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1.
Phys Rev Lett ; 124(2): 027401, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-32004011

RESUMO

We demonstrate a new approach for dynamically manipulating the optical response of an atomically thin semiconductor, a monolayer of MoSe_{2}, by suspending it over a metallic mirror. First, we show that suspended van der Waals heterostructures incorporating a MoSe_{2} monolayer host spatially homogeneous, lifetime-broadened excitons. Then, we interface this nearly ideal excitonic system with a metallic mirror and demonstrate control over the exciton-photon coupling. Specifically, by electromechanically changing the distance between the heterostructure and the mirror, thereby changing the local photonic density of states in a controllable and reversible fashion, we show that both the absorption and emission properties of the excitons can be dynamically modulated. This electromechanical control over exciton dynamics in a mechanically flexible, atomically thin semiconductor opens up new avenues in cavity quantum optomechanics, nonlinear quantum optics, and topological photonics.

2.
Pharmacol Res ; : 104688, 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32061838

RESUMO

Tibetan medicine (TM), the second largest traditional Chinese medicine system in China, boasts a long history and an integrated theoretical system. It abounds with classical medical works constituing a unique corpus of Tibetan materia medica (TMM). China has now conceived a modern education system of TM, and Tibetan medical hospitals at different levels have been set up. Many enterprises are granted the privileges to produce preparations of TM in compliance with Good Manufacturing Practices (GMP) regulations. However, there still exist unsolved issuess in TMM research as to the mechanism of action and the active constituents of TMM which are now been tackled through pharmacology and modern science and technology. Up till now, the mechanism of action and the active constituents of 141 medicines as well as 230 preparations of TM have been preliminarily revealed. This paper reviews in detail the development of TM and the status quo of TM's pharmacological research, in hope of serving a reference value for the promotion of the modernization of TM and understanding of TM among the medical scholars.

3.
Sci Rep ; 10(1): 2306, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32041987

RESUMO

Azadirachtin exhibits excellent bioactivities against several hundred arthropods. However, current knowlege of its biochemical effect on B. dorsalis larvae is not deep enough. In this study, integrated LC-MS and GC-MS-based untargeted metabolomics were used to analyze the changes of endogenous metabolites and the biochemical effects of azadirachtin on B. dorsalis larvae. Azadirachtin has excellent bioactivities against B. dorsalis larvae in this study, leading to a longer developmental duration, lower survival rate, and low pupa weight. The effect of azadirachtin was investigated on a total of 22 and 13 differentially abundant metabolites in the LC-MS and GC-MS-based metabolomics results, are selected respectively. Pathway analysis indicated that 14 differentially enriched metabolic pathways, including seven influential pathways, are worthy of attention. Further integrated key metabolic pathway analysis showed that histidine metabolism, D-glutamine and D-glutamate metabolism, biotin metabolism, ascorbate and aldarate metabolism, pentose and glucuronate interconversions, and alanine, aspartate and glutamate metabolism in B. dorsalis larvae are significantly relevant pathways affected by azadirachtin. Although extrapolating the bioactivity results in this study to the practical project of B. dorsalis pest management in the field has limitations, it was found that azadirachtin has a significant effect on the primary metabolism of B. dorsalis larvae.

4.
Pharmacol Res ; 153: 104655, 2020 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-31996327

RESUMO

Ischemia/reperfusion (IR) induces additional damage during the restoration of blood flow to ischemic myocardium. Urolithin B (UB) is one of the gut metabolites of ellagitannins, a class of antioxidant polyphenols, which was found to be protective against oxidative stress in multiple organs. However, the role of UB in cardiovascular disease remains elusive. Adult Sprague Dawley rats were subjected to left anterior descending artery ligation for 30 min followed by 120 min of reperfusion, with or without UB treatment. In vitro, the H9c2 cardiomyocytes were subjected to hypoxia (94 %N2/5 %CO2/1 %O2) for 3 h, followed by reoxygenation (74 %N2/5 %CO2/21 %O2) for 3 h (HR). UB was found to decrease myocardial infarct size and attenuate the cardiac dysfunction in the rats after IR, and protect against HR injury in H9c2 cardiomyocytes. Mechanistically, UB inhibited autophagy by activating Akt/mTOR/ULK1 pathway and protected against oxidative stress and caspase 3-dependent cell apoptosis. In particular, UB induced accumulation of p62 and its interaction with Keap1, which promoted Nrf2 nuclear translocation during HR insult. Of note, the protection of UB against superoxide production and apoptotic cell death was compromised with Nrf2 gene silencing. Taken together, our findings suggested that UB protected against myocardial IR injury at least partially via the p62/Keap1/Nrf2 signaling pathway, which highlights the potential of UB as a novel therapy for ischemic heart disease.

5.
J Cell Biochem ; 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31898364

RESUMO

The study aimed to investigate the expression and function of bladder cancer (BC) long noncoding RNAs (lncRNAs) using a high-throughput platform. High-throughput sequencing was used to compare the expression profiles of lncRNA in BC and adjacent normal tissues. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR), in situ hybridization, gene ontology, and Kyoto Encyclopedia of Genes and Genomes analysis were performed to verify differential expression of lncRNA. The effect of lncRNA overexpression on cellular proliferation, apoptosis, migration, and invasion was analyzed following the transfection of lncRNA overexpressing lentivirus into 5637 and T24 cell lines. The overexpressing cells were subcutaneously injected into nude mice to evaluate their effects on tumor growth. Tumor-associated RNA-binding proteins of lncRNA were analyzed by RNA pull-down combined with mass spectrometry. A total of 93 lncRNA genes were upregulated and 352 lncRNA genes were downregulated in the tissues of patients with BC. Of which, we investigated the function of downregulated lnc-MUC20-9. Overexpression of lnc-MUC20-9 in 5637 and T24 cells resulted in decreased tumor cell viability and cell clones, decreased migration and invasion, and increased apoptosis. Similarly, nude mice bearing lnc-MUC20-9 overexpressing tumor cells exhibited smaller tumor size and volume than that of mice bearing control cells. Mass spectrometry analysis showed that lnc-MUC20-9 binds to ROCK1, an oncogene whose expression was decreased in lnc-MUC20-9 overexpressing cells. The study revealed that lnc-MUC20-9 has the function of inhibiting tumor growth, migration, and invasion. In BC cells, lnc-MUC20-9 binds to ROCK1 and may be involved in lnc-MUC20-9-mediated tumor suppressor function, which might be potential therapeutic targets for BC.

6.
Cancer Sci ; 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31922633

RESUMO

The ECM protein EFEMP1 (fibulin-3) is associated with all types of solid tumor through its cell context-dependent dual function. A variant of fibulin-3 was engineered by truncation and mutation to alleviate its oncogenic function, specifically the proinvasive role in glioblastoma multiforme (GBM) cells at stem-like state. ZR30 is an in vitro synthesized 39-kDa protein of human fibulin-3 variant. It has a therapeutic effect in intracranial xenograft models of human GBM, through suppression of epidermal growth factor receptor/AKT and NOTCH1/AKT signaling in GBM cells and extracellular MMP2 activation. Glioblastoma multiforme is highly vascular, with leaky blood vessels formed by tumor cells expressing endothelial cell markers, including CD31. Here we studied GBM intracranial xenografts, 2 weeks after intratumoral injection of ZR30 or PBS, by CD31 immunohistochemistry. We found a 70% reduction of blood vessel density in ZR30-treated xenografts compared with that of PBS-treated ones. Matrigel plug assays showed the effect of ZR30 on suppressing angiogenesis. We further studied the effect of ZR30 on genes involved in endothelial transdifferentiation (ETD), in 7 primary cultures derived from 3 GBMs under different culture conditions. Two GBM cultures formed mesh structures with upregulation of ETD genes shortly after culture in Matrigel Matrix, and ZR30 suppressed both. ZR30 also downregulated ETD genes in two GBM cultures with high expression of these genes. In conclusion, multifaceted tumor suppression effects of human fibulin-3 variant include both suppression of angiogenesis and vasculogenic mimicry in GBM.

7.
Environ Technol ; : 1-44, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31996100

RESUMO

Biosorption is an emerging technology for the removal of heavy metals from industrial wastewater by natural or modified biomass. In this study, we proposed a novel protocol for making full use of seaweeds. Brown seaweed Sargassum carpophyllum residue (SCR) and green seaweed Caulerpa lentillifera residue (CLR) were obtained after extraction of the bioactive polysaccharides. The obtained residues were further chemical modified by butanedioic anhydride to obtained respective carboxylated product, named CSCR and CCLR. According to the titration results, CSCR and CCLR contained 2.77 mmol/g and 2.12 mmol/g of carboxyl group. After modification, the adsorption capacity for metal ions increased by 3-6 times. The adsorption capacity of CSCR for Cu2+, Pb2+, Cd2+ and Mn2+ was 52.37 mg/g, 107.11 mg/g, 85.62 mg/g, and 43.52 mg/g, and that of CCLR was 78.10 mg/g, 108.80 mg/g, 87.30 mg/g and 57.80 mg/g, respectively. The adsorption was well described by the pseudo-second order kinetic model and Langmuir adsorption isotherm equation.[Formula: see text].

8.
Ecotoxicol Environ Saf ; 189: 110020, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31809954

RESUMO

Azadirachtin, as the most promising and effective botanical insecticide, exhibits significant growth inhibition activity against agricultural and forestry pests. However, its biochemical effects at the metabolic level compared with those of other insect growth regulators have not been studied. Therefore, in this study, a GC-MS based untargeted metabolomics approach was applied to compare azadirachtin with pyriproxyfen (a juvenile hormone analog) and tebufenozide (a molting hormone analog) in terms of their metabolic effects on Bactrocera dorsalis larvae. The bioactivity of azadirachtin against B. dorsalis larvae was significantly different than those of pyriproxyfen and tebufenozide. A total of 693 mass features were recognized, and 112 metabolites were identified in this study. The results showed that a total of 16, 13 and 10 differentially regulated metabolites corresponding to 12, 5 and 8 pathways occur in Aza versus CK, Pyr versus CK and Teb versus CK group, respectively. Further analysis showed that 6 differentially regulated metabolites corresponding to 5 key pathways could be the primary differential metabolic response of B. dorsalis larvae to the three insect growth regulators. The pathways were myo-inositol corresponding to ascorbate and aldarate metabolism as the specific response of B. dorsalis larvae to azadirachtin; xylitol, xylulose and 3-aminopropionitrile corresponding to pentose and glucuronate interconversions, and cyanoamino acid metabolism as the common responses to azadirachtin and pyriproxyfen; and 3-hydroxypropionic acid and beta-alanine corresponding to propanoate metabolism and beta-alanine metabolism as the specific responses to tebufenozide. The results showed that the metabolic response of B. dorsalis larvae to azadirachitin is closer to that of pyriproxyfen than tebufenozide. The differentially regulated metabolites and pathways responsible for this difference are discussed.

9.
J Cell Biochem ; 121(2): 1747-1758, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31633225

RESUMO

miR-19a has been shown to be involved in coronary microvascular obstruction injury; however, the underlying molecular mechanisms remain unknown. In our study, we tried to explore the role of miR-19a in cardiomyocyte apoptosis and calcium overload in vivo and in vitro induced by hypoxia. We established the acute myocardial infarction (AMI) rat model by ligating the left anterior descending artery. The expression of miR-19a in the infarct zone of AMI rats and myocardial tissue in the same position in sham rats was analyzed using RT-qPCR while Na(+) /H(+) exchanger 1 (NHE-1) was detected by Western blotting. We also observed the effects of overexpressing miR-19a or administering an NHE-1 inhibitor (cariporide) on hypoxia-induced (HI) calcium overload and apoptosis in primary cardiomyocytes. In addition, dual-luciferase reporter assays were conducted to investigate the potential target of miR-19a on NHE-1. Decreased miR-19a expression, as well as increased apoptosis and NHE-1 expression, were observed in the AMI model. Furthermore, after hypoxia stimulation, miR-19a was gradually reduced as time increased in primary cardiomyocytes. Overexpressing miR-19a using mimics ameliorated the increase in NHE-1 in hypoxic cardiomyocytes and thereby reduced the HI cell calcium overload and cell apoptosis rate from 12.32% to 9.5% (P < .01). In addition, the dual-luciferase reporter gene assay results verified that NHE-1 was the direct target of miR-19a. Our findings suggest that miR-19a activation can attenuate HI cardiomyocyte apoptosis by downregulating NHE-1 expression and decreasing calcium overload.

10.
Neurosci Bull ; 36(1): 49-65, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31388930

RESUMO

Voltage-gated sodium channels (VGSCs) are transiently expressed in cochlear hair cells before hearing onset and play an indispensable role in shaping spontaneous activity. In this study, we showed that Na+ currents shaped the spontaneous action potentials in developing mouse inner hair cells (IHCs) by decreasing the time required for the membrane potential to reach the action-potential threshold. In immature IHCs, we identified 9 known VGSC subtypes (Nav1.1α-1.9α), among which Nav1.7α was the most highly expressed subtype and the main contributor to Na+ currents in developing hair cells. Electrophysiological recordings of two cochlea-specific Nav1.7 variants (CbmNav1.7a and CbmNav1.7b) revealed a novel loss-of-function mutation (C934R) at the extracellular linker between segments 5 and 6 of domain II. In addition, post-transcriptional modification events, such as alternative splicing and RNA editing, amended the gating properties and kinetic features of CbmNav1.7a(C934). These results provide molecular and functional characteristics of VGSCs in mammalian IHCs and their contributions to spontaneous physiological activity during cochlear maturation.

11.
Chemosphere ; 238: 124648, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524610

RESUMO

Deoxynivalenol (DON) is one of the most globally prevalent mycotoxins mainly produced by Fusarium species. It can cause pollution to water environmental quality due to its water solubility. Therefore, it is necessary to develop a green and efficient detoxification technology for DON. More importantly, the toxicity of the degradation products should be assessed. Photocatalytic degradation technology has attracted increasing attention in the field of pollutants treatment, especially for wastewater treatment. Herein, the as-prepared NaYF4:Yb,Tm@TiO2 composite (UCNP@TiO2) was employed as a novel photocatalyst for the NIR-enhanced photocatalytic degradation of DON. Three intermediate products were identified by using the ESI/MS analysis and secondary mass spectrogram, with the m/z values of 329.399, 311.243 and 280.913, respectively. Furthermore, the in vitro safety of the product mixtures with various degradation time (30 min, 60 min, 90 min and 120 min) were evaluated through the influences on cell viability, cell morphology, cell cycle, intracellular reactive oxygen species (ROS) level, cell apoptosis and antioxidant capacity of HepG2 cells. There were no significant differences in these investigated indicators between the control (free of DON) and 120 min products treatment. Overall, the results indicated that the toxicity of degradation products after 120 min irradiation was much lower and even nontoxic than that of DON.


Assuntos
Micotoxinas/química , Titânio/química , Tricotecenos/química , Purificação da Água/métodos , Sobrevivência Celular/efeitos dos fármacos , Células Hep G2/citologia , Células Hep G2/efeitos dos fármacos , Células Hep G2/metabolismo , Humanos , Micotoxinas/análise , Nanopartículas/química , Espécies Reativas de Oxigênio/metabolismo , Tricotecenos/toxicidade , Águas Residuárias/análise , Águas Residuárias/química , Poluentes da Água/química
12.
Org Lett ; 22(1): 140-144, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31858804

RESUMO

We report an I2/FeCl3-co-promoted formal [2 + 2+1] annulation of aryl methyl ketones, 2-aminobenzyl alcohols, and p-toluenesulfonylmethyl isocyanide (TosMIC) by neighboring group (-CH2OH) assistance. This is a novel example of using the Van Leusen reagent as a unique C1N1 "two-atom synthon" in the synthesis of imidazoles. Preliminary mechanism studies showed that TsCH2NH2 might be the key intermediate in this reaction. Furthermore, this reaction not only unlocks a novel strategy for imidazole synthesis, but also exploits a new reactivity of TosMIC.

13.
Biomaterials ; 231: 119669, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31865227

RESUMO

Antiretroviral therapy (ART) has improved the quality and duration of life for people living with human immunodeficiency virus (HIV) infection. However, limitations in drug efficacy, emergence of viral mutations and the paucity of cell-tissue targeting remain. We posit that to maximize ART potency and therapeutic outcomes newer drug formulations that reach HIV cellular reservoirs need be created. In a step towards achieving this goal we harnessed the aggregation-induced emission (AIE) property of the non-nucleoside reverse transcriptase inhibitor rilpivirine (RPV) and used it as a platform for drug cell and subcellular tracking. RPV nanocrystals were created with endogenous AIE properties enabling the visualization of intracellular particles in cell and tissue-based assays. The intact drug crystals were easily detected in CD4+ T cells and macrophages, the natural viral target cells, by flow cytometry and ultraperformance liquid chromatography tandem mass spectrometry. We conclude that AIE can be harnessed to monitor cell biodistribution of selective antiretroviral drug nanocrystals.

14.
J Sci Food Agric ; 100(4): 1822-1826, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31858597

RESUMO

BACKGROUND: Koumiss is a traditional fermented beverage made from mare's milk. The traditional backslopping method for koumiss production has shortcomings in terms of microbiological diversity and nutritional characteristics. In this study, a two-stage fermentation method was established to scale up the production of koumiss powder. The chemical composition and nutritional properties of a novel two-stage fermentation koumiss powder (TKP) were compared with backslopping koumiss powder (BKP). RESULTS: The TKP exhibited important nutritional and functional properties, including a high percentage of essential amino acids, and high polyunsaturated fatty acid, vitamin, and mineral content. The essential amino acid content of TKP was not significantly different from that of BKP. The oleic acid, linoleic acid, linolenic acid, and water-soluble vitamin content of TKP was higher than that of BKP. The Ca:P ratio of TKP was also close to the optimal Ca:P ratio in humans. CONCLUSION: The novel method could be applied for the scaled-up production of koumiss powder with similar nutritional properties to traditional backslopping koumiss powder. The successful production of koumiss powder could also promote the development of the koumiss industry. © 2019 Society of Chemical Industry.


Assuntos
Microbiologia de Alimentos/métodos , Kumis/análise , Leite/microbiologia , Pós/química , Aminoácidos/análise , Animais , Fermentação , Cavalos , Kumis/microbiologia , Lactobacillaceae/metabolismo , Leite/química , Minerais/análise , Valor Nutritivo , Vitaminas/análise
15.
Heart Fail Rev ; 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31820203

RESUMO

Heart failure (HF) is a worldwide disease with high levels of morbidity and mortality. The pathogenesis of HF is complicated and involves imbalances in hormone and electrolyte. B-type natriuretic peptide (BNP) has served as a biomarker of HF severity, and in recent years, it has been used to treat the disease, thanks to its cardio-protective effects, such as diuresis, natriuresis, and vasodilatation. In stage C/D HF, symptoms are severe despite elevated BNP. Disturbances in Ca2+ homeostasis are often a dominating feature of the disease, causing Ca2+-regulatory protein dysfunction, including reduced expression and activity of sarcoplasmic reticulum Ca2+-ATPase2a (SERCA2a), impaired ryanodine receptors (RYRs) function, intensive Na+-Ca2+ exchanger (NCX), and downregulation of S100A1. The relationship between natriuretic peptides (NPs) and Ca2+-regulatory proteins has been widely studied and represents important mechanisms in the etiology of HF. In this review, we present evidence that BNP may regulate Ca2+-regulatory proteins, in particular, suppressing SERCA2a and S100A1 expression. However, relationships between BNP and other Ca2+-regulatory proteins remain vague.

16.
Artigo em Inglês | MEDLINE | ID: mdl-31848248

RESUMO

Thermal emission is the process by which all objects at nonzero temperatures emit light and is well described by the Planck, Kirchhoff, and Stefan-Boltzmann laws. For most solids, the thermally emitted power increases monotonically with temperature in a one-to-one relationship that enables applications such as infrared imaging and noncontact thermometry. Here, we demonstrated ultrathin thermal emitters that violate this one-to-one relationship via the use of samarium nickel oxide (SmNiO3), a strongly correlated quantum material that undergoes a fully reversible, temperature-driven solid-state phase transition. The smooth and hysteresis-free nature of this unique insulator-to-metal phase transition enabled us to engineer the temperature dependence of emissivity to precisely cancel out the intrinsic blackbody profile described by the Stefan-Boltzmann law, for both heating and cooling. Our design results in temperature-independent thermally emitted power within the long-wave atmospheric transparency window (wavelengths of 8 to 14 µm), across a broad temperature range of ∼30 °C, centered around ∼120 °C. The ability to decouple temperature and thermal emission opens a gateway for controlling the visibility of objects to infrared cameras and, more broadly, opportunities for quantum materials in controlling heat transfer.

17.
Support Care Cancer ; 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31768732

RESUMO

PURPOSE: To evaluate the impact of disclosure/nondisclosure of cancer diagnosis on patients' posttraumatic stress symptoms (PTSS), posttraumatic growth (PTG), and quality of life (QOL). METHODS: Patients with primary hepatocellular carcinoma (HCC) who were admitted for potentially curative treatments in a teaching hospital were recruited. Patients were interviewed at admission regarding their QOL and their attitude towards disclosure of diagnosis. They were interviewed again for QOL, PTSS, and PTG at discharge and at 1 month after discharge. RESULTS: There were 300 patients recruited, 88.3% of whom preferred disclosure of cancer diagnosis. In fact, 162 patients (54.0%) received disclosure of their cancer diagnosis before discharge (disclosed group). However, for the 138 patients whose diagnoses were concealed by their families (uninformed group), 116 patients (84.1%) had learned of their diagnosis of HCC independently within 1 month after discharge. Comparing the scores at 1 month after discharge with scores at discharge showed that the PTSS score significantly declined for patients in the disclosed group and the PTG score significantly decreased for the uninformed patients at 1 month after discharge (p < 0.001 for both comparisons). Additionally, compared with the uninformed group, patients in the disclosed group had lower scores for PTSS (p < 0.001), higher scores for PTG (p < 0.001), better emotional functioning (p < 0.001), and better global QOL (p = 0.006) at 1 month after discharge. CONCLUSIONS: Our findings indicate that concealing the diagnosis of cancer from patients is unlikely to succeed. Additionally, disclosure of diagnosis is beneficial for HCC patients in reducing PTSS and improving PTG and QOL.

18.
Molecules ; 24(23)2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31757047

RESUMO

As there are increased levels and activity of butyrylcholiesterase (BChE) in the late stage of Alzheimer's disease (AD), development of selective BChE inhibitors is of vital importance. In this study, a workflow combining computational technologies and biological assays were implemented to identify selective BChE inhibitors with new chemical scaffolds. In particular, a pharmacophore model served as a 3D search query to screen three compound collections containing 3.0 million compounds. Molecular docking and cluster analysis were performed to increase the efficiency and accuracy of virtual screening. Finally, 15 compounds were retained for biological investigation. Results revealed that compounds 8 and 18 could potently and highly selectively inhibit BChE activities (IC50 values < 10 µM on human BChE, selectivity index BChE > 30). These active compounds with novel scaffolds provided us with a good starting point to further design potent and selective BChE inhibitors, which may be beneficial for the treatment of AD.

19.
Light Sci Appl ; 8: 80, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31666946

RESUMO

Optical metasurfaces have become versatile platforms for manipulating the phase, amplitude, and polarization of light. A platform for achieving independent control over each of these properties, however, remains elusive due to the limited engineering space available when using a single-layer metasurface. For instance, multiwavelength metasurfaces suffer from performance limitations due to space filling constraints, while control over phase and amplitude can be achieved, but only for a single polarization. Here, we explore bilayer dielectric metasurfaces to expand the design space for metaoptics. The ability to independently control the geometry and function of each layer enables the development of multifunctional metaoptics in which two or more optical properties are independently designed. As a proof of concept, we demonstrate multiwavelength holograms, multiwavelength waveplates, and polarization-insensitive 3D holograms based on phase and amplitude masks. The proposed architecture opens a new avenue for designing complex flat optics with a wide variety of functionalities.

20.
Can J Ophthalmol ; 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31712009

RESUMO

OBJECTIVES: The aim of this study is to report a case series of atypical presentations of intracranial dysgerminoma in which the diagnosis was delayed due to clinical and radiographic findings initially suggestive of CNS inflammatory or demyelinating diseases, such as MS. DESIGN/PARTICIPANTS/METHODS: This study is a case series detailing the history, clinical presentations, radiographic and laboratory results, and management of three patients with biopsy-proven intracranial dysgerminoma. RESULTS: All three patients demonstrated hyperintense lesions on MRI that were more suggestive of demyelinating or inflammatory diseases, including lesions involving the midbrain and corpus callosum. All three patients were serum positive for oligoclonal bands and negative for both AFP and beta-hCG (these two markers are commonly seen in dysgerminoma cases). One case involved a steroid-responsive tumor whereas the other two cases either did not respond to steroids or steroids were withheld due to uncertainty of etiology. Following biopsy, all three results were consistent with dysgerminoma. CONCLUSION: Clinicians should be aware that dysgerminoma may mimic the clinical and radiographic presentations of demyelinating diseases such as MS. These lesions can cause acute visual loss or diplopia, have MRI and CSF findings that might mimic MS, and have been shown to respond to steroids. Atypical clinical (e.g., headache, dorsal midbrain syndrome, bilateral optic neuropathy) or atypical radiographic features (e.g., mass effect, hydrocephalus) should prompt consideration for repeat imaging and possible biopsy even if serum or CSF tumor markers (beta-hCG and AFP) are negative for dysgerminoma.

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