Performance Evaluation of Hybrid Precoder Design for Multi-User Massive MIMO Systems with Low-Resolution ADCs/DACs

This paper presents a comprehensive analysis and design of a hybrid precoding system tailored for mmWave multi-user massive MIMO systems in both downlink and uplink scenarios. The proposed system employs a two-stage precoding approach, incorporating UQ and NUQ techniques, along with low-resolution DACs in downlink and ADCs in uplink to address hardware limitations. The system considers Zero Forcing and Minimum Mean Square Error algorithms as digital precoding methods for the uplink scenario, while exploring the impact of different DAC resolutions on system performance. Extensive simulations reveal that the proposed system surpasses conventional analog beamforming methods, particularly in multi-user scenarios involving inter-user interference. In downlink, the system demonstrates a trade-off between SE and EE, achieving higher Energy Efficiency with NUQ. In uplink, NUQ and UQ converters exhibit similar performance trends regardless of the chosen combiner algorithm. The proposed system attains enhanced Spectral and Energy Efficiency while maintaining reduced complexity and overhead. The study significantly contributes to the advancement of efficient and effective mmWave multi-user massive MIMO systems by providing a thorough analysis of various quantization schemes and precoding techniques. The findings of this research are expected to aid in the optimization of 5G and beyond technologies, particularly in high-density deployment scenarios

A comparative study of low multidirectional locked nailing and locking compression plating in management of distal tibia fractures

Background: Ideal management for distal tibial meta-diaphyseal fracture remains controversial, due to lack of adequate evidences about implants and multiple treatment modalities. Most commonly these fractures were dealt with either locking compression plate (LCP) or by multi directional intra-medullary nail (IMIL). Aim is to compare these two implants, to understand the mechanism and find out the ideal implant for the management of distal tibia fractures.Methods: This study is prospective and comparative done at the associated hospitals of KMC Mangalore, spanning a period of around 2 years (October 2014 to July 2016). All patients presented with distal tibial meta-diaphyseal fractures were included in the study. Patients were treated with either low multi directional IMIL nail or by LCP and followed up for a minimum period of 6 months. Outcome measures included Olerud Molander Ankle Score (OMAS), wound issues, union of the fracture and patient mobility.Results: 50 consecutive patients (mean age 40 years) were included in the study, divided equally into 2 groups. Group-A treated with multi directional IMIL nail and group-B with MIPPO plating. Mean functional OMAS score for nailing is 91 and for plating is 88. All fractures treated with nailing united within 6 months and 4% patient treated by plating goes mal union and 4% infected.Conclusions: For distal tibial fracture management, intra-medullary nailing proved reliable surgical option with regards to the OMAS score, fracture union and less infection rates

Intravenous pharmacokinetics, oral bioavailability, dose proportionality and in situ permeability of anti-malarial lumefantrine in rats

<p>Abstract</p> <p>Background</p> <p>Despite the wide spread use of lumefantrine, there is no study reporting the detailed preclinical pharmacokinetics of lumefantrine. For the development of newer anti-malarial combination(s) and selection of better partner drugs, it is long felt need to understand the detailed preclinical pharmacokinetics of lumefantrine in preclinical experimental animal species. The focus of present study is to report bioavailability, pharmacokinetics, dose linearity and permeability of lumefantrine in rats.</p> <p>Methods</p> <p>A single dose of 10, 20 or 40 mg/kg of lumefantrine was given orally to male rats (N = 5 per dose level) to evaluate dose proportionality. In another study, a single intravenous bolus dose of lumefantrine was given to rats (N = 4) at 0.5 mg/kg dose following administration through the lateral tail vein in order to obtain the absolute oral bioavailability and clearance parameters. Blood samples were drawn at predetermined intervals and the concentration of lumefantrine and its metabolite desbutyl-lumefantrine in plasma were determined by partially validated LC-MS/MS method. <it>In-situ </it>permeability study was carried in anaesthetized rats. The concentration of lumefantrine in permeability samples was determined using RP-HPLC.</p> <p>Results</p> <p>For nominal doses increasing in a 1:2:4 proportion, the C_maxand AUC_0-∞values increased in the proportions of 1:0.6:1.5 and 1:0.8:1.8, respectively. For lumefantrine nominal doses increasing in a 1:2:4 proportion, the C_maxand the AUC_0-tvalues for desbutyl-lumefantrine increased in the proportions of 1:1.45:2.57 and 1:1.08:1.87, respectively. After intravenous administration the clearance (Cl) and volume of distribution (Vd) of lumefantrine in rats were 0.03 (± 0.02) L/h/kg and 2.40 (± 0.67) L/kg, respectively. Absolute oral bioavailability of lumefantrine across the tested doses ranged between 4.97% and 11.98%. Lumefantrine showed high permeability (4.37 × 10^-5cm/s) in permeability study.</p> <p>Conclusions</p> <p>The pharmacokinetic parameters of lumefantrine and its metabolite desbutyl-lumefantrine were successfully determined in rats for the first time. Lumefantrine displayed similar pharmacokinetics in the rat as in humans, with multiphasic disposition, low clearance, and a large volume of distribution resulting in a long terminal elimination half-life. The absolute oral bioavailability of lumefantrine was found to be dose dependent. Lumefantrine displayed high permeability in the <it>in-situ </it>permeability study.</p

Global, regional, and national burden of chronic kidney disease, 1990–2017 : a systematic analysis for the Global Burden of Disease Study 2017

Background Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout. Methods The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function. Findings Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, −1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, −1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function. Interpretation Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI

DIGITAL IMAGE CORRELATION ON RCC BEAM WITH PARTIAL REPLACEMENT OF GGBS.

The cracks are common problem in all structural building ,the identification of micro cracks which are present in structure can be easily identified by the mat lab software. The beam is been tested in three point loading machine for the flexural strength of the beam and the displacement and stress also been identified using the digital image correlation technique. The image are been captured during the testing are used in the digital image correlation for the crack identification, strain, deformation.The micro crack which are present in inside the structure can also be identified using this software. The high resolution camera as been used in this technique for the high resolution pixel. This pixel will run on the mat lab programme for the deformation, displacement, strain .which occur in the beamwithout any contact process

Rapid discrimination between strains of beta haemolytic streptococci by intact Cell mass spectrometry

Background and objectives: Beta haemolytic streptococci belonging to Lancefield group A, B, C and G cause a wide spectrum of clinical diseases. Hence there is a need for rapid and accurate typing of these strains. The present study was undertaken to evaluate the use of intact cell matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for rapid discrimination between strains of beta haemolytic streptococci. Methods: Colonies of beta haemolytic streptococci were emulsified with chemical matrix on the sample slide, dried and analyzed by MALDI-TOF-MS. Results: The reproducibility of results for all groups of beta haemolytic streptococci was good and spectra obtained for Lancefield group A, C and G streptococci showed discrimination between the groups on visual comparison. A finer difference in spectrum was observed among group A streptococci isolated from different locations at different periods of time. Interpretation and conclusion: MALDI-TOF-MS may be a potential tool in discriminating between strains of beta haemolytic streptococci, and also in the characterisation of untypable strains of group A streptococci

Early empiric antibiotic use in COVID-19 patients: results from the international VIRUS registry

Objectives: COVID-19 escalated inappropriate antibiotic use. We determined the distribution of pathogens causing community-acquired co-infections, the rate, and factors associated with early empiric antibiotic (EEAB) treatment among hospitalized COVID-19 patients. Methods: The Society of Critical Care Medicine Discovery Viral Infection and Respiratory Illness Universal Study (VIRUS) COVID-19 Registry including 68,428 patients from 28 countries enrolled between January 2020 and October 2021 were screened. After exclusions, 7830 patients were included in the analysis. Azithromycin and/or other antibiotic treatment given within the first 3 days of hospitalization was investigated. Univariate and multivariate analyses were performed to determine factors associated with EEAB use. Results: The majority (6214, 79.4%) of patients received EEAB, with azithromycin combination being the most frequent (3146, 40.2%). As the pandemic advanced, the proportion of patients receiving EEAB regressed from 84.4% (786/931) in January-March 2020 to 65.2% (30/46) in April-June 2021 (P < 0.001). Beta-lactams, especially ceftriaxone was the most commonly used antibiotic. Staphylococcus aureus was the most commonly isolated pathogen. Multivariate analysis showed geographical location and pandemic timeline as the strongest independent predictors of EEAB use. Conclusions: EEAB administration decreased as pandemic advanced, which may be the result of intensified antimicrobial stewardship efforts. Our study provides worldwide goals for antimicrobial stewardship programs in the post-COVID-19 era