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1.
BMC Biol ; 22(1): 110, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38735918

RESUMEN

BACKGROUND: Plants differ more than threefold in seed oil contents (SOCs). Soybean (Glycine max), cotton (Gossypium hirsutum), rapeseed (Brassica napus), and sesame (Sesamum indicum) are four important oil crops with markedly different SOCs and fatty acid compositions. RESULTS: Compared to grain crops like maize and rice, expanded acyl-lipid metabolism genes and relatively higher expression levels of genes involved in seed oil synthesis (SOS) in the oil crops contributed to the oil accumulation in seeds. Here, we conducted comparative transcriptomics on oil crops with two different SOC materials. In common, DIHYDROLIPOAMIDE DEHYDROGENASE, STEAROYL-ACYL CARRIER PROTEIN DESATURASE, PHOSPHOLIPID:DIACYLGLYCEROL ACYLTRANSFERASE, and oil-body protein genes were both differentially expressed between the high- and low-oil materials of each crop. By comparing functional components of SOS networks, we found that the strong correlations between genes in "glycolysis/gluconeogenesis" and "fatty acid synthesis" were conserved in both grain and oil crops, with PYRUVATE KINASE being the common factor affecting starch and lipid accumulation. Network alignment also found a conserved clique among oil crops affecting seed oil accumulation, which has been validated in Arabidopsis. Differently, secondary and protein metabolism affected oil synthesis to different degrees in different crops, and high SOC was due to less competition of the same precursors. The comparison of Arabidopsis mutants and wild type showed that CINNAMYL ALCOHOL DEHYDROGENASE 9, the conserved regulator we identified, was a factor resulting in different relative contents of lignins to oil in seeds. The interconnection of lipids and proteins was common but in different ways among crops, which partly led to differential oil production. CONCLUSIONS: This study goes beyond the observations made in studies of individual species to provide new insights into which genes and networks may be fundamental to seed oil accumulation from a multispecies perspective.


Asunto(s)
Productos Agrícolas , Perfilación de la Expresión Génica , Redes Reguladoras de Genes , Aceites de Plantas , Productos Agrícolas/genética , Productos Agrícolas/metabolismo , Aceites de Plantas/metabolismo , Perfilación de la Expresión Génica/métodos , Transcriptoma , Semillas/genética , Semillas/metabolismo , Regulación de la Expresión Génica de las Plantas
2.
Opt Lett ; 49(7): 1640-1643, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38560825

RESUMEN

The development of super-oscillatory lens (SOL) offers opportunities to realize far-field label-free super-resolution microscopy. Most microscopes based on a high numerical aperture (NA) SOL operate in the point-by-point scanning mode, resulting in a slow imaging speed. Here, we propose a high-NA metalens operating in the single-shot wide-field mode to achieve real-time super-resolution imaging. An optimization model based on the exhaustion algorithm and angular spectrum (AS) theory is developed for metalens design. We numerically demonstrate that the optimized metalens with an NA of 0.8 realizes the imaging resolution (imaging pixel size) about 0.85 times the Rayleigh criterion. The metalens can achieve super-resolution imaging of an object with over 200 pixels, which is one order of magnitude higher than the unoptimized metalens. Our method provides an avenue toward single-shot far-field label-free super-resolution imaging for applications such as real-time imaging of living cells and temporally moving particles.

3.
Phys Rev Lett ; 132(17): 177001, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38728709

RESUMEN

Asymmetric transmission in a passive vortex system is highly desirable, as it enables the development of compact vortex-based devices. However, breaking the mirror symmetry of transmission via a single metasurface poses challenges due to the inherent symmetric transmission properties in reciprocity. Here, we theoretically propose and experimentally demonstrate a novel transmission-reflection phase coupling mechanism to achieve the broken mirror symmetry of sound vortex transmission. This mechanism establishes a special coupling link between transmission and reflection waves, superimposing asymmetric reflection phases on the transmission phases. By utilizing a single passive phase gradient metasurface with asymmetric reflection phase twists, distinct transmission phase twists for mirror-symmetric incident vortices can be achieved within a cylindrical waveguide. This is typically difficult to imple-ment in a reciprocal system. Numerical and experimental results both demonstrate the broken mirror symmetry of vortex transmission and reflection. Our findings offer a new strategy for controlling vortex wave propagation, which may inspire new directional applications and extend to the field of photonics.

4.
Phys Rev Lett ; 132(18): 183801, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38759196

RESUMEN

Optical amplification and massive information transfer in modern physics depend on stimulated radiation. However, regardless of traditional macroscopic lasers or emerging micro- and nanolasers, the information modulations are generally outside the lasing cavities. On the other hand, bound states in the continuum (BICs) with inherently enormous Q factors are limited to zero-dimensional singularities in momentum space. Here, we propose the concept of spatial information lasing, whose lasing information entropy can be correspondingly controlled by near-field Bragg coupling of guided modes. This concept is verified in gain-loss metamaterials supporting full-k-space BICs with both flexible manipulations and strong confinement of light fields. The counterintuitive high-dimensional BICs exist in a continuous energy band, which provide a versatile platform to precisely control each lasing Fourier component and, thus, can directly convey rich spatial information on the compact size. Single-mode operation achieved in our scheme ensures consistent and stable lasing information. Our findings can be expanded to different wave systems and open new scenarios in informational coherent amplification and high-Q physical frameworks for both classical and quantum applications.

5.
Nano Lett ; 23(9): 3921-3928, 2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37102437

RESUMEN

Twisted photons can in principle carry a discrete unbounded amount of orbital angular momentum (OAM), which are of great significance for quantum communication and fundamental tests of quantum theory. However, the methods for characterization of the OAM quantum states present a fundamental limit for miniaturization. Metasurfaces can exploit new degrees of freedom to manipulate optical fields beyond the capabilities of bulk optics, opening a broad range of novel and superior applications in quantum photonics. Here we present a scheme to reconstruct the density matrix of the OAM quantum states of single photons with all-dielectric metasurfaces composed of birefringent meta-atoms. We have also measured the Schmidt number of the OAM entanglement by the multiplexing of multiple degrees of freedom. Our work represents a step toward the practical application of quantum metadevices for the measurement of OAM quantum states in free-space quantum imaging and communications.

6.
Int J Mol Sci ; 25(4)2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38396637

RESUMEN

A citric acid cross-linked ß-cyclodextrin (ß-CD) polymer was synthesized and loaded on micro-ceramic balls to fabricate the solid-phase adsorbents (P-MCB) for adsorption and extraction of triazole pesticides from water. The stability of ß-CD polymer and P-MCB was investigated in solutions with different pH values at different temperatures. The adsorption properties and the influence of kinetics, sorbent amount, pesticide concentration, and temperature on the adsorption capacity were evaluated. The results showed P-MCB had favorable adsorption of 15.98 mg/g flutriafol in 3.5 h. The equilibrium data followed the Freundlich equation, and the adsorption of flutriafol and diniconazole followed the second-order kinetics. The recovery rate of P-MCB for triazole pesticides in water was satisfactory, and the recovery rate was still 80.1%, even at the 10th cycle. The P-MCB had good stability, with a degradation rate of 0.2% ± 0.08 within 10 days, which could ensure extraction and recycling.


Asunto(s)
Celulosa , Ciclodextrinas , Plaguicidas , Contaminantes Químicos del Agua , Plaguicidas/química , Agua/química , Polímeros/química , Extracción en Fase Sólida , Triazoles , Adsorción , Contaminantes Químicos del Agua/química
7.
Pharmacol Res ; 198: 107007, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37992915

RESUMEN

BACKGROUND: In the past, many meta-analyses (MAs) suggested that elemene injection (EI) played a complementary and alternative role in cancer treatment. However, some results were contradictory and a lot of evidences weren't classified. Thus, their clinical guidance effect was very limited. METHODS: Two reviewers independently retrieved 8 databases from their origin to May 19, 2023 and appropriate MAs were taken into consideration. A pooled analysis was conducted to merge results extracted from trials of included MAs. The methodological quality of MAs and the evidence certainty of pooled results were assessed. RESULTS: 31 MAs were taken into analysis with poor methodological quality. The main weaknesses were in the areas of heterogeneity analysis, bias risk, and literature selection. According to the present evidence, on the one hand, compared with conventional treatment (CT) alone, EI combined with CT may significantly enhance short-term or long-term efficacy and reduce adverse reactions caused by CT in multiple cancers. On the other hand, using EI alone also can improve ORR in the malignant (pleural) effusion and lessen the recurrence rate in bladder cancer obviously with fewer adverse reactions compared with CT alone. However, this evidence was rated as moderate to very low certainty mainly due to the risk of bias in clinical trials. CONCLUSION: EI may be a viable medication for the treatment of cancer although more convincing trials are still required to demonstrate its alternative and complementary benefits. Besides, it seems to have a broad potential for further development in immunotherapy, drug delivery technique, and predictive factor.


Asunto(s)
Sesquiterpenos , Neoplasias de la Vejiga Urinaria , Humanos
8.
Nano Lett ; 22(15): 6342-6349, 2022 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-35877932

RESUMEN

Coherence, similar to amplitude, polarization, and phase, is a fundamental characteristic of the light fields and is dominated by the statistical optical property. Although spatial coherence is one of the pivotal optical dimensions, it has not been significantly manipulated on the photonic platform. Here, we theoretically and experimentally manipulate the spatial coherence of light fields by loading different random phase distributions onto the wavefront with a metasurface. We achieve the generation of partially coherent light with a predefined degree of coherence and continuously modulate it from coherent to incoherent by controlling the phase fluctuation ranges or the beam sizes. This design strategy can be easily extended to manipulate arbitrary phase-only special beams with the same degree of coherence. Our approach provides straightforward rules to manipulate the coherence of light fields in an extra-cavity-based manner and paves the way for further applications in ghost imaging and information transmission in turbulent media.

9.
J Sci Food Agric ; 103(5): 2675-2680, 2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-36229969

RESUMEN

BACKGROUND: Kiwifruit is prone to chilling stress and displays chilling injury (CI) such as lignification; however, the underlying physicochemical mechanism remains largely unknown. Here, the changes in levels of quality attributes, lignin biosynthesis, antioxidant system and sugars were compared in kiwifruit between control and hydrogen-rich water (HRW) treatments during cold storage for 90 days at 0 °C. RESULTS: The results reveal that HRW is an effective measure for CI alleviation, as indicated by the decrease in lignification level with repressed peroxidase activity but enhanced polyphenol oxidase activity. The amelioration of membrane peroxidation was suggested by the repressed levels of H2 O2 and malondialdehyde. They were accompanied by the improvement of antioxidant system, which is supported by the enhancement of sugars including fructose and glucose. CONCLUSION: In conclusion, HRW can enhance chilling tolerance, as suggested by the alleviation of lignification through inhibiting peroxidase activity and elevating the antioxidant system to attenuate membrane peroxidation. © 2022 Society of Chemical Industry.


Asunto(s)
Antioxidantes , Peroxidasas , Malondialdehído , Hidrógeno/farmacología , Agua , Frío
10.
Angew Chem Int Ed Engl ; 62(15): e202300786, 2023 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-36792541

RESUMEN

Natural light-harvesting (LH) systems can divide identical dyes into unequal aggregate states, thereby achieving intelligent "allocation of labor". From a synthetic point of view, the construction of such kinds of unequal and integrated systems without the help of proteinaceous scaffolding is challenging. Here, we show that four octatetrayne-bridged ortho-perylene diimide (PDI) dyads (POPs) self-assemble into a quadruple assembly (POP)4 both in solution and in the solid state. The two identical PDI units in each POP are compartmentalized into weakly coupled PDIs (P520) and closely stacked PDIs (P550) in (POP)4 . The two extreme pools of PDI chromophores were unambiguously confirmed by single-crystal X-ray crystallography and NMR spectroscopy. To interpret the formation of the discrete quadruple assembly, we also developed a two-step cooperative model. Quantum-chemical calculations indicate the existence of multiple couplings within and across P520 and P550, which can satisfactorily describe the photophysical properties of the unequal quadruple assembly. This finding is expected to help advance the rational design of dye stacks to emulate functions of natural LH systems.

11.
J Hum Genet ; 67(3): 165-168, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34526651

RESUMEN

Heterozygous mutations in SPTAN1 are associated with a broad phenotypical spectrum ranging from axonal neuropathy phenotypes to neurodevelopmental phenotypes with or without epilepsy. Recently, biallelic mutations in SPTAN1 were reported as a potential cause of autosomal recessive pure hereditary spastic paraplegia (HSP). However, no further HSP cases with biallelic SPTAN1 mutations have been reported. Herein, we report the clinical and genetic findings of a patient with complicated HSP likely caused by a novel homozygous SPTAN1 mutation. A patient with complicated HSP from a consanguineous family was recruited. The proband underwent detailed neurological examinations. Homozygosity mapping was performed in the proband and her healthy sister. Whole exome sequencing was performed in the proband. Our patient had early onset motor symptoms with upper motor neuron paralysis and intellectual disability, which is compatible with complicated HSP. Genetic analysis identified a rare homozygous missense mutation in SPTAN1 (c.4162A>G, p.I1388V), which was predicted to be deleterious by in silico tools. Her healthy parents and sister all carried the heterozygous mutation. Our results provided further support for the association of biallelic SPTAN1 variants with HSP and suggested that screening for the SPTAN1 gene should be considered not only in patients with pure HSP but also in patients with complicated HSP.


Asunto(s)
Paraplejía Espástica Hereditaria , Femenino , Heterocigoto , Humanos , Mutación , Linaje , Fenotipo , Paraplejía Espástica Hereditaria/genética , Secuenciación del Exoma
12.
Opt Lett ; 47(18): 4814-4817, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-36107097

RESUMEN

Optical chirality plays a key role in optical biosensing and spin-selective optical field manipulation. However, the maximum optical intrinsic chirality, which is represented by near-unity circular dichroism (CD), is yet to be achieved in a wide bandwidth range based on nanostructures. Here, we utilize dielectric bilayer polyatomic metasurfaces to realize the maximum optical intrinsic chirality over a wide bandwidth range. The CD efficiency of the two designed metasurfaces with opposite chirality is 99.9% at 1350 nm and over 98% from 1340 nm to 1361 nm. Our work provides a straightforward and powerful method for the realization of maximum optical intrinsic chirality, which has great potential in spin-selective optical wave manipulation.


Asunto(s)
Nanoestructuras , Dicroismo Circular
13.
Chemistry ; 28(71): e202201925, 2022 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-36069042

RESUMEN

Polynucleotides, DNA and RNA (mRNA and non-coding RNAs) are critically involved in the molecular pathways of disease. Small molecule binding interactions with polynucleotides can modify functional polynucleotide topologies and/or their interactions with proteins. Current approaches to library design (lead-like or fragment-like libraries) are based on protein-ligand interactions and often include careful consideration of the 3-dimensional orientation of binding motifs and exclude π-rich compounds (polyfused aromatics) to avoid off-target R/DNA interactions. In contrast to proteins, where π,π-interactions are weak, polynucleotides can form strong π,π-interactions with suitable π-rich ligands. To assist in designing a polynucleotide-biased library, a scaffold-divergent synthesis approach to polyfused aromatic scaffolds has been undertaken. Initial screening hits that form moderately stable polynucleotide-ligand-protein ternary complexes can be further optimized through judicious incorporation of substituents on the scaffold to increase protein-ligand interactions. An example of this approach is given for topoisomerase-1 (TOP1), generating a novel TOP1 inhibitory chemotype.


Asunto(s)
Polinucleótidos , ARN , Polinucleótidos/química , Ligandos , ADN/química , Proteínas
14.
Eur J Neurol ; 29(6): 1610-1618, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35147270

RESUMEN

BACKGROUND AND PURPOSE: Recently, the pathogenic and intermediate GGC repeat expansion in NOTCH2NLC was detected in Parkinson's disease (PD). However, detailed clinical, neuroimaging, and pathological information of clinically diagnosed PD patients with pathogenic GGC repeat expansion in NOTCH2NLC remains scarce. Thus, we aimed to elucidate the clinical, neuroimaging, and pathological characteristics of PD patients carrying the pathogenic GGC repeat expansion in NOTCH2NLC. METHODS: The NOTCH2NLC GGC repeat expansion was screened in 941 sporadic PD patients and 244 unrelated probands. Comprehensive assessments were performed in three PD patients with pathogenic GGC repeat expansion in NOTCH2NLC. The repeat expansion length was estimated using CRISPR/Cas9-based targeted long-read sequencing. RESULTS: The three patients (two PD patients from Family 1 and one sporadic PD) carrying the pathogenic NOTCH2NLC expansion were reconfirmed with a diagnosis of clinically established PD. Although they lacked the typical neuronal intranuclear inclusion disease (NIID) magnetic resonance imaging (MRI) feature, the typical PD pattern of striatal dopamine transporter loss was detected. Notably, all three patients presented with systemic areflexia, and other secondary causes of polyneuropathy were excluded. Skin biopsy showed intranuclear inclusions and an absence of phosphorylated alpha-synuclein deposition in the skin nerve fibers of all three patients. CONCLUSIONS: Although these clinically diagnosed PD patients with pathogenic GGC repeat expansion in NOTCH2NLC were hardly distinguishable from idiopathic PD based on clinical course and neuroimaging features, the pathological findings indicated that their phenotype was a PD phenocopy of NIID. Systemic areflexia may be an important and unique clinical clue suggesting further genetic testing and skin biopsy examination to confirm the diagnosis of NIID in patients presenting with a PD phenocopy.


Asunto(s)
Enfermedad de Parkinson , Humanos , Cuerpos de Inclusión Intranucleares/genética , Cuerpos de Inclusión Intranucleares/patología , Enfermedades Neurodegenerativas , Neuroimagen , Enfermedad de Parkinson/diagnóstico por imagen , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/patología , Expansión de Repetición de Trinucleótido
15.
Ecotoxicol Environ Saf ; 234: 113384, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35286956

RESUMEN

Pregnant women have been ubiquitously exposed to pyrethroid pesticides. Previous studies, mainly based on third trimester measurements of maternal urinary pyrethroid metabolites, have reported inconsistent findings in the effects of prenatal pyrethroid exposure on children's neurodevelopmental outcomes. The purpose of this study was to clarify if pyrethroid exposure during the entire three trimesters of pregnancy may be associated with deleterious effects on infant neurodevelopmental status, particularly at a high dosage of exposure. We measured maternal urinary concentrations of pyrethroid metabolites in all trimesters of pregnancy and assessed children's neurodevelopment at one year of age using the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Multiple linear regression models were used to estimate the effects of metabolites (3-PBA, 4 F-3-PBA, cis-DBCA) in each trimester on BSID-III composite scores. Logistic regression analyses were applied to predict developmental delay vs non-delayed status (cut-off composite score of below 80 for developmental delay) based on the maternal levels of pyrethroid metabolites. In the first, second and third trimesters of pregnancy, the detection rates of pyrethroid metabolites were 94.7%, 90.7%, and 89.0%; the 50th percentiles of exposure level were 0.24 µg/g, 0.24 µg/g and 0.21 µg/g for 3-PBA, 0.14 µg/g, 0.17 µg/g and 0.15 µg/g for 4 F-3PBA, 0.21 µg/g, 0.25 µg/g and 0.19 µg/g for cis-DBCA respectively. In the second trimester, 3-PBA was inversely associated with Cognition and Language scores [ß = -3.34 (95% CI = -6.11, -0.57) and ß = -2.90 (95% CI = -5.20, -0.61), respectively], and significantly increased the risk of Cognition and Language developmental delay [OR= 1.64 (95% CI = 1.03, 2.62) and OR = 1.52 (95% CI = 1.06, 2.19), respectively]; cis-DBCA was inversely associated with Adaptive Behavior scores [ß = -0.73 (95% CI = -1.27, -0.19)], and significantly increased the risk of Adaptive Behavior developmental delay [OR= 1.11 (95% CI = 1.02, 1.21)]. When the maternal levels of pyrethroid metabolites were stratified into the regression models according to the 90th percentile of exposure, in the first trimester, Cognition and Motor scores were inversely associated with higher cis-DBCA [ß = -7.19 (95% CI = -12.97, -1.41) and ß = -8.20 (95% CI = -13.35, -3.05), respectively], Language scores were inversely associated with higher 3-PBA [ß = -6.01 (95% CI = -10.96, -1.06)]; in the second trimester, Cognition scores were inversely associated with higher cis-DBCA [ß = -6.64 (95% CI = -12.51, -0.76)], Language scores were inversely associated with higher 3-PBA [ß = -5.17 (95% CI = -10.07, -0.27)] and cis-DBCA [ß = -5.40 (95% CI = -10.28, -0.52)]. We concluded that pyrethroid exposure in the first and second trimesters was associated with poorer infants neurodevelopmental outcomes at one year of age, and these effects were particularly pronounced at high levels of pyrethroid exposure.

16.
Dysphagia ; 37(5): 1271-1278, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-34826007

RESUMEN

The current study sought to examine longitudinal changes of dysphagia in Parkinson's disease, identify predictors of dysphagia aggravation and elucidate the influence of dysphagia on other symptoms in Parkinson's disease patients. Forty-eight patients with Parkinson's disease were enrolled. All patients underwent videofluoroscopic study of swallowing evaluation and a battery of neuropsychological assessments at baseline in 2014 and at follow-up in 2020. We used t-tests or Wilcoxon tests for comparative analysis between patients with/without dysphagia and comparative analysis of longitudinal data. We used Spearman's correlation analysis to examine predictors of dysphagia aggravation, and the Wilcoxon test to compare neuropsychological aggravation between patients with/without dysphagia at baseline. Swallowing function, cognitive function, depression, anxiety, and quality of life were aggravated at follow-up. Dysphagia prevalence increased from 27.08 at baseline to 39.58% at follow-up. Spearman's correlation results showed that dysphagia was more likely to become aggravated in male patients compared with female patients (P = 0.0049). Cognitive impairment at baseline was significantly related to dysphagia aggravation (P = 0.042). Patients with dysphagia at baseline exhibited a significantly greater increase in anxiety scores than patients without dysphagia at baseline (P = 0.021). The results revealed that male sex and cognitive impairment predicted worsening dysphagia in Parkinson's disease patients, and suggested that dysphagia may have a negative impact on anxiety in Parkinson's disease patients. The results highlight the importance of swallowing function screening and necessary instrumental checks, such as videofluoroscopic study of swallowing, in Parkinson's disease patients.


Asunto(s)
Trastornos de Deglución , Enfermedad de Parkinson , Deglución , Trastornos de Deglución/diagnóstico , Trastornos de Deglución/epidemiología , Trastornos de Deglución/etiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Enfermedad de Parkinson/complicaciones , Calidad de Vida
17.
Appl Soft Comput ; 122: 108883, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35474916

RESUMEN

From early 2020, a novel coronavirus disease pneumonia has shown a global "pandemic" trend at an extremely fast speed. Due to the magnitude of its harm, it has become a major global public health event. In the face of dramatic increase in the number of patients with COVID-19, the need for quick diagnosis of suspected cases has become particularly critical. Therefore, this paper constructs a fuzzy classifier, which aims to detect infected subjects by observing and analyzing the CT images of suspected patients. Firstly, a deep learning algorithm is used to extract the low-level features of CT images in the COVID-CT dataset. Subsequently, we analyze the extracted feature information with attribute reduction algorithm to obtain features with high recognition. Then, some key features are selected as the input for the fuzzy diagnosis model to the training model. Finally, several images in the dataset are used as the test set to test the trained fuzzy classifier. The obtained accuracy rate is 94.2%, and the F1-score is 93.8%. Experimental results show that, compared with the deep learning diagnosis methods widely used in medical image analysis, the proposed fuzzy model improves the accuracy and efficiency of diagnosis, which consequently helps to curb the spread of COVID-19.

18.
Opt Express ; 29(20): 31488-31498, 2021 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-34615240

RESUMEN

Perfect absorbers with high quality factors (Q-factors) are of great practical significance for optical filtering and sensing. Moreover, tunable multiwavelength absorbers provide a multitude of possibilities for realizing multispectral light intensity manipulation and optical switches. In this study, we demonstrate the use of vanadium dioxide (VO2)-assisted metasurfaces for tunable dual-band and high-quality-factor perfect absorption in the mid-infrared region. In addition, we discuss the potential applications of these metasurfaces in reflective intensity manipulation and optical switching. The Q-factors of the dual-band perfect absorption in the proposed metasurfaces are greater than 1000, which can be attributed to the low radiative loss induced by the guided-mode resonances and low intrinsic loss from the constituent materials. By utilizing the insulator-metal transition in VO2, we further proved that a continuous tuning of the reflectance with a large modulation depth (31.8 dB) can be realized in the designed metasurface accompanied by a dual-channel switching effect. The proposed VO2-assisted metasurfaces have potential applications in dynamic and multifunctional optical devices, such as tunable multiband filters, mid-infrared biochemical sensors, optical switches, and optical modulators.

19.
Opt Lett ; 46(15): 3528-3531, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-34329216

RESUMEN

We propose an approach to realize a multi-band on-chip photonic spin Hall effect and selective excitation of whispering gallery modes (WGMs) by integrating metasurfaces with microcavities. Free-space circularly polarized light with opposite spin angular momentum can effectively excite WGMs with opposite propagation directions at fixed wavelengths. Moreover, the different WGMs with different propagation directions and polarizations can be selectively excited by manipulating the number of antennas. We demonstrate that the optical properties (i.e., coupling efficiency, peak positions, and peak widths) of the proposed metasurface-integrated microcavities can be easily tailored by adjusting different geometric parameters. This study enables the realization of chiral microcavities with exciting novel functionalities, which may provide a further step in the development of photonic integrated circuits, optical sensing, and chiral optics.

20.
J Am Chem Soc ; 142(8): 3712-3717, 2020 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-32036654

RESUMEN

Conventionally, z-direction modulation of two-dimensional covalent organic frameworks (2D-COFs) is difficult to achieve because they rely on spontaneous π-π interactions to form 3D architectures. Herein, we report a facile construction of a novel intercalated covalent organic framework (Intercalated-COF) by synchronizing operations of supramolecular donor-acceptor (D-A) interactions (A unit: 2,5,8,11-tetra(p-formylphenyl)-perylene diimide (PDI) 1; D unit: perylene 3, as intercalator) in the vertical directions, with polymerizations (by only reacting 1 with p-phenylenediamine 2) in the lateral directions. In this Intercalated-COF, the PDI-based covalent 2D layers are uniformly separated by perylene guest layers. This supramolecular strategy opens the possibility for z-direction modulation of 2D-COFs through "intercalating" various guest molecules and thus may contribute to the exploration of advanced applications of these porous and crystalline frameworks.

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