157 research outputs found

    Model for porous alumina template formation

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    Anodized alumina templates have emerged as an important material system for the low cost fabrication of semiconductor and metal nanostructure arrays. This material system utilizes natural self-organization for the creation of periodic arrays of nanoscale structures. The underlying principle is that when aluminum is anodized in a suitable acidic electrolyte under controlled conditions, it oxidizes to form a hydrated aluminum oxide (alumina) containing a two dimensional hexagonal array of cylindrical pores. Due to the excellent periodicity of the pores, and the ability to control the pore diameters, such anodized alumina films can be used as templates for the fabrication of periodic arrays of nanostructures. A process-model based on underlying physics and chemistry of the anodization process is developed. The model developed unravels the interplay of various physical and chemical processes and their dependence on the process parameters such as the electrolyte, temperature, current and voltages and yields, an analytical solution relating the voltage (in constant current anodization) and current (in constant voltage anodization) to time. The predicted time behavior agrees fairly well with experimental observations for sulfuric and oxalic acids. Thus, it is believed that the model is general enough and can be used for any anodization system with changes in appropriate model parameters

    Design of a Novel Convolutional Deep Network Model for Car Accident Prediction

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    Real-time collision risk estimation is thought to be essential to a sophisticated traffic management system. To swiftly determine accident probability is the goal of real-time crash risk prediction.  However, due to the complex traffic situation on urban arterials, urban arterials were rarely included in previous studies, which mostly focused on highways. This paper suggests using Convolutional Deep Network model (CDNM) to forecast the probability of vascular accidents in real time.  This model has the benefit of being able to use both LSTM and CNN.  CNN retrieves the time-invariant characteristics, while LSTM captures the data's long-term dependability. To estimate the likelihood of an accident, many sorts of data are used, including weather, traffic, and signal timing data. There are also many other data preparation methods employed. The problem of data imbalance is also addressed by normalization which oversamples the crash cases. Using a variety of measures, the CDNM is enhanced on the training data and assessed on the test data.  Five more benchmark models are constructed for model comparison. K-NN, ISVM, ANN, CNN, CNN-EVT and GAN are some of the models in this group. Experimental findings show that the proposed CDNM beats the competition in terms of sensitivity, specificity, accuracy, AUC and G-mean value. The findings of this paper demonstrate that CDNM can real-time prediction of crash risk at arterials

    Sub-millisecond Switching and Ferroelectric-like Polarization in a Bent Shaped Liquid Crystal Exhibiting Nematic and Twist-bend Nematic Phases

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    A fast switching liquid crystal (LC), especially in its nematic (N) phase, can significantly improve the performance and properties of present-day electro-optic devices and displays. We investigated the polar nature and switching behaviour of a bent shaped liquid crystal (LC) CB7CB at different temperatures, subjected to applied voltages of varying amplitude and frequency. A threshold-dependent polarization current response, with large spontaneous polarization, was observed in the nematic (N) and in the twist-bend nematic (Ntb) phases exhibited by the LC compound. The current response was identified as ferroelectric-like in nature, and the corresponding switching time was found to lie in the range of ~ 500 {\mu}s in the N phase, which is fast compared to the usual nematic switching time (in the range of milliseconds). The nematic switching is bi-stable in nature and the nematic polarization arises from the collective reorientation of cybotactic clusters on field-reversal. At larger voltages, the twist-bend helices were observed to unwind which can be considered as the main reason for the polar response in Ntb phase. The fast, bi-stable switching nature exhibited by the compound may become useful for application in next-generation of electro-optic devices.Comment: 18 pages, 17 figures, 1 tabl

    DESIGN OF THREE-INPUT XOR/XNORS GATES BASED ON SCDM TECHNIQUE FOR REDUCED AREA AND LESS ENERGY

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    In this paper we are proposing new systematic cell design methodology based efficient two three-input XOR/XNOR circuits in hybrid CMOS logic style. These XOR gates are used to design Full Adder with less area and less energy. SCDM, which is an extension of CDM, plays the essential role in designing efficient circuits. This paper evaluates and compares the performance of various XOR-XNOR circuits. We start with selecting a basic cell including three independent inputs and two complementary outputs. Next we combine this basic cell with various correction and optimization techniques to build a perfect XOR-XNOR circuit with full swing operation. The performance of the XOR-XNOR circuits  based on 90 nm CMOS technology process models at all range of the supply voltage is evaluated by the comparison of the simulation results obtained from MICRO WIND. Simulation output results shows that the proposed design consumes less power and less area than the conventional design

    Plant-Mediated Silencing of the Whitefly Bemisia tabaci Cyclophilin B and Heat Shock Protein 70 Impairs Insect Development and Virus Transmission

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    The whitefly B. tabaci is a global pest and transmits extremely important plant viruses especially begomoviruses, that cause substantial crop losses. B. tabaci is one of the top invasive species worldwide and have developed resistance to all major pesticide classes. One of the promising alternative ways for controlling this pest is studying its genetic makeup for identifying specific target proteins which are critical for its development and ability to transmit viruses. Tomato yellow leaf curl virus (TYLCV) is the most economically important and well-studied begomovirus transmitted by B. tabaci, in a persistent-circulative manner. Recently, we reported that B. tabaci Cyclophilin B (CypB) and heat shock protein 70 proteins (hsp70) interact and co-localize with TYLCV in the whitefly midgut, on the virus transmission pathway, and that both proteins have a significant role in virus transmission. Here, we extended the previous work and used the Tobacco rattle virus (TRV) plant-mediated RNA silencing system for knocking down both genes and testing the effect of their silencing on whitefly viability and virus transmission. Portions of these two genes were cloned into TRV constructs and tomato plants were infected and used for whitefly feeding and transmission experiments. Following whitefly feeding on TRV-plants, the expression levels of cypB and hsp70 in adult B. tabaci significantly decreased over 72 h feeding period. The knockdown in the expression of both genes was further shown in the first generation of silenced whiteflies, where phenotypic abnormalities in the adult, wing, nymph and bacteriosomes development and structure were observed. Additionally, high mortality rates that reached more than 80% among nymphs and adults were obtained. Finally, silenced whitefly adults with both genes showed decreased ability to transmit TYLCV under lab conditions. Our results suggest that plant-mediated silencing of both cypB and hsp70 have profound effects on whitefly development and its ability to transmit TYLCV

    A Checklist to Improve Patient Safety in General Radiology

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    Background: The role of checklist is to identify and classify the risks to the safety. Aim: The purpose of this study is to improve patient safety in radiology department. Methods: The study population included patients of both gender of age group 20-50 years. Overall patients included were 50. The data was collected on daily basis from 1 October 2021 to 31 March 2022. Result: The result involves the positive result with significance level of 0.05 which clearly proves that patient safety was improves by using checklist. Conclusion: This study proves that patient safety can be improves by using safety checklist and Chi- square test applied for the results

    Invasive insect species importance and possible pathways of their spreading in Serbia

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    Invasive insect species are alien species that have significant impact on biodiversity of certain area or specific country, and also can cause severe damage to cultivated plants. Many insects spread actively, but very often benefit from human activities and use transport of trades and passengers to travel all around the globe. Directions and stopover of these stowaways are usually unpredictable hence the importance of insect monitoring and investigation of their spreading pathways are of great importance for the country, and even for the whole potentially endangered region. One of the currently most important Hemipteran species, recorded for the first time in 2015 in Serbia, is Brown Marmorated Stink Bug, Halyomorpha halys StĂĄl (Pentatomidae). The species has been monitored for five consecutive years and nowadays it is considered as well established in the country. On the other side, another cosmopolitan Hemipteran species, in Serbia known as tobacco white fly, Bemisia tabaci (Gennadius) (Aleyrodidae) was recorded on the territory of Serbia in 2016 and 2017, but since then specimens of this species have not been recorded neither outside nor in green houses during regular monitoring, why it is considered as not established

    Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

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    Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty

    SARS-CoV-2 infection in acute pancreatitis increases disease severity and 30-day mortality: COVID PAN collaborative study

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    Objective: There is emerging evidence that the pancreas may be a target organ of SARS-CoV-2 infection. This aim of this study was to investigate the outcome of patients with acute pancreatitis (AP) and coexistent SARS-CoV-2 infection. Design: A prospective international multicentre cohort study including consecutive patients admitted with AP during the current pandemic was undertaken. Primary outcome measure was severity of AP. Secondary outcome measures were aetiology of AP, intensive care unit (ICU) admission, length of hospital stay, local complications, acute respiratory distress syndrome (ARDS), persistent organ failure and 30-day mortality. Multilevel logistic regression was used to compare the two groups. Results: 1777 patients with AP were included during the study period from 1 March to 23 July 2020. 149 patients (8.3%) had concomitant SARS-CoV-2 infection. Overall, SARS-CoV-2-positive patients were older male patients and more likely to develop severe AP and ARDS (p&lt;0.001). Unadjusted analysis showed that SARS-CoV-2-positive patients with AP were more likely to require ICU admission (OR 5.21, p&lt;0.001), local complications (OR 2.91, p&lt;0.001), persistent organ failure (OR 7.32, p&lt;0.001), prolonged hospital stay (OR 1.89, p&lt;0.001) and a higher 30-day mortality (OR 6.56, p&lt;0.001). Adjusted analysis showed length of stay (OR 1.32, p&lt;0.001), persistent organ failure (OR 2.77, p&lt;0.003) and 30-day mortality (OR 2.41, p&lt;0.04) were significantly higher in SARS-CoV-2 co-infection. Conclusion: Patients with AP and coexistent SARS-CoV-2 infection are at increased risk of severe AP, worse clinical outcomes, prolonged length of hospital stay and high 30-day mortality

    RNAi-based biocontrol of wheat nematodes using natural poly-component biostimulants

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    With the growing global demands on sustainable food production, one of the biggest challenges to agriculture is associated with crop losses due to parasitic nematodes. While chemical pesticides have been quite successful in crop protection and mitigation of damage from parasites, their potential harm to humans and environment, as well as the emergence of nematode resistance, have necessitated the development of viable alternatives to chemical pesticides. One of the most promising and targeted approaches to biocontrol of parasitic nematodes in crops is that of RNA interference (RNAi). In this study we explore the possibility of using biostimulants obtained from metabolites of soil streptomycetes to protect wheat (Triticum aestivum L.) against the cereal cyst nematode Heterodera avenae by means of inducing RNAi in wheat plants. Theoretical models of uptake of organic compounds by plants, and within-plant RNAi dynamics, have provided us with useful insights regarding the choice of routes for delivery of RNAi-inducing biostimulants into plants. We then conducted in planta experiments with several streptomycete-derived biostimulants, which have demonstrated the efficiency of these biostimulants at improving plant growth and development, as well as in providing resistance against the cereal cyst nematode. Using dot blot hybridization we demonstrate that biostimulants trigger a significant increase of the production in plant cells of si/miRNA complementary with plant and nematode mRNA. Wheat germ cell-free experiments show that these si/miRNAs are indeed very effective at silencing the translation of nematode mRNA having complementary sequences, thus reducing the level of nematode infestation and improving plant resistance to nematodes. Thus, we conclude that natural biostimulants produced frommetabolites of soil streptomycetes provide an effective tool for biocontrol of wheat nematode
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