Multiple Cross Research Articles

Rapid and sensitive detection of Pseudomonas aeruginosa using multiple cross displacement amplification and gold nanoparticle-based lateral flow biosensor visualization.

Pseudomonas aeruginosa causes nosocomial infections of burn patients and other immunocompromised individuals, but the conventional diagnosis of P. aeruginosa infection depends on time-consuming culture-based methods. Hence, a simple, fast, sensitive technique for detection of P. aeruginosa using multiple cross displacement amplification (MCDA) and gold nanoparticle-based lateral flow biosensors (LFB) was developed. By using this technique, the reaction could be completed at an optimized constant temperature (67°C) within only 40 min. The reaction product could be detected visually using an LFB, eliminating the need for special equipment. The P. aeruginosa-MCDA-LFB method was highly specific, and accurately distinguished P. aeruginosa from other pathogens. Just 10 fg of genomic DNA template (from pure culture) could be detected. The assay could also detect P. aeruginosa in clinical sputum samples and showed the same sensitivity and specificity as the reference (culture-biochemical) method. In the future, this rapid, simple and accurate P. aeruginosa-MCDA-LFB technique might be applied in clinical practice.

Combining ability studies in multiple cross derivatives of upland cotton (Gossypium hirsutum) for identifying desirable plant types suitable to High Density Planting System

To develop genotypes suitable for High Density Planting System (HDPS), six lines and seven testers that possessed compact plant type characteristics were crossed in Line × Tester mating design and the resulting 42 crosses along with their parents were evaluated at three different locations during kharif, 2014 to identify good general and specific combiners for plant type suitable for HDPS with desirable fibre quality. The results revealed significant differences among lines, testers and crosses for most of the traits and preponderance of non-additive gene action. Three lines MC 17-6, MC 16-3, MC 4-3 and two testers NH 630, MC 19-2 exhibited good gca and were found to possess compact plant type characteristics with desirable fibre quality. Among the 42 cross combinations, three crosses MC 9-1 × NH 630, MC 17-6 × MC 19-2 and MC 4-3 × MC 3-2 were identified as best specific combiners. The superior multiple cross derivatives and cross combinations can be used for developing hybrids suitable for high density planting system through heterosis breeding.

Multiple Cross Displacement Amplification Coupled With Nanoparticles-Based Lateral Flow Biosensor for Detection of Staphylococcus aureus and Identification of Methicillin-Resistant S. aureus.

Staphylococcus aureus (S. aureus), including methicillin-resistant S. aureus (MRSA), is one of the most important human pathogens, which is responsible for bacteremia, soft-tissue infections, and food poisoning. Hence, multiple cross displacement amplification (MCDA) is employed to detect all S. aureus strains, and differentiates MRSA from methicillin-sensitive S. aureus. Multiplex MCDA (m-MCDA), which targets the nuc gene (S. aureus-specific gene) and mecA gene (encoding penicillin-binding protein-2′), could detect S. aureus strains and identify MRSA within 85 min. Detection of the m-MCDA products is achieved using disposable lateral flow biosensors. A total of 58 strains, including various species of Gram-positive and Gram-negative strains, are used for evaluating and optimizing m-MCDA assays. The optimal amplification condition is found to be 63°C for 40 min, with detection limits at 100 fg DNA/reaction for nuc and mecA genes in the pure cultures, and 10 CFU/tube for nuc and mecA genes in the blood samples. The analytical specificity of m-MCDA assay is of 100%, and no cross-reactions to non-S. aureus strains are produced according to the specificity testing. Particularly, two additional components, including AUDG enzyme and dUTP, are added into the m-MCDA amplification mixtures, which are used for eliminating the unwanted results arising from carryover contamination. Thus, the m-MCDA technique appears to be a simple, rapid, sensitive, and reliable assay to detect all S. aureus strains, and identify MRSA infection for appropriate antibiotic therapy.

Rapid, sensitive and reliable detection of Klebsiella pneumoniae by label-free multiple cross displacement amplification coupled with nanoparticles-based biosensor

Klebsiella pneumoniae (K. pneumoniae), as an important hospital-acquired bacterium, is responsible for severe morbidity and mortality among the elderly, newborn and immune-compromised people. We established a rcsA gene-based label-free multiple cross displacement amplification (MCDA) assay for rapid, simple and sensitive detection of K. pneumoniae by using lateral flow biosensor (LFB). MCDA reaction was conducted at a fixed temperature (65 °C) for only 30 min, and amplification results were directly indicated using LFB. The results showed that reaction products were detectable from as little as 100 fg and 4.8 CFU of pure K. pneumoniae templates, and from approximately 480 CFU in 1 mL of spiked clinical samples. All K. pneumoniae strains examined were positive for label-free MCDA-LFB analysis, and all non-K. pneumoniae strains used in the report were negative for label-free MCDA-LFB assay, indicating the high selectivity of the label free MCDA-LFB assay. Furthermore, to remove false-positive results, the label-free MCDA-LFB assay was supplemented with antarctic thermal sensitive uracil-DNA-glycosylase (AUDG) to eliminate the carryover contamination. Thus, label-free MCDA-LFB assay complemented with AUDG enzyme was a rapid, simple, sensitive and reliable technique for detection of target pathogen, which has the ability to effectively avoid carryover contamination, and can be a valuable tool for “on-site” detection, clinical diagnosis, and primary quarantine purposes.

Mechanism of Allosteric Coupling into and through the Plasma Membrane by EGFR

Epidermal growth factor receptor (EGFR) interacts through its extracellular domain with seven different growth factors. These factors induce different structures within the cytoplasmic juxtamembrane (JM) segment of the dimeric receptor and propagate different growth factor-dependent signals to the cell interior. How this process occurs is unknown. Here we apply diverse experimental and computational tools to show that growth factor identity is encoded by the EGFR transmembrane (TM) helix into discrete helix dimer populations that differ in both cross-location and cross-angle. Helix dimers with smaller cross-angles at multiple cross locations are decoded to induce an EGF-type coiled coil in the adjacent JM, whereas helix dimers with larger cross-angles at fewer cross locations induce the TGF-α-type coiled coil. We propose an updated model for how conformational coupling across multiple EGFR domains results in growth factor-specific information transfer, and demonstrate that this model applies to both EGFR and the related receptor ErbB2.

Antarctic thermolabile uracil-DNA-glycosylase-supplemented multiple cross displacement amplification using a label-based nanoparticle lateral flow biosensor for the simultaneous detection of nucleic acid sequences and elimination of carryover contamination

Here, we report a novel and universal methodology, termed “Antarctic thermolabile uracil-DNA-glycosylase (AUDG)-supplemented nucleic acid amplification techniques (NAAs) using a labeled-based nanoparticle lateral flow biosensor (LFB)” (AUDG-NAAs-LFB), which merges enzymatic (AUDG) digestion of contaminant amplicons with different nucleic acid amplification techniques (NAAs), and uses a lateral flow biosensor (LFB) for the rapid and visual confirmation of the presence of a target nucleic acid sequence. AUDG-NNAs-LFB is a one-pot, closedvessel assay, that can effectively eliminate false-positive signals arising from either carryover contaminants or the interaction between labeled primers. A new LFB was devised for detecting three targets (two amplicons generated from amplification of target sequences, and a chromatography control), without the need for probe-hybridization or additional incubation steps. As a proof of concept, multiple cross displacement amplification (MCDA), which is a specific, sensitive, and rapid isothermal amplification method, was selected as the model amplification technique to demonstrate the feasibility of AUDG-NAAs-LFB. As a result, we demonstrate the applicability of the AUDG-MCDA-LFB method for simultaneously detecting high-risk human papillomaviruses genotypes 16 and 18, which are the most and second-most prevalent strains of the virus reported in women worldwide. We also confirm the principle behind the AUDG-MCDA-LFB assay and validate its sensitivity, reproducibility, and specificity using serial dilutions of the type-specific plasmids, as well as clinical samples. This proof-of-concept method (AUDG-MCDA-LFB) can be easily reconfigured to detect various nucleic acid sequences by redesigning the specific MCDA primers.

Wavelength-selective mid-infrared metamaterial absorbers with multiple tungsten cross resonators.

Wavelength-selective metamaterial absorbers in the mid-infrared range are demonstrated by using multiple tungsten cross resonators. By adjusting the geometrical parameters of cross resonators in single-sized unit cells, near-perfect absorption with single absorption peak tunable from 3.5 µm to 5.5 µm is realized. The combination of two, three, or four cross resonators of different sizes in one unit cell enables broadband near-perfect absorption at mid-infrared range. The obtained absorption spectra exhibit omnidirectionality and weak dependence on incident polarization. The underlying mechanism of near-perfect absorption with cross resonators is further explained by the optical mode analysis, dispersion relation and equivalent RLC circuit model. Moreover, thermal analysis is performed to study the heat generation and temperature increase in the cross resonator absorbers, while the energy conversion efficiency is calculated for the thermophotovoltaic system made of the cross resonator thermal emitters and low-bandgap semiconductors.

Ventilation and Air Quality in City Blocks Using Large-Eddy Simulation—Urban Planning Perspective

Buildings and vegetation alter the wind and pollutant transport in urban environments. This comparative study investigates the role of orientation and shape of perimeter blocks on the dispersion and ventilation of traffic-related air pollutants, and the street-level concentrations along a planned city boulevard. A large-eddy simulation (LES) model PALM is employed over a highly detailed representation of the urban domain including street trees and forested areas. Air pollutants are represented by massless and passive particles (non-reactive gases), which are released with traffic-related emission rates. High-resolution simulations for four different city-block-structures are conducted over a 8.2 km 2 domain under two contrasting inflow conditions with neutral and stable atmospheric stratification corresponding the general and wintry meteorological conditions. Variation in building height together with multiple cross streets along the boulevard improves ventilation, resulting in 7–9% lower mean concentrations at pedestrian level. The impact of smaller scale variability in building shape was negligible. Street trees further complicate the flow and dispersion. Notwithstanding the surface roughness, atmospheric stability controls the concentration levels with higher values under stably stratified inflow. Little traffic emissions are transported to courtyards. The results provide urban planners direct information to reduce air pollution by proper structural layout of perimeter blocks.

High-speed microscopy for in vivo monitoring of lymph dynamics.

The lymphatic system contributes to body homeostasis by clearing fluid, lipids, plasma proteins and immune cells from the interstitial space. Many studies have been performed to understand lymphatic function under normal conditions and during disease. Nevertheless, a further improvement in quantification of lymphatic behavior is needed. Here, we present advanced bright-field microscopy for in vivo imaging of lymph vessels (LVs) and automated quantification of lymphatic function at a temporal resolution of 2 milliseconds. Full frame videos were compressed and recorded continuously at up to 540 frames per second. A new edge detection algorithm was used to monitor vessel diameter changes across multiple cross sections, while individual cells in the LVs were tracked to estimate flow velocity. The system performance initially was verified in vitro using 6- and 10-μm microspheres as cell phantoms on slides and in 90-μm diameter tubes at flow velocities up to 4 cm/second. Using an in vivo rat model, we explored the mechanisms of lymphedema after surgical lymphadenectomy of the mesentery. The system revealed reductions of mesenteric LV contraction and flow rate. Thus, the described imaging system may be applicable to the study of lymphatic behavior during therapeutic and surgical interventions, and potentially during lymphatic system diseases.

Dynamics of anti-MSP3 and Pfs230 antibody responses and multiplicity of infection in asymptomatic children from southern Ghana

BackgroundDuring a Plasmodium infection, exposure of human host immune cells to both the asexual and the sexual stages of the parasite elicit immune responses. These responses may be protective and prevent the development of high parasitaemia and its associated clinical symptoms, or block the transmission of malaria to an uninfected person. This study aimed at examining the dynamics of naturally acquired immune responses against the asexual and sexual forms of Plasmodium falciparum as well as assessing differences in the multiplicity of infection (MOI) in asymptomatic Ghanaian children living in two communities with varying malaria transmission intensities.MethodsSchool children aged between 6 and 12 years were recruited from Obom, a high malaria prevalence setting and Abura, a low malaria prevalence setting and enrolled in monthly multiple cross sectional surveys between February and May 2015. Filter paper blood blots (DBS) as well as thick and thin blood smears were made from finger-pricked blood at each visit. Plasmodium falciparum parasite prevalence was determined by microscopy and PCR. Serum eluted from the DBS were used to assess anti-Pfs230 (sexual stage) and anti-MSP3 (asexual stage) antibody levels using indirect ELISA and DNA extracted from the DBS used to assess MOI.ResultsMalaria parasite point prevalence and MOI throughout the study was higher in Obom than Abura. The trend of parasite prevalence estimated by microscopy was similar to that determined by PCR in Obom but not in Abura. The trend of MSP3 antibody seroprevalence followed that of PCR-estimated parasite prevalence in Obom, while in Abura the trend of Pfs230 antibody seroprevalence followed that of PCR-estimated parasite prevalence.ConclusionsMicroscopy can more accurately predict changes in parasite prevalence in high transmission settings than low transmission settings. In high transmission settings, P. falciparum parasite prevalence can predict antibody seroprevalence to MSP3, whilst in low transmission settings, seroprevalence against Pfs230 may be a useful predictor of parasite prevalence.

Modified improved genetic algorithm to minimise tri-objective functions in a textile mill

Efficient scheduling has become essential for manufacturing industries to survive in today's competitive business environment. A flow shop scheduling problem with processing times in textile yarn manufacturing mill is considered in this paper. The objective is to minimise the tri objective function of makespan time, meanflow time and machine idle time by using the exact sequencing method. To solve this problem modified improved genetic algorithm (MIGA) is proposed in this paper wherein multiple cross over operators and multiple mutation operators are fine tuned to obtain the above performance measures and the results show that the proposed algorithm can provide better results in textile industry problems when comparing with the results obtained through genetic algorithm (GA) and improved genetic algorithm (IGA).

Synchronized Oscillations of Arterial Oxygen Saturation, Cerebral Tissue Oxygenation and Heart Rate in Preterm Neonates: Investigation of Long-Term Measurements with Multiple Einstein's Cross Wavelet Analysis.

In preterm neonates, the cardiovascular and cerebral vascular control is immature, making the brain vulnerable to an increased incidence of hypoxic and hyperoxic episodes. The aim of the study was to apply the recently developed multiple Einstein's cross wavelet analysis (MECWA) to quantify the coupling of fluctuations of peripherally measured arterial oxygen saturation (SpO2), cerebral tissue oxygen saturation (StO2) and heart rate (HR). Two long-term measurements on preterm neonates with a gestational age at birth of 26.4 and 26.8weeks and a postnatal age of 2.1 and 3.9weeks were analyzed. MECWA was applied to SpO2, StO2 and HR. MECWA showed that the fluctuations of SpO2, StO2 and HR were synchronized in the low-frequency range with periods of ~1h and ~0.5h. The amplitudes of the synchronization frequencies were dependent on the individual neonate. MECWA is a useful novel tool to assess the coupling of physiological signals. The parameters determined by MECWA seem to be related to the chronobiological processes, as well as constant regulations of the cardiovascular and cerebral perfusion state. MECWA was able to identify long-term synchronization of the cardiovascular and cerebral perfusion state in preterm neonates with periods of ~1h and ~0.5h.

Multiple Ionization Cross Sections of Ne and CO Induced by Very High-<i>q</i> Fast Projectiles (<i>q/v</i> > 1)

In this paper, we extend our previous work of classical over barrier ionization (COBI) model to study the multiple ionization cross section of Ne and CO molecule collided by very high-q fast projectiles(q/v > 1). The model gives similar results to the independent-electron-approximation calculation and is in good agreement with experimental data. The very small computational time required makes it a good candidate for studying the multiple ionization of complex molecules under high linear energy transfers.

Analysis of Effect of Agriculture Trade Liberalisation on Child Labour Supply, Factor Prices and Output Composition in a Small Open Perfectly Competitive Economy using a General Equilibrium Framework

Incidence of child labor is a disturbing feature of an emerging market economy. In the present paper, I would try to explore whether globalization policy namely agricultural trade liberalization has any negative impact on the incidence of child labor in a developing economy. For our work, I use a three-sector general equilibrium structure to highlight the linkage between different sectors and also focus on the fact that the effects of globalization are crucially dependent on the factor intensity ranking and factor specificity. Multiple cross effects that are present in a three-sector general equilibrium structure are the driving forces behind the results.

English

English

Impact of Industry 4.0 in service oriented firm

The first part of this study is devoted to concepts, approaches and some examples of the fourth industrial revolution. The basis of this revolution also well known as Industry 4.0 builds so called cyber-physical systems. They contain the integrated smart software systems including the internet address to enable the communication with environment as for product itself as for means of production and employees. All these enable the next level of efficiency and flexibility for both organizing and controlling of the value-creation chain over the whole lifecycle of products. In the first three chapters several Internet references and documents published by German Federal Ministry for Economic Affairs and Energy were used. Because of multiple cross references in documents, this report is written without detailed references in each paragraph of mentioned chapters. The last three chapters of the research presented undertake the short review of interdependencies between the Industry 4.0 and the well-known approach of computer-supported-cooperative-work established in the late 1980s. Long list of publications can be found in Wikipedia, and in many proceedings of ACM conferences on computer supported cooperative work (CSCW).

Nanoparticle-based lateral flow biosensor combined with multiple cross displacement amplification for rapid, visual and sensitive detection of Vibrio cholerae.

Vibrio cholerae is an important human pathogen that is responsible for cholera, a severe acute watery diarrhea. In the current study, a multiple cross displacement amplification (MCDA) coupled with amplicon detection by chromatographic lateral flow biosensor (LFB) method (MCDA-LFB) was successfully established and evaluated for the identification of V. cholerae. A set of 10 primers was designed specifically to recognize 10 different regions of the V. cholerae-specific gene ompW. The optimized time and temperature conditions for the MCDA were 30 min and 63°C, respectively. The MCDA-LFB assay correctly identified 31 strains of V. cholerae but did not detect 13 non-cholerae Vibrio strains and 30 non-Vibrio strains. The sensitivity of MCDA-LFB for target pathogen detection in pure culture was 10 fg per reaction. In the case of spiked shrimp samples without enrichment, the limit of detection was 4.1 CFUs per reaction or equivalent to 4.1×102 CFU g-1. The whole process, including shrimp homogenates processing (30 min), MCDA reaction (30 min) and results reporting (2 min), could be finished within 65 min. These results show that this assay is suitable for the rapid, sensitive and specific detection of V. cholerae in food, environmental and clinical samples.

Composite-pulse and partially dipolar dephased multiCP for improved quantitative solid-state 13C NMR

Improved multiple cross polarization (multiCP) pulse sequences for quickly acquiring quantitative 13C NMR spectra of organic solids are presented. Loss of 13C magnetization due to imperfect read-out and storage pulses in multiCP has been identified as a significant mechanism limiting polarization enhancement for 13C sites with weak couplings to 1H. This problem can be greatly reduced by composite 90° pulses with non-orthogonal phases that flip the magnetization onto the spin-lock field and back to the longitudinal direction for the 1H repolarization period; the observed loss is <3% for over ±10 kHz resonance offset and up to 20% flip-angle error. This composite-pulse multiCP (ComPmultiCP) sequence consistently provides performance superior to that of conventional multiCP, without any trade-off. The longer total CP time enabled by the composite pulses allows for a wider amplitude ramp during CP, which decreases the sensitivity to Hartmann-Hahn mismatch by a factor of two, with a <7% root-mean-square deviation within a 1-dB range for Boc-alanine. In samples with very short T1ρ, under-polarization of non-protonated carbons can be compensated by slight dipolar dephasing of CHn signals resulting from relatively weak decoupling during the Hahn spin echo period before detection. Quantitative spectra have been obtained by ComPmultiCP for low-crystallinity branched polyethylene at 4.5 kHz MAS, and in combination with partial dipolar dephasing for soil organic matter at 14 kHz MAS.

A novel isothermal amplification-based method to detect Mycobacterium tuberculosis complex

Mycobacterium tuberculosis (MTB) is the causative agent of pulmonary tuberculosis. Rapid and accurate diagnosis is crucial to tuberculosis control and prevention. A series of diagnostic methods has been available for MTB detection; however, new rapid, simple and affordable methods are needed. In this study, a multiple cross displacement amplification (MCDA)-based assay was developed to detect the IS6110 gene of the M. tuberculosis complex. Hydroxy naphthol blue (HNB), a colorimetric indicator, was used to detect amplification products. Amplification was carried out at a constant temperature (68°C) for only 40min, followed by direct determination of amplification products through observation of color variations. The entire detection procedure, from processing of specimens to reading of results, required only 85min. Moreover, this assay, hereafter designated MTB-MCDA-HNB, was able to detect as little as 1pg of DNA extracted from the Bacille Calmette-Guerin (BCG) strain of Mycobacterium bovis. No cross-reaction with nontuberculous mycobacteria (NTM) species was observed. Moreover, during testing of clinical samples, the sensitivity and specificity of MCDA results were 94.7% and 92.9%, respectively, when compared to results obtained using the Xpert MTB/RIF method. Therefore, the MTB-MCDA-HNB method developed in this study holds promise for application as an effective point-of-care test to detect M. tuberculosis.

Accuracy enhancement of navigation images using blind restoration method

Optical navigation is one of the most promising technologies in the area of deep space autonomous navigation. However, since the optical images are strict motion blurred images, it is difficult to extract the lines of sight (LOS) to the beacons to reckon the spacecraft attitude and orbital position during the deep space cruise phase. This paper proposes a new blind restoration approach to effectively recover the clear image. We use a modified median filter to eliminate the black and white noises, and also, construct a blind estimation model, built on the sparsity of the gradient of navigation image, to estimate the global point spread function (PSF). Moreover, we select a few bright beacons to recover the motion blurred image, where the average value of the beacon centroid is adopted to calculate the relative position for the optical navigation. We present the simulation and actual image restoration experiment to demonstrate the accuracy and consistency of the relative position of the recovered navigation image of the proposed method. We show that the proposed method presents superior performance in comparison with the multiple cross correlation method. The estimated PSF is close to real PSF and the distributed energy of the beacon is concentrated ensuring a high SNR, where the accuracy of the relative position is higher than 0.1 pixel.