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We report a new type of potentiometric pH sensor with sensitivity exceeding the theoretical Nernstian behavior (−59.1 mV/pH). For the pH-sensitive electrode, 1D tungsten oxide (WO3) nanofibers (NFs...

Under the conditions of low flow rate and strong noise, the current electromagnetic flowmeter (EMF) cannot satisfy the requirement for measurement or separate the actual flow signal and interference signal accurately. Correlation detection technology can reduce the bandwidth and suppress noise effectively using the periodic transmission of signal and noise randomness. As for the problem that the current anti-interference technology cannot suppress noise effectively, the noise and interference of the electromagnetic flowmeter were analyzed in this paper, and a design of the electromagnetic flowmeter based on differential correlation detection was proposed. Then, in order to verify the feasibility of the electromagnetic flow measurement system based on differential correlation, an experimental platform for the comparison between standard flow and measured flow was established and a verification experiment was carried out under special conditions and with flow calibration measurements. Finally, the data obtained in the experiment were analyzed. The research result showed that an electromagnetic flowmeter based on differential correlation detection satisfies the need for measurement completely. The lower limit of the flow rate of the electromagnetic flowmeter based on the differential correlation principle could reach 0.084 m/s. Under strong external interferences, the electromagnetic flowmeter based on differential correlation had a fluctuation range in output value of only 10 mV. This shows that the electromagnetic flowmeter based on the differential correlation principle has unique advantages in measurements taken under the conditions of strong noise, slurry flow, and low flow rate.

It remains a challenge to measure the capacitance of miniaturized capacitive sensors, usually on the order of pF, with a high accuracy and a fast speed. In this work, a novel differential capacitance measurement method is proposed, aiming for capacitance measurements for capacitive sensing devices. The design includes 7 modules: a sine wave generator, a low pass filter, amplification circuit, peak detection circuit, a differential amplification circuit, an A/D acquisition module circuit and a Bluetooth module. The system generates an AC signal with a frequency of 200 kHz and a variable peak-to-peak value up to 4 V. Our system has achieved a high measurement precision with the error below 0.1%, a high sensitivity of 1 V/pF, fast readout speed up to 10 kHz and excellent capacitance resolution of 3 fF.

Reliability and reproducibility of transcriptomics-based studies are dependent on RNA integrity. Microfluidics-based techniques targeting rRNA are currently the only approaches to evaluate RNA integrity. However, the relationship between rRNA and mRNA integrity is unknown. Here we present a new integrity index, the Ratio amplicon, Ramp, to monitor mRNA integrity based on the differential amplification of RT-Q-PCR amplicons of the glutamine-synthetase A (glnA) transcript. We showed, in a suite of experimental degradations of RNA extracted from sediment, that while the RIN generally reflected the degradation status of RNA the Ramp mapped mRNA degradation better. Furthermore, we examined the effect of degradation on transcript community structure byamplicon sequencing of the 16S rRNA, amoA and glnA transcripts. We successful sequenced transcripts for all three targets even from highly-degraded RNA samples. While RNA degradation changed the community structure of the mRNA profiles, no changes were observed for the 16S rRNA transcripts profiles. Since both RT-Q-PCR and sequencing results were obtained, even from highly degraded samples, we strongly recommend evaluating RNA integrity prior to downstream processing to ensure meaningful results. For this both the RIN and Ramp are useful, with the Ramp better evaluating mRNA integrity in this study.

We investigated the genetic diversity and connectivity patterns of mesophotic Corallium rubrum populations (from a depth of 87 to 107 m) near Sardinia (Western Mediterranean Sea) using microsatellite data. Firstly, we tested the hypotheses that (1) mesophotic areas represent ‘thermal and/or reproductive refugia’ for the species, and (2) strong genetic breaks separate the coral populations of the different sub-basins of the Western Mediterranean Sea. Secondly, we aimed to examine the impact of harvesting on the genetic features of populations. Genetic analyses pointed out the occurrence of significant genetic differentiation (overall F ST = 0.115, P value = 0) and an isolation-by-distance pattern. Bayesian assignment analyses revealed four distinct clusters. The differential amplification success of some microsatellite loci along a north–south gradient confirmed the existence of strongly differentiated red coral populations in the Tyrrhenian with respect to the Algero-Provencal Basin. From a management perspective, the high genetic diversity and the substantial demographic stability indicate that Sardinian red coral populations are stable and still sustainably exploited. Nevertheless, the significant spatial structuring at the scale of less than 10 km indicates that they are sustained largely by local recruitment, excluding the possibility that they can help in recovering shallower banks.

Skin resistance is one of the important indexes in psychological affective researches, and it can reflect the change of emotion by recording its changes. Generally, the skin resistance measurement method is connecting the electrode sensor to the two adjacent fingers of the object to record the resistance signal, and then amplifying, collecting and recording the signal by amplification circuit. However, the study found that in the actual measurement process, the skin resistance can produce non-emotional impact changes caused by the signal acquisition error and temperature fluctuation factors; thereby the actual measurement results can be interfered. This study improved the selection of sensor module and the amplification circuits to deal with this problem. As for the acquisition of signal, this study adopts the pet polyethylene glycol ester containing activated carbon as the electrode sensor material and selects the palm area as the signal collecting site; as for the amplification circuit, the differential amplification circuit which can restrain the drift effectively was chosen to realize the amplification signal function. The comparison experiment shows that the improved acquisition sensor module and differential amplification circuit can effectively improve the anti-interference ability of the skin resistance measuring device. Finally, this study proves that the experimental device can effectively measure the emotional changes of the object by using the experiment of fear and happy emotional stimuli.

Common bean (Phaseolus vulgaris) subtelomeres are highly enriched for khipu, the main satellite DNA identified so far in this genome. Here, we comparatively investigate khipu genomic organization in Phaseolus species from different clades. Additionally, we identified and characterized another satellite repeat, named jumper, associated to khipu. A mixture of P. vulgaris khipu clones hybridized in situ confirmed the presence of khipu-like sequences on subterminal chromosome regions in all Phaseolus species, with differences in the number and intensity of signals between species and when species-specific clones were used. Khipu is present as multimers of similar to 500 bp and sequence analyses of cloned fragments revealed close relationship among khipu repeats. The new repeat, named jumper, is a 170-bp satellite sequence present in all Phaseolus species and inserted into the nontranscribed spacer (NTS) of the 5S rDNA in the P. vulgaris genome. Nevertheless, jumper was found as a high-copy repeat at subtelomeres and/or pericentromeres in the Phaseolus microcarpus lineage only. Our data argue for khipu as an important subtelomeric satellite DNA in the genus and for a complex satellite repeat composition of P. microcarpus subtelomeres, which also contain jumper. Furthermore, the differential amplification of these repeats in subtelomeres or pericentromeres reinforces the presence of a dynamic satellite DNA library in Phaseolus.

This paper discusses the results obtained from MFDFA technique applied to isometric and isotonic muscle contraction under different loading condition using Electromyography. An attempt has been made towards quantization of muscle contraction with load. The research includes development of dedicated system for recording, monitoring and analysis of EMG signal with non-linear dynamics and frequency domain techniques as well. The signal is acquired through surface electrodes using an EMG acquisition circuit with differential amplification technology. The data is collected through the winsound port using Matlab®.

Transposable elements represent major components that support plant genome plasticity. Amplification of transposable elements has provided a significant contribution to plant genome size expansion and might represent an adaptive response to stress factors. The fact that, during the last decade, a number of plant genomes were either partially or completely sequenced provided an opportunity to analyze populations of transposable elements contained within plant genomes. Numerous studies have demonstrated that differential amplification of certain families of transposable elements during evolution contributed substantially to interspecies genome divergence and likely facilitated successful formation of allopolyploid genomes.

This paper reports a method of detecting nanoparticles using a microfluidic differential Resistive Pulse Sensor (RPS). Using a single microfluidic channel with two detecting arm channels placed at the two ends of the sensing section, the microfluidic differential RPS can achieve a high sensitivity allowing the detection of nanometer size particles. Two-stage differential amplification is used to further increase the signal-to-noise ratio. This method is able to detect nanoparticles of 490 nm and 220 nm on a microfluidic chip. The method described in this paper is simple and can be applied to develop a compact device without the need of bulky, sophisticated electronic instruments or complicated nano-fabrication processes.

Differential amplification of variant and wild-type alleles by PCR is often used for rare allele enrichment. We have combined allele-specific PCR, competitive probe blocking, asymmetric PCR, and melting analysis to enhance rare allele detection in a homogeneous system. Unlabeled, dual hybridization or molecular beacon probes were used for competitive blocking of the wild-type allele at a concentration 10 times that of the allele-specific primer. In each case, rare alleles were detected by probe melting analysis at a sensitivity of >0.001% (1 variant copy within 100,000 wild-type copies), providing single copy detection in typical PCRs. Ninety-one thyroid biopsies were tested for the BRAF mutation p.V600E (c.1799 T > A) by both dual hybridization probes without enrichment and an allele-specific, competitive blocking melting analysis with unlabeled probes. Eighty-seven samples were concordant between methods (43 positive, 44 negative), while 4 samples that were negative by direct analysis became positive after enrichment. Probes that both block wild-type amplification and detect rare variants by melting analysis improve the detection sensitivity of allele-specific PCR for rare alleles. In particular, melting analysis using unlabeled probes and amplification by rapid-cycle PCR provides cost-effective and fast enrichment and detection of rare alleles.

In many H-reflex studies, the modulation of the H-reflex is usually compared relative to the normal EMG activity within the muscle. Such comparisons enable the investigators to infer whether the change in the amplitude of the H-reflex was independent of normally occurring muscle activity. This interpretation of the H-reflex is regarded as H-reflex gain, a popular dependent variable in human H-reflex studies. However, in many studies to date, the muscle activity level has been determined from the same EMG signal from which the H-reflex is recorded. This leads to an important methodological consideration: measuring the ongoing normal EMG activity from the same signal might result in an inaccurate measurement, since this EMG signal will need to be minimally amplified to capture the synchronous volley of the H-reflex amplitude. In this study we examined this possibility and found that comparing the EMG activity level from the seated position to standing position yields different results (on average 8.03% in the measurement of the increase of muscle activity). This difference was both dependent on the task and also on the EMG instrumentation used. To solve this problem we suggest the bifurcation of the EMG signal from the recording electrodes with differential amplification of the signal. With this method, both the naturally occurring muscle activity and the H-reflex signal are collected from the same area of the muscle and a more accurate measurement of the H-reflex gain will be yielded.

This paper describes a Non-Dispersive Infrared (NDIR) CO 2 gas sensor with auto-temperature compensation in order to apply HVAC systems. The developed gas sensor amplifies differentially both the output of thermopile and output of temperature sensor that has linear output characteristics. With differential amplification circuits, the output voltage of sensor module according to the CO 2 concentration shows the independent temperature output characteristics from 10 ∘ C to 40 ∘ C. The developed sensor module shows ±30 ppm error at 1,000 ppm and ±50 ppm error at 2,000 ppm CO 2 concentration regardless of temperature variations.

Current strategies to amplify helper-dependent adenovirus, based on excision of the packaging signal, do not routinely reduce helper adenovirus contamination below 1%. Here, we have tested if reducing the efficiency of the packaging process of the helper adenovirus could impair its packaging without affecting helper-dependent adenovirus production. Interestingly, insertion of attB/attP-ΦC31 sequences flanking the packaging signal significantly lengthens adenovirus cycle up to 60 h without reducing virus viability or production yield. This delay occurs in the absence of ΦC31 recombinase indicating that other mechanisms different from excision of packaging signal must be involved. In addition, at 36 h post-coinfection helper-dependent adenovirus are efficiently produced, while production levels of helper attB/attP-modified adenovirus are 100–1000 times lower than controls. Therefore, these results suggest that attB/attP-mediated packaging impairment of the adenovirus genome is an attractive strategy to significantly reduce helper adenovirus contamination in helper-dependent adenovirus preparations, which in turn would facilitate scaling-up processes for clinical grade preparations.

In view of the practical problems that exist in the yarn flaws detection circuits, which has employed the traditional DC drive in the industry field, this essay, however, based on the two kinds of Matlab simulation results of the detection circuit that used by DC d rive and sinusoidal drive separately, has designed a photoelectric yarn flaws detection circuit through sinusoidal drive, which , including a 100 kHz sine wave generating circuit, a current source circuit, a infrared sensor, a yarn signal acquisition circuit, a precision full-wave rectification circuit, a differential amplification circuit and so on. Through the experiment and test on site, the photoelectric yarn flaws detection for circuits that driven by sine wave could perfectly meet the requirements of yarn testing standards. Comparing to the DC drive, the sinusoidal drive does better in anti-interference and environmental adaptation.

Major satellites of species in the genus Pimelia comprise large portions of their genomes and belong to seven major satellite families which all originate from a common ancestral sequence. Here we present the results of comprehensive screening of 26 Pimelia species belonging to three distinct geographic groups (Ibero-Balearic, African and Canary Islands) for the presence of different Pimelia satellite families in their genomes. Dot-blot hybridization experiments suggest that together with one dominant, highly abundant satellite family, other families are also present in genomes of the majority of examined Pimelia species, but as low-copy number repeats. The estimated abundance of these underrepresented repeats is about 4, 000 copies per haploid genome. Signals of highly abundant satellite family from P. scabrosa (PSCA) in examined congeneric species, obtained after PCR amplification and Southern hybridization under high stringency conditions, corroborate sequence preservation of low-copy representatives of satellite families. PRINS localized low-copy repeats within the pericentromeric regions of all chromosomes. These results point to the existence of an extensive library of repetitive DNAs that was already present in the genome of the common ancestor of extant Pimelia taxa, and shifts the period of diversification of Pimelia satellites far in the history of this genus.

The use of mitochondrial DNA in forensic genetics has allowed researchers to answer questions relating to diversity, population scale and movements. Field sampling as well as transportation and storage, can negatively affect the quality of DNA for research. This project aims to investigate the common problem of PCR dropout of the longest mtDNA fragments. Fresh and archived DNA samples were used in multiplexed PCRs amplifying human HVS1, HVS2 and the intervening region. PCR products ranging from 120 to 1100 base pairs (bps) were amplified in different stages. Amplicons were separated using PAGE and stained with SYBR-Gold to identify specific amplification profiles. Over all, dropout of larger products was seen for the oldest samples. Fresher stored samples showed predictable amplification patterns, as expected from recently extracted DNA. Less than 25% of older samples yielded products between 146 and 506bps. In older samples, the dropout rate for the longest products was 1.5 times that of the shortest. PCR across the HVS1–HVS2 region was significantly hampered in older samples. Follow-up PCRs may have been affected by the abundance of mtDNA in the cell and the prevalence of smaller fragments in degraded DNA. This study suggests that degradation of mtDNA D-loop is progressive and provides strong indication that the process may be confined to specific regions of the molecule.

Collective foraging in group living animal populations displaying behavioral polymorphism is considered. Using mathematical modeling it is shown that symmetric, spatially homogeneous (food sources are used equally) and asymmetric, spatially inhomogeneous (only one food source is used) regimes can coexist, as a result of differential amplification of choice depending on behavioral type. The model accounts for recent experimental results on social caterpillars not only confirming this coexistence, but also showing the relationship between the two types of regime and the ratio of active to inactive individuals.

We use the general formalism of squeezed rotated states to calculate baryon asymmetry in the wake of inflation through parametric amplification. We base our analysis on a B and CP violating Lagrangian in an isotropically expanding universe. The B and CP violating terms originate from the coupling of complex fields with non-zero baryon number to a complex background inflaton field. We show that a differential amplification of particle and anti-particle modes gives rise to baryon asymmetry., Comment: 21 pages, 2 figures

We present a theoretical study of optical bistability and differential amplification, arising as a consequence of the nonlinear Kerr effect in mutually coupled nonlinear microcavity resonators. The dependence of the bistability and differential amplification on various parameters of the coupling range and the resonators is investigated. Multiple closely spaced bistability of the internal intensity in the microresonator is found with appropriate parameters. The results may be useful for a complex logic, memory or switch operation system.

The quasispecies nature of hepatitis C virus (HCV) has been well documented over its whole genome and the most variable domain is located at the 5′ end of the second envelope region, the so-called hypervariable region 1 (HVR1). HVR1 has therefore been extensively used as the target for characterizing HCV quasispecies profiles. In this study, we reported our finding that partially mismatched primers preferentially amplify different HVR1 sequences in a heterogeneous virus population. This finding suggests a possible mechanism of bias during the amplification of HVR1 sequences and may be responsible for some conflicting data regarding evolutionary or clinical implications of HCV quasispecies.

We predict that chromatic and spectroscopic effects are likely to appear for a significant fraction of microlensing events. Differential amplification across a stellar disc produces a time and wavelength dependent signature which constrains the parameters of the lenses and can be used for 3-D mapping of stellar atmospheres.

The objective is to acquaint the microscopist with the crystallographic and contrast effects of electron channeling. The initial emphasis is on channeling experiments which can be performed on any conventional scanning electron microscope: large area channeling patterns of single crystals and channeling contrast images to reveal the crystalline microstructure of polycrystalline materials. The optional advanced experiments on covering area electron channeling patterns can only be carried out on an SEM which is equipped with special scanning and/or electron optical modifications. More detail on this topic may be found in ASEMXM, Chapter 3.

To cancel in-phase components acting on vibrators of first and second sensor units in an angular velocity sensing direction Y, a differential amplification circuit obtains a differential waveform between a first angular velocity sensing waveform J1 and a second angular velocity waveform J2. Furthermore, to reduce a residual in-phase component of the obtained differential waveform, input gain adjusting circuits adjust an input gain of the first angular velocity sensing waveform J1 and an input gain of the second angular velocity sensing waveform J2 before these waveforms J1 and J2 are entered into the differential amplification circuit.