This paper presents a low-noise reconfigurable sensor readout circuit with a multimodal sensing chain for voltage/current/resistive/capacitive microsensors such that it can interface with a voltage, ...current, resistive, or capacitive microsensor, and can be reconfigured for a specific sensor application. The multimodal sensor readout circuit consists of a reconfigurable amplifier, programmable gain amplifier (PGA), low-pass filter (LPF), and analog-to-digital converter (ADC). A chopper stabilization technique was implemented in a multi-path operational amplifier to mitigate 1/f noise and offsets. The 1/f noise and offsets were up-converted by a chopper circuit and caused an output ripple. An AC-coupled ripple rejection loop (RRL) was implemented to reduce the output ripple caused by the chopper. When the amplifier was operated in the discrete-time mode, for example, the capacitive-sensing mode, a correlated double sampling (CDS) scheme reduced the low-frequency noise. The readout circuit was designed to use the 0.18-µm complementary metal-oxide-semiconductor (CMOS) process with an active area of 9.61 mm2. The total power consumption was 2.552 mW with a 1.8-V supply voltage. The measured input referred noise in the voltage-sensing mode was 5.25 µVrms from 1 Hz to 200 Hz.
The causative agent of acute hepatopancreatic necrosis disease (AHPND) is the bacterium, Vibrio parahaemolyticus, which secretes toxins into the gastrointestinal tract of its host. Vibrio ...parahaemolyticus toxins A and B (PirAvp/PirBvp) have been implicated in the pathogenesis of this disease, and are, therefore, the focus of studies developing treatments for AHPND. We previously produced recombinant antibodies based on the hagfish variable lymphocyte receptor B (VLRB) capable of neutralizing some viruses, suggesting that this type of antibody may have a potential application for treatment of AHPND. Here, recombinant PirAvp/PirBvp, produced using a bacterial expression system, were used as antigens to screen a hagfish VLRB cDNA library to obtain PirAvp/PirBvp-specific antibodies. A cell line secreting these antibodies was established by screening and cloning the DNA extracted from hagfish B cells. Supernatants collected from cells secreting the PirAvp/PirBvp antibodies were collected and concentrated, and used to passively immunize shrimp to neutralize the toxins PirAvp or PirBvp associated with AHPND. Briefly, 10 μg of PirAvp and PirBvp antibodies, 7C12 and 9G10, respectively, were mixed with the shrimp feed, and fed to shrimp for three days consecutive days prior to experimentally infecting the shrimp with V. parahaemolyticus (containing toxins A and B), and resulting mortalities recorded for six days. Results showed significantly higher level of survival in shrimp fed with the PirBvp-9G10 antibody (60%) compared to the group fed the PirAvp-7C12 antibody (3%) and the control group (0%). This suggests that VLRB antibodies may be a suitable alternative to immunoglobulin-based antibodies, as passive immunization treatments for effective management of AHPND outbreaks within shrimp farms.
Erythropoiesis-stimulating agents are widely used to treat anemia for chronic kidney disease (CKD) and cancer, however, several clinical limitations impede their effectiveness. Nonviral gene therapy ...systems are a novel solution to these problems as they provide stable and low immunogenic protein expression levels. Here, we show the application of an arginine-grafted bioreducible poly(disulfide amine) (ABP) polymer gene delivery system as a platform for in vivo transfer of human erythropoietin plasmid DNA (phEPO) to produce long-term, therapeutic erythropoiesis. A single systemic injection of phEPO/ABP polyplex led to higher hematocrit levels over a 60-day period accompanied with reticulocytosis and high hEPO protein expression. In addition, we found that the distinct temporal and spatial distribution of phEPO/ABP polyplexes contributed to increased erythropoietic effects compared to those of traditional EPO therapies. Overall, our study suggests that ABP polymer-based gene therapy provides a promising clinical strategy to reach effective therapeutic levels of hEPO gene.
Gene-modified replication-competent adenoviruses (Ads) are emerging as a promising new modality for the treatment of cancer. We have previously shown that E1B 19kDa and E1B 55kDa gene-deleted Ad ...(Ad-DeltaE1B19/55) exhibits improved tumor-specific replication and cell lysis, leading to an enhanced antitumor effect. In an effort to increase cancer cell selectivity of a replicating adenovirus, we first generated 11 E1A mutant Ads (Ad-E1mt1 to Ad-E1mt11) with deletion or substitution in retinoblastoma (pRb)-binding sites of E1A. Of these, Ad-E1mt7 demonstrated significant improvement in cytopathic effect (CPE) and viral replication in a cancer cell-specific manner. To further enhance the cancer cell specificity of Ad-E1mt7, Ad-DeltaE1Bmt7 was generated, in which both the E1B 19kDa and E1B 55kDa genes were deleted. As assessed in CPE assay and immunoblot analysis for Ad fiber expression, Ad-DeltaE1Bmt7 exerted marked enhancement in cancer cell-specific killing as well as viral replication in comparison with its comparative controls (Ad-E1mt7, Ad-DeltaE1B55). Furthermore, the growth of established human cervical carcinoma in nude mice was significantly suppressed by intratumoral injection of Ad-DeltaE1Bmt7. In summary, we have developed an oncolytic adenovirus with a significantly improved therapeutic profile for cancer treatment.
In this paper, we present a secure circuit with a low-power on-chip temperature sensor for the detection of temperature fault injection attacks. Such attacks stress an electronic circuit by heating ...it beyond the allowed operation temperature range, inducing random modifications of the data in the memory cell or limiting the function of the target device. The objective of the proposed secure circuit with an on-chip temperature sensor is to detect temperature-based fault injection attacks and protect the secure contents of the target device. The proposed secure circuit detects and allows the shutdown of the protected circuit when the temperature is below −10 ℃ or above 80 ℃. The protected circuit operates normally in the operation temperature range from −10 to 80 ℃ and can be shut down by the control block of the secure circuit outside of this operation temperature range. The proposed secure circuit has a simple structure and a small active area, and consists of a low-power temperature sensor, two comparators, and an XOR gate. It is fabricated using a standard 0.18 μm complementary metal-oxide-semiconductor (CMOS) process with a small active area of 0.04 mm2 and consuming 19.72 μW with a 1.8 V power supply.
Invasive physical attacks on integrated circuits (ICs), such as de-packaging, focused ion beam (FIB) chip editing, and micro-probing attempts, constitute security threats for chips with potentially ...valuable information, such as smart cards. Using a state-of-the-art circuit-editing technique, an attacker can remove an IC’s top metal layer, leaving its secure information exposed to micro-probing attacks. Security ICs can be seriously threatened by such attacks and thus require on-chip countermeasures. Conventional active shields, however, have difficulty coping with physical attacks based on FIB chip editing (i.e., bypassing the top metal shield). This study presents a novel countermeasure against physical attacks based on the use of a reconfigurable metal shield for both top metal removal and micro-probing attack detection. This shield consists of two circuits: an FIB chip editing detection circuit consisting of a random number generator and a micro-probing attempt detection circuit consisting of two conditionally synchronized ring oscillators. Both circuits share a randomly reconfigured top metal shield, which represents a promising solution for security against state-of-the-art invasive attacks. KCI Citation Count: 0
In this paper, a low-noise 16-bit capacitance-to-digital convertor (CDC) for a capacitive humidity sensor is proposed. The proposed sensor interface circuit is implemented as a firstorder incremental ...delta-sigma structure and directly converts the capacitance change of the humidity sensor to a 16-bit digital code. A switched capacitor (SC) integrator of the deltasigma modulator is adopted in the chopper stabilization technique for a low-noise characteristic. The chopper stabilization technique can avoid the offset and low-frequency flicker noise of an amplifier. The offset cancellation programmable capacitor array of the input stage is used for eliminating the mismatched capacitance from the parasitic capacitor and process variations. The proposed delta-sigma CDC has an accumulator with a simple 16-bit dual counter that converts the delta-sigma modulator output to a 16-bit digital code for reducing the power consumption of the back-end digital processing. The proposed sensor interface circuit is fabricated using the standard 0.18 μm complementary metal-oxide-semiconductor process with an active area of 0.66 mm2 . The effective resolution of the worst case is 14.4 bits, and the active power consumption of the proposed delta-sigma CDC is 376 μW with a 1.8 V supply.
The replicative construction of metal–organic frameworks (MOFs) templated with solvent‐insoluble solid substrates is of marked importance, as it allows for the assembly of 2D and 3D macro‐ and ...mesoscopic architectures with properties that are challenging to attain by the conventional solution‐based synthesis approach. This work reports an in situ and direct construction of MOFs from zero‐valent metal substrates via a green hydrothermal oxidation–MOF construction chemistry without the use of any additional metal source, chemical reagents, or acidification of solvent, and elucidates the zero‐valent metal derived formation mechanisms of MOFs and their structure modulation to 1D nanofibers (NFs), 2D film, and 3D core–shell microstructures. Through modulation of the competing surface oxidation‐dissolution and MOF crystallization kinetics, Al@MIL‐53 core–shell microstructures and MIL‐53 (Al) NFs are obtained that exhibit unique morphologies and marked properties superior to the conventional MIL‐53 (Al) powders. The generality of zero‐valent metal‐templated synthesis of MOFs is demonstrated with formation of MIL‐53 (Al), HKUST‐1, and ZIF‐7 polycrystalline films on Al, Cu, and Zn metal meshes, elucidating the significance of the approach utilizing solid metal substrate that can be easily processed into various shapes, architectures, and compositions.
Metal–organic frameworks (MOFs) can be constructed directly from a zero‐valent metal substrate by templated in situ growth via hydrothermal oxidation and MOF construction chemistry. Modulation of the metal surface oxidation‐dissolution and the MOF crystallization kinetics allow for variation of MIL‐53 (Al) morphologies to unique 1D nanofibers, 2D film, and 3D core–shell microstructures.
PDF
