A Digital Watermarking Approach Based on DCT Domain Combining QR Code and Chaotic Theory

This paper proposes a robust watermarking approach based on Discrete Cosine Transform domain that combines Quick Response Code and chaotic system.Comment: 7 pages, 6 figure

Melatonin Mitigates Salt Stress in Wheat Seedlings by Modulating Polyamine Metabolism

Melatonin, a small molecular weight indoleamine molecule, is involved in various biological processes and responses to environmental cues in plants. However, its function in abiotic stress response and the underlying mechanisms is less clear. In this study, we investigated the effect of melatonin on wheat seedlings growth under salt stress condition. Exogenous melatonin pretreatment partially mitigated the salt-induced inhibition of whole-plant growth as judged from shoot dry weight, IAA content, leaf photosynthesis rate, maximum photochemistry efficiency of photosystem II, and chlorophyll. The mitigation was also observed in reduced accumulation of H2O2 in melatonin-pretreated wheat seedlings exposed to salt stress. Exogenous melatonin increased endogenous melatonin content by evaluating the levels of TaSNAT transcript, which encodes a key regulatory enzyme in the melatonin biosynthetic pathway. Furthermore, melatonin increased polyamine contents by accelerating the metabolic flow from the precursor amino acids arginine and methionine to polyamines; melatonin also decreased the degradation of salt-induced polyamines. Taken together, these results provide the evidence that melatonin mitigates salt stress mainly through its regulation on polyamine metabolism of wheat seedlings

Highly sensitive and broadband meta-mechanoreceptor via mechanical frequency-division multiplexing

Abstract Bio-mechanoreceptors capable of micro-motion sensing have inspired mechanics-guided designs of micro-motion sensors in various fields. However, it remains a major challenge for mechanics-guided designs to simultaneously achieve high sensitivity and broadband sensing due to the nature of resonance effect. By mimicking rat vibrissae, here we report a metamaterial mechanoreceptor (MMR) comprised of piezoelectric resonators with distributed zero effective masses featuring a broad range of local resonances, leading to near-infinite sensitivity for micro-motion sensing within a broad bandwidth. We developed a mechanical frequency-division multiplexing mechanism for MMR, in which the measured micro-motion signal is mechanically modulated in non-overlapping frequency bands and reconstructed by a computational multi-channel demodulation approach. The maximum sensitivity of MMR is improved by two orders of magnitude compared to conventional mechanics-guided mechanoreceptors, and its bandwidth with high sensitivity is extendable towards both low-frequency and high-frequency ranges in 0–12 kHz through tuning the local resonance of each individual sensing cell. The MMR is a promising candidate for highly sensitive and broadband micro-motion sensing that was previously inaccessible for mechanics-guided mechanoreceptors, opening pathways towards spatio-temporal sensing, remote-vibration monitoring and smart-driving assistance

Meta-Analysis of the Effect of Nitric Oxide Application on Heavy Metal Stress Tolerance in Plants

Substantial single-species studies have reported the facility of nitric oxide (NO) in alleviating heavy metal-induced stress in plants. Understanding the mechanisms of NO-involved stress alleviation is progressing; however, a quantitative description of the alleviative capacity of NO against heavy metal stress is still lacking. We combined the results of 86 studies using meta-analysis to statistically assess the responses of heavy metal-stressed plants to NO supply across several metal stresses and plant families. The results showed that plant biomass was consistently improved following NO supply to metal-stressed plants. NO played an important role in mitigating oxidative damage caused by heavy metal stress by significantly stimulating the activities of antioxidant enzymes. Moreover, NO supply consistently increased the Ca, Fe, and Mg contents in both leaves and roots. Plant tissues accumulated less heavy metals when exposed to heavy metal stress after NO addition. Additionally, the best concentration of SNP (an NO donor) for hydroponic culture is in the range of 75–150 μM. We further confirmed that NO application can generally alleviate plant heavy metal stress and its action pathway. The results presented here can help guide future applications of NO as a plant growth regulator in agriculture and breeding plants for heavy metal stress tolerance

Regression of atherosclerosis in ApoE-/- mice via modulation of monocyte recruitment and phenotype, induced by weekly dosing of a novel ‘cytotopic’ anti thrombin without prolonged anticoagulation.

Background: Coagulation proteases play an important role in atherogenesis. Accordingly, anticoagulants can induce regression in animal models of atherosclerosis, but exploiting this clinically has been limited by major bleeding events that occur after systemic anticoagulation. Here we test a novel thrombin inhibitor, PTL060, that comprises hirulog covalently linked to a synthetic myristoyl electrostatic switch to tether it to cell membranes. Methods and Results: ApoE-/- mice, fed either chow or high fat diets were used. Transplantation of congenic aortic segments was used to demonstrate the impact of expressing anticoagulants on endothelium. PTL060, parental hirulog or controls were tested to assess suppression of vessel wall chemokine gradients, impact on plaque development and regression of existing plaques. Adoptive transfer of labelled CD11b positive cells was used to assess recruitment of monocytes and inform on how PTL060 influenced monocyte phenotype. Transgenic expression of anticoagulant fusion proteins based on TFPI or hirudin on EC led to complete suppression of MIF and CCL2 expression throughout the vessel wall and segments of aorta transplanted into ApoE-/- mice did not develop atherosclerosis. A single IV injection of PTL060, but not parental (unmanipulated) hirulog inhibited the same chemokines for >1 week and atheroma formation was reduced by >50% compared to controls when assessed 4 weeks later. Mice had prolonged bleeding times for only 1/7th of the time that PTL060 was biologically active. Repeated weekly injections of PTL060 but not parental hirulog caused regression of atheroma in ApoE-/- mice fed either chow or high fat diets. Mechanistically, 100% of circulating monocytes quickly became coated with PTL060 after the first dose, following which >70% of CCR2+ monocytes recruited into plaques expressed CCR7, ABCA1 and IL-10, a phenotype associated with regression, compared to 90%) had a similar regression-associated phenotype. The impact of PTL060 on circulating monocytes appeared 1 dominant, as regression equivalent to that induced by IV PTL060 was induced by adoptive transfer of CD11b+ cells pre-coated with PTL060. Conclusions: PTL060, a novel tethered direct thrombin inhibitor causes regression of atherosclerosis in ApoE-/- mice, via an effect at the endothelial surface but also through a direct effect on monocytes, causing differentiation into macrophages capable of plaque regression. Covalent linkage of a myristoyl electrostatic switch onto hirulog uncouples the pharmacodynamic effects on haemostasis and atherosclerosis, such that regression is accompanied by only transient anticoagulation

Regression of atherosclerosis in ApoE-/- mice via modulation of monocyte recruitment and phenotype, induced by weekly dosing of a novel ‘cytotopic’ anti thrombin without prolonged anticoagulation.

Background: Coagulation proteases play an important role in atherogenesis. Accordingly, anticoagulants can induce regression in animal models of atherosclerosis, but exploiting this clinically has been limited by major bleeding events that occur after systemic anticoagulation. Here we test a novel thrombin inhibitor, PTL060, that comprises hirulog covalently linked to a synthetic myristoyl electrostatic switch to tether it to cell membranes. Methods and Results: ApoE-/- mice, fed either chow or high fat diets were used. Transplantation of congenic aortic segments was used to demonstrate the impact of expressing anticoagulants on endothelium. PTL060, parental hirulog or controls were tested to assess suppression of vessel wall chemokine gradients, impact on plaque development and regression of existing plaques. Adoptive transfer of labelled CD11b positive cells was used to assess recruitment of monocytes and inform on how PTL060 influenced monocyte phenotype. Transgenic expression of anticoagulant fusion proteins based on TFPI or hirudin on EC led to complete suppression of MIF and CCL2 expression throughout the vessel wall and segments of aorta transplanted into ApoE-/- mice did not develop atherosclerosis. A single IV injection of PTL060, but not parental (unmanipulated) hirulog inhibited the same chemokines for >1 week and atheroma formation was reduced by >50% compared to controls when assessed 4 weeks later. Mice had prolonged bleeding times for only 1/7th of the time that PTL060 was biologically active. Repeated weekly injections of PTL060 but not parental hirulog caused regression of atheroma in ApoE-/- mice fed either chow or high fat diets. Mechanistically, 100% of circulating monocytes quickly became coated with PTL060 after the first dose, following which >70% of CCR2+ monocytes recruited into plaques expressed CCR7, ABCA1 and IL-10, a phenotype associated with regression, compared to <20% of CCR2+ recruits in control mice.. Multiple doses caused a significant reduction in the number of monocytes recruited, and a switch to recruitment of CCR2-negative cells, the majority of which (>90%) had a similar regression-associated phenotype. The impact of PTL060 on circulating monocytes appeared 1 dominant, as regression equivalent to that induced by IV PTL060 was induced by adoptive transfer of CD11b+ cells pre-coated with PTL060. Conclusions: PTL060, a novel tethered direct thrombin inhibitor causes regression of atherosclerosis in ApoE-/- mice, via an effect at the endothelial surface but also through a direct effect on monocytes, causing differentiation into macrophages capable of plaque regression. Covalent linkage of a myristoyl electrostatic switch onto hirulog uncouples the pharmacodynamic effects on haemostasis and atherosclerosis, such that regression is accompanied by only transient anticoagulation