107 research outputs found

    Growth of compact arrays of optical quality single crystalline ZnO nanorods by low temperature method

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    We report the synthesis and optical properties of compact and aligned ZnO nanorod arrays (dia, ∼50-200 nm) grown on a glass substrate with varying seed particle density. The suspension of ZnO nanoparticles (size, ∼15 nm) of various concentrations are used as seed layer for the growth of nanorod arrays via selfassembly of ZnO from solution. We studied the effect of various growth parameters (such as seeding density, microstructure of the seed layer) as well as the growth time on the growth and alignment of the nanorods. We find that the growth, areal density and alignment of the nanorods depend on the density of seed particles which can be controlled. It is observed that there is a critical density of the seed particles at which nanorod arrays show maximum preferred orientation along [002] direction. The minimum and maximum radius of the aligned nanorods synthesized by this method lie in the range 50-220 nm which depend on the seeding density and time of growth. These nanorods have a bandgap of 3.3 eV as in the case of bulk crystals and show emission in the UV region of the spectrum (∼400 nm) due to excitonic recombination and defect related emission in the visible region

    Studies on Symptomatic Profiles of Dengue Fever (DF) vis- -vis Non-Dengue Fever (NDF) in District Dehradun, Uttarakhand

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    AbstractDengue is considered to be common in most tropical and subtropical regions. The unplanned development of Dehradun city along with increasing circumference of slum areas has resulted in proportional increase of dengue prevalence. Dengue detection by conducting molecular and virological tests is complex, tedious to perform, and is less feasible for routine laboratory practices. Hence, this study was sought to describe the clinical, laboratory and ultrasonic manifestation of dengue fever based on two year’s (2013 and 2014) record in order to classify the features between DF and NDF. Out of a total of 15,556 cases (8253 cases in 2013 and 7303 cases in 2014) of suspected dengue fever, 242 cases (122 in 2013 and 120 in 2014) were reported positive confirming 1.56% serologically by ELISA, which were classified as DF cases and rest as NDF cases. The significant features in DF cases were myalgia, body ache, nausea, retro-orbital pain, skin rash, leukopenia, ALT <50, splenomegaly and hepatomegaly.The sensitivity was found highest in myalgia (91.32%), followed by body ache (88.02%) and nausea (81.82%), whereas highest specificity was found in skin rash (97.56%), trailed by leukopenia (96.63%) and hepatomegaly (96.06%). These predictive values can help the clinician to be more confident that a patient lacking these features does have the disease because of high negative prediction values. Changing characteristics of the disease deserve serious research attention, especially in shifts in modal age, rural spread, social and biological determinants of race; and sex related susceptibility have major implications for health service planning and control strategies

    A CdZnTeSe Gamma Spectrometer Trained by Deep Convolutional Neural Network for Radioisotope Identification

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    We report the implementation of a deep convolutional neural network to train a high-resolution room-temperature CdZnTeSe based gamma ray spectrometer for accurate and precise determination of gamma ray energies for radioisotope identification. The prototype learned spectrometer consists of a NI PCI 5122 fast digitizer connected to a pre-amplifier to recognize spectral features in a sequence of data. We used simulated preamplifier pulses that resemble actual data for various gamma photon energies to train a CNN on the equivalent of 90 seconds worth of data and validated it on 10 seconds worth of simulated data

    Dynamic excitatory and inhibitory gain modulation can produce flexible, robust and optimal decision-making

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    <div><p>Behavioural and neurophysiological studies in primates have increasingly shown the involvement of urgency signals during the temporal integration of sensory evidence in perceptual decision-making. Neuronal correlates of such signals have been found in the parietal cortex, and in separate studies, demonstrated attention-induced gain modulation of both excitatory and inhibitory neurons. Although previous computational models of decision-making have incorporated gain modulation, their abstract forms do not permit an understanding of the contribution of inhibitory gain modulation. Thus, the effects of co-modulating both excitatory and inhibitory neuronal gains on decision-making dynamics and behavioural performance remain unclear. In this work, we incorporate time-dependent co-modulation of the gains of both excitatory and inhibitory neurons into our previous biologically based decision circuit model. We base our computational study in the context of two classic motion-discrimination tasks performed in animals. Our model shows that by simultaneously increasing the gains of both excitatory and inhibitory neurons, a variety of the observed dynamic neuronal firing activities can be replicated. In particular, the model can exhibit winner-take-all decision-making behaviour with higher firing rates and within a significantly more robust model parameter range. It also exhibits short-tailed reaction time distributions even when operating near a dynamical bifurcation point. The model further shows that neuronal gain modulation can compensate for weaker recurrent excitation in a decision neural circuit, and support decision formation and storage. Higher neuronal gain is also suggested in the more cognitively demanding reaction time than in the fixed delay version of the task. Using the exact temporal delays from the animal experiments, fast recruitment of gain co-modulation is shown to maximize reward rate, with a timescale that is surprisingly near the experimentally fitted value. Our work provides insights into the simultaneous and rapid modulation of excitatory and inhibitory neuronal gains, which enables flexible, robust, and optimal decision-making.</p></div

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely
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