152 research outputs found
Label-free electrochemical aptasensor for the detection of SARS-CoV-2 spike protein based on carbon cloth sputtered gold nanoparticles
No full textThe proliferation and transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), or the (COVID-19) disease, has become a threat to worldwide biosecurity. Therefore, early diagnosis of COVID-19 is crucial to combat the ongoing infection spread. In this study we propose a flexible aptamer-based electrochemical sensor for the rapid, label-free detection of SARS-CoV-2 spike protein (SP). A platform made of a porous and flexible carbon cloth, coated with gold nanoparticles, to increase the conductivity and electrochemical performance of the material, was assembled with a thiol functionalized DNA aptamer via S–Au bonds, for the selective recognition of the SARS-CoV-2 SP. The various steps for the sensor preparation were followed by using scanning electron microscopy, cyclic voltammetry and differential pulse voltammetry (DPV). The proposed platform displayed good mechanical stability, revealing negligible changes on voltammetric responses to bending at various angles. Quantification of SARS-CoV-2 SP was performed by DPV and chronopotentiometry (CP), exploiting the changes of the electrical signals due the [Fe(CN)6]3-/4- redox probe, when SARS-CoV-2 SP binds to the aptamer immobilized on the electrode surface. Current density, in DPV, and square root of the transition time, in CP, varied linearly with the log[ SARS-CoV-2 SP], providing lower limits of detection (LOD) of 0.11 ng/mL and 37.8 ng/mL, respectively. The sensor displayed good selectivity, repeatability, and was tested in diluted human saliva, spiked with different SARS-CoV-2 SP concentrations, providing LODs of 0.167 ng/mL and 46.2 ng/mL for DPV and CP, respectively
Association of Wilms Tumor with Crossed Fused Renal Ectopia in Children: A Case Report
No full textIntroduction: Wilms tumor is the most common renal malignancy in children. The occurrence of Wilms tumor with various congenital genitourinary anomalies has been reported, particularly in horseshoe kidneys, hypospadias, disorder of sexual development, and double collecting system. However, Wilms tumor with crossed renal ectopia is a rare finding.
Case Description: We are reporting a case report of Wilms tumor in a 3-year-old girl who presented with a huge left flank mass with cross-fused renal ectopia. After the initial workup and triphasic computed tomography (CT) scan of the chest, abdomen, and pelvis for confirmation of diagnosis and metastasis, the patient underwent image-guided tissue biopsy followed by neo-adjuvant chemotherapy, left radical nephrectomy with separation of fused right ectopic renal moiety and adjuvant chemoradiation.
Practical Implication: This report shows an association of Wilms tumor with cross-fused renal ectopia, a rare combination. Unusual findings on imaging with unilateral flank mass should be considered as part of the differential diagnosis for this rare finding. Adjuvant chemotherapy and modern imaging helped delineate the anatomy and ease the surgery for safe resection, improving the overall outcome
Statistical analysis of received signal strength in fog using sliding window technique for FSO links
No full textTime Synchronization in Photon-Limited Deep Space Optical Communications
No full textRandom jitter or offset between the transmitter/receiver clocks is an important parameter that has to be accurately estimated for optimal detection of pulse position modulation (PPM) symbols for high-data-rate optical communications. This parameter, in general, is modeled as an unknown random quantity that depends on the clock drift between the transmitter/receiver clocks and the random motion between the transmitter and receiver stations. In this paper, we have modeled the time jitter for two scenarios - phase modulation jitter and frequency modulation jitter. The phase modulation jitter is modeled as a Gaussian random variable which is estimated with the help of a maximum a posteriori probability (MAP) estimator. The frequency modulation jitter is characterized as a random walk, and this leads to the modeling of the jitter as a state space variable in the context of a dynamical system. Since the observations are the photon counts in each slot of a PPM symbol (for both MAP estimation and tracking), the resulting dynamical model is highly nonlinear, and particle filters are employed for tracking the frequency modulation jitter. We evaluate the performance of both the maximum a posteriori estimators and the particle filters in terms of the relative mean-square error and probability of error. We conclude that with MAP estimation and particle filters that estimate/track the time offset, we achieve a significant performance gain in terms of probability of error as compared to systems that do not have a time synchronization system in place
کلیاتِ فیض۔ "نسخہ ہائے وفا": ایک جائزہ
No full textThis paper is critical and Research Evaluation of Faiz Ahmad Faiz's complete poetic works known as "Nuskha Haiya Wafa". By evaluating this Quliyat of Faiz, the author of this article has provided a detailed suty of Faiz's Poetry. This Quliyat consist of seven collection of Faiz. While giving a comprehensive view or the back-ground of Faiz's Poetry and ideology, author has also pointed out the main aspects and trends of his poetic genius. By doing so, writer has given examples of relevant verses and poems from the whole Quliyat. In this way, it is brief selection of Faiz's most representative verses
Analysis of Continental Fog Micro-physical Parameters: Effect of PSA on Optical Attenuation
No full textDeterminants of Bank Liquidity: Evidence from Local, Foreign and Islamic Commercial Banks in Pakistan
No full textThe purpose of this paper is to investigate the effects of bank-specific variables (i.e. bank size, profitability, deposits, cost of funds and capital ratio) on liquidity of local, foreign and Islamic commercial banks in Pakistan. Data was obtained from the publications of SBP titled ‘Financial Statement Analysis of Financial Firms’. Data of 26 banks found completed during 2007-2015 (i.e. 19 local banks, 02 foreign banks and 05 Islamic banks). Pooled OLS method used to analyze the effects of internal variables on liquidity. Descriptive statistics show that foreign banks are far better than local and Islamic commercial banks in terms of profitability and liquid assets. Alternatively, Islamic banks are in a better position than local conventional banks in terms of liquid assets, deposit ratio and capital ratio. In contrast, local conventional banks are better than Islamic banks in terms of size and profitability. More importantly, Islamic commercial banks are younger than local conventional banks but amazingly having higher deposit ratio due to strong equity-base and sufficient liquid assets. Notably, the trend toward Islamic banking is increasing day-by-day which posed threats to the conventional commercial banks, and resultantly a number of conventional banks have either introduced the ‘window’ of Islamic banking or completely started the Islamic banking operations. Regression results indicate that profitability is positively while bank size, deposits, cost of fund and capital ratio is negatively related to liquidity in a sample of all banks. Deposits are positively while cost of fund is negatively linked to liquidity in a sample of local banks. Finally, bank size is the only variable that is negatively linked to liquidity of foreign and Islamic commercial banks
Residential Solar options in Karachi: comparative analysis and decision factors
No full textThe purpose of this research is to identify the factors driving the decision of potential customers in installing a solar power system in Karachi. Pakistan is currently facing an energy crisis along with economic instability leading to highest inflation rates of all times. Subsequently, the people are looking at alternatives to mitigate the inflation effects and reduce the dependency on the electricity grid, which is not only expensive but also unreliable. Solar power system is an alternative that is highly popular and has the potential to resolve these issues.
The research used interviews to collect data from customers who had already installed solar power systems at their residences to identify the factors. These interviews also brought the opportunity to understand the challenges and advantages of the solar power systems that the customers experienced firsthand. The analysis produced six decision factors that are considered by the customers when going for a solar power system installation.
It was also important to understand and test these factors with a wider audience. For this reason, data from residents of Karachi was collected using a survey questionnaire to gauge the relative importance of the identified decision factors. Out of the six factors, the top three factors were high energy bills, load shedding and energy independence.
The research also included development of a financial model that can be used in real- life scenarios for decision making on the basis of financial metrics such as payback, return on investment and internal rate of return. The model takes various economic and technical inputs into consideration and outputs a detailed sensitivity analysis that allows the customers to base their decisions on.
Based on the combined knowledge gained from this research, it is recommended that policy making should be done by the government to allow easy access to the solar power systems to the common people, especially those who belong to the lower socio-economic classes. Adequate policies cannot only support the national grid by reducing the burden on it but can also help in alleviating poverty, fight inflation, and boost the overall economic conditions of the country
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