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In this manuscript we present a nonlinear site amplification model for ground-motion prediction equations (GMPEs) in Japan, using a site period-based site class and a site impedance ratio as site parameters. We used a large number of shear-wave velocity profiles from the Kiban-Kyoshin network (KiK-net) and the Kyoshin network (K-NET) to construct the one-dimensional (1D) numerical models. The strong-motion records from rock-sites in Japan with different earthquake categories and taken from the Pacific Earthquake Engineering Research Center dataset were used in this study. We fit a set of 1D site amplification models using the spectral amplification ratios derived from 1D equivalent linear analyses. Parameters of site impedance ratios for both linear and nonlinear site response were included in the 1D model. The 1D model could be implemented into GMPEs using a new proposed adjustment method. The adjusted site amplification ratios retain the nonlinear characteristics of the 1D model for strong motions and match the linear amplification ratio in GMPE for weak motions. The nonlinearity of the present site model is reasonably similar to that of the historical models, and the present site model could satisfactorily capture the nonlinear site response in empirical data.

For a singularly perturbed reaction–diffusion–advection equation, called in applications a Burgers-type equation and having a time-periodic solution with an internal transition layer, asymptotic analysis is used to solve some inverse problems of reconstructing model parameters (determining the linear amplification factor and boundary conditions) from known information about the observed solution of the direct problem in a given time interval (period). Numerical experiments demonstrating the efficiency of the approach proposed are conducted.

Recombinase polymerase amplification (RPA) is an isothermal DNA amplification method with broad applications as a point-of-care test and in molecular biology techniques. Currently, most of the applications are focused on target-specific amplification. Because RPA has the advantage of amplifying DNA under isothermal conditions, we utilized RPA as a DNA library amplification tool. In this study, we used a sheared genomic DNA library and an oligonucleotide (oligo) library for the comparison of polymerase chain reaction and RPA. For the sheared DNA library, we observed biased amplification after RPA was conducted. Thus, to amplify the size-variable DNA library uniformly, we introduced a linear amplification strategy with RPA and successfully improved the uniformity. On the other hand, using the same-sized oligo library, we confirmed that RPA amplified this library uniformly without modification of the protocol. These results demonstrate that RPA can be applied not only to amplify a specific target as previously demonstrated but also to amplify a complex DNA library composed of a large number of different DNA molecules.

We address de-Gaussification of continuous variables Gaussian states by optimal non-deterministic noiseless linear amplifier (NLA) and analyze in details the properties of the amplified states. In particular, we investigate the entanglement content and the non-Gaussian character for the class of non-Gaussian entangled state obtained by using NL-amplification of two-mode squeezed vacua (twin-beam, TWB). We show that entanglement always increases, whereas improved EPR correlations are observed only when the input TWB has low energy. We then examine a Braunstein-Kimble-like protocol for the teleportation of coherent states, and compare the performances of TWB-based teleprotation with those obtained using NL-amplified resources. We show that teleportation fidelity and security may be improved for a large range of NLA parameters (gain and threshold).

Asymptotic analysis of a singularly perturbed reaction—diffusion—advection equation, which is called a Burgers-type equation in applications and has a solution with a sharp transition layer, is applied to solve the coefficient inverse problem of determining the coefficient of linear amplification from known information on the observed solution of the direct problem at the final moment of time. The efficiency of the approach proposed in this study is shown using a series of model numerical experiments.

Accurate next generation sequencing (NGS) is critical for understanding genetic predisposition to human disease and thus aiding clinical diagnosis and personalized precision medicine. Recent breakthroughs in massively parallel sequencing, especially when coupled with sample multiplexing, have driven sequencing cost down and made clinical genetic tests broadly affordable. However, intractable index mis-assignment (commonly exceeds 1%) has been reported on some widely used sequencing platforms. Burdensome unique dual indexing is now used to reduce this problem. Here, we investigated this quality issue on BGI sequencers using three major library preparation methods: whole genome sequencing (WGS) with PCR, PCR-free WGS, and two-step targeted PCR. BGI sequencers utilize a unique DNA nanoball (DNB) technology that is based on rolling circle replication (RCR) for array preparation; this linear amplification is PCR free and can avoid error accumulation. We demonstrate here that single index mis-assignment from free indexed oligos on these sequencers occurs at a rate of only one in 36 million reads, suggesting virtually no index hopping during DNB creation and arraying, as expected for the RCR process. Furthermore, the DNB-based NGS applications have achieved an unprecedentedly low sample-to-sample mis-assignment rate of 0.0001% to 0.0004% using only single indexing. Therefore, single indexing with DNB sequencing technology provides a simple but effective method for sensitive research and clinical genetic assays that require the detection of low abundance sequences in a large number of samples.

This paper deals with the Peak to Average Power Ratio (PAPR) drawback appeared in Filter-Bank Multi-Carriers with Offset-QAM (FBMC-OQAM) which is the candidate waveform in 5G wireless communication systems. A post-Inverse Discrete Fourier Transform (IDFT) Discrete Sliding Norm Transform (DSNT) is proposed based on L2-metric and the norm of five samples at each sliding operation. The overlapping structure of FBMC-OQAM is considered in the proposed L2-by-5 DSNT formulation. It can significantly reduce the PAPR in FBMC-OQAM systems, which ensures a linear amplification at the High Power Amplifier (HPA) and avoids signal distortion. The main advantages of this technique are its lower computational complexity compared to the known techniques, and the fact that it does not require any Side Information (SI) at the receiver. Simulation results show that the L2-by-5 DSNT technique can achieve an improvement of 40% in PAPR reduction at CCDF = 10–3 compared to the original FBMC-OQAM system.

Obtaining a full short tandem repeat (STR) profile from a low template DNA (LT-DNA) still presents a challenge for conventional methods due to significant stochastic effects and polymerase slippage. A novel amplification method with a lower cost and higher accuracy is required to improve the DNA amount. Previous studies suggested that DNA polymerases without bypass activity could not perform processive DNA synthesis beyond abasic sites in vitro and our results showed a lack of bypass activity for Phusion, Pfu and KAPA DNA polymerases in this study. Based on this feature, we developed a novel linear amplification method, termed Linear Aamplification for double-stranded DNA using primers with abasic sites near 3′ end (abLAFD), to limit the replication error. The amplification efficiency was evaluated by qPCR analysis with a result of approximately a 130-fold increase in target DNA. In a LT-DNA analysis, the abLAFD method can be employed as a pre-PCR. Similar to nested PCRs, primer sets used for the abLAFD method were designed as external primers suitable for commercial multiplex STR amplification assays. The practical performance of the abLAFD method was evaluated by coupling it to a routine PP21 STR analysis using 50 pg and 25 pg DNA. Compared to reference profiles, all abLAFD profiles showed significantly recovered alleles, increased average peak height and heterozygote balance with a comparable stutter ratio. Altogether, our results support the theory that the abLAFD method is a promising strategy coupled to STR typing for forensic LT-DNA analysis.

Background CRISPR/Cas9-mediated transcriptional interference (CRISPRi) enables programmable gene knock-down, yielding loss-of-function phenotypes for nearly any gene. Effective, inducible CRISPRi has been demonstrated in budding yeast, and genome-scale guide libraries enable systematic, genome-wide genetic analysis. Results We present a comprehensive yeast CRISPRi library, based on empirical design rules, containing 10 distinct guides for most genes. Competitive growth after pooled transformation revealed strong fitness defects for most essential genes, verifying that the library provides comprehensive genome coverage. We used the relative growth defects caused by different guides targeting essential genes to further refine yeast CRISPRi design rules. In order to obtain more accurate and robust guide abundance measurements in pooled screens, we link guides with random nucleotide barcodes and carry out linear amplification by in vitro transcription. Conclusions Taken together, we demonstrate a broadly useful platform for comprehensive, high-precision CRISPRi screening in yeast.

One of the main obstacles for systematic evolution of ligands by exponential enrichment (SELEX) failure is the generation of a non-specific product, as selection-inherent amplification procedures tend to form by-products, which prevents the enrichment of target-binding aptamers. Herein, we reported a dual-microfluidic amplified system (dual-MAS) based on the real-time polymerase chain reaction (PCR) detection chip and the large volume PCR chip for one-step specific PCR and for evaluating the SELEX process. First, it is a simple method to accomplish analytical PCR and amplification PCR in one step, and the optimal number of cycles for generating the specific PCR product is the cycles when the slope of the linear amplification period of the real-time PCR curve begins to decrease. Second, the time used by the dual-MAS for generating a specific PCR product is reduced to 30 min, and the multi-functional dual-MAS can simultaneously evaluate the SELEX process by providing important information on the amounts of enriched sequences and the library diversity in every round of SELEX. In addition, pollution contamination and fragment loss can be significantly avoided in the closed chip. Last, the specific PCR product, the amounts of enriched sequences, and the library diversity can be obtained for every single SELEX in just 30 min. Compared with current methods, this system can reduce the time for generating a specific PCR product and SELEX, and it is easier to choose the optimal number of cycles for a specific PCR product. In a word, it is a sensitive, simple, and rapid strategy to improve the specificity of the PCR product and make the process of SELEX in a controlled way.

Hyperentanglement is a quantum system which simultaneously entangles in several degrees of freedom. It is an important resource in quantum communication field. In practical application of hyperentanglement, the photon transmission loss is a big obstacle. In the paper, we propose an entanglement-assisted noiseless linear amplification (NLA) protocol to protect the two-photon polarization–time-bin hyperentanglement. Our protocol can effectively increase the fidelity of this hyperentanglement, while preserve its polarization and time-bin features. Our NLA protocol can be realized under current experimental condition and further extended to protect the general N-photon polarization–time-bin hyperentanglement in the multi-directional transmission process. This NLA protocol may have important applications in future hyperentanglement-based quantum communication network field.

By combining azobenzene-tethered oligonucleotides as modulators and poly(l-lysine)-graft-dextran (PLL-g-Dex), a chaperone polymer, to facilitate strand displacement, we successfully developed a photo-regulatable DNA isothermal amplification method. By alternating UV and visible irradiation, linear amplification was achieved. The method enables photo-regulatability and mismatch discrimination in linear amplification of the DNA target.

LAM-HTGTS = linear amplification mediated high-throughput genomic translocations sequencing The presented version is our working version of the Frederick Alt and Richard Frock paper "Detecting DNA double-stranded breaks in mammalian genomes by linear amplification–mediated high-throughput genome-wide translocation sequencing" published in Nature Protocols in 2016. The main application of the method is sequencing of the unknown sequences that flank known regions. It can be used in two ways: 1. inside-out (in genomic engineering it can be used to characterize the off-targets, for example). 2. outside-in (in the same setting of genomic engineering it can be used to measure the on-target efficiency and characterize the on-target events). Main advantage of the method is its unbiased nature: the template genomic DNA is sheared by sonication which is presumably sequence-independent. Original protocol is here: Hu, J., Meyers, R. M., Dong, J., Panchakshari, R. A., Alt, F. W., & Frock, R. L. (2016). Detecting DNA double-stranded breaks in mammalian genomes by linear amplification-mediated high-throughput genome-wide translocation sequencing. Nature Protocols, 11(5), 853–871. https://doi.org/10.1038/nprot.2016.043 These are the changes that made it work in our hands.

Although the ability to integrate information across the senses is compromised in some individuals for unknown reasons, similar defects have been observed when animals are reared without multisensory experience. The experience-dependent development of multisensory integration has been studied most extensively using the visual-auditory neuron of the cat superior colliculus (SC) as a neural model. In the normally-developed adult, SC neurons react to concordant visual-auditory stimuli by integrating their inputs in real-time to produce non-linearly amplified multisensory responses. However, when prevented from gathering visual-auditory experience, their multisensory responses are no more robust than their responses to the individual component stimuli. The mechanisms operating in this defective state are poorly understood. Here we examined the responses of SC neurons in “naïve” (i.e., dark-reared) and “neurotypic” (i.e., normally-reared) animals on a millisecond-by-millisecond basis to determine whether multisensory experience changes the operation by which unisensory signals are converted into multisensory outputs (the “multisensory transform”), or whether it changes the dynamics of the unisensory inputs to that transform (e.g., their synchronization and/or alignment). The results reveal that the major impact of experience was on the multisensory transform itself. Whereas neurotypic multisensory responses exhibited non-linear amplification near their onset followed by linear amplification thereafter, the naive responses showed no integration in the initial phase of the response and a computation consistent with competition in its later phases. The results suggest that multisensory experience creates an entirely new computation by which convergent unisensory inputs are used cooperatively to enhance the physiological salience of cross-modal events and thereby facilitate normal perception and behavior.

Amplification of long DNA segments with the highest possible specificity and lowest bias is one of the main goals of modern genomics. Quadruplex priming amplification (QPA) is a single-primer isothermal method, which employs the free energy of quadruplex structures as the driving force for DNA amplification without any extra reaction components. As a result, QPA represents one of the simplest isothermal assays and was previously shown to be suitable for amplification of relatively short DNA sequences. The current study reveals that single-primer QPA can be used for both exponential and linear amplification of relatively long DNA segments (>100 nt), and switching between these modes can be accomplished by simple re-design of the primer used. While exponential amplification resulted in production of some undesired higher molecular weight species, linear QPA demonstrated highly specific amplification of the target molecules without any side products.

Current genome walking methods are very time consuming, and many produce non-specific amplification products. To amplify the flanking sequences that are adjacent to Tn5 transposon insertion sites in Serratia marcescens FZSF02, we developed a genome walking method based on TAIL-PCR. This PCR method added a 20-cycle linear amplification step before the exponential amplification step to increase the concentration of the target sequences. Products of the linear amplification and the exponential amplification were diluted 100-fold to decrease the concentration of the templates that cause non-specific amplification. Fast DNA polymerase with a high extension speed was used in this method, and an amplification program was used to rapidly amplify long specific sequences. With this linear and exponential TAIL-PCR (LETAIL-PCR), we successfully obtained products larger than 2 kb from Tn5 transposon insertion mutant strains within 3 h. This method can be widely used in genome walking studies to amplify unknown sequences that are adjacent to known sequences. Electronic supplementary material The online version of this article (10.1186/s13568-017-0495-x) contains supplementary material, which is available to authorized users.

We generalize the concept of optical state truncation and noiseless linear amplification to enable truncation of the Fock-state expansion of an optical state to higher order and to simultaneously amplify it using linear optics. The resulting generalized quantum scissors are more efficient for noiseless linear amplification than employing multiple scissors in parallel and are experimentally practical. As a particular example, we focus on a third-order scissor device and demonstrate advantages in terms of fidelity with the target state, probability of success, distillable entanglement, and the amount of non-Gaussianity introduced., Comment: 11 pages, 10 figures

This paper addresses the use of dual-polarized power-combining microstrip antennas to realize an efficient LINC (LInear amplification using Non-linear Components) phased-array. A small antenna array consisting of two LINC antenna elements has been designed and experimentally validated. We have realized an EVM (Error Vector Magnitude) below 0.3% for a scan range up to ±45°.

We introduce a class of topological lasers based on the photonic Floquet topological insulator concept. The proposed system is realized as a truncated array of the lasing helical waveguides, where the pseudo-magnetic field arises due to twisting of the waveguides along the propagation direction that breaks the time-reversal symmetry and opens up a topological gap. When sufficient gain is provided in the edge channels of the array then the system lases into the topological edge states. Topological lasing is stable only in certain intervals of the Bloch momenta, that ensure a dynamic, but stable balance between the linear amplification and nonlinear absorption leading to the formation of the breathing edge states. We also illustrate topological robustness of the edge currents by simulating lattice defects and triangular arrangements of the waveguides., 23 pages, 5 figures

In this paper a novel outphasing amplification architecture, Transmitted Linear Amplification with Nonlinear Components (T-LINC), is proposed and evaluated. Different from conventional LINC techniques that combine the outphased signals before transmission, the proposed architecture transmits both outphased signals and implements the signal combination in the base-band domain at the receiver side. By digitally combining the signals in the receiver, it is easier to correct gain or phase mismatch existing between the two outphased signals, without adding any extra complexity in the transmitter. Additionally, a power combiner is no longer required in the transmitter. Simulations show that the proposed technique is able to correct transmitter gain and phase imbalance and achieve an ACPR level of -42 dBc and EVM below 2.5 % for 16-QAM signals. Index Terms—Digital combination, digital mismatch correction, linear amplification with nonlinear components (LINC), outphasing amplification, Transmitted LINC (T-LINC). With the recent popularization of nanosatellite technologies, the industry is putting a notable effort into increasing the performance of the systems integrated in these small spacecrafts. In this paper, a novel outphasing amplification architecture to enhance the power efficiency of a satellite downlink is presented and evaluated. Based on a conventional LINC (LInear amplification with Nonlinear Components) architecture, the proposed architecture transmits both outphased signals, and carry out the signal combination in the receiver in the base-band domain. The resulted architecture takes advantage of an efficient signal amplification given by the nonlinear power amplifiers, while the elimination of the signal power combiner from the transmitter, increases the overall power efficiency. We outline and analyze those elements that restrict the performance of this novel approach. The simulations and laboratory experimentation probes the proposed architecture is feasible, and able to improve a ?? % the power efficiency, compared to a classic transmitter front-end architecture.

How to realize the detection of tiny birefringence is an important but challenging issue for investigations and applications in optics. In weak measurements, weak-value amplification has been widely applied to the precise estimation of time delay. Here, we show that the linear amplification in weak measurements has the potential to outperform standard weak-value amplification for ultra-small parameter characterization. The higher measurement accuracy in the linear amplification enables us to achieve a measurement of stress-induced birefringence with a high resolution of 5 × 10 − 10. Compared with existing methods, the accuracy based on weak measurements for birefringence detection can improve two orders of magnitude. Our method may have important applications in a variety of fields involving the precise measurement of time delay or birefringence.

The development of high-throughput sequencing (next-generation sequencing technology (NGS)) and the continuous increase in experimental throughput require the upstream sample processing steps of NGS to be as simple as possible to improve the efficiency of the entire NGS process. The transposition system has fast “cut and paste” and “copy and paste” functions, and has been innovatively applied to the NGS field. For example, the Assay for Transposase-Accessible Chromatin with high throughput sequencing (ATAC-Seq) uses high-throughput sequencing to detect chromatin regions accessible by Tn5 transposase. Linear Amplification via Transposon Insertion (LIANTI) uses Tn5 transposase for linear amplification, haploid typing, and structural variation detection. Not only is it efficient and simple, it effectively shortens the time for NGS sample library construction, realizes large-scale and rapid sequencing, improves sequencing resolution, and can be flexibly modified for more technological innovation.

Single-cell RNA sequencing has revolutionized the way we look at cell populations. Of the methods available, CEL-Seq was the first to use linear RNA amplification. With early barcoding and 3' sequencing, it is sensitive, cost-effective and easy to perform. Here we describe a protocol for performing CEL-Seq2 on sorted cells, which can be performed without any special equipment.

The linear amplification mechanisms leading to streamwise-constant large-scale structures in laminar and turbulent channel flows are considered. A key feature of the analysis is that the Orr--Sommerfeld and Squire operators are each considered separately. Physically this corresponds to considering two separate processes: (i) the response of wall-normal velocity fluctuations to external forcing; and (ii) the response of streamwise velocity fluctuations to wall-normal velocity fluctuations. In this way we exploit the fact that, for streamwise-constant fluctuations, the dynamics governing the wall-normal velocity are independent of the mean velocity profile (and therefore the mean shear). The analysis is performed for both plane Couette flow and plane Poiseuille flow; and for each we consider linear amplification mechanisms about both the laminar and turbulent mean velocity profiles. The analysis reveals two things. First, that the most amplified structures (with a spanwise spacing of approximately $4h$, where $h$ is the channel half height) are to a great extent encoded in the Orr-Sommerfeld operator alone, thus helping to explain their prevalence. Second---and consistent with numerical and experimental observations---that Couette flow is significantly more efficient than Poiseuille flow in leveraging wall-normal velocity fluctuations to produce large-scale streamwise streaks.

We address quantum state engineering of single- and two-mode states by means of nondeterministic noiseless linear amplifiers (NLAs) acting on Gaussian states. In particular, we consider the optimal implementation of a NLA proposed by Pandey et al. [Phys. Rev. A 88, 033852 (2013)] and we show that it provides an effective scheme to generate highly non-Gaussian and nonclassical states, when used outside the regime of high-fidelity amplification. Additionally, we show that in this regime also the amplification of a two-mode squeezed vacuum state (twin-beam) highly increases entanglement.

Single carrier modulations with high order constellations or orthogonal frequency division multiplexing (OFDM) modulations can be employed to obtain spectrally efficient communications. However, such modulations lead to signals with large envelope variations, where the amplification is challenging and usually energy-inefficient. The linear amplification with nonlinear components (LINC) makes use of two efficient, nonlinear power amplifiers for an efficient amplification. In this work, we propose the multi-branch LINC (MB-LINC) technique, which allows the use of highly-efficient nonlinear amplifiers without increasing the nonlinear distortion effects, even if the amplifiers are not balanced1.

Background Non-invasive prenatal testing (NIPT) as alternative screening method had been proven to have very high sensitivity and specificity for detecting common aneuploidies such as T21, T18, and T13, with low false positive and false negative rates. Unfortunately, recent studies suggested that the NIPT achieved lower accuracy in sex chromosomal aneuploidies (SCAs) detection than autosomal aneuploidies detection. BGISEQ-500 powered by Combinatorial Probe-Anchor Synthesis (CPAS) and DNA Nanoballs (DNBs) technology that combined linear amplification and rolling circle replication to reduce the error rate while enhancing the signal. Therefore, NIPT based on CPAS might be a good method for SCAs screening in routine clinical practice. In the study, we intended to evaluate the clinical utility of NIPT based on CPAS on screening for fetal SCAs. Results A total of 570 pregnant women were included in the retrospective study. Maternal blood samples were collected for NIPT; amniocentesis was performed on all pregnant women. NIPT was carried out by BGISEQ-500 sequencing platform based on CPAS. Karyotype analysis of amniotic cells was performed by standard G-banding techniques. 43 out of the total 570 pregnant women tested by NIPT showed fetal SCAs (19 of 45,X, 12 of 47,XXY, 10 of 47,XXX, and 2 of 47,XYY). The following amniocentesis confirmed that 26 cases were true positive (7 of true positive 45,X, 9 of true positive 47,XXY, 9 of true positive 47,XXX as well as 1 of 47,XYY) and the positive predictive value (PPV) for fetal SCAs was 60.47%. In addition, the PPV of advanced maternal age group (67.74%) was higher than the other indications group (45.45%) or serological screening high-risk /critical-risk group (0%). Conclusions NIPT based on CPAS could be a potential method for SCAs screening. However, it still had high false positive rates, especially for 45,X. The pregnant women with fetal SCAs detected by NIPT, especially those with non-age-related prenatal diagnostic indications, should be advised to accept invasive prenatal karyotype analysis.

Whole-transcriptome evaluation by next-generation sequencing (NGS) has been widely applied in the investigation of diverse transcriptional scenarios. In many clinical situations, including needle biopsy samples or laser microdissected cells, limited amounts of RNA are usually available for the assessment of the whole transcriptome. Here, we describe an mRNA amplification protocol based on in vitro T7 transcription for transcriptome evaluation by NGS. Initially, we performed RNAseq from two human mammary epithelial cell lines and evaluated several aspects of the transcriptomes generated by linear amplification of Poly (A)+ mRNA species, including transcript representation, variability and abundance. Our protocol showed to be efficient with respect to full-length transcript coverage and quantitative expression levels. We then evaluated the applicability of using this protocol in a more realistic research scenario, analyzing tumor tissue samples microdissected by laser capture. In order to increase the quantification power of the libraries only the 3′ end of transcripts were sequenced. We found highly reproducible RNAseq data among amplified tumor samples, with a median Spearman's correlation of 80%, strongly suggesting that the amplification step and library protocol preparation lead to a consistent transcriptional profile. Altogether, we established a robust protocol for assessing the polyadenylated transcriptome derived from limited amounts of total RNA that is applicable to all NGS platforms.

The most important property of the Doherty amplifier is the load modulation, which carries out the perfect combining of the asymmetrical powers from the two amplifiers. Thereby, only one amplifier (called carrier amplifier) operates at a low power level, and the two amplifiers (the second one is called peaking amplifier) generate powers at a higher power level. Also the carrier amplifier operates at the peak efficiency mode, while the peaking amplifier is operational due to the nice load modulation characteristic. Another important characteristic of the Doherty load modulation is that the overall gain of the amplifier is constant, providing a linear amplification. The Doherty circuit can modulate the real part of impedance only. To get the proper load modulation for a device with a complex impedance, an offset line is needed to provide the imaginary impedance transformation. The load modulation principle and the offset line operation are discussed. Several load modulation methods are also described.

We present CPA-free linear amplification of 6:3 ps pulses in Ho:YLF crystals up to 100 μJ pulse energy at 10 kHz repetition rate. The seed pulses at a wavelength of 2:05 μm are provided by a Ho-based all-fiber system consisting of a soliton oscillator and a subsequent pre-amplifier followed by a free-space AOM as pulse-picker. Considering the achieved pulse peak power at MW-level, this system is a powerful tool for efficient pumping of parametric amplifiers addressing the highly demanded mid-IR spectral region. In detailed numerical simulations we verified our experimental results and discuss scaling options for pulse duration and energy. © 2018 SPIE.

A horn-waveguide reflective semiconductor optical amplifier was studied. Experimental results reveal that it has an excellent saturation effect for the downstream signal and linear amplification for the upstream signal compared to the straight design.

We study non-Hermitian photonic lattices that exhibit competition between conservative and non-Hermitian (gain/loss) couplings. A bipartite sublattice symmetry enforces the existence of non-Hermitian flat bands, which are typically embedded in an auxiliary dispersive band and give rise to non-diffracting "compact localized states". Band crossings take the form of non-Hermitian degeneracies known as exceptional points. Excitations of the lattice can produce either diffracting or amplifying behaviors. If the non-Hermitian coupling is fine-tuned to generate an effective $\pi$ flux, the lattice spectrum becomes completely flat, a non-Hermitian analogue of Aharonov-Bohm caging in which the magnetic field is replaced by balanced gain and loss. When the effective flux is zero, the non-Hermitian band crossing points give rise to asymmetric diffraction and anomalous linear amplification., Comment: Revised manuscript. 8 pages, 5 figures

Purpose – The purpose of this paper is to present the design of a microgripper system that comprises a dual jaw actuation mechanism with contact sensing. Design/methodology/approach – Interdigitated lateral comb-drive-based electrostatic actuator is used to move the gripper arms. Simultaneous contact sensing of the gripper jaws has been achieved through transverse comb-based capacitive sensor. The fabricated microgripper produces a displacement of 16 μm at gripper jaws for an applied actuation voltage of 45 V. Findings – It is observed that the microgripper fails to operate for the maximum performance limits (70 μm jaws displacement) and produces uncontrolled force at the tip of the jaws > 45 V. Originality/value – A novel behavioral model of the microgripper system is proposed using the fabricated dimensions of the system to carry out a detailed analysis to understand the cause of this failure. The failure analysis shows that the microgripper system failed to operate in its designed limits due to the presence of side instability in the designed combs structure. Our proposed failure model helps in redesigning the actuator to ensure its operation above 45 V so that the gripper jaw can be displaced to its maximum limit of 70 μm and also result in the increase of the controlled force from 250 to 303 μN at the microgripper jaws.

Linear-after-the-exponential (LATE)-PCR describes a novel approach to asymmetric PCR which uses adjusted melting temperatures of the limited primer to increase PCR efficiency. In this proof-of-principle study we show that linear amplification is possible over a wide range of amplification cycles. The curve characteristics of the real time PCR show that the plateau effect of conventional PCR can be avoided by this innovative technique.

We introduce a weakly coupled photonic crystal waveguide as a promising and realistic model for all-optical amplification. A symmetric pillar type coupled photonic crystal waveguide consisting of dielectric rods periodically distributed in a free space is proposed as all-optical amplifier. Using, the unique features of the photonic crystals to control and guide the light, we have properly chosen the frequency at which only one mode (odd mode) becomes the propagating mode in the coupled photonic crystal waveguide, whereas another mode (even mode) is completely reflected from the guiding structure. Under this condition, the all-optical amplification is fully realized. The amplification coefficient for the continuous signal and the Gaussian pulse is calculated.

Nucleic acid circuits have played important roles in biological engineering and have increasingly attracted researchers' attention. They are primarily based on nucleic acid hybridizations and strand displacement reactions between nucleic acid probes of different lengths. Signal amplification schemes that do not rely on protein enzyme show great potential in analytical applications. While the single amplification circuit often achieves linear amplification that may not meet the need for detection of target in a very small amount, it is very necessary to construct cascade circuits that allow for larger amplification of inputs. Herein, we have successfully engineered powerful amplification cascades of FRET-based two-layer nonenzymatic nucleic acid circuits, in which the outputs of catalyzed hairpin assembly (CHA) activate hybridization chain reactions (HCR) circuits to induce repeated hybridization, allowing real-time monitoring of self-assembly process by FRET signal. The cascades can yield 50000-fold signal amplification with the help of the well-designed and high-quality nucleic acid circuit amplifiers. Subsequently, with coupling of structure-switching aptamer, as low as 200 pM adenosine is detected in buffer, as well as in human serum. To our knowledge, we have for the first time realized real-time monitoring adaptation of HCR to CHA circuits and achieved amplified detection of nucleic acids and small molecules with relatively high sensitivity.

A modified linear amplification with nonlinear component (LINC) transmitter is presented using a novel power combination scheme.By using multiple LINC sections in parallel with a compact adaptive power combining network, the output power of power amplifiers can be boosted, together with obtaining higher efficiency over a large power back-off region. Compared to existing designs, no gate bias adaptation is needed and efficiency can be further improved. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26086

Forensic analysis of genetic material is often limited by the quantity and quality of DNA available for examination. Stochastic effects associated with low amounts of starting template can lead to a reduction in the quality of the result, making interpretation difficult. This paper presents an amplification method to copy target DNA in a linear fashion prior to short tandem repeat (STR) analysis to increase the available starting template without introducing the amplification bias seen in other methods used to increase the sensitivity of PCR. Results show that implementing the pre- PCR procedure allows for greater allele recovery in multiplex STR analysis compared with samples that were not subjected to prior processing.

In this paper, we analyse the effect of the path imbalances(gain and phase mismatches) in LINC(LInear amplification with Nonlinear Component) system, and propose a simple scheme using LUTs(Look Up Table) to compensate the path imbalances. The EVM(Error Vector Magnitude) and ACPR(Adjacent Channel Power Ratio) of the LINC system are degraded significantly by the path imbalances because it adopts an outphasing technique. The EVM and ACPR are theoretically extracted for two variables(gain and phase mismatch factors) and 2-D LUTs for those are generated based on the analysis. The efficient and simple compensation scheme for the path imbalances is proposed using the 2-D LUTs. A LINC system with the suggested compensation scheme is implemented, and the proposed method is verified with an experiment. A 16-QAM signal with 1.5 MHz bandwidth is used. Before the compensation, the path gain ratio was 95 % and phase error was . The proposed scheme adjusts those values with 99 % and , and improves ACPR about 18.1 dB.

We study the parametric amplification of electromagnetically induced transparency-assisted Rydberg six- and eight-wave mixing signals through a cascaded nonlinear optical process in a hot rubidium atomic ensemble both theoretically and experimentally. The shift of the resonant frequency (induced by the Rydberg–Rydberg interaction) of parametrically amplified six-wave mixing signal is observed. Moreover, the interplays between the dressing effects and Rydberg–Rydberg interactions in parametrically amplified multiwave mixing signals are investigated. The linear amplification of Rydberg multiwave mixing processes with multichannel nature acts against the suppression caused by Rydberg–Rydberg interaction and dressing effect.

In this article, we propose a new impedance match method in serial Chireix combiner to improve the efficiency of Linear amplification with Nonlinear Components (LINC) amplifier. Based on the impedance characteristics of the serial Chireix combiner, two transmission lines are added between power amplifiers (PAs) and Chireix combiner in LINC. For experimental verification, the PAs and combiner are implemented and tested. From the measured results, this method is proved available for improving efficiency of LINC, and convenient for design as well as tuning work. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1418–1421, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25205

In this letter, an active metamaterial sample embedded with miniature monolithic microwave amplifiers is designed, experimentally realized, and measured. Experiments show that by proper design and direct current (DC) bias, the metamaterial sample provides almost linear amplification to an electromagnetic incidence, which can be used to compensate the loss inherent in traditional passive metamaterial and magnify the signal entered the metamaterial. This property would have important potentials in promoting the further researches of metamaterial-based applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 92–95, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24871

This study aimed to determine the low- and high-frequency compression ratios of a fast-acting device that were preferred by people with moderately severe to profound hearing loss. Three compression ratios (1:1, 1.8:1, and 3:1) were combined in the low and high frequencies to produce nine schemes that were evaluated pair-wise for three weeks in the field using an adaptive procedure. The evaluation was performed by 21 experienced hearing aid users with a moderately severe to profound hearing loss. Diaries and an exit interview were used to monitor preferences. Generally, the subjects preferred lower compression ratios than are typically prescribed, especially in the low frequencies. Specifically, 11 subjects preferred linear amplification in the low frequencies, and 14 subjects preferred more compression in the high than in the low frequencies. Preferences could not be predicted from audiometric data, onset of loss, or past experience with amplification. The data suggest that clients with moderately severe to profound hearing loss should be fitted with low-frequency compression ratios in the range 1:1 to 2:1 and that fine-tuning is essential. Este estudio trató de determinar las tasas de compresión de alta y baja frecuencia de un dispositivo de acción rápida, que resultara preferido por personas con hipoacusias moderadamente severas a profundas. Se combinaron tres tasas de compresión (1:1, 1.8:1, y 3:1) en las frecuencias graves y agudas para producir nueve esquemas que fueron evaluados en el campo, en pares, durante tres semanas, utilizando un procedimiento de adaptación. La evaluación fue realizada por 21 usuarios experimentados de audífono con hipoacusias moderadamente severas a profundas. Se usaron diarios y un cuestionario final para monitorear las preferencias. Generalmente, los sujetos prefirieron menores tasas de compresión de lo que típicamente se prescribe, especialmente en las bajas frecuencias. Específicamente, 11 sujetos prefirieron la amplificación lineal en las frecuencias graves y 14 sujetos prefirieron más compresión en las frecuencias altas. Las preferencias no podían predecirse a partir de los datos audiométricos, del inicio de la pérdida, o por experiencias anteriores con amplificación. Los datos sugieren que los clientes con hipoacusias moderadamente severas a profundas, deberían adaptarse con tasas de compresión en las frecuencias graves en el rango de 1:1 a 2:1, y que un ajuste fino es esencial.

Simultaneous detection of cancer biomarkers holds great promise for the early diagnosis of different cancers. However, in the presence of high-concentration biomarkers, the signals of lower-expression biomarkers are overlapped. Existing techniques are not suitable for simultaneously detecting multiple biomarkers at concentrations with significantly different orders of magnitude. Here, we propose an asymmetric signal amplification method for simultaneously detecting multiple biomarkers with significantly different levels. Using the bifunctional probe, a linear amplification mode responds to high-concentration markers, and quadratic amplification mode responds to low-concentration markers. With the combined biobarcode probe and hybridization chain reaction (HCR) amplification method, the detection limits of microRNA (miRNA) and ATP via surface-enhanced Raman scattering (SERS) detection are 0.15 fM and 20 nM, respectively, with a breakthrough of detection concentration difference over 11 orders of magnitude. Furthermore, successful determination of miRNA and ATP in cancer cells supports the practicability of the assay. This methodology promises to open an exciting new avenue for the detection of various types of biomolecules.

Multiplexed amplification of specific DNA sequences, by PCR or by strand-displacement amplification, is an intrinsically biased process. The relative abundance of amplified DNA can be altered significantly from the original representation and, in extreme cases, allele dropout can occur. In this paper, we present a method of linear amplification of DNA that relies on the cooperative, sequence-dependent functioning of the DNA mismatch-repair enzyme endonuclease V (EndoV) from Thermotoga maritima (Tma) and Bacillus stearothermophilus (Bst) DNA polymerase. Tma EndoV can nick one strand of unmodified duplex DNA, allowing extension by Bst polymerase. By controlling the bases surrounding a mismatch and the mismatch itself, the efficiency of nicking by EndoV and extension by Bst polymerase can be controlled. The method currently allows 100-fold multiplexed amplification of target molecules to be performed isothermally, with an average change of

Various hydraulic test and numerical simulations have reported that under the condition in which doublerow bars initially form, the mode of bars is reduced and alternate bars are formed over time. In this study, weakly nonlinear analysis is performed in order to elucidate the interaction between the modes of double-row bars and alternate bars. A concept of the rate of linear amplification is introduced in to the weakly nonlinear analysis in order to enable a consistent expansion of alternate bars and double-row bars. This analysis succeeds in reproducing the characteristics of bar mode decrease process. According to this analysis, neither of both modes (alternate bars and double-row bars ) can grow up simultaneously.

Objective Traditionally in the United Kingdom, children with severe and profound hearing loss have been fitted with linear, analog hearing aids. Fast-acting, wide-dynamic-range compression (WDRC) has been shown to give better discrimination of speech than linear amplification for moderately hearing-impaired young adults. For severe and profound hearing losses, higher compression ratios are needed. The resultant distortion of the temporal envelope and reduced modulation depth may offset improvements in audibility offered by WDRC. In this study, speech recognition and discrimination were assessed for severely and profoundly hearing-impaired children, using three different amplification strategies, including WDRC. Design Fifteen children (ages 7 to 15 yr) with severe and profound hearing loss were fitted bilaterally with high-power, multichannel compression hearing aids, incorporating one of three different amplification strategies: linear with peak clipping, linear with compression limiting, or WDRC. Output responses were matched to Desired Sensation Level (DSL i/o) targets. The children wore hearing aids programmed with each of the amplification strategies in turn, for at least 1 wk, in a counterbalanced order across children. After using a particular amplification strategy for at least 1 wk, speech perception tests were carried out. Results Speech scores on closed-set testing for the profound group showed significant benefit for WDRC over the other two algorithms. None of the other results showed a statistically significant effect of algorithm on speech performance. Conclusions WDRC amplification sometimes led to better performance than linear amplification with peak clipping or output limiting, and it never led to poorer performance. Therefore, it appears to be safe to use well-designed WDRC for hearing-impaired children with severe or profound hearing loss.