A unified description of multiple feedback common-gate low-noise amplifiers (LNAs) is presented, providing analytical expressions for gain, noise figure, linearity, and stability conditions. ...Moreover, from the theory, a new methodology for LNA optimization is developed. This new approach, called adaptive optimization, uses the ability to reconfigure the feedback network to match the amplifier characteristics to the changing working conditions. Results of simulation of LNAs with different feedback types are shown, and they confirm the theory presented.
Some urban solid waste landfill sites in Spain are located on geological substrates of gypsiferous lithology. Although this type of substrate is assumed to be of low permeability, it can develop ...secondary pores by dissolution and, under favourable environmental conditions, form a karstic system that may pose serious geotechnical problems in the medium and long term. The purpose of this work was to study alterations caused by selective tests in various sections of a gypsum lithological column obtained from the Colmenar de Oreja landfill site (Spain). The tests were used to assess the influence of individual environmental factors and involved the addition of milli-RO water, solutions containing a 1%, 5% or 10% concentration of landfill leachate, and 2, 5, 10 and 15
mg
l
−1 solutions of NaCl in successive immersion–drying cycles at −15, 20 or 60
°C. Differences in alterability between the six studied segments of the lithological column were found to be due to differences in lutite content, specific crystal habit and type of cement. Segments with specular gypsum were the strongest in the tests, while the segment with the highest amount of detrital materials was the most responsive to temperature and moisture changes. The treatments that produce greater alterations are those that contain only milli-RO water.
Cytochrome c oxidase (Cco) has been reported to be a receptor for some of the beneficial effects of low intensity visible and near-infrared light on cells and tissues. Here, we have explored the role ...of low intensity light in affecting a newly described function of Cco, its ability to catalyze nitrite–dependent nitric oxide (NO) synthesis (Cco/NO). Using a new assay for Cco/NO we have found that both yeast and mouse brain mitochondrial Cco produce NO over a wide range of oxygen concentrations and that the rate of NO synthesis increases as the oxygen concentration decreases, becoming optimal under hypoxic conditions. Low intensity broad-spectrum light increases Cco/NO activity in an intensity-dependent fashion but has no effect on oxygen consumption by Cco. By using a series of bandpass filters and light emitting devices (LEDs) we have determined that maximal stimulation of Cco/NO activity is achieved by exposure to light whose central wavelength is 590
±
14
nm. This wavelength of light stimulates Cco/NO synthesis at physiological nitrite concentrations. These findings raise the interesting possibility that low intensity light exerts a beneficial effect on cells and tissues by increasing NO synthesis catalyzed by Cco and offer a new explanation for the increase in NO bioavailability experienced by tissue exposed to light.
Treatment of adolescents with growth hormone deficiency (GHD) during the transition period is a controversial issue. This paper is a contribution from the Italian community of paediatric and adult ...endocrinologists surveyed in a Delphi panel. The Delphi method is a structured communication technique, originally developed as a systematic, interactive forecasting method that relies on a panel of experts. The experts answer questionnaires in two or more rounds. There was substantial agreement on the definition of the problems associated with the diagnosis and treatment of adolescents with GHD in the transition period, as well as on the identification of the controversial issues which need further studies. There is general consensus on the need of re-testing all isolated idiopathic GHD after at least 30-day withdrawn from treatment, while in patients with multiple pituitary deficiency and low IGF-I levels there is generally no need to re-test. In patients with permanent or confirmed GHD, a starting low rhGH dose (0.01–0.03 mg per day) to be adjusted according to IGF-I concentrations is also widely accepted. For those continuing treatment, the optimal therapeutic schedule to obtain full somatic maturation, normalization of body composition and bone density, cardiovascular function and Quality of Life, need to be evaluated.
Larval vomiting during a mission in Haïti Aigle, L; Castello, R; Breton, A-L
Médecine et santé tropicales (Montrouge, France),
2016-May-01, Letnik:
26, Številka:
2
Journal Article
Recenzirano
Following an original case report of massive regurgitation of maggots and the difficulty of medical management, we return to the fecal contamination problem for troops in the field. The survey of ...maggots has allowed for the diagnosis of contamination by ingestion of house fly eggs as a major infection vector. The successive ingestion of anti-acid and gastric dressing can induce an important diminution of gastric acidity that can allow for the proliferation of germs. In an operational context or natural catastrophe andin addition to field hygiene rules that are very important, it can also be useful to propose exclusive field rationsfor few daysin order to limit the interhuman contamination.
A CMOS low-pass filter with programmable boost is presented. The architecture is a G/sub m//C type with the G/sub m/ value controlled through a resistor servo approach. The transfer function has been ...optimized in order to reduce the sensitivity to component parameter variations. The 1:4 tuning range is achieved by exploiting a dual-loop control over a degenerated differential pair. At the nominal output voltage swing of 200 mV/sub pp/ differential, a THD better than 40 dB is guaranteed. The high-frequency boost is programmable between 6 and 14 dB. This filter, realized as a cascade of biquad and first-order cells, is implemented in a 0.25-/spl mu/m 2.5-V CMOS technology. It dissipates 120 mW with f/sub c/=120 MHz and has a die area of 0.23 mm/sup 2/.
Abstract Bacille Calmette Guérin substrain Moreau Rio de Janeiro is an attenuated strain of Mycobacterium bovis that has been used extensively as an oral tuberculosis vaccine. We assessed its ...potential as a challenge model to study clinical and immunological events following repeated mycobacterial gut infection. Seven individuals received three oral challenges with approximately 107 viable bacilli. Clinical symptoms, T-cell responses and gene expression patterns in peripheral blood were monitored. Clinical symptoms were relatively mild and declined following each oral challenge. Delayed T-cell responses were observed, and limited differential gene expression detected by microarrays. Oral challenge with BCG Moreau Rio de Janeiro vaccine was immunogenic in healthy volunteers, limiting its potential to explore clinical innate immune responses, but with low reactogenicity.
A low-voltage switched capacitor (SC) filter operated from a single 1 V supply and realized in a standard 0.5-/spl mu/m CMOS technology is presented. Proper operation is obtained using the ...switched-opamp technique without any clock voltage multiplier or low-threshold devices. This makes the circuit compatible with future deep submicrometer technology. As opposed to previous switched-opamp implementations, the filter uses a fully differential topology. This allows operation with a rail-rail output swing and reduction of the number of opamps required to build high order infinite impulse response (IIR) filters. On the other hand, a low-voltage common-mode feedback (CMFB) circuit is required. In addition, the circuit uses an opamp which is only partially turned off during the off phase. This enables an increase in the maximum sampling frequency. The filter implements a bandpass response (f/sub s//f/sub o/=4, Q=7) and it has been characterized with a 1.8 MHz sampling frequency. Its power consumption is about 160 /spl mu/W. The filter is still fully functional down to 0.9 V supply voltage.
This work proposes and studies a new internal model for discrete-time passive or finite-frequency positive-real systems which can be used in repetitive control designs to track or to attenuate ...periodic signals. The main characteristic of the proposed internal model is its passivity. This property implies closed-loop stability when it is used with discrete-time passive plants, as well as the broader class of discrete-time finite-frequency positive real plants. This work discusses the internal model energy function and its frequency response. A design procedure for repetitive controllers based on the proposed internal model is also presented. Two numerical examples are included.
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