10 research outputs found

    Chronic Q fever diagnosis—consensus guideline versus expert opinion

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    Chronic Q fever, caused by Coxiella burnetii, has high mortality and morbidity rates if left untreated. Controversy about the diagnosis of this complex disease has emerged recently. We applied the guideline from the Dutch Q Fe­ver Consensus Group and a set of diagnostic criteria pro­posed by Didier Raoult to all 284 chronic Q fever patients included in the Dutch National Chronic Q Fever Database during 2006–2012. Of the patients who had proven cas­es of chronic Q fever by the Dutch guideline, 46 (30.5%) would not have received a diagnosis by the alternative cri­teria designed by Raoult, and 14 (4.9%) would have been considered to have possible chronic Q fever. Six patients with proven chronic Q fever died of related causes. Until results from future studies are available, by which current guidelines can be modified, we believe that the Dutch lit­erature-based consensus guideline is more sensitive and easier to use in clinical practice

    Consensus guidelines for the use and interpretation of angiogenesis assays

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    The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference

    A 0.06–3.4-MHz 92- μ W Analog FIR Channel Selection Filter With Very Sharp Transition Band for IoT Receivers

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    Analog FIR filtering is proposed to improve the performance of a single stage gm -C channel selection filter for ultra low power Internet-of-Things receivers. The transconductor is implemented as a digital-to-analog converter; allowing a varying transconductance in time, which results in a very sharp FIR filter. The filter is manufactured in 22-nm FDSOI and has a core area of 0.09 mm 2 . It consumes 92 μW from a 700-mV supply and achieves f−60dB/f−3dB=3.8 . The filter has 31.5 dB gain, out-of-band OIP3 of 28 dBm and output referred 1-dB compression point of 3.7 dBm. The filter bandwidth is tunable from 0.06 to 3.4 MHz

    Low-Power Highly Selective Channel Filtering Using a Transconductor–Capacitor Analog FIR

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    Analog finite-impulse-response (AFIR) filtering is proposed to realize low-power channel selection filters for the Internet-of-Things receivers. High selectivity is achieved using an architecture based on only a single-time-varying- transconductance and integration capacitor. The transconductance is implemented as a digital-to-analog converter and is programmable by an on-chip memory. The AFIR operating principle is shown step by step, including its complete transfer function with aliasing. The filter bandwidth and transfer function are highly programmable through the transconductance coefficients and clock frequency. Moreover, the transconductance programmability allows an almost ideal filter response to be realized by careful analysis and compensation of the parasitic circuit impairments. The filter, manufactured in 22-nm FDSOI, has an active area of 0.09 mm2. Its bandwidth can be accurately tuned from 0.06 to 3.4 MHz. The filter consumes 92 µW from a 700-mV supply. This low power consumption is combined with a high selectivity: f−60 dB/f−3 dB = 3.8. The filter has 31.5-dB gain and 12-nV/√ Hz input-referred noise for a 0.43-MHz bandwidth. The OIP3 is 28 dBm, independent of the frequency offset. The output-referred 1-dB-compression point is 3.7 dBm, and the in-band gain compresses by 1 dB for an −3.7-dBm out-of-band input signal while still providing >60 dB of filtering

    Systems and methods for analog finite impulse response filters

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    Systems and methods for analog finite impulse response (FIR) filters are provided. In certain embodiments, a receiver includes a cascade of a mixer, an analog FIR filter, and an analog-to-digital converter (ADC). By including the analog FIR filter along the signal path between the mixer and the ADC, design constraints of the ADC are relaxed. For example, the ADC can operate with relaxed specifications with respect to resolution and/or dynamic range when the analog FIR filter is included. The analog FIR filter can include a controllable transconductance circuit that delivers an integration current to a capacitor over an integration period, with the analog FIR filter's coefficients used to change the transconductance setting of the controllable transconductance circuit to different values over the integration period

    30.4 A 370µW 5.5dB-NF BLE/BT5.0/IEEE 802.15.4-Compliant Receiver with >63dB Adjacent Channel Rejection at >2 Channels Offset in 22nm FDSOI

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    Upcoming Internet-of-Things (IoT) applications require low-power multi-standard RF receiver (RX) front-ends. Interference rejection becomes increasingly important as ever more devices compete in the scarce 10w-GHz spectrum. Typically, low-power RXs do not possess very steep filtering [1]-[6]. On the other hand, very selective RXs - e.g. using analog FIR or Filtering-by-Aliasing [7] - have very high power consumption, not suitable for IoT applications. A recent Analog Finite-Impulse-Response (AFIR) filter [8] shows promising results to improve channel filtering. [8] uses a much lower FIR update rate than [7] to considerably reduce power consumption. This comes at the cost of a filter alias, but the inherent windowed integration sinc filtering mitigates this filter alias. Achieving low RX Noise Figure (NF), while improving selectivity is challenging at ultra-low power, where all blocks tend to contribute significantly to the total power consumption [1]-[6]

    2.4-GHz Highly Selective IoT Receiver Front End With Power Optimized LNTA, Frequency Divider, and Baseband Analog FIR Filter

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    High selectivity becomes increasingly important with an increasing number of devices that compete in the congested 2.4-GHz industrial, scientific, and medical (ISM)-band. In addition, low power consumption is very important for Internet-of-Things (IoT) receivers. We propose a 2.4-GHz zero-intermediate frequency (IF) receiver front-end architecture that reduces power consumption by 2 \times compared with state-of-the-art and improves selectivity by >20-dB without compromising on other receiver metrics. To achieve this, the entire receive chain is optimized. The low-noise transconductance amplifier (LNTA) is optimized to combine low noise with low power consumption. State-of-the-art sub-30-nm complementary metal-oxide-semiconductor (CMOS) processes have almost equal strength complementary field-effect transistors (FETs) that result in altered design tradeoffs. A Windmill 25%-duty cycle frequency divider architecture is proposed, which uses only a single NOR-gate buffer per phase to minimize power consumption and phase noise. The proposed divider requires half the power consumption and has 2 dB or more reduced phase noise when benchmarked against state-of-the-art designs. An analog finite impulse response (FIR) filter is implemented to provide very high receiver selectivity with ultralow power consumption. The receiver front end is fabricated in a 22-nm fully depleted silicon-on-insulator (FDSOI) technology and has an active area of 0.5 mm2. It consumes 370 W from a 700-mV supply voltage. This low power consumption is combined with a 5.5-dB noise figure. The receiver front end has -7.5-dBm input-referred third-order-intercept point (IIP3) and 1-dB gain compression for a -22-dBm blocker, both at maximum gain of 61 dB. From three channels offset onward, the adjacent channel rejection (ACR) is ≥63 dB for Bluetooth Low-Energy (BLE), BT5.0, and IEEE802.15.4

    Maintaining physiological testosterone levels by adding dehydroepiandrosterone to combined oral contraceptives: I. Endocrine effects.

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    OBJECTIVE: To determine whether adding dehydroepiandrosterone to combined oral contraceptives (COCs) maintains physiological levels of free testosterone. STUDY DESIGN: A randomized, double-blind, placebo-controlled, two-way crossover study conducted in 81 healthy women (age range: 20-35 years; Body mass index (BMI) range: 18-35 kg/m(2)) using oral contraceptives. Androgens, sex hormone-binding globulin (SHBG), estradiol (E2) and estrone (E1) were measured, and free testosterone and the free testosterone index were calculated. Subjects discontinued oral contraceptive use for at least one menstrual cycle before being randomized to receive five cycles of ethinyl estradiol (EE) combined with either levonorgestrel (EE/LNG group) or drospirenone (EE/DRSP group) together with either dehydroepiandrosterone (DHEA) (50 mg/day orally) or placebo. Subsequently, all subjects crossed over to the other treatment arm for an additional five cycles. RESULTS: Both COCs decreased the levels of all androgens measured. Significant decreases (p<.05) were found with EE/LNG and EE/DRSP for total testosterone (54.5% and 11.3%, respectively) and for free testosterone (66.8% and 75.6%, respectively). Adding DHEA to the COCs significantly increased all androgens compared to placebo. Moreover, including DHEA restored free testosterone levels to baseline values in both COC groups and total testosterone levels to baseline in the EE/LNG group and above baseline in the EE/DRSP group. SHBG concentrations were significantly higher with EE/DRSP compared to EE/LNG (p<.0001). The addition of DHEA did not affect the levels of SHBG. CONCLUSIONS: Taking COCs reduces total and free testosterone levels and increases SHBG concentrations. By coadministration with DHEA, physiological levels of total and free testosterone are restored while using EE/LNG. With EE/DRSP, only the free testosterone level is normalized by DHEA coadministration. IMPLICATIONS: A daily oral dose of 50-mg DHEA maintains physiological free and total testosterone levels in women who are using an EE/LNG-containing COC
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