9 research outputs found
Towards a Seamless Future Generation Network for High Speed Wireless Communications
YesThe MIMO technology towards achieving future
generation broadband networks design criteria is presented.
Typical next generation scenarios are investigated. The MIMO
technology is integrated with the OFDM technology for effective
space, time and frequency diversity exploitations for high speed
outdoor environment. Two different OFDM design kernels (fast
Fourier transform (FFT) and wavelet packet transform (WPT))
are used at the baseband for OFDM system travelling at
terrestrial high speed for 800MHz and 2.6GHz operating
frequencies. Results show that the wavelet kernel for designing
OFDM systems can withstand doubly selective channel fading for
mobiles speeds up to 280Km/hr at the expense of the traditional
OFDM design kernel, the fast Fourier transform
A Multi-Antenna Design Scheme based on Hadamard Matrices for Wireless Communications.
YesA quasi-orthogonal space time block coding (QO-STBC) scheme that exploits Hadamard matrix
properties is studied and evaluated. At first, an analytical solution is derived as an extension of
some earlier proposed QO-STBC scheme based on Hadamard matrices, called diagonalized
Hadamard space-time block coding (DHSBTC). It explores the ability of Hadamard matrices
that can translate into amplitude gains for a multi-antenna system, such as the QO-STBC
system, to eliminate some off-diagonal (interference) terms that limit the system performance
towards full diversity. This property is used in diagonalizing the decoding matrix of the QOSTBC
system without such interfering elements. Results obtained quite agree with the analytical
solution and also reflect the full diversity advantage of the proposed QO-STBC system design
scheme. Secondly, the study is extended over an interference-free QO-STBC multi-antenna
scheme, which does not include the interfering terms in the decoding matrix. Then, following
the Hadamard matrix property advantages, the gain obtained (for example, in 4x1 QO-STBC
scheme) in this study showed 4-times louder amplitude (gain) than the interference-free QOSTBC
and much louder than earlier DHSTBC for which the new approach is compared with
The global burden of cancer attributable to risk factors, 2010–19: a systematic analysis for the Global Burden of Disease Study 2019
BACKGROUND: Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. METHODS: The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk–outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. FINDINGS: Globally, in 2019, the risk factors included in this analysis accounted for 4·45 million (95% uncertainty interval 4·01–4·94) deaths and 105 million (95·0–116) DALYs for both sexes combined, representing 44·4% (41·3–48·4) of all cancer deaths and 42·0% (39·1–45·6) of all DALYs. There were 2·88 million (2·60–3·18) risk-attributable cancer deaths in males (50·6% [47·8–54·1] of all male cancer deaths) and 1·58 million (1·36–1·84) risk-attributable cancer deaths in females (36·3% [32·5–41·3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20·4% (12·6–28·4) and DALYs by 16·8% (8·8–25·0), with the greatest percentage increase in metabolic risks (34·7% [27·9–42·8] and 33·3% [25·8–42·0]). INTERPRETATION: The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial
Background:
In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation.
Methods:
This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation <92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg–800 mg (depending on weight) given intravenously. A second dose could be given 12–24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936).
Findings:
Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76–0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12–1·33; p<0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77–0·92; p<0·0001).
Interpretation:
In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids.
Funding:
UK Research and Innovation (Medical Research Council) and National Institute of Health Research
Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial
Background:
Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19.
Methods:
This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.
Findings:
Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79).
Interpretation:
In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes.
Funding:
UK Research and Innovation (Medical Research Council) and National Institute of Health Research
Surface Response Methodology for Mildsteel Corrosion Inhibition by Ethyl Esters of Castor and Rubber Seed Oils
Surface Response Methodology was conducted for Mildsteel Corrosion Inhibition by Ethyl esters of Castor and Rubber Seed Oils. Inhibitor concentration-in-acid medium, temperature and time were considered as the independent variables, in order to know the effect of the response (dependent) variable, which is the weight loss. The design matrix was constructed on the basis of different conditions of the independent variables at varying coded levels of design consideration (-α, -1, 0, +1 and +α), upon which corrosion inhibition experiments were conducted. Contour plots were used to show the combined effects of the factors (concentration, temperature and time) on the inhibition rate of the two study samples: Castor Seed Oil (CSO) and Rubber Seed Oil, RSO. Weight loss for CSO at combined effects of temperature-concentration, time-concentration and time-temperature were found to be 33.01g, 41.11g and 43.30g respectively, while those of RSO are 30.99g 38.16g and 40.15g respectively. This indicates that the time of the corrosion reaction is the most significant factor among the three factors considered in this study, while reaction temperature is more significant, and the inhibitor concentration is least significant. This high significance of reaction time was eventually manifested at the point of optimization, which indicated the highest response value of 44.52g and 43.89g for CSO and RSO respectively. The results, therefore, identifies RSO (with least weight loss, Z=30.99g) as possessing a better inhibition efficiency, when compared to CSO, and the model equations for both samples are of second order (Pure Quadratic)
Antidiabetic and antioxidant potentials of Pleurotus ostreatus -derived compounds: An in vitro and in silico approach
Many health benefits have reportedly been associated with mushroom consumption. This study determined the chemical constituents of Pleurotus ostreatus methanol extract (MEPO) and investigated its antioxidant and antidiabetic effects using in vitro and in silico approaches. The chemical composition of MEPO was determined using the gas chromatography-flame ionization detector (GC-FID) technique, while 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods were used to determine antioxidant activity. The antidiabetic activity was evaluated using α-amylase and α-glucosidase inhibition assays, while molecular docking was done to give insight into the binding potentials of MEPO constituents against α-amylase, α-glucosidase, and phosphoenolpyruvate (PEP) carboxykinase activities. Thirteen compounds, including ephedrine, oxalate, rutin, naringin, and kaempferol, were identified in MEPO. The extract showed moderate antioxidant activity, as observed from the DPPH (IC50 = 732.41 mg/ml) and FRAP studies. The extract also demonstrated stronger inhibition of α-glucosidase activity (IC50 = 246.58 mg/ml) than α-amylase activity (IC50 = 1074.05 mg/ml). Docking studies revealed that rutin and naringin interacted effectively with amino acid residues crucial for α-amylase, α-glucosidase, and PEP carboxykinase activities via hydrogen bonds. The result shows that MEPO is a rich store of beneficial compounds which could be explored for the management of diabetes and associated complications