High-throughput screening of human mercury exposure based on a low-cost naked eye-recognized biosensing platform.

Whole-cell biosensors could be helpful for in situ disease diagnosis. However, their use in analyzing biological samples has been hindered by unstable responses, low signal enhancement, and growth inhibition in complex media. Here, we offered a solution by building a visual whole-cell biosensor for urinary mercury determination. With deoxyviolacein as the preferred signal for the mercury biosensor for the first time, it enabled the quantitative detection of urinary mercury with a favorable linear range from 1.57 to 100 nM. The biosensor can accurately diagnose urine mercury levels exceeding the biological exposure index with 95.8% accuracy. Thus, our study provided a biosensing platform with great potential to serve as a stable, user-friendly, and high-throughput alternative for the daily monitoring or estimating of urinary mercury.

[Analysis of Formation Processes and Sources of PM2.5 Ammonium During Winter and Summer in Suburban Area of the Yangtze River Delta].

As the main pollutants of secondary inorganic aerosols(SIAs) in fine particulate matter(PM2.5), aerosol ammonium(p-NH4+) plays a significant role in the formation of haze. However, the contribution ratio of each potential source of atmospheric NHx(p-NH4+ and NH3) still remains controversial. In this study, 3 h high-frequency PM2.5 samples were collected in Dongshan, Suzhou during winter and summer in 2015, respectively. Meanwhile, we determined concentrations and δ15N isotope ratios of total nitrogen(TN) and p-NH4+ and quantitatively analyzed formation processes and sources of p-NH4+ based on the Bayesian mixing model(SIAR). SO42-, NO3-, and NH4+ were the main water-soluble ions(WSIs) both in winter and summer, accounting for more than 70% in general. The concentration change trends of PM2.5, TN, and p-NH4+ were consistent, and the concentrations in winter were 2-3 times those in summer. The δ15N-NH4+ value was in direct proportion to the p-NH4+ concentration both in winter and summer. However, δ15N-NH4+ values in winter(-1.7‰±4.3‰) were lower than those in summer(7.8‰±5.9‰). This indicated that the differences in δ15N-NH4+ were caused by different contribution rates of each potential source within each season, whereas it was mainly led by nitrogen isotope fractionation during ammonium-ammonia gas particle distribution in different seasons. The SIAR model calculated that non-agricultural sources were the dominant source of p-NH4+ in Dongshan, with the contribution rate of 59% in winter and 69% in summer, which indicated that NH3 emitted by fossil fuel combustion more easily formed particle aerosol ammonium than that volatilized from agricultural sources.

Surface Functionalised Optical Fibre for Detection of Hydrogen Sulphide.

Dysregulated production of hydrogen sulphide in the human body has been associated with various diseases including cancer, underlining the importance of accurate detection of this molecule. Here, we report the detection of hydrogen sulphide using fluorescence-emission enhancement of two 1,8-naphthalimide fluorescent probes with an azide moiety in position 4. One probe, serving as a control, featured a methoxyethyl moiety through the imide to evaluate its effectiveness for hydrogen sulphide detection, while the other probe was modified with (3-aminopropyl)triethoxysilane (APTES) to enable direct covalent attachment to an optical fibre tip. We coated the optical fibre tip relatively homogeneously with the APTES-azide fluorophore, as confirmed via x-ray photoelectron spectroscopy (XPS). The absorption and fluorescence responses of the control fluorophore free in PBS were analysed using UV-Vis and fluorescence spectrophotometry, while the fluorescence emission of the APTES-azide fluorophore-coated optical fibres was examined using a simple, low-cost optical fibre-based setup. Both fluorescent probes exhibited a significant increase (more than double the initial value) in fluorescence emission upon the addition of HS- when excited with 405 nm. However, the fluorescence enhancement of the coated optical fibres demonstrated a much faster response time of 2 min (time for the fluorescence intensity to reach 90% of its maximum value) compared to the control fluorophore in solution (30 min). Additionally, the temporal evolution of fluorescence intensity of the fluorophore coated on the optical fibre was studied at two pH values (7.4 and 6.4), demonstrating a reasonable overlap and confirming the compound pH insensitivity within this range. The promising results from this study indicate the potential for developing an optical fibre-based sensing system for HS- detection using the synthesised fluorophore, which could have significant applications in health monitoring and disease detection.

Evaluation of metoprolol standard dosing pathway in Chinese patients with acute coronary syndrome: a prospective multicenter single-arm interventional study.

OBJECTIVE: To evaluate the feasibility and tolerability of metoprolol standard dosing pathway (MSDP) in Chinese patients with acute coronary syndrome (ACS). METHODS: In this multicenter, prospective, open label, single-arm and interventional study that was conducted from February 2018 to April 2019 in fifteen Chinese hospitals. A total of 998 hospitalized patients aged ≥ 18 years and diagnosed with ACS were included. The MSDP was applied to all eligible ACS patients based on the standard treatment recommended by international guidelines. The primary endpoint was the percentage of patients achieving the target dose at discharge (V2). The secondary endpoints included the heart rate and blood pressure at V2 and four weeks after discharge (V4), and percentage of patients experiencing bradycardia (heart rate < 50 beats/min), hypotension (blood pressure < 90/60 mmHg) and transient cardiac dysfunction at V2 and V4. RESULTS: Of the 998 patients, 29.46% of patients achieved the target dose (≥ 95 mg/d) at V2. The total population was divided into two groups: target group (patients achieving the target dose at V2) and non-target group (patients not achieving the target dose at V2). There was significant difference in the reduction of heart rate from baseline to discharge in the two groups (-4.97 ± 11.90 beats/min vs. -2.70 ± 9.47 beats/min, P = 0.034). There was no significant difference in the proportion of bradycardia that occurred in the two groups at V2 (0 vs. 0, P = 1.000) and V4 (0.81% vs. 0.33%, P = 0.715). There was no significant difference in the proportion of hypotension between the two groups at V2 (0.004% vs. 0.004%, P = 1.000) and V4 (0 vs. 0.005%, P = 0.560). No transient cardiac dysfunction occurred in two groups during the study. A total of five adverse events (1.70%) and one serious adverse event (0.34%) were related to the pathway in target group. CONCLUSIONS: In Chinese ACS patients, the feasibility and tolerability of the MSDP have been proved to be acceptable.

Performance of the PRISM I, PIM2, PELOD-2 and PRISM IV scoring systems in western China: a multicenter prospective study.

BACKGROUND: The aim of this study was to evaluate the performance of the four scoring tools in predicting mortality in pediatric intensive care units (PICUs) in western China. METHODS: This was a multicenter, prospective, cohort study conducted in six PICUs in western China. The performances of the scoring systems were evaluated based on both discrimination and calibration. Discrimination was assessed by calculating the area under the receiver operating characteristic curve (AUC) for each model. Calibration was measured across defined groups based on mortality risk using the Hosmer-Lemeshow goodness-of-fit test. RESULTS: A total of 2034 patients were included in this study, of whom 127 (6.2%) died. For the entire cohort, AUCs for Pediatric Risk of Mortality Score (PRISM) I, Pediatric Index of Mortality 2 (PIM2), Pediatric Logistic Organ Dysfunction Score-2 (PELOD-2) and PRISM IV were 0.88 [95% confidence interval (CI) 0.85-0.92], 0.84 (95% CI 0.80-0.88), 0.80 (95% CI 0.75-0.85), and 0.91 (95% CI 0.88-0.94), respectively. The Hosmer-Lemeshow goodness-of-fit Chi-square value was 12.71 (P = 0.12) for PRISM I, 4.70 (P = 0.79) for PIM2, 205.98 (P < 0.001) for PELOD-2, and 7.50 (P = 0.48) for PRISM IV [degree of freedom (df) = 8]. The standardized mortality ratios obtained with the PRISM I, PIM2, PELOD-2, and PRISM IV models were 0.87 (95% CI, 0.75-1.01), 0.97 (95% CI, 0.85-1.12), 1.74 (95% CI, 1.58-1.92), and 1.05 (95% CI, 0.92-1.21), respectively. CONCLUSIONS: PRISM IV performed best and can be used as a prediction tool in PICUs in Western China. However, PRISM IV needs to be further validated in NICUs.

A Decreased Absolute Number of Treg Cells in Patients with Active Rheumatoid Arthritis is Associated with Elevated Serum Osteopontin Levels with Disease Progression.

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic and refractory autoimmune disease characterized by synovial inflammation with unknown aetiology. Immune system dysfunction mediated by CD4+ T lymphocytes, which is regulated by the cytokine osteopontin (OPN), plays an important role in the pathogenesis of RA. METHODS: In this study, the levels of peripheral CD4+ T subsets and serum OPN in patients with active RA were measured and analysed to determine the possible pathogenesis of RA and to provide potential therapeutic targets. RESULTS: Serum OPN levels in both patients with active RA and patients with refractory RA were higher than those in healthy controls (HCs). Compared with HCs, the absolute numbers of Th2 cells increased in patients with active RA, while the absolute counts of Th1 and Treg cells decreased. There was no significant difference in CD4+ T subset levels between new-onset and refractory patients. As the condition persisted or deteriorated, a gradual increase in the levels of OPN and gradual declines in the absolute counts of Th1 and Treg cells were observed in patients with active RA. The fewest Th1 and Treg cells and the highest OPN levels were observed in patients with high disease activity. The serum OPN level was only significantly negatively correlated with the absolute counts of Treg cells in the CD4+ T lymphocyte subsets. CONCLUSIONS: Fewer Treg cells with the increase in disease activity may be related to the increased OPN concentration, which may provide new ideas and directions for the targeted immunoregulatory treatment of RA.

Serial and parallel convolutional neural network schemes for NFDM signals.

Two conceptual convolutional neural network (CNN) schemes are proposed, developed and analysed for directly decoding nonlinear frequency division multiplexing (NFDM) signals with hardware implementation taken into consideration. A serial network scheme with a small network size is designed for small user applications, and a parallel network scheme with high speed is designed for places such as data centres. The work aimed at showing the potential of using CNN for practical NFDM-based fibre optic communication. In the numerical demonstrations, the serial network only occupies 0.5 MB of memory space while the parallel network occupies 128 MB of memory but allows parallel computing. Both network schemes were trained with simulated data and reached more than 99.9% accuracy.

Development of an optical fiber-based redox monitoring system for tissue metabolism.

An optical redox ratio can potentially be used to report on the dynamics of cell and tissue metabolism and define altered metabolic conditions for different pathologies. While there are methods to measure the optical redox ratio, they are not particularly suited to real-time in situ or in vivo analysis. Here, we have developed a fiber-optic system to measure redox ratios in cells and tissues and two mathematical models to enable real-time, in vivo redox measurements. The optical redox ratios in tissue explants are correlated directly with endogenous NADH/FAD fluorescence emissions. We apply the mathematical models to the two-photon microscopy data and show consistent results. We also used our fiber-optic system to measure redox in different tissues and show consistent results between the two models, hence demonstrating proof-of-principle. This innovative redox monitoring system will have practical applications for defining different metabolic disease states.

Formation Mechanisms and Source Apportionments of Airborne Nitrate Aerosols at a Himalayan-Tibetan Plateau Site: Insights from Nitrogen and Oxygen Isotopic Compositions.

Formation pathways and sources of atmosphere nitrate (NO3-) have attracted much attention as NO3- had detrimental effects on Earth's ecosystem and climate change. Here, we measured nitrogen (δ15N-NO3-) and oxygen (δ18O-NO3- and Δ17O-NO3-) isotope compositions in nitrate aerosols at the Qomolangma station (QOMS) over the Himalayan-Tibetan Plateau (HTP) to quantify the formation mechanisms and emission sources of nitrate at the background site. At QOMS, the enhanced NO3- concentrations were observed in the springtime. The average δ15N-NO3-, δ18O-NO3-, and Δ17O-NO3- values were 0.4 ± 4.9, 64.7 ± 11.5 and 27.6 ± 6.9‰, respectively. Seasonal variations of isotope ratios at QOMS can be explained by the different emissions and formation pathways to nitrate. The average fractions of NO2 + OH and N2O5 + H2O to nitrate production were estimated to be 43 and 52%, respectively, when the NO3 + hydrocarbon (HC)/dimethyl sulfide (DMS) (NO3 + HC/DMS) pathway was assumed to be 5%. Using stable isotope analysis in the R (SIAR) model, the relative contributions of biomass burning (BB), biogenic soil emission, traffic, and coal combustion to nitrate were estimated to be 28, 25, 24, and 23%, respectively, on yearly basis. By FLEXible PARTicle (FLEXPART) dispersion model, we highlighted that NOx from BB emission over South Asia that had undergone N2O5 + H2O processes enhanced the nitrate concentrations in the springtime over the HTP region.

Direct decoding of nonlinear OFDM-QAM signals using convolutional neural network.

Nonlinear Fourier transform, as a technique that has a great potential to overcome the capacity limit in fibre optical communication system, faces speed and accuracy bottlenecks in practice. Machine learning using convolutional neural networks shows great potential in NFT-based applications. We have developed a convolutional neural network for decoding information in NFT-based communication and numerically demonstrated its performance in comparison to a fast NFT algorithm. The comparison indicates the potential of conventional neural network to replace NFT calculations for decoding of information.

PPM1H is an independent prognostic biomarker of non-small cell lung cancer.

Protein phosphatase 1H (PPM1H) is the metal-dependent protein phosphatase, however, its role in tumorigenesis and tumor progression remains controversial. Non-small-cell lung cancer (NSCLC) is the most common histological type of lung cancer but the expression and clinical significance of PPM1H in NSCLC is unknown. In our study, we detected the mRNA of PPM1H in 25 pairs of NSCLC tissues and their corresponding adjacent tissues with qRT-PCR. Moreover, we investigated PPM1H expression in 474 NSCLC tissues and divided them into subgroups with low and high PPM1H. We further evaluated its correlation with the clinicopathological factors. The correlation between PPM1H and other biomarkers involved in tumor progression including chromosome segregation 1-like protein (CSE1L), p53, and Ki67 was also estimated. In addition, the prognostic significance of PPM1H was investigated by univariate and multivariate analyses. The mRNA levels of PPM1H in NSCLCs were significantly higher than those in tumor-adjacent tissues. Patients with low and high PPM1H expression accounted for 54.64% (259/474) and 45.36% (215/474) respectively in all the NSCLCs. PPM1H expression (p=0.012), patients' sex (p=0.009), tumor size (p<0.001), histological grade (p=0.026), T stage (p=0.002), N stage (p<0.001), M stage (p=0.011), and TNM stage (p<0.001) were all associated with the poor prognosis. With multivariate analysis, PPM1H was determined as an independent prognostic factor of NSCLC (HR=1.42, 95% CI=1.14-1.75, p=0.001). Moreover, high PPM1H was significantly with high Ki67 (p=0.022), indicating the oncogenic role of PPM1H. PPM1H is an independent prognostic factor indicating an unfavorable prognosis of NSCLC. Our results indicated that PPM1H was an important supplement of NSCLC molecular profile and detecting PPM1H may help recognize the high-risk patients for further treatment.

A correlation propagation model for nonlinear fourier transform of second order solitons.

Inverse scattering transform or nonlinear Fourier transform (NFT) has been proposed for optic communication to increase channel capacity beyond the well known Shannon limit. Within NFT, solitons, as discrete outputs of the transform, can be a type of resource to carry information. Second-order solitons as the most basic higher order solitons show correlations among their parameters in the nonlinear Fourier domain as they propagate along a fibre. In this work, we report, for the first time, a correlation propagation model for second-order soliton pulses in the nonlinear Fourier domain. The model can predict covariance matrices of soliton pulses at any propagation distance using only the covariance matrices calculated at the input of the fibre with different phases in the nonlinear Fourier domain without the need of propagating the pulses.

Development of a Monitoring System for Semicontinuous Measurements of Stable Carbon Isotope Ratios in Atmospheric Carbonaceous Aerosols: Optimized Methods and Application to Field Measurements.

Carbon content constitutes a major fraction of atmospheric particulate matter (PM) and directly influences the earth's climate and human health. The stable carbon isotope ratios (δ13C) can be used to track potential sources and atmospheric processes of carbonaceous aerosols. Previously, determination of δ13C was always conducted in offline carbonaceous aerosol samples. The poor time-resolution results cannot provide information regarding the temporal evolution of δ13C at a short-time scale. In this study, we developed a new system for online measurements of δ13C in atmospheric carbonaceous aerosols by combining a semicontinuous organic carbon/elemental carbon (OC/EC) analyzer and online cavity ring-down spectroscopy (CRDS) (OC/EC analyzer-CRDS). To provide better stability in the determination of δ13C, a carrier gas with CO2 (∼200 ppm) in "balance gas" was used, and Keeling analysis was employed to separate the δ13C signal of the sample from background CO2 gas. Our results showed that the accuracy and absolute precision of the δ13C measurements by the OC/EC analyzer-CRDS system were better than 0.1‰ and 0.5‰, respectively, for the samples containing carbon content more than 5 µg. Furthermore, we employed this system to monitor δ13C (δ13C-TC) in particulate total carbon (TC) with a time resolution of 2-4 h over Beijing in late summer and early autumn, 2019. During the sampling period, the TC concentrations varied from 0.1 to 12.0 µg m-3 with a mean value of 6.0 ± 2.4 µg m-3. The δ13C-TC ranged from -28.2 to -24.2‰ (mean value was -25.9 ± 0.9‰) without significant diurnal variations, suggesting similar contributing sources to TC. Comparing the δ13C signatures of different emissions, we found that liquid fuels and primary and secondary C3 plants were likely the dominant sources of particulate TC. Finally, we found that atmospheric heavy precipitation washed out the aged aerosols from the polluted air, resulting in significant depletion (∼2.4‰) of δ13C-TC in the atmosphere. This paper described a novel system for conducting online measurements of δ13C in atmospheric carbonaceous aerosols and provided us information to better understand the temporal evolution of emission sources and atmospheric processes of carbonaceous aerosols.

Dysregulation of the Urothelial Cancer Associated 1 Long Noncoding RNA Promotes Proliferation of Vascular Smooth Muscle Cells by Modulating Expression of P27KIP1/CDK2.

Background: Atherosclerosis is one of the leading causes of morbidity and mortality worldwide. A variety of long noncoding RNAs (lncRNAs) have been reported to be significantly involved in vascular smooth muscle cell (VSMC) proliferation, which is an essential process for atherosclerotic plaque formation. The aim of this study was to investigate the mechanism of lncRNA urothelial cancer associated 1 (UCA1) involvement in atherosclerosis. Method: The effects of oxidized low-density lipoprotein (oxLDL) and UCA1 on VSMC proliferation and colony-forming ability was measured by 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyl-2H-tetrazolium bromide (MTT) assays, real-time polymerase chain reaction (PCR), and western blots, as well as to determine the effect that oxLDL has on UCA1 expression, and the effect of oxLDL and UCA1 on the expression of cyclin-dependent kinase 2 (CDK2). Results: oxLDL treatment increased the proliferation rate of VSMCs in a concentration-dependent manner. Importantly, UCA1 apparently increased the viability of VSMCs as the VSMCs exhibited a significantly reduced growth rate when UCA1 expression was knocked down by specific small interfering RNAs (siRNAs). In conjunction with increasing cell viability, oxLDL also enhanced the colony-forming ability of VSMCs while UCA1 siRNA decreased the colony-forming ability of VSMCs. Furthermore, UCA1 significantly decreased the percentage of VSMCs in G1 phase, while increasing their percentage in S phase. In contract siRNA knockdown of UCA1 caused an increased percentage of cell in G1 phase, and a reduction in the percentage of cells in S phase. Using real-time PCR and western blot assays, we showed that oxLDL significantly increased the expression levels of UCA1 and CDK2. Furthermore, UCA1 siRNA and CDK2 siRNA almost abolished the positive effect of oxLDL on CDK2 expression. Finally, overexpression of UCA1 induced an increase in CDK2 levels, and knockdown of UCA1 caused inhibition of CDK2 expression. Conclusion: Upregulation of UCA1 enhances abnormal proliferation of VSMC by promoting G1/S transition through modulating the expression of CDK2.

MicroRNA-34c suppresses proliferation of vascular smooth muscle cell via modulating high mobility group box protein 1.

BACKGROUND: Atherosclerosis is the most frequent pathological process that causes cardiovascular diseases. OBJECTIVE: The present study aimed to confirm miRNAs associated with atherosclerosis and explore the molecular mechanism of miR-34c and its target high mobility group box protein 1 (HMGB1) in the control of growth of smooth muscle cells in the development of atherosclerosis. METHODS: Real-time PCR was firstly performed to confirm miRNA correlation with atherosclerosis, and computational analysis and luciferase assay were performed to explore the target of miR-34c, Western blot, and real-time PCR were also utilized to reveal the effect of whether high glucose (HG) and miR-34c affect miR-34c, HMGB1 levels, NF-κB p65 and TNF-α levels, and the role of miR-34c on vascular smooth muscle cells (VSMCs) viability induced by HG. Students' unpaired t test was performed to compare data between two groups. RESULTS: MiR-34c level was associated with atherosclerosis with different expression between VSMCs treated with high glucose or normal VSMCs. Then, HMGB1 is a virtual target of miR-34c with predicted binding site resided in HMGB1 3'UTR and further verified by that miR-34c remarkably reduced luciferase activity of wild HMGB1 3'UTR under a concentration-dependent fashion, and miR-34c cannot influence luciferase activity of mutant HMGB1 3'UTR. CONCLUSIONS: The results suggested miR-34c might be a novel therapeutic strategy in the management of atherosclerosis by suppressing the expression of HGMB1 and its downstream effectors.

Correlated Eigenvalues of Multi-Soliton Optical Communications.

There is a fundamental limit on the capacity of fibre optical communication system (Shannon Limit). This limit can be potentially overcome via using Nonlinear Frequency Division Multiplexing. Dealing with noises in these systems is one of the most critical parts in implementing a practical system. In this paper, we discover and characterize the correlations among the NFT channels. It is demonstrated that the correlation is universal (i.e., independent of types of system noises) and can be exploited to maximize transmission throughput. We propose and experimentally confirm a noise model showing that end-to-end noise can be modelled as the accumulation of noise associated with each segment of optical communication which can be dealt with independently. Also, each point noise can be further decomposed into different components, some of which are more significant (and even dominating) than others. Hence, one can further approximate and simplify the noise model by focusing on the significant component.

[Characteristics and Source Analysis of Carbonaceous Components of PM2.5 During Autumn in the Northern Suburb of Nanjing].

In this study, PM2.5 samples were collected from October to November of 2015 in the northern suburb of Nanjing. The mass concentrations of organic carbon (OC), elemental carbon (EC), and levoglucosan in the samples were analyzed by thermal optical transmittance (TOT) and ion chromatography. The average concentrations of OC and EC were respectively (11.3±4.9) µg·m-3 and (1.1±0.9) µg·m-3. The average total carbon (TC) was 22.9%, and the OC/EC was 7.4. The quality concentrations of PM2.5, OC, EC, and SOC all reflected daytime features, and the correlation between OC and EC was better during the day than at night (correlation coefficients of 0.86 for day and 0.7 for night). By analyzing the mass concentrations of PM2.5, levoglucosan, and SOC, as well as the data of backward trajectories and fire point data, it was determined that the northern suburb of Nanjing is affected by the long-distance transportation of biomass from Hebei and other places from October 13-16. The correlations between levoglucosan and OC, EC, or SOC were significant (correlation coefficients of 0.78, 0.79, and 0.65, respectively), and the contribution of biomass combustion during sampling to OC was 21.9%.

Femtosecond-laser-written Microstructured Waveguides in BK7 Glass.

There is a deficiency of low-loss microstructured waveguides that can be fabricated with a single laser-pass to minimize stress build-up, which can enable enhanced functionality and higher compactness for integrated optical devices. We demonstrate, for the first time, a series of multi-ring claddings each with a pair of cores in BK7 glass. Each waveguide was fabricated using only a single laser-pass at 1 MHz pulse repetition rate, 5 mm/s translation speed, 250 fs pulse width, over a set of pulse energies. We obtained the lowest-reported propagation loss of 0.062 dB/cm, measured at 1155 nm wavelength from the waveguide written with 340 nJ pulse energy. The maximum observed numerical aperture is 0.020, measured at 1155 nm wavelength from the waveguide written with 620 nJ pulse energy. Such waveguides could be incorporated in integrated Raman laser platforms for biomedical applications.

Synchronised dual-wavelength mode-locking in waveguide lasers.

We present a novel approach to study continuous-wave mode-locking in a waveguide laser in the presence of a gain profile with complex features. We introduce a new simulation approach where we separate the role of gain, nonlinearity, dispersion and saturable absorption elements to provide a better understanding of the interplay between these elements. In particular, we use the simulation to explain synchronised dual-wavelength mode-locking. The results show that despite the existence of dispersion which tends to form separate pulse trains in the laser cavity, the saturable absorber plays a critical role in keeping the different wavelength components synchronised. This work, for the first time, provides insight into existing experimental results. It also demonstrates new methods for studying lasers, especially mode-locking laser, with short laser cavities.

Heterologous Expression of the Cotton NBS-LRR Gene GbaNA1 Enhances Verticillium Wilt Resistance in Arabidopsis.

Verticillium wilt caused by Verticillium dahliae results in severe losses in cotton, and is economically the most destructive disease of this crop. Improving genetic resistance is the cleanest and least expensive option to manage Verticillium wilt. Previously, we identified the island cotton NBS-LRR-encoding gene GbaNA1 that confers resistance to the highly virulent V. dahliae isolate Vd991. In this study, we expressed cotton GbaNA1 in the heterologous system of Arabidopsis thaliana and investigated the defense response mediated by GbaNA1 following inoculations with V. dahliae. Heterologous expression of GbaNA1 conferred Verticillium wilt resistance in A. thaliana. Moreover, overexpression of GbaNA1 enabled recovery of the resistance phenotype of A. thaliana mutants that had lost the function of GbaNA1 ortholog gene. Investigations of the defense response in A. thaliana showed that the reactive oxygen species (ROS) production and the expression of genes associated with the ethylene signaling pathway were enhanced significantly following overexpression of GbaNA1. Intriguingly, overexpression of the GbaNA1 ortholog from Gossypium hirsutum (GhNA1) in A. thaliana did not induce the defense response of ROS production due to the premature termination of GhNA1, which lacks the encoded NB-ARC and LRR motifs. GbaNA1 therefore confers Verticillium wilt resistance in A. thaliana by the activation of ROS production and ethylene signaling. These results demonstrate the functional conservation of the NBS-LRR-encoding GbaNA1 in a heterologous system, and the mechanism of this resistance, both of which may prove valuable in incorporating GbaNA1-mediated resistance into other plant species.