课程文献中心 更多>>

关键词： Infrared image   Image fusion   Infrared image enhancement   Image processing  

摘要： We propose an infrared and visible image fusion method based on an iterative differential thermal information filter to generate a fusion image with the salient thermal targets of the infrared image and detailed information of the visible image. Firstly, we enhance thermal information of infrared images using a dynamic threshold thermal information filter. Then, we use the multiple difference rolling guidance filter feature fusion method to separate and enhance the detailed information of the visible image. Finally, we gain the fusion image by a weighted-averaging strategy. The advantages and effectiveness of the proposed method are experimentally demonstrated by qualitatively and quantitatively comparing with the deep learning and non deep learning-based methods.

关键词： Reliability   Photovoltaic systems   Solar power generation   Stress   Optimization   Process control   Voltage control   Differential power processing (DPP)   maximum power point (MPP) tracking   mismatched photovoltaic (PV)   power-rating balancing (PRB)  

摘要： With the increase of the component number, the power stress distribution among differential power processing (DPP) converters, control implementation, system cost, and reliability become the most challenging issues for a practical photovoltaic (PV) DPP system. This article introduces an improved power-rating balance (IPRB) control for the PV-to-bus based DPP architecture that ensures each PV submodule operate at its true maximum power point (MPP) while achieving more balanced power stress distribution and higher reliability. Specifically, a submodule-level finite-state-machine-based MPP tracking is implemented to guarantee always maximum power yield, whereas a string-level power-rating balancing (PRB) control is adopted to balance the unit-maximum proceeded power by DPP converters based on the built power flow model with respect to the string current. A comprehensive comparison of advanced control strategies for PV-to-bus DPP architectures, including least power point tracking, voltage equalization (VE) based PRB control, and the proposed IPRB, has been carried out with the mission-profile-based reliability assessment under different partial shading scenarios. Component-failure-rate-based reliability analysis shows that the PV-to-bus DPP architecture with the proposed IPRB control can significantly improve the system reliability. Main simulation and experimental evaluations are carried out to verify the effectiveness of the proposed control.

关键词： Crop residue   Amino sugar   Microbial necromass   Soil fertility   Soil organic carbon  

摘要： Soil organic carbon (SOC) has significant implications in regulating soil health. Emerging insights emphasize the important role of microbial anabolism in SOC storage by continuously transforming plant fragments into persistent microbial residues. However, knowledge of the sequestration pathway of root versus shoot carbon (C) is under debate. While recent studies have shown that labile shoot residue is disproportionately important for stable SOC accumulation through microbial assimilation, how plant root vs. shoot residue retention impacts microbial-derived C under different soil fertility conditions remains elusive. Here, we conducted a 500-d in situ experiment using Alfisols with low fertility (LF) and high fertility (HF) amended with maize root or shoot (both stem and leaf) residues. The microbial residues (amino sugar biomarkers) and microbial communities (lipid biomarkers) were analyzed at 60, 90, 150, and 500 d after the amended materials were added. The results showed that shoot residue input facilitated microbial residue accumulation more efficiently than root input before 150 d. However, at the end of the experiment, the treatment containing added root residue accumulated more microbial residues and produced a higher proportion of microbial residue in SOC, compared with shoot treatment. These results provide novel evidence that root residue can also yield SOC efficiently through the organic substrate-microbial anabolism pathway, but it depends on the decomposition period. Moreover, soil fertility plays an important role in regulating the quantity and relative composition of microbial residues. Specifically, crop residue application greatly increased the contribution of microbial residue C to SOC in the LF treatment compared to that in the HF treatment on day 500. Meanwhile, crop residue addition had a more positive effect on fungal residue accumulation in the LF soil, while it facilitated the accumulation of bacterial residue in the HF soil. These findings

关键词： Ca2+ signalling   FERONIA   halophytes   osmotic stress   ROS   salt stress sensing  

摘要： Significant variation in epidermal bladder cell (EBC) density and salt tolerance (ST) exists amongst quinoa accessions, suggesting that salt sequestration in EBCs is not the only mechanism conferring ST in this halophyte. In order to reveal other traits that may operate in tandem with salt sequestration in EBCs and whether these additional tolerance mechanisms acted mainly at the root or shoot level, two quinoa (Chenopodium quinoa) accessions with contrasting ST and EBC densities (Q30, low ST with high EBC density versus Q68, with high ST and low EBC density) were studied. The results indicate that responses in roots, rather than in shoots, contributed to the greater ST in the accession with low EBC density. In particular, the tolerant accession had improved root plasma membrane integrity and K+ retention in the mature root zone in response to salt. Furthermore, superior ST in the tolerant Q68 was associated with faster and root-specific H2O2 accumulation and reactive oxygen species-induced K+ and Ca2+ fluxes in the root apex within 30 min after NaCl application. This was found to be associated with the constitutive up-regulation of the membrane-localized receptor kinases regulatory protein FERONIA in the tolerant accession. Taken together, this study shows that differential root signalling events upon salt exposure are essential for the halophytic quinoa;the failure to do this limits quinoa adaptation to salinity, independently of salt sequestration in EBCs.

关键词： neurofibroma   neurofibromatosis   plexiform   RNAseq  

摘要： Although most commonly benign, neurofibromas (NFs) can have devastating functional and cosmetic effects in addition to the possibility of malignant transformation. Orbitofacial NFs, in particular, may cause progressive, disfiguring tumors of the lid, brow, temple, face, and orbit, and clinical evidence suggests that they may have increased local aggressiveness compared to NFs developing at other sites. The purpose of this study was to identify biological differences between orbitofacial NFs and those occurring at other anatomic sites. We performed RNA-sequencing in orbitofacial (n = 10) and non-orbitofacial (n = 9) NFs. Differential gene expression analysis demonstrated that a variety of gene sets including genes involved in cell proliferation, interferon, and immune-related pathways were enriched in orbitofacial NF. Comparisons with publicly available databases of various Schwann cell tumors and malignant peripheral nerve sheath tumor (MPNST) revealed a significant overlap of differentially expressed genes between orbitofacial versus non-orbitofacial NF and plexiform NF versus MPNST. In summary, we identified gene expression differences between orbitofacial NF and NFs occurring at other locations. Further investigation may be warranted, given that orbitofacial NF are notoriously difficult to treat and associated with disproportionate morbidity.

关键词： Engineering Fluid Dynamics   Fluid- and Aerodynamics   Engineering Thermodynamics   Heat and Mass Transfer  

摘要： A novel method for assimilating and extending measured turbulent Rayleigh-Benard convection data is presented, which relies on the fractional step method also used to solve the incompressible Navier-Stokes equation in direct numerical simulations. Our approach is used to make measured tomographic particle image velocimetry (tomo PIV) fields divergence-free and to extract temperature fields. Comparing the time average of the extracted temperature fields with the temporally averaged temperature field, measured using particle image thermometry in a subdomain of the flow geometry, shows that extracted fields correlate well with measured fields with a correlation coefficient of C-T (T) over tilde = 0.84. Additionally, extracted temperature fields as well as divergence-free velocity fields serve as initial fields for subsequent direct numerical simulations with and without feedback which generate small-scale turbulence initially absent in the experimental data. Although the tomo PIV data set was spatially under-resolved and did not include any information on the boundary layers, the here-proposed method successfully generates velocity and temperature fields featuring small-scale turbulence and thermal as well as kinetic boundary layers, without disturbing the large-scale circulation contained in the original experimental data significantly. The latter is underpinned by high vertical and horizontal velocity correlation coefficients-computed from velocity fields averaged in time and horizontal x-direction obtained from the measurement and from the simulation without feedback-of C-v (v) over tilde = 0.92 and C-w (w) over tilde = 0.91 representing the large-scale structure. For simulations with feedback, the generated velocity fields resemble the experimental data increasingly well for higher feedback gain values, whereas the temperature fluctuation intensity deviates noticeably from the values obtained from a direct numerical simulation without feedback for gain values alpha

摘要： BACKGROUND: Chronic arsenic exposure via drinking water is associated with an increased risk of developing cancer and noncancer chronic diseases. Pre-mRNAs are often subject to alternative splicing, generating mRNA isoforms encoding functionally distinct protein isoforms. The resulting imbalance in isoform species can result in pathogenic changes in critical signaling pathways. Alternative splicing as a mechanism of arsenic-induced toxicity and carcinogenicity is understudied. OBJECTIVE: This study aimed to accurately profile differential alternative splicing events in human keratinocytes induced by chronic arsenic exposure that might play a role in carcinogenesis. METHODS: Independent quadruplicate cultures of immortalized human keratinocytes (HaCaT) were maintained continuously for 28 wk with 0 or 100 nM sodium arsenite. RNA-sequencing (RNA-Seq) was performed with poly(A) RNA isolated from cells harvested at 7, 19, and 28 wk with subsequent replicate multivariate analysis of transcript splicing (rMATS) analysis to detect and quantify differential alternative splicing events. Reverse transcriptase-polymerase chain reaction (RT-PCR) for selected alternative splicing events was performed to validate RNA-Seq predictions. Functional enrichment was performed by gene ontology (GO) analysis of the differential alternative splicing event data set at each time point. RESULTS: At least 600 differential alternative splicing events were detected at each time point tested, comprising all the five main types of alternative splicing and occurring in both open reading frames (ORFs) and untranslated regions (UTRs). Based on functional relevance ELK4, SHC1, and XRRA1 were selected for validation of predicted alternative splicing events at 7 wk by RT-PCR. Densitometric analysis of RT-PCR data corroborated the rMATS predicted alternative splicing for all three events. Protein expression validation of the selected alternative splicing events was challenging given that very few isoform-

关键词： benzenoids   C6 alcohols   C6 aldehydes   light   monoterpenes   norisoprenoid  

摘要： Background and Aims Bunch bagging is a grapevine canopy management strategy to protect bunches from light, heat stress and disease pressure. The aim of this study was to unveil the effects of timing and duration of bunch bagging on grape volatile organic compounds (VOCs) at the transcriptomic and metabolic levels. Methods and Results Seven bunch bagging treatments of varying timing and duration were implemented with Cabernet Sauvignon grapes. Regardless of timing and duration, bagging significantly reduced nerol, benzaldehyde, benzeneacetaldehyde and p-cymene, and increased the concentration of phenol and 3,5-dimethylbenzaldehyde. The decrease of nerol by bagging was associated with the down-regulation of the gene encoding glycosyltransferase14 at veraison. Bagging and re-exposing bunches at the preharvest stage inhibited and benefited the accumulation of C6 alcohols. Furthermore, we infer that the higher concentration of total benzenoids in all bagged berries was due to the down-regulated expression of phenylpropanoid biosynthesis genes. The concentration of the dominant norisoprenoid, beta-damascenone, was not impacted by bunch bagging from veraison to harvest and was increased by bagging from veraison to post-veraison. All other treatments, however, reduced this compound, which was due to a lower concentration of beta-carotene and lutein, and the down-regulation of VviCCD4a and VviCCD4b. Conclusions Both timing and duration of bunch bagging can affect biosynthesis and accumulation of VOCs. Significance of the Study Insights from this study provide new knowledge on bunch bagging, as well as information regarding the sensitivity of VOCs to light and the timing of light exposure during grape ripening.

关键词： child   copeptin   diabetes insipidus   paediatric   polydipsia   polyuria   reference values  

摘要： Objectives Polyuria-polydipsia syndrome (PPS) is a common presentation in children but the differential diagnosis rests on burdensome water deprivation tests. The aims of this study were to determine a copeptin threshold to distinguish patients with central diabetes insipidus from those with primary polydipsia and to estimate the normal range of copeptin concentrations in children. Design Single-centre retrospective descriptive study. Patients Two hundred and seventy-eight children aged 2 months to 18 years who consulted for PPS (N = 40) or other reasons (control group, N = 238) at La Timone University Hospital in Marseille, France, between April 2015 and September 2019 and had a copeptin assay. Measurements Ultrasensitive copeptin assays on blood samples. Results Among the children with PPS, the mean copeptin concentrations were 1.72, 55.2 and 15.7 pmol/l in those with central diabetes insipidus (N = 21), nephrogenic diabetes insipidus (N = 3), and primary polydipsia (N = 16), respectively. Copeptin levels lower than 3.53 pmol/l were diagnostic of central diabetes insipidus with 100% sensitivity and 87.4% specificity (p < .001). The 5th-95th copeptin percentile range in the control group was 2.53-21.03 pmol/L. Copeptin levels were significantly higher in boys than in girls but there was no association with age, pubertal stage, body mass index, or the reason for consulting. Conclusions Our results indicate copeptin assays may be valuable in the differential diagnosis of PPS in children. Larger prospective studies are required to establish their accuracy in everyday clinical practice.

关键词： C-1 exponential stability   high-gain observers   Lyapunov analysis   nonlocal terms   partial integro-differential equations (PIDEs)   quasi-linear hyperbolic systems   SIR epidemic models  

摘要： This article addresses the problem of high-gain observer design for a class of quasi-linear hyperbolic systems (with one characteristic velocity), possibly including nonlocal terms, making them systems of partial integro-differential equations. The design relies on distributed measurement of a part of the state vector. The observer is presented and discussed and the exponential stability in the C-1 spatial norm of the origin for the error system is fully established via Lyapunov-based analysis. Its use is illustrated via an application to an age-dependent susceptible, infected, recovered (SIR) epidemic model.