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1.
J Environ Manage ; 355: 120460, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38430881

ABSTRACT

The practice of returning straw to agricultural fields is a globally employed technique. Such agricultural fields also receive a significant amount of nitrogen (N) and phosphorus (P) fertilizers, because these two macronutrients are essential for plant growth and development. However, the consequences of such macronutrients input on straw decomposition, soil dissolved organic matter (DOM), key microbes, and lignocellulolytic enzymes are still unclear. In a similar aim, we designed a long-term straw returning study without and with different N and P nutrient supplementation: CK (N0P0), T1 (N120P0), T2 (N120P60), T3 (N120P90), T4 (N120P120), T5 (N0P90), T6 (N60P90), and T7 (N180P90), and evaluated their impact on rice and oilseed rape yield, soil DOM, enzymes, lignocellulose content, microbial diversity, and composition. We found straw returning improved overall yield in all treatments and T7 showed the highest yield for oilseed rape (30.31-38.87 g/plant) and rice (9.14-9.91 t/ha) during five-years of study. The fertilizer application showed a significant impact on soil physicochemical properties, such as water holding capacity and soil porosity decreased, and bulk density increased in fertilized treatments, as compared to CK. Similarly, significantly low OM, cellulose, hemicellulose, and lignin content were found in T7, T4, T3, and T2, while high values were found in CK and T5, respectively. The fluorescence excitation-emission matrix spectra of DOM of different treatments revealed that T3, T7, T4, and T6 showed high peak M (microbial by-products), peak A and peak C (humic acid-like) as compared to others. The microbial composition was also distinctive in each treatment and a high relative abundance of Chloroflexi, Actinobacteriota, Ascomycota, and Basidiomycota were found in T2 and T3 treatments, respectively. These findings indicate that the decomposition of straw in the agricultural field was dependent on nutrients input, which facilitated key microbial growth and impacted positively on lignocellulolytic enzymes, which further aided the breakdown of all components of straw in the field efficiently. On the other hand, high input of chemical based fertilizers to soil can lead to several environmental issues, such as nutrient imbalance, nutrient runoff, soil pH change and changes in microbial activities. Keeping that in consideration, we recommend moderate fertilizer dosage (N120P90) in such fields to achieve higher decomposition of crop straw with a small yield compromise.


Subject(s)
Fertilizers , Oryza , Agriculture/methods , Soil/chemistry , Humic Substances , Nitrogen/analysis
2.
Nat Commun ; 15(1): 1973, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38438342

ABSTRACT

Seawater electrolysis offers a renewable, scalable, and economic means for green hydrogen production. However, anode corrosion by Cl- pose great challenges for its commercialization. Herein, different from conventional catalysts designed to repel Cl- adsorption, we develop an atomic Ir catalyst on cobalt iron layered double hydroxide (Ir/CoFe-LDH) to tailor Cl- adsorption and modulate the electronic structure of the Ir active center, thereby establishing a unique Ir-OH/Cl coordination for alkaline seawater electrolysis. Operando characterizations and theoretical calculations unveil the pivotal role of this coordination state to lower OER activation energy by a factor of 1.93. The Ir/CoFe-LDH exhibits a remarkable oxygen evolution reaction activity (202 mV overpotential and TOF = 7.46 O2 s-1) in 6 M NaOH+2.8 M NaCl, superior over Cl--free 6 M NaOH electrolyte (236 mV overpotential and TOF = 1.05 O2 s-1), with 100% catalytic selectivity and stability at high current densities (400-800 mA cm-2) for more than 1,000 h.

3.
Front Aging Neurosci ; 15: 1244191, 2023.
Article in English | MEDLINE | ID: mdl-37876876

ABSTRACT

Objective: To investigate the effects of brain-derived neurotrophic factor (BDNF) gene polymorphism on cognitive function, neuroimaging and blood biological markers in patients with subcortical ischaemic vascular dementia (SIVD). Methods: A total of 81 patients with SIVD were included. According to their BDNF gene polymorphism, the participants were divided into the Val/Val (n = 26), Val/Met (n = 35), and Met/Met (n = 20) groups. A comprehensive neuropsychological evaluation and multimodal brain MRI scan were performed. MRI markers for small vessel disease were visually rated or quantitatively analysed. Moreover, 52 patients were further evaluated with blood marker assays, including amyloid beta (Aß), phosphorylated tau at threonine-181 (P-tau181), glial fibrillary acidic protein (GFAP), total tau (T-tau) and neurofilament light chain (NfL). Results: There were no significant differences in demographics, disease duration or MRI markers of small vessel disease between the three groups. Compared with the Val/Val and Val/Met groups, the Met/Met group showed worse performance in the verbal fluency test and higher levels of plasma NfL. Conclusion: The rs6265 polymorphism of the BDNF gene is associated with semantic language fluency in patients with SIVD. The Met genotype may be a risk factor for cognitive impairment and neuronal injury.

4.
Molecules ; 28(17)2023 Aug 25.
Article in English | MEDLINE | ID: mdl-37687073

ABSTRACT

Vinyl acetate is a restricted substance in food products. The quantification of the organic impurities in vinyl acetate is a major problem due to its activity, instability, and volatility. In this paper, while using the mass balance method to determine the purity of vinyl acetate, an improved method was established for the determination of the content of three impurities in vinyl acetate reference material, and the GC-FID peak area normalization for vinyl acetate was calibrated. The three trace organic impurities were identified by gas chromatography tandem high-resolution mass spectrometry to be methyl acetate, ethyl acetate, and vinyl propionate. The content and relative correction factors for the three organic impurities were measured. The purity of vinyl acetate determined by the mass balance method was 99.90% with an expanded uncertainty of 0.30%, and the total content of organic impurities was 0.08% with a relative correction factor of 1.23%. The vinyl acetate reference material has been approved as a national certified reference material in China as GBW (E) 062710.

5.
Pak J Pharm Sci ; 36(4(Special)): 1313-1317, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37606021

ABSTRACT

Protection roles of serum vitamin D levels in the cardiovascular system. This observational study enrolled 286 young ACI patients with type 2 diabetes mellitus in our Hospital from October 2016 to April 2020 as the study group. 127 healthy individuals as the control group. Serum levels of vitamin D and blood pressure indexes of the two groups were measured and the correlation between vitamin D levels and the clinical phenotype of young cerebral infarction was explored. Significantly higher 25-hydroxyvitamin D was observed in the study group vs. control group. During the day, The values of systolic and diastolic blood pressure and mean blood pressure was well-balanced between the two groups. However, at night and within 24 hours, significant differences in systolic and diastolic blood pressure and mean value were observed between the two groups. The higher the vitamin D level, the greater the decrease in blood pressure at night. Serum 25-hydroxyvitamin D was positively correlated with the reduction of night systolic and diastolic blood pressure. Low levels of 25-hydroxyvitamin D led to a small decrease in blood pressure at night, resulting in a vulnerable cardiovascular system and an increased incidence of cerebral infarction in the young population.


Subject(s)
Cardiovascular System , Diabetes Mellitus, Type 2 , Humans , Blood Pressure , Vitamin D , Cerebral Infarction
6.
Angew Chem Int Ed Engl ; 62(40): e202309882, 2023 Oct 02.
Article in English | MEDLINE | ID: mdl-37603411

ABSTRACT

The direct seawater electrolysis at high current density and low overpotential affords an effective strategy toward clean and renewable hydrogen fuel production. However, the severe corrosion of anode as a result of the saturation of Cl- upon continuous seawater feeding seriously hamper the electrolytic process. Herein, cobalt ferricyanide / cobalt phosphide (CoFePBA/Co2 P) anodes with Cap/Pin structure are synthesized, which stably catalyze alkaline saturated saline water oxidation at 200-2000 mA cm-2 over hundreds of hours without corrosion. Together with the experimental findings, the molecular dynamics simulations reveal that PO4 3- and Fe(CN)6 3- generated by the electrode play synergistic role in repelling Cl- via electrostatic repulsion and dense coverage, which reduced Cl- adsorption by nearly 5-fold. The novel anionic synergy endow superior corrosion protection for the electrode, and is expected to promote the practical application of saline water electrolysis.

7.
J Sci Food Agric ; 103(14): 7302-7313, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37499162

ABSTRACT

BACKGROUND: Chalkiness in rice reduces its market value and affects consumer acceptance. Research on the mechanism of chalkiness formation has focused primarily on the activity of key enzymes of carbon metabolism and starch accumulation. The relationship between the formation of chalkiness induced by N fertilizer and rice starch's multi-level structure and thermal properties still needs to be fully elucidated. RESULTS: In this study, the rates of chalky grains and degree of chalkiness decreased with the increase in N fertilizer dosage. This was attributed to an increased proportion of short chains, ordered structure carbon chains, small starch granules, and branched starches, and a higher degree of crystallinity and ΔHg in protein, and a decreased proportion of amylose, large starch granules, and weighted average diameter of starch granule surface area and volume. Application of N fertilizer promoted an increased proportion of short-branched chain amylopectin to develop a more ordered carbohydrate structure and crystalline lamella. These effects enhanced the normal development and compactness of starch granules in grains, and improved their arrangement morphology, thereby reducing the chalkiness in rice. CONCLUSION: These changes in starch multi-level structure and protein improve the physicochemical characteristics of starch and enhance the fullness, crystallinity and compactness of starch granules, while synergistically increasing the regularity and homogeneity of starch granules and thus optimizing the stacking pattern of starch granules, leading to a reduction in rice chalkiness under nitrogen fertilization and thus improving the appearance of rice. © 2023 Society of Chemical Industry.

8.
Plants (Basel) ; 11(17)2022 Sep 02.
Article in English | MEDLINE | ID: mdl-36079688

ABSTRACT

(1) Background: Sheath blight is one of the most economically significant rice diseases worldwide. A study was conducted in order to find the relationship and impact of the amount of nitrogen (N) and phosphorus (P) application on the hybrid rice population microclimate and the severity of sheath blight. (2) Methods: Four N and four P application levels were used to determine their impact on plant type, temperature, and humidity variation in different positions of population and the severity of sheath blight in the later stage. (3) Results: We found that N and P application levels could affect the plant type and change the population temperature and humidity by increasing the leaf length and leaf angle. (4) Conclusions: N application had a more significant (p < 0.05) impact on the plant type. High N application caused decreased temperature (hybrid rice population), while increased humidity (especially the population base layer at grain filling stage) resulted in severe sheath blight. High P application had similar impacts; however, P application increased material and nitrogen transport in plants and reduced the severity of sheath blight.

9.
Front Psychol ; 13: 935875, 2022.
Article in English | MEDLINE | ID: mdl-36092060

ABSTRACT

The California Verbal Learning Test-Second Edition (CVLT-II), is a commonly used tool to assess episodic memory. This study analyzed learning and memory characteristics in a cognitively healthy Chinese population, as well as the effects of age, sex and education on CVLT-II factors. In total, 246 healthy people aged 20-80 years and 29 persons with multiple sclerosis (MS) were included in this study and completed the CVLT-II. Factors including total learning, learning strategy, serial position effects, short-delay free and cued recall, long-delay free and cued recall, repetitions and intrusions during recall, hits and false positives of recognition, and total recognition discriminability were calculated. The effects of age, sex and education on these factors were analyzed using ANCOVA or independent two-sample t-tests and further confirmed by multiple regression analysis. The regression-based normative data were then computed by the equivalent scores method. Moreover, differences in learning and memory were compared between persons with MS and age-, sex- and education-matched healthy individuals. Most CVLT-II factors significantly differed between different age and education groups; in particular, better performance in total learning, recall, semantic clustering and recognition was observed in the younger and more educated groups than in the older and less educated groups. Male participants showed higher recency effect scores, more repetitions and fewer hits than female participants. Compared with healthy individuals, persons with MS showed extensive impairments in memory processes, such as learning, recall, learning strategy and recognition (p < 0.05). These findings indicated that verbal learning and memory were highly dependent on age and educational level but not strongly affected by sex. The CVLT-II effectively assesses episodic memory impairment in the Chinese-speaking population.

10.
Comput Math Methods Med ; 2022: 2914484, 2022.
Article in English | MEDLINE | ID: mdl-35799673

ABSTRACT

Objective: Vitamin D is associated with neurological deficits in patients with cerebral infarction. This study uses machine learning to evaluate the prediction model's efficacy of the correlation between vitamin D and neurological deficit in patients with cerebral infarction. Methods: A total of 200 patients with cerebral infarction admitted to the Department of Neurology of our hospital from July 2018 to June 2019 were selected. The patients were randomly divided into a training set (n = 140) and a test set (n = 60) in a 7 : 3 ratio. The prediction model is constructed from the training set's data, and the model's prediction effect was evaluated by test set data. The area under the receiver operator characteristic curve was used to assess the prediction efficiency of models. Results: In the training set, the area under the curve (AUC) of the logistic regression model and XGBoost algorithm model was 0.727 (95% CI: 0.601~0.854) and 0.818 (95% CI: 0.734~0.934), respectively. While in the test set, the AUC of the logistic regression model and XGBoost algorithm model was 0.761 (95% CI: 0.640~0.882) and 0.786 (95% CI: 0.670~0.902), respectively. Conclusion: The prediction model of the correlation between vitamin D and neurological deficit in patients with cerebral infarction based on machine learning has a good prediction efficiency.


Subject(s)
Machine Learning , Vitamin D , Area Under Curve , Cerebral Infarction , Humans , Logistic Models , Retrospective Studies
11.
Eur Spine J ; 31(11): 2920-2934, 2022 11.
Article in English | MEDLINE | ID: mdl-35842490

ABSTRACT

BACKGROUND: The completeness of the intervertebral disc proteome is fundamental to the integrity and functionality of the intervertebral disc. METHODS: The 20 experimental rats were placed into two groups randomly, normal group (NG) and acupuncture pathological degeneration group-2 weeks (APDG-2w). The ten 24-month-old rats were grouped into physiological degeneration group (PDG). Magnetic resonance imaging, X-ray examination, histological staining (hematoxylin & eosin, safranin-O cartilage, and alcian blue staining), and immunohistochemical examination were carried out for assessing the degree of disc degradation. Intervertebral disc was collected, and protein composition was determined by LC- MS, followed by bioinformatic analysis including significance analysis, subcellular localization prediction, protein domain prediction, GO function and KEGG pathway analysis, and protein interaction network construction. LC-PRM was done for protein quantification. RESULTS: Physiological degeneration and especially needle puncture decreased T2 signal intensity and intervertebral disc height. Results from hematoxylin & eosin, safranin-O, and alcian blue staining revealed that the annulus fibrosus apparently showed the wavy and collapsed fibrocartilage lamellas in APDG-2w and PDG groups. The contents of the nucleus pulposus were decreased in physiological degeneration group and APDG-2w group compared with NG. Results from immunohistochemical analysis suggested the degeneration of intervertebral disc and inflammation in APDG-2w and PDG groups. The protein composition and expression between needle puncture rat models and the physiological degeneration group showed significant difference. CONCLUSIONS: Our studies produced point-reference datasets of normal rats, physiological degeneration rats, and needle puncture rat models, which is beneficial to subsequent pathological studies. There is differential expression of protein expression in degenerative discs with aging and acupuncture, which may be used as a potential discriminating index for different intervertebral degenerations.


Subject(s)
Intervertebral Disc Degeneration , Intervertebral Disc , Animals , Rats , Alcian Blue/metabolism , Disease Models, Animal , Eosine Yellowish-(YS)/metabolism , Hematoxylin/metabolism , Intervertebral Disc/pathology , Intervertebral Disc Degeneration/pathology , Proteomics , Punctures
12.
Article in English | MEDLINE | ID: mdl-35586691

ABSTRACT

Objective: To investigate the effects of alteplase thrombolysis on coagulation function and nerve function of patients with ischemic stroke. Methods: 76 cases with ischemic stroke receiving thrombolytic therapy in Cangzhou Central Hospital from November 2018 to November 2019 were recruited. They were assigned via the random number table method at a ratio of 1 : 1 to receive alteplase thrombolysis either within 3h after the onset (observation group) or within 3-4.5 h after the onset (control group), followed by aspirin administration after no bleeding in cranial computed tomography (CT). Outcome measures included plasma fibrinogen (FIB), activated partial prothrombin time (APTT), platelet (PLT) levels, the National Institute of Health stroke scale (NIHSS) score, and adverse events. Results: Alteplase thrombolysis within 3 h was associated with better prothrombin time (PT), APTT, FIB, and PLT levels versus thrombolysis within 3-4.5 h (P < 0.05). Thrombolysis within 3 h showed significantly lower NIHSS scores versus within 3-4.5 h (P < 0.05). The two groups showed a similar incidence of adverse events (X 2 = 2.963, P=0.615). Conclusion: Alteplase thrombolysis showed benefits in mitigating the coagulation function and nerve function damage of patients with ischemic stroke, especially within 3 hours after the onset, with a high safety profile.

13.
J Food Biochem ; 46(2): e14066, 2022 02.
Article in English | MEDLINE | ID: mdl-34984696

ABSTRACT

To promote the reduction and efficiency of chemical fertilizers in rice production, two hybrid rice varieties with different amylose contents (16.43% and 27.58%) were selected to study the yield and quality performance of different quality rice varieties under reduced nitrogen/phosphorus conditions. Thus, the specific mechanism of the long-term nitrogen/phosphorus reduction effect on the quality of low- and high-amylose content (16.43% and 27.58%) rice was investigated by comparative analyses of the rapid visco analyzer and X-ray diffraction patterns, amylose contents, and starch structures of the samples. The results revealed that the effect of nitrogen fertilizer on the quality and yield of the hybrid rice was greater than that of phosphorus fertilizer. Indeed, reducing the former increased the Wx gene expression and amylose content of the rice varieties. Moreover, it reduced the starch crystallinity of Yixiangyou 1108 (2.16%), increasing the space between the starch grains and thus, chalkiness. Reducing nitrogen/phosphorus application did not significantly affect the yield and quality of the high-amylose rice but affected that of the high-quality rice with lower amylose contents. Thus, for high-amylose rice created for processing, appropriate chemical fertilizer reduction will not affect their yield and processing demand. PRACTICAL APPLICATIONS: Fertilization with different nitrogen and phosphorus fertilizers will seriously affect rice quality. The rice varieties with low amylose content (AC) could produce high taste quality rice by increasing nitrogen fertilizer and decreasing phosphorus fertilizer. The rice varieties with relatively high ACs should reduce the application of nitrogen/phosphorus fertilizer to appropriately increase AC, which can be used to produce healthy food with high resistant starch.


Subject(s)
Fertilizers , Oryza , Amylose , Nitrogen , Oryza/chemistry , Oryza/genetics , Starch/metabolism
14.
Gerontology ; 68(8): 854-860, 2022.
Article in English | MEDLINE | ID: mdl-34607327

ABSTRACT

INTRODUCTION: Guillain-Barré syndrome (GBS) is a common autoimmune disease in the peripheral nervous system. This study aimed to elucidate the role of IL-27 gene polymorphisms in elderly people with GBS. METHODS: A total of 395 healthy subjects and 422 GBS patients with an average age of 63 years old were included in this study. Peripheral blood samples were collected. The 2 single-nucleotide polymorphisms (SNPs) of IL-27, namely, rs153109 and rs785575, of GBS patients were analyzed using the PCR method and compared with those of the healthy controls. The correlations of IL-27 SNPs with disease severity, disease outcome, level of anti-GM1 antibodies, and Campylobacter jejuni infection were assessed. Serum levels of IL-27 of healthy subjects and GBS patients were analyzed using enzyme-linked immunosorbent assay. RESULTS: No significant differences in the frequencies of rs785575 SNPs between GBS and healthy subjects were observed. In analyzing rs153109 SNPs, the G allele was found to be more prevalent in the GBS patients (p = 0.012). More alleles show GG genotype in GBS patients (p = 0.023). The -964A>G allele has a higher prevalence in severely affected and anti-GM1-Ab-positive GBS patients. GBS patients with the rs153109 SNP showed a poor clinical outcome than those without rs153109 SNP (p = 0.012). GBS patients showed higher serum IL-27 levels than healthy subjects (p < 0.001). The levels of IL-27 were also higher in GBS patients with genotypes of AG and GG, and those with GG genotypes showed the highest IL-27 levels. CONCLUSION: The rs153109 SNP is more prevalent in GBS patients with the GG and G allele and is associated with severer GBS, poorer clinical outcomes, and higher IL-27 levels.


Subject(s)
Guillain-Barre Syndrome , Interleukin-27 , Aged , Alleles , Genotype , Guillain-Barre Syndrome/genetics , Humans , Interleukin-27/genetics , Interleukins , Polymorphism, Single Nucleotide
15.
Mol Biol Rep ; 48(12): 8009-8021, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34665398

ABSTRACT

BACKGROUND: Chemical fertilization helped modern agriculture in grain yield improvement to ensure food security. The response of chemical fertilization for higher hybrid rice production is highly dependent on optimal fertilization management in paddy fields. To assess such responses, in the current work we examine the yield, root growth, and expression of related genes responsible for stress metabolism of nitrogen (N) and phosphorus (P) in two hybrid-rice cultivars Deyou4727 (D47) and Yixiangyou2115 (Y21). METHODS AND RESULTS: The experiment followed four nitrogen (N) (N0, N60, N120, and N180 kg/ha) and phosphorus (P) (P0, P60, P90, and P120 kg/ha) fertilizer levels. The grain yield in D47 was more sensitive to nitrogen application, while Y21 was more sensitive to phosphorus application, which resulted in comparatively higher biomass and yield. Our findings were corroborated by gene expression studies of glutamine synthetase OsGS1;1 and OsGS1;2 and phosphate starvation-related genes PHR1 and SPX, confirming sensitivity to N and P application. The number of roots was less sensitive to nitrogen application in D47 between N0 and N60, but the overall nutrient response difference was significantly higher due to the deep rooting system as compared to Y21. CONCLUSIONS: The higher yield, high N and P use efficiency, and versatile root growth of D47 make it suitable to reduce unproductive usage of N and P from paddy fields, improving hybrid rice productivity, and environmental safety in the Sichuan basin area of China.


Subject(s)
Agriculture/methods , Oryza/genetics , Oryza/metabolism , Biomass , China , Fertilizers/analysis , Nitrogen/metabolism , Nutrients , Phosphorus/metabolism , Plant Roots/metabolism , Soil
16.
Am J Transl Res ; 13(3): 1884-1889, 2021.
Article in English | MEDLINE | ID: mdl-33841715

ABSTRACT

OBJECTIVE: To determine the risk factors for cognitive impairment (CI) in patients with first-time ischemic stroke. METHODS: The clinical data of 180 patients with ischemic stroke who were admitted to our hospital from January 2018 to December 2019 was retrospectively analyzed. Patients with MMSE score ≤24 were included into the CI group and the rest of the patients were placed into the normal group. Multivariate logistic regression was applied to describe risk factors for CI in patients with first-time ischemic stroke. RESULTS: Among the patients with first-time ischemic stroke, 96 cases (53%) developed CI, 84 cases (47%) were normal. In different subtypes of TOAST classifications, patients with large-artery atherosclerosis had the highest CI incidence (66.96%). For different infarction sites, the highest CI incidence occurred in the frontal lobe (82.35%), and the lowest was from cerebellar infarction (37.50%). The difference of CI incidences in the frontal lobe, parietal lobe, temporal lobe and occipital lobe was significant between the two groups (P<0.05). Logistic regression analysis indicated that independent risk factors for CI in patients with first ischemic stroke include age ≥60 years old, diabetes history, CRP >6.53 mg/L, Hcy >13.84 µmol/L, NIHSS score >4.37, VD <45.16 nmol/L, and the difference was statistically significant (P<0.05). CONCLUSION: The study showed a high CI incidence in patients with preexisting ischemic stroke. Age ≥60 years old, history of diabetes mellitus, CRP >6.53 mg/L, Hcy >13.84 µmol/L, NIHSS score >4.37 score, VD <45.16 nmol/L are independent risk factors for CI in patients with first-time ischemic stroke.

17.
Sci Rep ; 11(1): 1481, 2021 01 15.
Article in English | MEDLINE | ID: mdl-33452308

ABSTRACT

Vessel train formation as a new trend has been raised in cooperative control for multiple vessels. This paper addresses formation control design for a group of unmanned surface vehicles platoon considering input delay. To account for connectivity-preserving and collision-avoiding, Barrier Lyapunov function is incorporated into the constraints design of line-of-sight range and bearing. To alleviate the computational burden, neural dynamic model is employed to simplify the control design and smooth the input signals. Besides, input control arising from time delay due to mechanisms and communication is considered in the marine vessels. Within the framework of the backstepping technique, distributed coordination is accomplished in finite time and the uniformly ultimately boundness of overall system is guaranteed via rigorous stability analysis. Finally, the simulation is performed to verify the effectiveness of the proposed control method.

18.
Appl Opt ; 59(13): 4122-4130, 2020 May 01.
Article in English | MEDLINE | ID: mdl-32400688

ABSTRACT

A dual-wavelength tunable lidar system that simultaneously detects the Ca and Ca+ layers has been established in Yanqing Station (40.41°N, 116.01°E). The lidar system implements a pulsed Nd:YAG laser that simultaneously pumps two dye lasers, which reduces the hardware configuration of the lidar system. The two dye lasers use infrared laser dyes with high conversion efficiency suitable for long-term observation. The resonance wavelengths of Ca and Ca+ are generated by frequency doubling of the two infrared laser beams. We compared the dual-wavelength tunable lidar system to previous dye-based systems and performed experiments to determine resonance frequencies to within 0.4 pm and to test the dual optical fiber receiving system and found it does not cause cross talk. Three nights of preliminary simultaneous observations of Ca and Ca+ layers are reported; the diversity of these observations begs for more systematic observations and challenging interpretations in terms of Ca processes in the ionosphere and illustrates the effectiveness of this system for aeronomy and space physics studies.

19.
Appl Opt ; 59(6): 1529-1536, 2020 Feb 20.
Article in English | MEDLINE | ID: mdl-32225652

ABSTRACT

Due to the severe interference from strong solar background light on the received signal, daytime ground-based lidar observation of the sodium (Na) layer is challenging. In this paper, a Na lidar permitting full-diurnal-cycle observation of the metal Na layer over Beijing, China (40.5°N, 116°E) was reported. In order to suppress the skylight background during daytime effectively with less signal losses, a dual-channel Faraday filtering unit was implemented in the lidar receiver. Based on the diurnal Na lidar system, a good number of continuous observational results that lasted more than 120 h with good signal-to-noise ratio were obtained, demonstrating its reliability. Considerable variations within the Na layer during the day were revealed, especially on the layer top and bottom side. In particular, strong sporadic Na layer (Nas) events that occurred during the daytime of 3 consecutive days were also captured with complete evolution process. These observational results showed the advantages of the diurnal Na lidar for investigating the metal layer photochemistry and dynamics in the mesosphere and lower thermosphere region. Na layer observations over the whole diurnal cycle not only benefit the improvements of current theoretical models, but also can allow for a specialized analysis of Nas that occur in the daytime and provide valuable observational support for investigating the rapid production and disappearance mechanisms of Na atoms.

20.
Cell Death Dis ; 11(2): 126, 2020 02 18.
Article in English | MEDLINE | ID: mdl-32071301

ABSTRACT

Worldwide, lung cancer remains a leading cause of cancer mortality. Bruceine D (BD) has been shown to induce pancreatic cancer cell death via several different mechanisms. In this study, we demonstrated that BD inhibited lung cancer cell proliferation. Apoptosis and autophagy were the most important mechanisms involved in BD-induced lung cancer cell death, and complete autophagic flux was observed in A549 and NCI-H292 cells. In addition, BD significantly improved intracellular reactive oxygen species (ROS) levels. BD-mediated cell apoptosis and autophagy were almost inhibited in cells pretreated with N-acetylcysteine (NAC), an ROS scavenger. Furthermore, MAPK signaling pathway activation contributed to BD-induced cell proliferation inhibition and NAC could eliminate p-ERK and p-JNK upregulation. Finally, an in vivo study indicated that BD inhibited the growth of lung cancer xenografts. Overall, BD is a promising candidate for the treatment of lung cancer owing to its multiple mechanisms and low toxicity.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/drug effects , Autophagy/drug effects , Extracellular Signal-Regulated MAP Kinases/metabolism , JNK Mitogen-Activated Protein Kinases/metabolism , Lung Neoplasms/drug therapy , MAP Kinase Signaling System/drug effects , Quassins/pharmacology , Reactive Oxygen Species/metabolism , A549 Cells , Animals , Cell Proliferation/drug effects , Female , Humans , Lung Neoplasms/enzymology , Lung Neoplasms/pathology , Mice, Inbred BALB C , Mice, Nude , Phosphorylation , Tumor Burden/drug effects , Xenograft Model Antitumor Assays
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