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Background Recent studies indicate that amylase-trypsin inhibitors (ATIs) and certain carbohydrates referred to as FODMAPs (fermentable oligo-, di-, monosaccharides and polyols) play an important role in promoting wheat sensitivity. Hitherto, no study has investigated the accumulation of ATIs during the development of the wheat caryopsis. We collected caryopses of common wheat cv. ‘Arnold’ at eight different grain developmental stages to study compositional changes in ATI and FODMAP content. Results The harvested caryopses were analysed for their size, protein and carbohydrate concentrations. ATIs were further characterized by MALDI-TOF MS, and their trypsin inhibition was evaluated by an enzymatic assay. The results showed that ATI accumulation started about 1 week after anthesis and subsequently increased steadily until physiological maturity. However, the biological activity of ATIs in terms of enzyme inhibition was not detectable before about 4 weeks after anthesis. Carbohydrate analysis revealed the abundance of short-chain fructans in early stages of grain development, whereas non-water-soluble carbohydrates increased during later developmental stages. Conclusions The results provide new insights into the complex metabolisms during grain filling and maturation, with particular emphasis on the ATI content as well as the inhibitory potential towards trypsin. The time lag between ATI accumulation and development of their biological activity is possibly attributed to the assembling of ATIs to dimers and tetramers, which seems to be crucial for their inhibitory potential.

This paper presents a performance analysis of a system for electrochemical impedance spectroscopy (EIS). The system, composed by an analog front-end (AFE) and a custom microcontroller (MCU) board, performs the impulse response (IR) measurement of linear and time-invariant (LTI) systems with pseudo-random excitation signals. As a novelty, a specific AFE for the interfacing of two-terminal resistive and capacitive sensors is covered in detail. The paper proposes, for the first time, a mathematical model to predict the impact of the main noise sources in the measured IR. Thanks to the proposed approach, the AFE and the system’s parameters can be properly designed in order to reduce the error, thus, minimizing the energy-per-error figure of merit (FOM) as well. The AFE is realized as discrete-components circuit and it has been included in a custom MCU-based measurement system as an expansion module. The predicted results from the mathematical model, in terms of noise power, SNR, and measurement error are validated through system-level simulation and experimental measurements. The system performs the IR measurement with 1023 points, showing root-mean-square (RMS) measurement errors of 1% and 1.4% for the tested ADC sampling frequencies of 62.5 kHz and 125 kHz, respectively. These lead to excellent FOM values of 128.9 mJ · % 2 and 252.6 mJ · % 2 that outstand the state of the art.

Amylase/trypsin inhibitors (ATIs) are widely consumed in cereal-based foods and have been implicated in adverse reactions to wheat exposure, such as respiratory and food allergy, and intestinal responses associated with coeliac disease and non-coeliac wheat sensitivity. ATIs occur in multiple isoforms which differ in the amounts present in different types of wheat (including ancient and modern ones). Measuring ATIs and their isoforms is an analytical challenge as is their isolation for use in studies addressing their potential effects on the human body. ATI isoforms differ in their spectrum of bioactive effects in the human gastrointestinal (GI), which may include enzyme inhibition, inflammation and immune responses and of which much is not known. Similarly, although modifications during food processing (exposure to heat, moisture, salt, acid, fermentation) may affect their structure and activity as shown in vitro, it is important to relate these changes to effects that may present in the GI tract. Finally, much of our knowledge of their potential biological effects is based on studies in vitro and in animal models. Validation by human studies using processed foods as commonly consumed is warranted. We conclude that more detailed understanding of these factors may allow the effects of ATIs on human health to be better understood and when possible, to be ameliorated, for example by innovative food processing. We therefore review in short our current knowledge of these proteins, focusing on features which relate to their biological activity and identifying gaps in our knowledge and research priorities.

The reduction of the nominal supply voltage of CMOS technologies with scaling comes with the decrease of the maximum tolerable voltage of the devices. This poses challenges in implementing circuit blocks that are compliant with standardized communication protocols or deal with off-chip signals in voltage domains larger than the nominal supply (e.g., 1.8 V, 3.3 V, 5 V). Design techniques such as cascoding, voltage shifting and adaptive biasing are effective at removing the need for customized voltage resistant input/output (I/O) devices since they prevent intolerable voltage drops. However, at the input of multiple-channel blocks, the design of switches of multiplexers results critical as the input and the output nodes can assume values beyond the signal range, causing harmful biasing configurations. This paper presents the architecture of a switch for input channel multiplexers able to handle signals up to twice the nominal supply voltage of the employed devices. Its effectiveness has been proved by implementing a 1.6V switch with the core MOS transistors of the 28nm CMOS technology with 0.96V nominal supply voltage. The comparison with a benchmark switch based on 1.8V I/O devices showed that both a larger area (slightly more than twice) and static current consumption ( $40\mu \text{A}$ ) are required.

An energy-efficient, wide dynamic-range (DR) CMOS analog front-end (AFE) for chemiresistive sensors is presented. The circuit is specifically designed for the Metal Oxide (MOX) gas sensors, a special technology of chemiresistive sensors, broadly diffused in modern portable devices due to their low-cost and simplicity of use. Energy efficiency is mandatory for the AFE in order to prolong the battery life that supply these devices. The proposed circuit implements the resistance-to-time (R-to-T) conversion of the sensor’s resistance by adopting a relaxation oscillator-based architecture. A limiting resistor in series with the sensor is introduced for reducing the circuit’s energy-per-measurement (EpM), while mitigating the error due to the sensor’s parasitic capacitance. The analysis of the circuit is presented with emphasis on the design trade-off between error due to the sensor’s parasitic capacitance and power consumption on one side and read-out sensitivity on the other. The chip prototype is realized in AMS $0.35 ~\mu m$ process and has been tested in the DR between $100\Omega $ and $4.7M\Omega $ with an accuracy less than 0.1% and a precision less than 0.029%. The efficacy of the presented AFE is proved by adopting the circuit in a real chemical environment with a commercial sensor. The proposed AFE shows a maximum EpM of $296nJ$ which is three times better than the state of the art.

Fructan analysis is challenging due to several mono-, di-, and oligosaccharides as well as starch and proteins present in wheat grains which interfere with the analysis. So far, a sensitive and fully validated LC–MS/MS method is missing although even small amounts of short-chain fructans such as 1-kestose are suggested to elicit gastrointestinal symptoms in patients suffering from irritable bowel syndrome. Therefore, the aim of this study was to validate a LC–MS/MS method for the detection of 1-kestose in a complex wheat matrix according to international guidelines. The chromatographic separation was performed on a C18 column coupled with a triple quadrupole MS in MRM mode using the transition m/z 503 → m/z 119 for the quantitation of 1kestose. Accuracy of 1-kestose quantitation in an aqueous solution was 105.5 %. However, the poor recovery of 64.1 % in a complex wheat matrix demonstrated the great impact of proteins and other constituents present in wheat. Nevertheless, the proposed method allows precise quantification of 1-kestose amounts ≥0.1 ppm. The robustness of the method was confirmed by the results being within 6.03 % of the target value. The validated method was successfully applied for the measurement of 10 different wheat samples with 1-kestose amounts between 7.0 and 50.2 ppm.

Amylase/trypsin-inhibitors (ATIs) comprise about 2–4% of the total wheat grain proteins and may contribute to natural defense against pests and pathogens. However, they are currently among the most widely studied wheat components because of their proposed role in adverse reactions to wheat consumption in humans. ATIs have long been known to contribute to IgE-mediated allergy (notably Bakers' asthma), but interest has increased since 2012 when they were shown to be able to trigger the innate immune system, with attention focused on their role in coeliac disease which affects about 1% of the population and, more recently, in non-coeliac wheat sensitivity which may affect up to 10% of the population. This has led to studies of their structure, inhibitory properties, genetics, control of expression, behavior during processing, effects on human adverse reactions to wheat and, most recently, strategies to modify their expression in the plant using gene editing. We therefore present an integrated account of this range of research, identifying inconsistencies, and gaps in our knowledge and identifying future research needs.Note This paper is the outcome of an invited international ATI expert meeting held in Amsterdam, February 3-5 2020

Although wheat is used worldwide as a staple food, it can give rise to adverse reactions, for which the triggering factors have not been identified yet. These reactions can be caused mainly by kernel proteins, both gluten and non-gluten proteins. Among these latter proteins, &alpha, amylase/trypsin inhibitors (ATI) are involved in baker&rsquo, s asthma and realistically in Non Celiac Wheat Sensitivity (NCWS). In this paper, we report characterization of three transgenic lines obtained from the bread wheat cultivar Bobwhite silenced by RNAi in the three ATI genes CM3, CM16 and 0.28. We have obtained transgenic lines showing an effective decrease in the activity of target genes that, although showing a higher trypsin inhibition as a pleiotropic effect, generate a lower reaction when tested with sera of patients allergic to wheat, accounting for the important role of the three target proteins in wheat allergies. Finally, these lines show unintended differences in high molecular weight glutenin subunits (HMW-GS) accumulation, involved in technological performances, but do not show differences in terms of yield. The development of new genotypes accumulating a lower amount of proteins potentially or effectively involved in allergies to wheat and NCWS, not only offers the possibility to use them as a basis for the production of varieties with a lower impact on adverse reaction, but also to test if these proteins are actually implicated in those pathologies for which the triggering factor has not been established yet.

This paper presents a 4th-order low-pass continuous-time Diode-RC filter with 24 MHz cut-off frequency. The filter structure is based on the combination of positive (passive) and negative (using cross-coupled MOS transistors) cells to synthesize complex-conjugate-poles pairs. Moreover, the filter is designed and optimized to have high-linearity along all the filter pass-band. The filter exhibits 16 dBm-$$\text {IIP}_3$$ with 2–3 MHz input tones and 5 dBm-$$\text {IIP}_3$$ with 23–24 MHz, whereas the current consumption remains limited to $$100 \, \upmu \hbox {A}$$ from 1.8 V supply voltage.

This paper presents a 28 nm-bulk-CMOS 3rd-order 132 MHz low-pass filter based on an improved Active-gm-RC stage. Challenges related to the design of analog circuits in 28 nm-bulk-CMOS process node are faced, mitigated and exploited by operating at both architecture and circuit design levels. The filter uses a single-opamp two-stage topology where both poles are used for synthesizing a 3rd-order low-pass transfer function. The proposed filter operates from a single 0.9 V supply voltage, consumes 340 µW and performs high linearity (IIP3 = 11.5 dBm at 21 and 22 MHz input tones) and large Signal-to-Noise ratio (58 dB). This enables one of the higher Figure-of-Merit (163.2 dB) with respect to the state-of-the-art.

This paper introduces the use of duo-binary modulation for a 10-Gbps RF on-chip long range serial link. RF signaling is used to reduce the delay so that a 5 mm line is crossed in less than 50 ps. Furthermore, the duo-binary approach is used to reach higher bandwidth efficiency since this modulation uses a two-time smaller bandwidth for the transmission. The RF design complexity is also reduced thanks to duo-binary modulation.

Thermoelectric energy harvesting represents a promising approach to partially or totally supply ultra-low power wearable devices, by using the human body heat as energy source. Few works were published on wearable and truly ready-to-use TEGs. The work presented in this contribute proposes development and assessment of operational properties of a system composed by a flexible heat sink free thermoelectric generator (TEG) and a DC–DC ASIC converter with 80 mV start-up input voltage. For a first functional investigation, a prototype of 45 thermocouples into a footprint area of about 2.2 × 10−3 m2 was fabricated and tested to evaluate its thermoelectric performance stand-alone and coupled with the DC–DC converter. A mean Seebeck coefficient of about 60 µV/K for pn couple was calculated from experimental data, and a power of about 27 nW was measured at 10 K on matched load of about 6.8 kΩ. A temperature difference of about 1.8 ℃ was achieved between the junctions in working conditions next to those typical of human body wearing in indoors.

In this paper, a fourth-order continuous-time follow-the-leader-feedback (FLFB) low-pass (LP) filter is presented. The outstanding FLFB noise behavior is exploited to minimize power consumption. This is achieved by means of customized implementation solutions based on combination of Active- RC /Active- $g_{m}$ - RC cells. The 0.18- $\mu \text{m}$ CMOS prototype performs 22.5-MHz −3 dB LP frequency response. Large linearity and dynamic range were achieved resulting in 21.5-dBm in-band (iB) IIP3 and 87- $\mu \text{V}_{\mathrm {RMS}}$ input referred iB integrated noise. The SNR for a −40 dB HD3 is 63 dB. The overall power consumption is 12.6 mW (i.e., 7 mA from a 1.8-V supply). The efficiency of the proposed technique is demonstrated by the achieved figure-of-merit (150.8 dB $\cdot ~\text{J}^{-1})$ , which favourably compares to the state-of-the-art active- RC analog filters.

A 28 nm CMOS-bulk lowpass analogue filter architecture is hereby proposed. The filter is based on an improved Active-Gm -RC structure, where both poles of a Miller-compensated operational amplifier (OPAMP) have been used for synthesising a third-order filter. Several well-known issues related to the 28 nm process node have been hereby mitigated by proper circuit/design techniques, enabling large signal-to-noise ratio (SNR) and 13.5 dBm IIP3. The proposed circuital solution performs 59 dB-SNR at 340 µW power consumption from a single 0.9 V supply-voltage. This allows one of the higher figure-of-merit (156 dB) in sub-1 V analogue filters state of the art.

We report a first measurement for ultrahigh energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid air-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary masses in the cosmic-ray flux. Up till now, constraints on the spread of primary masses have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of air showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the ‘ankle’ at lg⁡(E/eV)=18.5–19.0 differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with mass A>4. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavored as the sole explanation of the ultrahigh-energy cosmic-ray flux at Earth., 0, SCOPUS: ar.j, info:eu-repo/semantics/published

According to EC Regulation No 2073/2005, for food business operators that produce ready-to-eat (RTE) product, it is crucial to be able to demonstrate if the product supports the growth of Listeria monocytogenes. The objective of the study was therefore to evaluate the behaviour of L. monocytogenes in sliced RTE turkey bresaola (made by cured turkey breast 4.5% NaCl, 1% sodium lactate, sodium nitrite 150 ppm and flavouring) during the shelf life of the product, simulating a contamination during the slicing operation. Considering a shelf life of 90 days, as defined by manufacturer, the packages of sliced bresaola were stored at 5°C for 7 days and at 8°C for the remaining storage time (83 days). L. monocytogenes count decreased during storage test from 1.43/1.98 log cfu/g in the three batches tested to 1.03 log cfu/g in one batch and to undetectable levels in the other two batches. The results show that the investigated product is unable to support the growth of L. monocytogenes.

In this paper, a UHF-RFID power management circuit is presented. It is able to power body sensor networks nodes, starting from -25dBm UHF-RFID input signal power. It is based on an initial Dickson's RF-DC rectifier circuit, followed by an ultra-low-voltage integrated boost converter, realized in 180nm CMOS technology, that is used to further step-up of the rectified DC-voltage and to guarantee the RF-to-load isolation. Measurements demonstrate the ability of the power management circuit to provide 400mV output voltage when a -25dBm continuous wave at 866.5MHz (European UHF RFID frequency) is applied at the input. © 2015 IEEE.

In this brief, a 28.8-MHz −3-dB frequency low-pass analog filter is presented. The filter synthesizes a fourth-order Butterworth transfer function, exploiting the well-known Sallen-Key (SK) biquadratic cell. The out-of-band zeros typically present in SK implementations are hereby completely canceled by using a low-power auxiliary path. This leads to a significant improvement of the stop-band rejection, at the cost of a small power for the same auxiliary path biasing. The design exhibits very large in-band IIP3 over the entire filter bandwidth (20 dBm at 10 MHz and 11 MHz), at 3.2-mW power consumption. The filter prototype has been designed in CMOS 0.18- $ {\mu }\text{m}$ technological node. The total area occupancy is 0.12 mm $^{ {2}}$ and the in-band integrated noise is $101~ {\mu }{\mathrm{V}}_{\mathrm{RMS}}$ .

This paper presents a DC-DC converter to be embedded in the pixel front-end of detectors in Large Hadron Collider (LHC) experiment at CERN. The DC-DC converter has to operate in a hostile environment due to the radiation. Under radiation, the value of the resistances, R on , of the MOS switches changes. In addition, the load current, I out , can change, ranging around the nominal value of 400mA from 200mA to 600mA. Both R on and I out , determine the optimum frequency that maximize the efficiency. In order to improve the efficiency as the operation conditions of the DC-DC converter changes, a tracking circuit of the peak efficiency was implemented. The tracking circuit performs a closed loop control of the clock frequency of the DC-DC converter. This converter provides an 800mV output voltage from a 1.2V input supply reaching an 80.22% peak efficiency. It is integrated in 65nm bulk CMOS technology with an area of 1.31mm2.

On September 14, 2015 the Advanced LIGO detectors observed their first gravitational wave (GW) transient GW150914. This was followed by a second GW event observed on December 26, 2015. Both events were inferred to have arisen from the merger of black holes in binary systems. Such a system may emit neutrinos if there are magnetic fields and disk debris remaining from the formation of the two black holes. With the surface detector array of the Pierre Auger Observatory we can search for neutrinos with energy Eν above 100 PeV from pointlike sources across the sky with equatorial declination from about -65° to +60°, and, in particular, from a fraction of the 90% confidence-level inferred positions in the sky of GW150914 and GW151226. A targeted search for highly inclined extensive air showers, produced either by interactions of downward-going neutrinos of all flavors in the atmosphere or by the decays of tau leptons originating from tau-neutrino interactions in the Earth's crust (Earth-skimming neutrinos), yielded no candidates in the Auger data collected within ±500 s around or 1 day after the coordinated universal time (UTC) of GW150914 and GW151226, as well as in the same search periods relative to the UTC time of the GW candidate event LVT151012. From the nonobservation we constrain the amount of energy radiated in ultrahigh-energy neutrinos from such remarkable events., La lista completa de autores que integran el documento puede consultarse en el archivo., Facultad de Ciencias Exactas, Instituto de Física La Plata

A low power 7.5---10.6 GHz frequency synthesizer for impulse radio ultra-wide band (IR-UWB) is designed and fabricated in 65 nm CMOS technology. The synthesizer is based on an integer-N type-II 4th-order PLL architecture. A 7-bit voltage-controlled oscillator with 31 % tuning range and a set of high-speed dividers are used to synthesize all the carriers defined by the IEEE standard 802.15.4a. The frequency dividers are based on true single phase clock logic resulting in compact implementation and low power consumption. The 0.33 mm2 fully integrated synthesizer consumes 5.13 mA from a 1.2 V supply. With a 3-dB closed-loop bandwidth of 100 kHz, the settling time is 15 µs. It features

A 4th-order single-loop follow-the-leader-feedback (FLFB) low-pass continuous-time filter in CMOS 0.18 μm is hereby presented. The outstanding FLFB noise behaviour is exploited to allocate the power consumption to linearity performance. The low-pass filter prototype features 22.5 MHz-3 dB frequency, 21.5 dBm-IIP3 and 76 μVRMS input referred in-band integrated noise. The overall power consumption is 7 mA from a 1.8 V supply voltage. The signal-to-noise ratio for a -40 dB-total harmonic distortion is 69 dB.

In this paper, an energy harvesting system composed by a flexible thermoelectric generator (TEG) with a DC — DC converter is shown. The proposed generator has been produced by screen printing technology on 80μm thick common paper and thin Kapton foil and integrates about 280 thermocouples, for an output voltage of about 75mV with 5K of the thermal gradient, useful for wearable — oriented applications. To increase the voltage provided by TEG, a DC — DC converter is implemented in 65nm CMOS technology. It operates for an input voltage (Vjn) range from 80mV to 370mV. This converter achieves an automatic control based on pulse width modulation (PWM), that ensure 1V output voltage (VOUT), for the various input voltages. The peak efficiency is 73% at 370mV of input voltage.

This paper presents a −19dBm sensitivity RF-DC converter for energy harvesting applications. It is able to harvest the energy from a dipole antenna operating at 866.5MHz (European UHF RFID frequency) providing a regulated output voltage in the range between 1.9V to 2.4V over a 2MΩ resistive load. Such voltage level is suitable to supply body sensor nodes. The four stages Dickson's RF-DC rectifier converts the UHF RF input signal to a 2V DC output, feeding the following two stages DC-DC Pelliconi's charge pump. The DC-DC charge pump, powered by a 90kHz ring oscillator, is used to further step-up the RF-DC rectifier output voltage and to realize the RF to load isolation. The output voltage regulation is performed by a feedback network made by a hysteresis comparator and a Vt-based voltage reference. The RF-DC converter shows a 38% power conversion efficiency at 0dbm input power level.

In this paper, a 4th-order low-pass continuous-time analog filter is presented, that is implemented with the cascade of two efficient and compact biquadratic cells, realized using the Super-Source-Follower topology. The biquadratic cell uses only two capacitors and four transistors: two transistors for the signal processing and two transistors as current sources for biasing pur- pose. The 4th-order filter prototype has been integrated in 0.18 μm CMOS technology. For a 33 MHz cut-off frequency, the filter per- forms 18 dBm-IIP3 for two tones at 2 MHz and 3 MHz, with total current of 770 μA from a single 1.8 V supply voltage.

61 The upgrade of the Pierre Auger Observatory required a larger number of detectors that implies a dramatic increase of the power consumption. As the analog-to-digital converter (ADC) is the most critical circuit block, an integrated solution is here proposed. A 10 b 50-MSps 5-stage pipeline ADC is implemented in 65 nm digital CMOS. It achieves 50.3 dB signal-to-noise and distortion ratio (SNDR), 52.3 dB signal-to-noise ratio (SNR), 59.2 dB spurious free dynamic range (SFDR) for a full-scale input sinewave at Nyquist frequency. The ADC features 12 mW power consumption from a 1.2 V supply, while occupying 0.8 mm2 die area. © 2014 IEEE.

In this paper a 4th-order low-pass continuous-time analog filter is presented. A smart and compact biquadratic cell has been realized using the super-source-follower circuit. The biquadratic cell synthesizes a 2nd-order low-pass transfer function, using only two capacitors and four transistors per stage: two transistors for gm-C transfer function and two transistors as current sources for biasing purpose. A 4th-order filter prototype has been integrated in CMOS 0.18μm technological node. The achieved Signal-to-Noise-Ratio is 70dB, with 8nV/√Hz in-band input referred noise. In-Band IIP3 is 18dBm. The current consumption for the entire 4th-order filter is 770μA, from a single 1.8V supply voltage.

A low-power analog baseband section suitable for 60-GHz receivers using orthogonal frequency-division multiplexing (OFDM) with 16 quadrature amplitude modulation (16-QAM) modulation is presented in this paper. Power efficiency is achieved by combining active-RC with source-follower-based topologies in order to synthesize a custom sixth-order transfer function. The complete chain consists of the cascade of a first-order transimpedance amplifier with finely programmable gain, a fourth-order source-follower-based filter, and a coarse gain first-order programmable gain amplifier. The prototype is implemented in 90-nm CMOS. It achieves a 1-GHz cutoff frequency and programmable gain from 0 to 20 dB with 1-dB step control, drawing 9.5 mA (0-9 dB gain range) or 10.8 mA (10-20 dB gain range) from a 1-V supply. An 8.2-dBm third-order input intercept point and a -145-dBm/Hz input-referred noise power density are measured at 0- and 20-dB gain, respectively. The entire circuit occupies an area of 400 × 390 μm2. © 2014 IEEE.

In this paper a highly linear-dual band RF front-end (LNA and Mixer) for IR-UWB (IEEE 802.15.4a) applications is proposed. LNA exploits a common-gate (CG) stage in parallel to a common-source (CS). It performs single-ended to differential-ended operation, avoiding balun stage. It features 18 dB maximum gain, +11.8 dBm IIP3. The RF front-end receiver has been designed in 65nm CMOS technology consuming 13.5 mW. © 2014 IEEE.

Analog filters are key blocks in analog signal processing. They are widely employed in many systems, like wireless transceivers, detectors read-out, sensors interfaces, etc. The IC technology choice for such systems is mainly dictated by the requirements of high speed and low power consumption of digital circuits. This pushed an impressive movement towards scaled technology and this has important consequences on the analog circuits design. The impact of technology scaling down to nanometre scale on analog filters design is here investigated. For instance, supply voltage reduction in analog filters limits circuits design solutions and could result in higher power consumption. Moreover, at the same time, innovative systems push analog filters to get higher and higher operation frequencies, due to the increasing bandwidth/speed requirements. Recent solutions for efficient low-voltage and high frequency analog filters in nanometre technology are described. © 2014 IOP Publishing Ltd and Sissa Medialab srl.

Formagelle di capra is a raw goat cheese produced from whole chilled goat milk; traditional technology involving unpasteurised milk and indigenous lactic starter cultures is employed for its production in Italy. The purpose of this study was to assess the behaviour of Escherichia coli O157:H7 during the manufacturing and ripening of this raw goat milk cheese. Raw milk was experimentally inoculated with E. coli O157:H7 in a laboratory scale plant and the count was monitored during production and 30 days of ripening required for this cheese. Results showed that E. coli O157:H7 count increased to more than 1.5 Log cfu g–1 during cheese production and remained constant until the end of ripening. The evidence that E. coli O157:H7 is able to survive during the manufacturing and ripening process suggests that the 30-day ripening period alone is insufficient to eliminate levels of viable E. coli O157:H7 in Formaggelle di capra cheese and that the presence of low numbers of E. coli O157:H7 in milk destined for the production of raw goat milk cheeses could represent a potential source of infection for humans and a threat for consumers.

Power consumption of high-speed low-resolution analog-to-digital converters (ADCs) can be reduced by means of calibration. However, this solution has some drawbacks such as time slot allocation for calibration and die area increase. This paper presents a 5-bit 1-Gs/s ADC without calibration, fabricated in 90-nm CMOS. Low power consumption has been ensured by operating at both architecture and comparator levels. A folded interpolated architecture has been adopted. However, compared to standard solutions that use static preamplifiers, the interpolation technique has been implemented by taking recourse to dynamic comparators, enabling significant power saving. Moreover, despite the high operating frequency, intrinsic matching has been ensured while keeping low power consumption. The ADC uses double-tail dynamic comparators, operating with a fixed bias current and with reduced kickback noise. Large input transistors are used to guarantee the targeted matching, thereby avoiding calibration. The ADC achieves 4.3b-ENOB (effective number of bits) and 260-MHz effective resolution bandwidth while consuming 7.65 mW from a 1.2 V supply. The ADC figure of meritis 0.39 pJ/conv. step, which is the state-of-the-art performance for an uncalibrated ADC at this sampling frequency and resolution. © 2013 IEEE.

In this work we present a thermoelectric energy harvesting system consisting of a miniaturized and wearable flexible thermoelectric generator (TEG) and a dedicated ASIC, finalized to efficiently recover and manage energy from heat dispersed into the environment. The proposed TEG was realized on flexible Kapton substrate, which is particularly appreciated for its optimum properties of chemical and physical stability, permeability to atmospheric agents (humidity, oxygen) and thermal conductivity. Contrary to a conventional rigid substrate, like glass or silicon, a flexible one adds to the device lighter weight, increased robustness, freedom of shape, compactness, and low cost. Although the TEG was designed as "electronic garment" for wearable use in Ambient Assisted Living (AAL) applications, the device can be easily adapted to different contexts thanks to its flexibility and design that extend the application range to various sectors, from home automation and structural health monitoring to biotechnology. A Transfer Length Method (TLM) analysis was performed on three different multi-layer contact schemes in order to select the best solution to use for the deposition of both embedded thermometers to monitor the thermocouples junctions temperature and contact pads to electrically test single partitions of the array. A custom designed ASIC, based on step-up principle was coupled to the TEG in order to ensure a 1.2 V output and complete power management solution for wireless sensing and data acquisition.

The design of an automatic biasing system for High-Electron-Mobility-Transistors is here presented (HEMT-Biasing-System, HBS). The HBS automatically regulates the operating point of an off-chip multistage HEMT block. A proper automatic algorithm is implemented in order to maximize the HEMT transconductance (gm) efficiency (defined as gm/IDS ratio). This is an important feature in several HEMT-based systems, since they are used in LNA stages, where noise/power trade-off is a key aspect. Interfacing CMOS and HEMT technologies features several design issues, like negative gate-source voltage (to be managed by a CMOS circuits for HEMT switch-off operation) and closed-loop stability (due to the presence of very large off-chip capacitance - 100nF). The System here presented manages all these issues with tailored circuit solutions. A prototype has been designed in CMOS 0.35μm technology. It consumes 6.2mW (excluding the current consumption for HEMT driving).

This paper investigates the improvement margins in term of energy efficiency of analog filters. Starting from a landscape of analog filters presented at ISSCC until 2012, energy limits for most common analog filters architectures (Gm-C and Active-RC) are traced. Active-RC filters with reduced bandwidth requirements have larger margins of improvements compared to Gm-C. Technology scaling impact is also evaluated. Supply reduction that join the technology scaling seems to have a limited effect on Gm-C filters, as their energy limit depends on the SNR only. However, technology scaling enables larger bandwidth opamps, pushing the Active-RC technique at higher and higher frequency, where Gm-C approach generally dominates. Results have been confirmed by the detailed analysis of two of the most performing analog filters from literature.

The A-to-D converter here presented is part of a bigger system able to sense and monitor electrical/physical parameters in particles detectors, for LHC experiments. The CMOS integrated circuits operating in high-energy environments experience large leakage current and voltage/temperature variations. For this reason in LHC experiments, a proper sensing and monitoring system has been designed with the aim to provide real time information about the electrical/physical scenario for the detectors in LHC. The A-to-D converter has a resolution of 12 bits, is based on single slope architecture and is able to manage 32 input analog channels. The design is challenging for several reasons, considering the required conversion accuracy and the critical physical scenario. The entire A-to-D converter has been fully characterized with process-voltage-temperature variations, obtaining a definitive 11bit accuracy in the worst-case simulation corner. The A-to-D has been designed in CMOS 0.13 mu m technology, consumes 350 mu W (including dynamic power due to the digital circuits) and operates at 20MHz clock frequency, for a definitive 2.3kHz sample rate