digital) into cash or another asset without loss and is shown by the relationship between the time scale and the price scale of an investment. This article examines the illiquidity of Bitcoin (BTC). Bitcoin hash rate information was collected at three different time intervals; parallel to these data, textual information related to these intervals was collected from Twitter for each day. Due to the regression nature of illiquidity prediction, approaches based on recurrent networks were suggested. Seven approaches: ANN, SVM, SANN, LSTM, Simple RNN, GRU, and IndRNN, were tested on these data. To evaluate these approaches, three evaluation methods were used: random split (paper), random split (run) and linear split (run). The research results indicate that the IndRNN approach provided better results.Peer Reviewe

Design and development of a nozzle-free electrospinning device for the high-throughput production of biomaterial nanofibers

This technical note provides a step-by-step guide for the design and construction of a temperature-controlled nozzle-free electrospinning device. The equipment uses a rotating mandrel partially immersed within a polymer solution to produce fibers in an upward motion by inducing the formation of multiple Taylor cones and subsequently multi-jetting out of an electrified open surface. Free-surface electrospinning can overcome limitations and drawbacks associated with single and multi-nozzle spinneret configurations, such as low yield, limited production capacity, nonuniform electric field distribution, and clogging. Most importantly, this lab-scaled high-throughput device can provide an alternative economical route for needleless electrospinning research, in contrast to the high costs associated with industrially available upscaling equipment. Among the device's technical specifications, a key feature is a cryo-collector mandrel, capable of collecting fibers in sub-zero temperatures, which can induce ultra-porous nanostructures, wider pores, and subsequent in-depth penetration of cells. A multi-channel gas chamber allows the conditioning of the atmosphere, temperature, and airflow, while the chamber's design averts user exposure to the high-voltage components. All the Computer-Aided Design (CAD) files and point-by-point assembly instructions, along with a list of the materials used, are provided.</p

Electronic cigarettes use and perception amongst medical students: a cross sectional survey from Sindh, Pakistan

Objective: The manufacturers of electronic cigarettes (e-cigarettes) are actively marketing their product through electronic and social media. Undergraduate medical students are expected to have better knowledge and awareness as they directly interact with patients in their training, The purpose of this study is therefore, to determine knowledge, use and perception regarding e-cigarettes among medical students from Sindh, Pakistan. Results: A cross-sectional study was conducted between 1st July and 30th September 2016 at five different medical colleges situated in the second largest province of Sindh, Pakistan. The data was collected through a structured, self-administered questionnaire. Of the 500 students, the mean age was 21.5 ± 1.7 years and 58% were females. Over (65.6%) students were aware of e-cigarettes, 31 (6.2%) reported having used e-cigarettes, of whom 6 (1.2%) self-reported daily use. Users of conventional tobacco products were significantly more likely to have heard of e-cigarettes (87.6% vs 51.6%, p \u3c 0.001) and having used them (13.9% vs 1.3%, p \u3c 0.001). On multivariable logistic regression analysis we found a strong association of e-cigarette use with consumption of conventional cigarettes [OR: 10.6, 95% CI 3.6-30.8, p \u3c 0.001], use of smokeless tobacco products [OR: 7.9, 95% CI 2.7-23.4, p \u3c 0.001] however a weak association was observed for Shisha use [OR: 3.05, 95% CI 0.9-9.6, p = 0.05]