137 research outputs found

    Index Modulation-based Information Harvesting for Far-Field RF Power Transfer

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    While wireless information transmission (WIT) is evolving into its sixth generation (6G), maintaining terminal operations that rely on limited battery capacities has become one of the most paramount challenges for Internet-of-Things (IoT) platforms. In this respect, there exists a growing interest in energy harvesting technology from ambient resources, and wireless power transfer (WPT) can be the key solution towards enabling battery-less infrastructures referred to as zero-power communication technology. Indeed, eclectic integration approaches between WPT and WIT mechanisms are becoming a vital necessity to limit the need for replacing batteries. Beyond the conventional separation between data and power components of the emitted waveforms, as in simultaneous wireless information and power transfer (SWIPT) mechanisms, a novel protocol referred to as information harvesting (IH) has recently emerged. IH leverages existing WPT mechanisms for data communication by incorporating index modulation (IM) techniques on top of the existing far-field power transfer mechanism. In this paper, a unified framework for the IM-based IH mechanisms has been presented where the feasibility of various IM techniques are evaluated based on different performance metrics. The presented results demonstrate the substantial potential to enable data communication within existing far-field WPT systems, particularly in the context of next-generation IoT wireless networks.Comment: 13 pages, 9 figure

    Association of adverse perinatal outcomes of intrahepatic cholestasis of pregnancy with biochemical markers: results of aggregate and individual patient data meta-analyses

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    Intrahepatic cholestasis of pregnancy is associated with adverse perinatal outcomes, but the association with the concentration of specific biochemical markers is unclear. We aimed to quantify the adverse perinatal effects of intrahepatic cholestasis of pregnancy in women with increased serum bile acid concentrations and determine whether elevated bile acid concentrations were associated with the risk of stillbirth and preterm birth. We did a systematic review by searching PubMed, Web of Science, and Embase databases for studies published from database inception to June 1, 2018, reporting perinatal outcomes for women with intrahepatic cholestasis of pregnancy when serum bile acid concentrations were available. Inclusion criteria were studies defining intrahepatic cholestasis of pregnancy based upon pruritus and elevated serum bile acid concentrations, with or without raised liver aminotransferase concentrations. Eligible studies were case-control, cohort, and population-based studies, and randomised controlled trials, with at least 30 participants, and that reported bile acid concentrations and perinatal outcomes. Studies at potential higher risk of reporter bias were excluded, including case reports, studies not comprising cohorts, or successive cases seen in a unit; we also excluded studies with high risk of bias from groups selected (eg, a subgroup of babies with poor outcomes were explicitly excluded), conference abstracts, and Letters to the Editor without clear peer review. We also included unpublished data from two UK hospitals. We did a random effects meta-analysis to determine risk of adverse perinatal outcomes. Aggregate data for maternal and perinatal outcomes were extracted from case-control studies, and individual patient data (IPD) were requested from study authors for all types of study (as no control group was required for the IPD analysis) to assess associations between biochemical markers and adverse outcomes using logistic and stepwise logistic regression. This study is registered with PROSPERO, number CRD42017069134. We assessed 109 full-text articles, of which 23 studies were eligible for the aggregate data meta-analysis (5557 intrahepatic cholestasis of pregnancy cases and 165 136 controls), and 27 provided IPD (5269 intrahepatic cholestasis of pregnancy cases). Stillbirth occurred in 45 (0·83%) of 4936 intrahepatic cholestasis of pregnancy cases and 519 (0·32%) of 163 947 control pregnancies (odds ratio [OR] 1·46 [95% CI 0·73-2·89]; I2=59·8%). In singleton pregnancies, stillbirth was associated with maximum total bile acid concentration (area under the receiver operating characteristic curve [ROC AUC]) 0·83 [95% CI 0·74-0·92]), but not alanine aminotransferase (ROC AUC 0·46 [0·35-0·57]). For singleton pregnancies, the prevalence of stillbirth was three (0·13%; 95% CI 0·02-0·38) of 2310 intrahepatic cholestasis of pregnancy cases in women with serum total bile acids of less than 40 μmol/L versus four (0·28%; 0·08-0·72) of 1412 cases with total bile acids of 40-99 μmol/L (hazard ratio [HR] 2·35 [95% CI 0·52-10·50]; p=0·26), and versus 18 (3·44%; 2·05-5·37) of 524 cases for bile acids of 100 μmol/L or more (HR 30·50 [8·83-105·30]; p<0·0001). The risk of stillbirth is increased in women with intrahepatic cholestasis of pregnancy and singleton pregnancies when serum bile acids concentrations are of 100 μmol/L or more. Because most women with intrahepatic cholestasis of pregnancy have bile acids below this concentration, they can probably be reassured that the risk of stillbirth is similar to that of pregnant women in the general population, provided repeat bile acid testing is done until delivery. Tommy's, ICP Support, UK National Institute of Health Research, Wellcome Trust, and Genesis Research Trust

    MODELING PERMEATION OF MODIFIED ATMOSPHERE GAS-MIXTURES THROUGH A LOW-DENSITY POLYETHYLENE PACKAGE FILM

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    Permeation of individual gases through a low density polyethylene package film with CO2-N2 and CO2-O2-N2 mixtures was simulated with a simple mathematical model. Permeabilities of carbon dioxide were of the order of 10(-12) m3/s m2atm/m with CO2-N2 systems. Including oxygen in the system did not change carbon dioxide permeabilities. Permeabilities of oxygen were of the order of magnitude of 10(-9) m3/s m2atm/m with this system. When a CO2-O2-N2 mixture was humidified no substantial change was observed in CO2 permeability, but the O2 permeability decreased almost 10 times. These results and the mathematical model presented may help in the modified atmosphere package design to increase the shelf life of produce

    Comparison of the clinical effects of two different canine retraction springs

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    Bu çalışmada, iki farklı kanin retraksiyon zembereğinin üst kaninler ve birinci büyük azılar üzerindeki etkileri incelenmiştir. Küçük azı çekimi gereken yirmibeş hasta çalışmaya dahil edilmiştir. Grubun yaş ortalaması 14.08+1.88 yıldır. Sağ üst kaninler 'Ladanyi' zembereğiyle ve sol üst kaninler 'LasVegas' zembereğiyle retrakte edilmiştir. Başlangıçta 100 gr şiddetinde kuvvet uygulanmıştır ve her dört haftada bir (ayda bir) zembereklerin aktivasyonları yenilenmiştir. 'Ladanyi' tarafının retraksiyon süresi ortalama 4.77±1.08 ay ve 'LasVegas' tarafının retraksiyon süresi ortalama 5.0±0.83 aydır. Ölçümler yan kafa filmleri, çalışma modellerinin fotokopileri ve panoramik filmler üzerinde yapılmıştır. 'Ladanyi' tarafının retraksiyon hızı ortalama 1.39±0.88 mm / ay ve 'LasVegas' tarafının retraksiyon hızı ortalama 1.04±0.96mm / ay'dır. Her iki taraf karşılaştırıldığında kanin hareketlerinin şeklinde anlamlı farklılık bulunmamıştır. Kaninler belirgin miktarda distale devrilerek hareket etmişlerdir. Her iki tarafta da önemsiz miktarda ankraj kaybı ölçülmüştür. Ortodontistlerin bu iki zemberek arasındaki tercihleri manipulasyonlarınmın kolaylığı ve hasta rahatlığı gibi faktörlere dayanmalıdır.In this study, effects of two different canine retraction springs on maxillary canines and maxillary molars were evaluated. Twenty-five patients, requiring premolar extractions, were included to the study. The mean age of the group was 14.08±1.88 years. Upper right canines were retracted by 'Ladanyi' springs and upper left canines by 'LasVegas' springs. The forces initially applied were 100 grams and the springs were reactivated every four weeks (every month). The mean retraction duration of the 'Ladanyi' side was 4.77±1.08 months and the mean retraction duration of the 'Las-Vegas' side was 5.0+0.83 months. Measurements were done on the lateral cephalograms, photocopies of the study casts and panoramic radiographs. The mean retraction rate of the 'Ladanyi' side was 1.39±0.88 mm / month and the mean retraction rate of the 'LasVegas' side was 1.04±0.96 mm / month. A comparison among the two sides revealed insignificant difference in the type of upper canine movements. The canines moved distally with a considerable amount of tipping. Insignificant amount of anchorage loss was measured for both sides. Decision by the orthodontist to se-lect one of these two springs should be based on the factors, such as ease of manipulation and patient comfort

    Dimethyl sulfoxide reduces the stability but enhances catalytic activity of the main SARS-CoV-2 protease 3CLpro

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for coronavirus disease 2019 (COVID-19), one of the most challenging global pandemics of the modern era. Potential treatment strategies against COVID-19 are yet to be devised. It is crucial that antivirals that interfere with the SARS-CoV-2 life cycle be identified and developed. 3-Chymotrypsin-like protease (3CLpro) is an attractive antiviral drug target against SARS-CoV-2, and coronaviruses in general, because of its role in the processing of viral polyproteins. Inhibitors of 3CLpro activity are screened in enzyme assays before further development of the most promising leads. Dimethyl sulfoxide (DMSO) is a common additive used in such assays and enhances the solubility of assay components. However, it may also potentially affect the stability and efficiency of 3CLpro but, to date, this effect had not been analyzed in detail. Here, we investigated the effect of DMSO on 3CLpro-catalyzed reaction. While DMSO (5%-20%) decreased the optimum temperature of catalysis and thermodynamic stability of 3CLpro, it only marginally affected the kinetic stability of the enzyme. Increasing the DMSO concentration up to 20% improved the catalytic efficiency and peptide-binding affinity of 3CLpro. At such high DMSO concentration, the solubility and stability of peptide substrate were improved because of reduced aggregation. In conclusion, we recommend 20% DMSO as the minimum concentration to be used in screens of 3CLpro inhibitors as lead compounds for the development of antiviral drugs against COVID-19
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