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1.
Int J Med Sci ; 17(2): 176-181, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32038101

RESUMO

Background: To evaluate the long-term efficacy and safety of topical 1% atropine for retarding moderate myopia. Methods: A randomized, controlled study evaluating atropine and placebo in 660 Chinese children. Patients received drops q1month for 24 months, then q2month for 12 months, followed by no drops for 12 months. Spherical equivalent, axial length, intraocular pressure and atropine-related side effects were examined at 6, 12, 24, 36 and 48 months for all children. Results: Spherical equivalent, myopic progression, axial length augmentation, and progression rate were significantly reduced in the atropine group than those in the placebo group (all P<0.05), indicating that 1% atropine effectively retarded myopia. Moreover, myopic rebound and adverse effects of 1% atropine were eliminated by gradual withdrawal and elimination of 1% atropine. Furthermore, pupil size, near visual acuity, and amplitude of accommodation returned to pretreatment levels after withdrawal of atropine. Conclusion: Topical 1% atropine periodically and alternatively in phase I with gradual reduction in phase II and final withdrawal in phase III may effectively improve atropine efficacy, retard moderate myopia, reduce atropine side effects, minimize myopic rebound, and increase compliance of children simultaneously.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32086626

RESUMO

OBJECTIVE: Increased myelopoiesis has been linked to risk of atherosclerotic cardiovascular disease (ACD). Excessive myelopoiesis can be driven by dyslipidemia and cholesterol accumulation in hematopoietic stem and progenitor cells (HSPC) and may involve increased signaling via Janus kinase 2 (JAK2). Constitutively activating JAK2 mutants drive biased myelopoiesis and promote development of myeloproliferative neoplasms (MPN) or clonal hematopoiesis, conditions associated with increased risk of ACD. JAK2 inhibitors have been developed as a therapy for MPNs. The potential for JAK2 inhibitors to protect against atherosclerosis has not been tested. We therefore assessed the impact of JAK2 inhibition on atherogenesis. METHODS: A selective JAK2 inhibitor TG101348 (fedratinib) or vehicle was given to high-fat high-cholesterol Western diet (WD)-fed wild-type (WT) or Apoe-/- mice. Hematopoietic cell profiles, cell proliferation, and atherosclerosis in WT or Apoe-/- mice were assessed. RESULTS: TG101348 selectively reversed neutrophilia, monocytosis, HSPC, and granulocyte-macrophage progenitor (GMP) expansion in Apoe-/- mice with decreased cellular phosphorylated STAT5 and ERK1/2 and reduced cell cycling and BrdU incorporation in HSPCs, indicating inhibition of JAK/STAT signaling and cell proliferation. Ten-week WD feeding allowed the development of marked aortic atherosclerosis in Apoe-/- mice which was substantially reduced by TG101348. CONCLUSIONS: Selective JAK2 inhibition reduces atherogenesis by suppressing excessive myelopoiesis in hypercholesterolemic Apoe-/- mice. These findings suggest selective JAK2 inhibition as a potential therapeutic approach to decrease ACD risk in patients with increased myelopoiesis and leukocytosis.

3.
Otolaryngol Head Neck Surg ; : 194599819900342, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31959048

RESUMO

OBJECTIVES: To determine the relationship, if any, between body mass index (BMI) and attenuation of the arcuate eminence (AE). STUDY DESIGN: Case series with chart review. SETTING: Tertiary neurotologic referral center. SUBJECTS AND METHODS: Submillimeter distances were recorded from high-resolution temporal bone computed tomography (CT) scans of 50 patients (100 sides). The AE (defined as the superiormost location of the petrous bone over the otic capsule), the bony apex of the superior semicircular canal (SSC), and the geniculate ganglion (GG) were identified and 3-dimensional distances measured. The height of the AE relative to the bony apex of the superior semicircular canal was determined using Euclidean geometry using the fixed anatomical landmark of the GG as the origin. Correlations between AE and BMI were calculated using Pearson's, linear mixed effects, and sensitivity analysis models. RESULTS: The mean (SD) BMI was 30 (8.1) kg/m2, with 16 (30%) patients falling in the underweight/normal category (BMI <25 kg/m2), 10 (20%) overweight patients (25 kg/m2≤ BMI ≤ 30 kg/m2), and 24 (48%) patients considered obese (BMI >30 kg/m2). The mean (SD) AE heights for the left and right ears were 2.5 (1.11) and 2.6 (1.09), respectively. The results of the linear mixed-effects models indicated little evidence that BMI is associated with AE height when including all patients (partial R2 = 0.040) and when using BMI categories (partial R2 = 0.025). CONCLUSION: Contrary to other structures within the lateral skull base, the relative prominence of the arcuate eminence does not correlate with BMI or any other demographic variables.

4.
Mult Scler Relat Disord ; 39: 101924, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31927153

RESUMO

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is an autoimmune neurological disorder associated with the presence of anti-GFAP IgG. Meningoencephalitis is the predominant clinical presentation of autoimmune GFAP astrocytopathy in published case series. We report a case of autoimmune GFAP astrocytopathy with the unusual feature of radiculoneuritis in addition to encephalomyelitis, resulting in flaccid paralysis unresponsive to immunotherapy. Imaging data confirmed involvement of brain, spinal cord and nerve roots. Electrodiagnostic testing showed changes consistent with a severe sensorimotor neuropathy with active denervation. The results of this case suggest the need for future studies to assess the impact of peripheral nerve involvement on the outcome of autoimmune GFAP astrocytopathy.

5.
Int J Biol Sci ; 16(2): 228-238, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31929751

RESUMO

The incidence of colorectal cancer is increasing, and cancer metastasis is one of the major causes of poor outcomes. BEX2 has been reported to be involved in tumor development in several types of cancer, but its role in metastatic colorectal cancer remains largely undefined. Herein, we demonstrated that BEX2 knockout resulted in enhanced migratory and metastatic potential in colorectal cancer cells both in vitro and in vivo, and re-expression of BEX2 in knockout cells could reverse the enhanced migratory capacity. RNA-Seq results indicated that the hedgehog signaling pathway was activated after BEX2 knockout; moreover, the hedgehog signaling inhibitors, GANT61 and GDC-0449 could reverse the migratory enhancement of BEX2-/- colorectal cancer cells. We also demonstrated that the nuclear translocation of Zic2 after BEX2 silencing could activate the hedgehog signaling pathway, while Zic2 knockdown abrogated the migratory enhancement of BEX2-/- cells and inhibited the hedgehog signaling pathway. In summary, our findings suggest that BEX2 negatively modulates the hedgehog signaling pathway by retaining Zic2 in the cytoplasm in colorectal cancer cells, thereby inhibiting migration and metastasis of colorectal cancer cells.

6.
Curr Protoc Stem Cell Biol ; 52(1): e103, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31977148

RESUMO

Translating human induced pluripotent stem cell (hiPSC)-derived cells and tissues into the clinic requires streamlined and reliable production of clinical-grade hiPSCs. This article describes an entirely animal component-free procedure for the reliable derivation of stable hiPSC lines from donor peripheral blood mononuclear cells (PBMCs) using only autologous patient materials and xeno-free reagents. PBMCs are isolated from a whole blood donation, from which a small amount of patient serum is also generated. The PBMCs are then expanded prior to reprogramming in an animal component-free erythroblast growth medium supplemented with autologous patient serum, thereby eliminating the need for animal serum. After expansion, the erythroblasts are reprogrammed using either cGMP-grade Sendai viral particles (CytoTune™ 2.1 kit) or episomally replicating reprogramming plasmids (Epi5™ kit), both commercially available. Expansion of emerging hiPSCs on a recombinant cGMP-grade human laminin substrate is compatible with a number of xeno-free or chemically defined media (some available as cGMP-grade reagents), such as E8, Nutristem, Stemfit, or mTeSR Plus. hiPSC lines derived using this method display expression of expected surface markers and transcription factors, loss of the reprogramming agent-derived nucleic acids, genetic stability, and the ability to robustly differentiate in vitro to multiple lineages. © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Isolating peripheral blood mononuclear cells using CPT tubes Support Protocol 1: Removal of clotting factors to produce serum from autologous plasma collected in Basic Protocol 1 Basic Protocol 2: PBMC expansion in an animal-free erythroblast expansion medium containing autologous serum Basic Protocol 3: Reprogramming of expanded PBMCs with Sendai viral reprogramming particles Alternate Protocol: Reprogramming of expanded PBMCs with episomal plasmids Basic Protocol 4: Picking, expanding, and cryopreserving hiPSC clones Support Protocol 2: Testing Sendai virus kit-reprogrammed hiPSC for absence of Sendai viral RNA Support Protocol 3: Testing Epi5 kit-reprogrammed hiPSC for absence of episomal plasmid DNA Support Protocol 4: Assessing the undifferentiated state of human pluripotent stem cell cultures by multi-color immunofluorescent staining and confocal imaging Support Protocol 5: Coating plates with extracellular matrices to support hiPSC attachment and expansion.

7.
Radiat Oncol ; 15(1): 9, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31915028

RESUMO

BACKGROUND: Homeodomain-interacting protein kinase 2 (HIPK2) has increasingly drawn attention as recent researches demonstrated its unique role in the regulation of multiple fundamental processes such as apoptosis, proliferation and DNA damage repair. Most importantly, HIPK2 was shown to play regulatory role in inflammation and influence the phenotype and activity of fibroblasts. In this study, we aimed to evaluate the impact of HIPK2 gene variant on risk of radiation pneumonitis for patients with pulmonary malignancies. METHODS: 169 lung cancer patients with radiotherapy were included in our prospective study and genotyped by Sanger Sequence method. Multivariable Cox hazard analysis and multiple testing were applied to estimate the hazard ratio (HR) and 95% confidence intervals (CIs) of all factors possibly related to the risk of radiation pneumonitis (RP). RESULTS: Patients with Mean Lung Dose (MLD) ≥ 15Gy, Lung V20 ≥ 24% had higher risk of RP ≥ grade 2 compared with those counterparts (HR = 1.888, 95% CI: 1.186-3.004, P = 0.007; HR = 2.126, 95% CI: 1.338-3.378, P = 0.001, respectively). Importantly, CC genotype of HIPK2: rs2030712 were strongly related to an increased occurrence of RP ≥ grade 2 (HR = 2.146, 95% CI: 1.215-3.791, P = 0.009). CONCLUSION: HIPK2: rs2030712 was found to be significantly related to RP of grade ≥ 2 in our cohort, and may thus be one of the important predictors of severe RP before radiotherapy, if further validated in larger population. TRIAL REGISTRATION: Our study was prospective and observational. The research was registered in ClinicalTrials.gov database as NCT02490319.

8.
IEEE Trans Cybern ; 50(2): 729-738, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30307888

RESUMO

Cyber-security is of the fundamental importance for cyber-physical systems (CPSs), since CPSs are vulnerable to cyber attack. In order to make the defensive measures better, one needs to understand the behavior from the view of an attacker. In this paper, the problem of false data injection attack on remote state estimation with resource constraints is studied in two cases, where the first case is that the attacker adds a Gaussian noise to the innovation, while the other is that the attacker employs a Gaussian noise to replace the innovation. In addition, the attacker is assumed to has a resource constraint, i.e., he/she cannot attack all the sensors, at the same time should decide which sensors to attack. By using the matrix theory, the optimal attack strategy problem, which aims to maximize the trace of the remote estimation error covariance, is converted into a convex optimization problem that can be solved. Thus, an optimal attack strategy is given to illustrate which sensors should be attacked. An example is given to show the effectiveness of the theoretical results.

9.
ChemSusChem ; 13(1): 88-96, 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31638336

RESUMO

The reliable and accurate quantification of ammonia in electrochemical and photochemical experiments has been a technical challenge owing to the extremely low concentration of generated ammonia, interference from trace amounts of cations and organic compounds, and ammonia contamination from various sources. As a result, overestimation and significant errors may happen in many research works. Herein, accuracy and precision of ion chromatography (IC) are evaluated at different pH; excellent performance with a low detection limit (<2 µg L-1 ) under acidic and neutral conditions is found, whereas the linearity is unsatisfactory in the low NH4 + concentration range (0-100 µg L-1 ) under alkaline conditions. High concentrations of Li+ and Na+ are difficult to separate from NH4 + in conventional IC, but this can be solved by employing a high-exchange-capacity column or gradient elution. The interference effects of 14 common transition metal cations and 6 common organic compounds on the quantification of ammonium with low-level concentration (500 µg L-1 ) using IC are systematically investigated, and the results demonstrate good robustness. The overestimation caused by ammonia contamination from reagent water, surroundings, and even the analytical grade of inorganic and organic reagents are confirmed and the results indicate the necessity to prepare and test fresh electrolyte solutions before each experiment, owing to the high sensitivity of acidic and neutral solutions to ammonia contamination from the surroundings. The ammonization of a Nafion membrane during experiments and the underestimation in quantification are also discussed. Finally, a reliable level of synthesized ammonia is identified and some recommendations are presented to improve the reliability and accuracy of ammonia quantification.

10.
Anal Chem ; 92(1): 782-791, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31829560

RESUMO

Despite the recent advances in mass spectrometry (MS)-based methods for glycan structural analysis, characterization of glycomes remains a significant analytical challenge, in part due to the widespread presence of isomeric structures and the need to define the many structural variables for each glycan. Interpretation of the complex tandem mass spectra of glycans is often laborious and requires substantial expertise. Broad adoption of MS methods for glycomics, within and outside the glycoscience community, has been hindered by the shortage of bioinformatics tools for rapid and accurate glycan sequencing. Here, we developed an online porous graphitic carbon liquid chromatography (PGC-LC)-electronic excitation dissociation (EED) MS/MS method that takes advantage of the superior isomer resolving power of PGC and the structural details provided by EED MS/MS for characterization of glycan mixtures. We also made improvements to GlycoDeNovo, our de novo glycan sequencing algorithm, so that it can automatically and accurately identify glycan topologies from EED tandem mass spectra acquired online. The majority of linkages can also be determined de novo, although in some cases, biological insight may be needed to fully define the glycan structure. Application of this method to the analysis of N-glycans released from ribonuclease B not only revealed the presence of 18 high-mannose structures, including new isomers not previously reported, but also provided relative quantification for each isomeric structure. With fully automated data acquisition and topology analysis, the approach presented here holds great potential for automated and comprehensive glycan characterization.

11.
ACS Appl Mater Interfaces ; 12(1): 1721-1727, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31880424

RESUMO

Quasi-two-dimensional (quasi-2D) perovskites with a multiple quantum well structure can enhance the exciton binding energy and controllable quantum confine effect, which are attractive materials for efficient perovskite light-emitting diodes (PeLEDs). However, the multiphase mixtures contained in these materials would cause nonradiative recombination at the perovskite film surface. Here, a facile solution surface treatment is adopted to improve the multiple quantum well structure of the quasi-2D perovskite emitting layer, which can reduce the influence of defectinduced nonradiative recombination and the electric-field-induced dissociation of excitons for the PeLEDs. The improved multiple quantum well structure is verified by UV absorption spectra and temperature-dependent photoluminescence spectra measurements. The photoluminescence quantum yield of the quasi-2D perovskite film with surface treatment has been approximately increased by 200%. Meanwhile, the electroluminescence device achieves a current efficiency of 45.9 cd/A.

12.
Oncol Lett ; 18(6): 5871-5878, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31788060

RESUMO

Macrophages are a heterogeneous group of phagocytes that play critical roles in inflammation, infection and tumor growth. Macrophages respond to different environmental factors and are thereby polarized into specialized functional subsets. Although hypoxia is an important environmental factor, its impact on human macrophage polarization and subsequent modification of the inflammatory microenvironment have not been fully established. The present study aimed to elucidate the effect of hypoxia exposure on the ability of human macrophages to polarize into the classically activated (pro-inflammatory) M1, and the alternatively activated (anti-inflammatory) M2 phenotypes. The effect on the inflammatory microenvironment and the subsequent modification of A549 lung carcinoma cells was also investigated. The presented data show that hypoxia promoted macrophage polarization towards the M2 phenotype, and modified the inflammatory microenvironment by decreasing the release of proinflammatory cytokines. Modification of the microenvironment by proinflammatory M1 macrophages under hypoxia reversed the inhibition of malignant behaviors within the proinflammatory microenvironment. Furthermore, it was identified p38 signaling (a major contributor to the response to reactive oxygen species generated by hypoxic stress), but not hypoxia-induced factor, as a key regulator of macrophages under hypoxia. Taken together, the data suggest that hypoxia affects the inflammatory microenvironment by modifying the polarization of macrophages, and thus, reversing the inhibitory effects of a proinflammatory microenvironment on the malignant behaviors of several types of cancer cell.

13.
Sci Prog ; : 36850419881106, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31829890

RESUMO

In drilling and completion operations, a packer is a downhole tool to seal the annular space between various sizes of string and borehole. As a key component of packer, slip plays a role of fixed support in the process of setting, thus ensuring a long-term stable sealing of the packer. Aiming at the problem of damage caused by casing pressure on the slip after setting, based on the stress analysis of slip during setting, the slip material with hardness lower than casing was selected, and its finite element analysis model was established. Then, the pressure-bearing law of the slip teeth under three tooth parameters was analyzed. The results of analysis were as follows. With the increase of the number of slips or the distance between teeth or tooth top angle, the strain of slips decreased, but the bending moment of slips increased. At the same time, orthogonal test method was used to optimize the parameters of the slips. The conclusion is that the tooth top angle is 90 degrees, the distance between teeth is 6 mm and the number of teeth is 16, which is the best combination of compressive effect. It will provide a reference for improving the long-term effectiveness of the packer seal in drilling and completion engineering.

14.
BMC Plant Biol ; 19(1): 562, 2019 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-31852439

RESUMO

BACKGROUND: Soybean (Glycine max) is an economically important oil and protein crop. Plant height is a key trait that significantly impacts the yield of soybean; however, research on the molecular mechanisms associated with soybean plant height is lacking. The CRISPR (clustered regularly interspaced short palindromic repeat)/Cas9 (CRISPR-associated system 9) system is a recently developed technology for gene editing that has been utilized to edit the genomes of crop plants. RESULTS: Here, we designed four gRNAs to mutate four LATE ELONGATED HYPOCOTYL (LHY) genes in soybean. In order to test whether the gRNAs could perform properly in transgenic soybean plants, we first tested the CRISPR construct in transgenic soybean hairy roots using Agrobacterium rhizogenes strain K599. Once confirmed, we performed stable soybean transformation and obtained 19 independent transgenic soybean plants. Subsequently, we obtained one T1 transgene-free homozygous quadruple mutant of GmLHY by self-crossing. The phenotypes of the T2-generation transgene-free quadruple mutant plants were observed, and the results showed that the quadruple mutant of GmLHY displayed reduced plant height and shortened internodes. The levels of endogenous gibberellic acid (GA3) in Gmlhy1a1b2a2b was lower than in the wild type (WT), and the shortened internode phenotype could be rescued by treatment with exogenous GA3. In addition, the relative expression levels of GA metabolic pathway genes in the quadruple mutant of GmLHY were significantly decreased in comparison to the WT. These results suggest that GmLHY encodes an MYB transcription factor that affects plant height through mediating the GA pathway in soybean. We also developed genetic markers for identifying mutants for application in breeding studies. CONCLUSIONS: Our results indicate that CRISPR/Cas9-mediated targeted mutagenesis of four GmLHY genes reduces soybean plant height and shortens internodes from 20 to 35 days after emergence (DAE). These findings provide insight into the mechanisms underlying plant height regulatory networks in soybean.

15.
Mar Drugs ; 17(12)2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31766406

RESUMO

A pair of stereoisomers possessing novel structures with 6/6/5 fused-ring systems, neo-debromoaplysiatoxin E (1) and neo-debromoaplysiatoxin F (2), were isolated from the marine cyanobacterium Lyngbya sp. Their structures were elucidated using various spectroscopic techniques including high resolution electrospray ionization mass spectroscopy (HRESIMS) and nuclear magnetic resonance (NMR). The absolute stereochemistry was determined by calculated electronic circular dichroism (ECD) and gauge-independent atomic orbital (GIAO) NMR shift calculation followed by DP4+ analysis. Significantly, this is the first report on aplysiatoxin derivatives with different absolute configurations at C9-C12 (1: 9S, 10R, 11S, 12S; 2: 9R, 10S, 11R, 12R). Compounds 1 and 2 exhibited potent blocking activities against Kv1.5 with IC50 values of 1.22 ± 0.22 µM and 2.85 ± 0.29 µM, respectively.

16.
Opt Express ; 27(22): 31435-31445, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31684378

RESUMO

In this paper, we propose a tunable, multi-band, selective absorber composed of multiple layers. Each layer consisted of SiO2/graphene/SiC, and a layer of silver was used as the ground plane of the entire structure. Simulation results show that we can passively and actively coordinate the resonant frequency of the perfect absorption peak by changing the geometric parameters of the array and the Fermi level of the graphene. The absorber is not sensitive to the angle of incidence and the direction of polarization. We propose a theoretical basis for the formation of multiple absorption peaks. The theoretical calculations are in good agreement with the simulation results. In addition, we simulated the three- and four-layer structures. The results show that in the terahertz (THz) band, composite structures of three and four layers can obtain three and four perfect absorption peaks, respectively. Our results provide new insights into the THz band of harmonizable multi-band absorbers that can be applied to THz imaging to coordinate sensors and other optoelectronic devices.

17.
Front Oncol ; 9: 1133, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31709191

RESUMO

Background: DNA methyltransferase 3A (DNMT3A) plays a unique role in hematopoiesis and acute myeloid leukemia (AML) pathogenesis. While the influences of DNMT3A mutation subtypes are still under debate. Purpose: Exploration of the clinical and molecular differences between AML patients carrying DNMT3A R882 mutations and DNMT3A frameshift mutations. Methods: Next generation of sequencing (NGS) and clinical data of 118 AML patients in our center were analyzed and compared. NGS, mRNA and miRNA profiling and clinical data from 12 patients in TCGA database were integrative analyzed. Results: Among all patients enrolled, 113 patients were positive for the variants of interest. Overall, a total of 295 variants were discovered, among which 24 DNMT3A mutations were detected, including 1 non-sense, 20 missense, 3 frameshift mutations. And 7 DNMT3A R882 mutations (3 R882H, 2 R882C, and 2 R882P) were found. Clinical analysis from our cohort and TCGA database indicated that patients carrying DNMT3A R882 mutation exhibited significantly higher levels of peripheral blood hemoglobin and non-significantly inferior prognosis compared with patients with DNMT3A frameshift mutations. Integrative analysis indicated that miR-10b, miR-143, and miR-30a were significantly decreased in the DNMT3A R882 group. High miR-143 expression is significantly associated with better prognosis in AML patients with DNMT3A mutations. Conclusion: Different molecular and clinical characteristics existed between patients with DNMT3A variant subtypes. The distinct microRNA expression pattern for DNMT3A R882 AML patients might not only act as markers to predict disease prognosis, but also could be further investigated to develop novel therapeutic targets for patients with DNMT3A mutations.

18.
Artigo em Inglês | MEDLINE | ID: mdl-31634849

RESUMO

This article presents a secure communication scheme based on the quantized synchronization of master-slave neural networks under an event-triggered strategy. First, a dynamic event-triggered strategy is proposed based on a quantized output feedback, for which a quantized output feedback controller is formed. Second, theoretical criteria are derived to ensure the bounded synchronization of master-slave neural networks. With these criteria, an explicit upper bound is given for the synchronization error. Sufficient conditions are also provided on the existence of quantized output feedback controllers. A Chua's circuit is chosen to illustrate the effectiveness of our theoretical results. Third, a secure communication scheme is presented based on the synchronization of master-slave neural networks by combining the basic principle of cryptology. Then, a secure image communication is studied to verify the feasibility and security performance of the proposed secure communication scheme. The impact of the quantization level and the event-triggered control (ETC) on image decryption is investigated through experiments.

19.
Phys Chem Chem Phys ; 21(43): 24132-24138, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31657397

RESUMO

In this paper, we theoretically and numerically demonstrate a dual-band independently adjustable absorber comprising an array of stacked molybdenum disulfide (MoS2) coaxial nanodisks and a gold reflector that are separated by two dielectric insulating layers. The array plane functionality is explained by the dipole resonances with the MoS2 nanodisks. As a result, strong absorption is achieved at a wide range of incident angles under TE and TM polarizations. The structural parameters of the entire array and the carrier concentration in the MoS2 layers were varied to get the optimized absorption. The absorptance positioning can be adjusted by scaling the diameters of the MoS2 disks. We also proposed the array modification where nanodisks are replaced by a layer with nanoholes. The position of both absorptance peaks can be adjusted individually by changing the carrier concentration in the array. This structure can be useful for the design of chemical sensors, detectors or multi-band absorbers.

20.
J Environ Qual ; 48(5): 1507-1516, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31589715

RESUMO

The chemical and stable isotopic compositions (δS and δO) of Xijiang River water in southwest China, were measured to determine the extent of rock weathering and associated CO consumption rates, and to assess the contamination sources of river water. The SO concentration in the river water was in the range of 0.05 to 0.96 mmol L (mean value = 0.32 mmol L) and was characterized by δS values ranging from -9.1 to 5.1‰ (mean value = -2.1‰) and δO values ranging from -0.4 to 10.8‰ (mean value = 5.0‰). The δS and δO values ranged from high to low from the upper reaches to the lower reaches in all the river water samples. The results indicate that the oxidation of sulfide and anthropogenic inputs are the dominant processes affecting SO sources and S cycling of the Xijiang River during high-discharge conditions, which are controlled by regional hydrological processes that are affected by natural processes and anthropogenic inputs.


Assuntos
Rios , Poluentes Químicos da Água , China , Monitoramento Ambiental , Isótopos de Oxigênio , Sulfatos , Enxofre
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