1,852 research outputs found
Prevalence of retinopathy of prematurity: a 3-year retrospective study
Background: Retinopathy of prematurity (ROP) is a vasoproliferative disease of premature infants which leads to permanent blindness. Early screening is needed to diagnose ROP and prevent blindness.Methods: Retrospective study was conducted in 225 neonates from January 2018 to December 2020. All neonates with birth weight 0.05). Out of 148 neonates who were given oxygen 19 (12.83%) developed ROP (odds ratio: 5.52). Out of 42 neonates who had sepsis, 2 (4.76%) developed ROP (odds ratio: 0.43).Conclusions: The prevalence of ROP was 9.33%. The prevalence is showing a decreasing trend. ROP is not affected by gender. Oxygen given to neonates is associated with greater ROP. But sepsis in neonates is not associated with development of ROP
Psychoacoustic analysis of high frequency elasto-acoustic emissions from hollow driveshaft tubes
Lightly damped non-linear systems such as vehicular drivelines undergo a plethora of Noise, Vibration and Harshness (NVH) problems. The clonk phenomenon is one concern which occurs as the result of impulsive torque input in the form of sudden clutch actuation or throttle tip-in and back-out. The resulting impact of meshing gear pairs propagate structural waves down the driveline. With lightly damped thin-walled tubes having high modal density, elasto-acoustic coupling occurs. High frequency noise emission is of metallic nature and quite disconcerting to vehicle occupants as well as passers-by. It is perceived as structural failure and/or poor-quality build. Therefore, the occurrence of the phenomenon is a concern to vehicle manufacturers and progressively constitutes a warranty concern. This paper investigates the clonk phenomenon through use of a long-wheel base rear drive light truck test rig. The investigation uses psychoacoustic metrics to establish the severity of clonk noise in different maneuvers. This is an attempt to quantify the effect of transient clonk event which is usually ascertained through subjective evaluation ratings in a customer/jury clinic in industry. Alternatively, detailed numerical analysis is carried out with parametric studies to quantify different clonk events, a very time consuming approach which is not usually correlated with occupants’ perception of the event. Therefore, the experimental NVH monitoring-psycho-acoustic approach is new for the case of clonk and not hitherto reported in literature. The study corroborates the results and conclusions of previous work, pointing to the loudness and sharpness of high frequency short-lived “metallic” response, which is attuned to human aural perception. The psychoacoustic analysis has shown this to be as the result of short duration hard impact (accelerative period). This hard impact duration accounts for the bulk loudness and sharpness of the overall event. Therefore, effective palliation should focus on the attenuation of particular frequency bands, which carry the main contribution to loudness and sharpness
Comparison of ocular manifestations in diabetic vs. non-diabetic patients in southern Rajasthan
Background: Effects of DM are gradual, progressive and due to chronic exposure to high blood sugar levels. DM also affect the eyes which can lead to ocular morbidity as DR can cause blindness. In that view, it becomes increasingly important to diagnose them at the earliest for proper management and prevention of complications.Methods: A total of 182 patients examined, out of which 91 were diabetic and 91 were non diabetic. Complete ocular examination was done that included visual acuity, anterior segment and fundus. Diabetic retinopathy was graded according to ETDRS classification. Diabetic patients were divided into 3 groups on the basis of HbA1c level (%): group-A (6-8), group-B (8-10) and group-C (>10). Patients were divided into 3 groups on the basis of duration (years): group1 (10).Results: Ocular manifestations were more prevalent in diabetics than non-diabetics along with that DR was found in diabetic patients and no retinopathy was found in non-diabetic patients. Out of 91 diabetic patients, DR was found in 30(33.3%) patients. Out of 30 DR, NPDR was found in 25(75%) and PDR was found in 5 (15%). DR in group A, B and C: 0, 17 (58%) and 13 (86%) respectively. DR in group1,2 and 3 was 3 (7.5%), 11 (35.4%) and 16 (80%) respectively.Conclusions: Longer duration of diabetes and higher HbA1c level are associated with increased prevalence and severity of DR
Efficient Photon Coupling from a Diamond Nitrogen Vacancy Centre by Integration with Silica Fibre
A central goal in quantum information science is to efficiently interface
photons with single optical modes for quantum networking and distributed
quantum computing. Here, we introduce and experimentally demonstrate a compact
and efficient method for the low-loss coupling of a solid-state qubit, the
nitrogen vacancy (NV) centre in diamond, with a single-mode optical fibre. In
this approach, single-mode tapered diamond waveguides containing exactly one
high quality NV memory are selected and integrated on tapered silica fibres.
Numerical optimization of an adiabatic coupler indicates that
near-unity-efficiency photon transfer is possible between the two modes.
Experimentally, we find an overall collection efficiency between 18-40 % and
observe a raw single photon count rate above 700 kHz. This integrated system
enables robust, alignment-free, and efficient interfacing of single-mode
optical fibres with single photon emitters and quantum memories in solids
Imaging-Guided Treatment for Cardiac Amyloidosis
PURPOSE OF REVIEW: This review will explore the role of cardiac imaging in guiding treatment in the two most commonly encountered subtypes of cardiac amyloidosis (immunoglobulin light-chain amyloidosis [AL] and transthyretin amyloidosis [ATTR]). RECENT FINDINGS: Advances in multi-parametric cardiac imaging involving a combination of bone scintigraphy, echocardiography and cardiac magnetic resonance imaging have resulted in earlier diagnosis and initiation of treatment, while the evolution of techniques such as longitudinal strain and extracellular volume quantification allow clinicians to track individuals' response to treatment. Imaging developments have led to a deeper understanding of the disease process and treatment mechanisms, which in combination result in improved patient outcomes. The rapidly expanding treatment regimens for cardiac amyloidosis have led to an even greater reliance on cardiac imaging to help establish an accurate diagnosis, monitor treatment response and aid the adjustment of treatment strategies accordingly
Cardiovascular Magnetic Resonance Parametric Mapping Techniques: Clinical Applications and Limitations
Purpose of Review: Parametric mapping represents a significant innovation in cardiovascular magnetic resonance (CMR) tissue characterisation, allowing the quantification of myocardial changes based on changes on T1, T2 and T2* relaxation times and extracellular volume (ECV). Its clinical use is rapidly expanding, but it requires availability of dedicated equipment as well as expertise in image acquisition and analysis. This review focuses on the principles of CMR parametric mapping, its current clinical applications, important limitations, as well as future directions of this technique in cardiovascular medicine. Recent Findings: There is increasing evidence that CMR parametric mapping techniques provide accurate diagnostic and prognostic tools that can be applied to and support the clinical management of patients with a range of cardiovascular disease. Summary: The unique capability of CMR myocardial tissue characterisation in cardiovascular diseases has further expanded by the introduction of parametric mapping. Its use in clinical practice presents opportunities but has also limitations
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