64 research outputs found
A modified multiphase oscillator with improved phase noise performance
This paper investigates the factors that influence the phase noise
performance of an oscillator and proposes a modified structure for improved
phase noise performance. A single and multiphase oscillator analysis using
the harmonic balance method is presented. The modified structure increases
the oscillation amplitude without increasing the bias current and leads to
improved phase noise performance as well as decreased power consumption.
The modification is analyzed and the figure of merit of the oscillator shows a
significant improvement of 21 dB. Numerical and analytical solutions are
presented to predict the oscillation frequency and phase noise. The analytical
solution is used to approximate the first harmonic and can be combined with
numerical simulations to extrapolate phase noise performance.The measurements relating to this work were enabled through the support of
SAAB Electronic Defence Systems (EDS). Funding was also received from
the National Research Foundation (NRF), Department of Science and
Technology, South Africa. NRF funding was for measurement equipment â
a millimeter-wave vector network analyzer (under grant ID: 72321) and
wafer-prober (under grant ID: 78580). NRF funding (under grant ID: 72321)
also allowed collaboration with Prof Luca Larcher, UniversitĂ degli studi di
Modena e Reggio Emilia, Italy.http://www.elsevier.com/locate/mejo2018-04-30am2017Electrical, Electronic and Computer Engineerin
CMOS avalanche electroluminescence applications : microdisplay and high speed data communication
All-CMOS silicon light sources, although not the choice semiconductor process for light
generation, offer the possibility of large scale manufacturing, integration with digital and driver
electronics as well as a wide operating temperature range. These advantages do however come at a
cost of reduced efficiency, but offer significant cost advantages inherent when using a standard
CMOS technology. This paper presents two applications of standard CMOS integrated light sources.
A fully functional microdisplay utilising avalanche electroluminescence for visible light generation
and implemented in a completely standard 0.35 ÎŒm CMOS technology is presented. The microdisplay
has an operating temperature range of -50 to 125 °C, which cannot be achieved by competing
microdisplay technologies. Utilising the same silicon light sources, a 10 Mb/s optical communication
link is established operating at a BER of less than 10-12. The data communication link presented in
this paper constitutes the fastest all-silicon data communication link achieved thus far.The authors would like to thank INSiAVA (Pty) Ltd
(http://www.insiava.com) for funding this research.http://www.saiee.org.za//content.php?pageID=200#am2013ai201
Soil loss by water erosion in areas under maize and jack beans intercropped and monocultures
Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.
BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
Perdas de ĂĄgua, solo, matĂ©ria orgĂąnica e nutriente por erosĂŁo hĂdrica na cultura do milho implantada em ĂĄrea de campo nativo, influenciadas por mĂ©todos de preparo do solo e tipos de adubação
The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set
Background
Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables.
Methods
Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set.
Results
Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15â0.23), higher ASA scores (OR 0.19, 95% CI 0.15â0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58â0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48â0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34â0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of â€5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (pâ<â0.001).
Conclusions
The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy
Blockade of Tim-1 and Tim-4 Enhances Atherosclerosis in Low-Density Lipoprotein Receptor-Deficient Mice
Objective - T cell immunoglobulin and mucin domain (Tim) proteins are expressed by numerous immune cells, recognize phosphatidylserine on apoptotic cells, and function as costimulators or coinhibitors. Tim-1 is expressed by activated T cells but is also found on dendritic cells and B cells. Tim-4, present on macrophages and dendritic cells, plays a critical role in apoptotic cell clearance, regulates the number of phosphatidylserine-expressing activated T cells, and is genetically associated with low low-density lipoprotein and triglyceride levels. Because these functions of Tim-1 and Tim-4 could affect atherosclerosis, their modulation has potential therapeutic value in cardiovascular disease. Approach and Results - ldlr-/- mice were fed a high-fat diet for 4 weeks while being treated with control (rat immunoglobulin G1) or anti-Tim-1 (3D10) or -Tim-4 (21H12) monoclonal antibodies that block phosphatidylserine recognition and phagocytosis. Both anti-Tim-1 and anti-Tim-4 treatments enhanced atherosclerosis by 45% compared with controls by impairment of efferocytosis and increasing aortic CD4+T cells. Consistently, anti-Tim-4-treated mice showed increased percentages of activated T cells and late apoptotic cells in the circulation. Moreover, in vitro blockade of Tim-4 inhibited efferocytosis of oxidized low-density lipoprotein-induced apoptotic macrophages. Although anti-Tim-4 treatment increased T helper cell (Th)1 and Th2 responses, anti-Tim-1 induced Th2 responses but dramatically reduced the percentage of regulatory T cells. Finally, combined blockade of Tim-1 and Tim-4 increased atherosclerotic lesion size by 59%. Conclusions - Blockade of Tim-4 aggravates atherosclerosis likely by prevention of phagocytosis of phosphatidylserine-expressing apoptotic cells and activated T cells by Tim-4-expressing cells, whereas Tim-1-associated effects on atherosclerosis are related to changes in Th1/Th2 balance and reduced circulating regulatory T cells
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