Diverse tumorigenic consequences of human papillomavirus integration in primary oropharyngeal cancers.

Human papillomavirus (HPV) causes 5% of all cancers and frequently integrates into host chromosomes. The HPV oncoproteins E6 and E7 are necessary but insufficient for cancer formation, indicating that additional secondary genetic events are required. Here, we investigate potential oncogenic impacts of virus integration. Analysis of 105 HPV-positive oropharyngeal cancers by whole-genome sequencing detects virus integration in 77%, revealing five statistically significant sites of recurrent integration near genes that regulate epithelial stem cell maintenance (i.e., SOX2, TP63, FGFR, MYC) and immune evasion (i.e., CD274). Genomic copy number hyperamplification is enriched 16-fold near HPV integrants, and the extent of focal host genomic instability increases with their local density. The frequency of genes expressed at extreme outlier levels is increased 86-fold within ±150 kb of integrants. Across 95% of tumors with integration, host gene transcription is disrupted via intragenic integrants, chimeric transcription, outlier expression, gene breaking, and/or de novo expression of noncoding or imprinted genes. We conclude that virus integration can contribute to carcinogenesis in a large majority of HPV-positive oropharyngeal cancers by inducing extensive disruption of host genome structure and gene expression.

Broadband Tunable Infrared Light Emission from Metal-Oxide-Semiconductor Tunnel Junctions in Silicon Photonics.

Broadband near-infrared light emitting tunnel junctions are demonstrated with efficient coupling to a silicon photonic waveguide. The metal oxide semiconductor devices show long hybrid photonic-plasmonic mode propagation lengths of approximately 10 µm and thus can be integrated into an overcoupled resonant cavity with quality factor Q ≈ 49, allowing for tens of picowatt near-infrared light emission coupled directly into a waveguide. The electron inelastic tunneling transition rate and the cavity mode density are modeled, and the transverse magnetic (TM) hybrid mode excitation rate is derived. The results coincide well with polarization resolved experiments. Additionally, current-stressed devices are shown to emit unpolarized light due to radiative recombination inside the silicon electrode.

Preoperative topical estrogen application in the management of hypospadias: a systematic review.

Local estrogen therapy has been explored as an alternative to conventional testosterone therapy in children requiring urethroplasty for hypospadias. Our objective is to evaluate if preoperative estrogen stimulation reduces post-urethroplasty complications and enhances penile dimensions. A systematic search was conducted on various databases, selecting only randomized controlled trials (RCTs) that tested estrogen on hypospadias patients under 18 years. Articles underwent sorting following PRISMA guidelines and bias risk was assessed using the JBI clinical appraisal tool for RCTs. Out of 607 screened records, 10 underwent full-text review, and 4 randomized controlled trials (RCTs) were selected for analysis. The total patient cohort across studies was 387 with 174 in the estrogen group. All studies utilized topical estrogen, but in different formulations and timings. Prudence is necessary for interpreting results due to variations in formulation, timing, and hypospadias type across studies. Limited by a small number of studies and outcome presentation non-uniformity, the review suggests no change in penile dimensions or postoperative complications with topical estrogen. Further research is needed to explore wound-healing properties of estrogen in hypospadias through animal and human studies.Registration and protocol: Registered in Prospero CRD42024502183.

Dielectric Metasurface Enabled Compact, Single-Shot Digital Holography for Quantitative Phase Imaging.

Quantitative phase imaging (QPI) enables nondestructive, real-time, label-free imaging of transparent specimens and can reveal information about their fundamental properties such as cell size and morphology, mass density, particle dynamics, and cellular fluctuations. Development of high-performance and low-cost quantitative phase imaging systems is thus required in many fields, including on-site biomedical imaging and industrial inspection. Here, we propose an ultracompact, highly stable interferometer based on a single-layer dielectric metasurface for common path off-axis digital holography and experimentally demonstrate quantitative phase imaging. The interferometric imaging system leveraging an ultrathin multifunctional metasurface captures image plane holograms in a single shot and provides quantitative phase information on the test samples for extraction of its physical properties. With the benefits of planar engineering and high integrability, the proposed metasurface-based method establishes a stable miniaturized QPI system for reliable and cost-effective point-of-care devices, live cell imaging, 3D topography, and edge detection for optical computing.

Generation of Perfect Electron Vortex Beam with a Customized Beam Size Independent of Orbital Angular Momentum.

The electron vortex beam (EVB)-carrying quantized orbital angular momentum (OAM) plays an essential role in a series of fundamental research. However, the radius of the transverse intensity profile of a doughnut-shaped EVB strongly depends on the topological charge of the OAM, impeding its wide applications in electron microscopy. Inspired by the perfect vortex in optics, herein, we demonstrate a perfect electron vortex beam (PEVB), which completely unlocks the constraint between the beam size and the beam's OAM. We design nanoscale holograms to generate PEVBs carrying different quanta of OAM but exhibiting almost the same beam size. Furthermore, we show that the beam size of the PEVB can be readily controlled by only modifying the design parameters of the hologram. The generation of PEVB with a customized beam size independent of the OAM can promote various in situ applications of free electrons carrying OAM in electron microscopy.

Trial Sequential Analysis and Meta-Analysis of Olanzapine in Pediatric Patients for Chemotherapy-Induced Nausea and Vomiting (CINV).

Background and Objective: Olanzapine (OLZ) containing regimens are approved in adults for chemotherapy-induced nausea and vomiting (CINV) receiving highly emetogenic chemotherapy (HEC) or moderately emetogenic chemotherapy (MEC), and the same has not been approved in the pediatric population. In order to generate data regarding the efficacy and safety of OLZ as an adjunct to the standard of care (SoC) for CINV in pediatric patients receiving HEC/MEC, the review authors performed this systematic review and meta-analysis. Methods: A systematic literature search was performed through the databases Cochrane Library, Pub Med, and clinicaltrials.gov, from inception to September 2023, using keywords: "chemotherapy" and "olanzapine," "nausea" and "vomiting." Randomized clinical trials published in English that analyzed the efficacy and safety of olanzapine as an adjunct to SoC were included. The essential outcomes included in this study were the proportion of patients with no emesis in the acute and delayed phase, patients with no nausea in the acute and delayed phase, the proportion of patients requiring rescue medication, and the proportion of patients with reduced CNS arousal. Results: In the OLZ group, a greater number of patients had no emesis both in the acute and delayed phase (RR = 1.22; 95% CI = 1.09-1.37; P = .0004); and (RR = 1.23; 95% CI = 0.92-1.63; P = .16) respectively. Similarly, a higher number of patients showed no nausea both in the acute and delayed phase (RR = 1.08; 95% CI = 0.78-1.48; P = .66) and (RR = 1.12; 95% CI = 0.79-1.61; P = .52) respectively. The use of rescue medication was significantly less in the OLZ group (RR = 0.62; 95% CI = 0.42-0.91; P = .01). More patients experienced reduced CNS arousal in the OLZ group (RR = 2.97; 95% CI = 2.02-4.38; P < .0001). Conclusions: Olanzapine as an adjunct to the SoC may be effective in acute emesis, which may also reduce the use of rescue medication. Reduced CNS alertness was the significant adverse effect observed. For other endpoints, more studies are required to substantiate its role in CINV.

Diagnostic and therapeutic cystoscopy in bladder pain syndrome/interstitial cystitis: systematic review of literature and consensus on methodology.

INTRODUCTION AND HYPOTHESIS: Cystoscopy has been routinely performed in patients suspected to be suffering from bladder pain syndrome/interstitial cystitis (BPS/IC) across the globe. The methodology reported by various guidelines appears to have differences in the techniques and hence there is a need for a review of all those techniques in order to arrive at a consensus. The aim was to review the literature describing the prevalent techniques of cystoscopy for patients of BPS/IC and try to evolve a consensus. METHODS: The group the Global Interstitial Cystitis, Bladder Pain Society (GIBS) has worked collectively to systematically review the literature using the key words, "Cystoscopy in Hunner's lesions, bladder pain syndrome, painful bladder syndrome and interstitial cystitis" in the PubMed, COCHRANE, and SCOPUS databases. A total of 3,857 abstracts were studied and 96 articles referring to some part of technique of cystoscopy were short-listed for review as full-length articles. Finally, six articles with a description of a technique of cystoscopy were included for final tabulation and comparison. The group went on to arrive at a consensus for a stepwise technique of diagnostic and therapeutic cystoscopy in cases of BPS/IC. This technique has been compared with the previously described techniques and may serve to be a useful practical guide for treating physicians. CONCLUSION: It is important to have a uniform standardized technique for performing a diagnostic and therapeutic cystoscopy in patients with BPS/IC. Consensus on one such a technique has been arrived at and described in the present article.

Systematic scoping review of papilledema in vestibular schwannoma without hydrocephalus.

BACKGROUND: Vestibular schwannoma is a common pathology encountered by neurosurgeons worldwide. Often vestibular schwannoma presents with obstructive hydrocephalus. Papilledema is present in 8% of the patients with vestibular schwannoma, primarily due to obstructive hydrocephalus. Hyperproteinorrhachia is believed to be responsible for papilledema in the absence of hydrocephalus in vestibular schwannoma. However, there is a paucity of literature on the mechanism of papilledema in vestibular schwannoma patients with hydrocephalus. OBJECTIVE: The aim of this study was to conduct a scoping review of scientific literature on papilledema in vestibular schwannoma patients without hydrocephalus. METHODS: Design: This was a systematic scoping review and critical appraisal. Literature Search from PubMed was done following PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) and Joanna Briggs Institute guidelines for conducting and reporting scoping reviews. RESULTS: A total of seven studies, including eight patients, were identified for inclusion in the review. The studies were heterogeneous in terms of reporting for various variables. All the included studies were case reports, with the earliest publication in 1954 and the latest publication in 2020. The mean age of the patients in the included studies was 35 years, with a minimum age of 20 years and maximum age of 64 years. Approximately 62.5% were females, and 37.5% were males in the included study. Only three studies have studied cerebrospinal fluid (CSF) proteins levels in these patients. CONCLUSIONS: There is paucity in literature and a lack of evidence to conclusively state hyperproteinorrhachia as an antecedent to the development of papilledema in vestibular schwannoma patients without hydrocephalus. Younger age and female gender are risk factors for developing papilledema in the absence of hydrocephalus in vestibular schwannoma patients. Brainstem compression due to the large size of vestibular schwannoma can still have a patent aqueduct of Sylvius and no obstruction to CSF flow. The development of papilledema in vestibular schwannoma is a complex interplay of multiple factors that must be studied comprehensively for complete understanding.

Non-dysraphic extramedullary intradural spinal lipoma with neurocutaneous melanocytosis.

INTRODUCTION: Intradural spinal lipomas are very rare and constitute less than 1% of all spinal tumors. Such tumors are usually associated with spinal dysraphism and occur mostly in the lumbosacral or cervical region. Intradural spinal lipomas tends to be intramedullary or subpial. Meningeal melanocytoma is further rarer cases that comprise less than 0.1% of cases. These usually occur in the fifth or fifth decade and chances of malignant transformation are high. CASE REPORT: Here, we report an extremely rare case (first to the best of our knowledge) of a 9 years female child who presented to us with rapid progressing paraparesis. She was operated and found to have an intradural purely extramedullary spinal lipoma without spinal dysraphism. Moreover, she had melanin pigment deposits all over her meninges which is further rare. On presentation, the patient was bedridden but after surgery, the patient improved and could walk without support. CONCLUSIONS: To the best of our knowledge, this is the first case of spinal cord lipoma in dorsal location along with melanin pigments in the meninges. We discuss the pathogenesis, presentation and management of intradural extramedullary spinal lipomas.

Dicke-Cooperativity-Assisted Ultrastrong Coupling Enhancement in Terahertz Metasurfaces.

A system of N two-level atoms cooperatively interacting with a photonic field can be described as a single giant atom coupled to the field with interaction strength ∝N. This enhancement, known as Dicke cooperativity in quantum optics, has recently become an indispensable element in quantum information technology. Here, we extend the coupling beyond the standard light-matter interaction paradigm, enhancing Dicke cooperativity in a terahertz metasurface with N meta-atoms. The cooperative enhancement is manifested through the hybridization of the localized surface plasmon resonance in individual meta-atoms and surface lattice resonance due to the periodic array. Furthermore, through engineering of the capacitive split-gap in the meta-atoms, we were able to enhance the coupling rate into the ultrastrong coupling regime by a factor of N. Our strategy can serve as a new platform for demonstrating effective control of fermionic systems by weak pumping, superradiant emission, and ultrasensitive sensing of molecules.

Purple urinary bag syndrome: Our experience.

Background: Purple urinary bag syndrome (PUBS) is a visually striking and rare manifestation of urinary tract infection characterised by purple discolouration of the catheter and the urobag, which are seen primarily in patients who are on long-term indwelling catheter. This rare syndrome results due to the breakdown of indole, a by-product of dietary tryptophan metabolism, to coloured pigments indigo and indirubin by urinary bacteria, which reacts with the catheter and the bag to impart a purple colour. Methods: This was a prospective observational study, wherein all cases of PUBS diagnosed between March 2012 and February 2020 were analysed and followed up. Results: A total of five patients were presented with PUBS. Among them, four were women, and four were chronically constipated. All of them were elderly and debilitated with either being bed bound or having restricted mobility. Three of them had associated chronic kidney disease. All of them were treated successfully with change of catheters and antibiotics. Conclusion: This rare but alarming condition occurs in elderly patients who are on long-term indwelling catheters. The diagnosis is visually apparent, and the treatment may be just a simple change of catheter with oral antibiotics. The awareness may help in correct diagnosis and treatment.

Human papillomavirus and the landscape of secondary genetic alterations in oral cancers.

Human papillomavirus (HPV) is a necessary but insufficient cause of a subset of oral squamous cell carcinomas (OSCCs) that is increasing markedly in frequency. To identify contributory, secondary genetic alterations in these cancers, we used comprehensive genomics methods to compare 149 HPV-positive and 335 HPV-negative OSCC tumor/normal pairs. Different behavioral risk factors underlying the two OSCC types were reflected in distinctive genomic mutational signatures. In HPV-positive OSCCs, the signatures of APOBEC cytosine deaminase editing, associated with anti-viral immunity, were strongly linked to overall mutational burden. In contrast, in HPV-negative OSCCs, T>C substitutions in the sequence context 5'-ATN-3' correlated with tobacco exposure. Universal expression of HPV E6*1 and E7 oncogenes was a sine qua non of HPV-positive OSCCs. Significant enrichment of somatic mutations was confirmed or newly identified in PIK3CA, KMT2D, FGFR3, FBXW7, DDX3X, PTEN, TRAF3, RB1, CYLD, RIPK4, ZNF750, EP300, CASZ1, TAF5, RBL1, IFNGR1, and NFKBIA Of these, many affect host pathways already targeted by HPV oncoproteins, including the p53 and pRB pathways, or disrupt host defenses against viral infections, including interferon (IFN) and nuclear factor kappa B signaling. Frequent copy number changes were associated with concordant changes in gene expression. Chr 11q (including CCND1) and 14q (including DICER1 and AKT1) were recurrently lost in HPV-positive OSCCs, in contrast to their gains in HPV-negative OSCCs. High-ranking variant allele fractions implicated ZNF750, PIK3CA, and EP300 mutations as candidate driver events in HPV-positive cancers. We conclude that virus-host interactions cooperatively shape the unique genetic features of these cancers, distinguishing them from their HPV-negative counterparts.

Endothermic reaction at room temperature enabled by deep-ultraviolet plasmons.

Metallic nanoparticles have been used to harvest energy from a light source and transfer it to adsorbed gas molecules, which results in a reduced chemical reaction temperature. However, most reported reactions, such as ethylene epoxidation, ammonia decomposition and H-D bond formation are exothermic, and only H-D bond formation has been achieved at room temperature. These reactions require low activation energies (<2 eV), which are readily attained using visible-frequency localized surface plasmons (from ~1.75 eV to ~3.1 eV). Here, we show that endothermic reactions that require higher activation energy (>3.1 eV) can be initiated at room temperature by using localized surface plasmons in the deep-UV range. As an example, by leveraging simultaneous excitation of multiple localized surface plasmon modes of Al nanoparticles by using high-energy electrons, we initiate the reduction of CO2 to CO by carbon at room temperature. We employ an environmental transmission electron microscope to excite and characterize Al localized surface plasmon resonances, and simultaneously measure the spatial distribution of carbon gasification near the nanoparticles in a CO2 environment. This approach opens a path towards exploring other industrially relevant chemical processes that are initiated by plasmonic fields at room temperature.

Nonlinear rotation of spin-orbit coupled states in hollow ring-core fibers.

We experimentally demonstrate that when two spin-orbit coupled orbital angular momentum (OAM) modes of opposite topological charge co-propagate in the Kerr nonlinear regime in a hollow ring-core optical fiber, the vectorial mode superposition exhibits a unique power-dependent rotation effect. This effect is analogous to nonlinear polarization rotation in single-mode fibers, however, the added spatial dimension produces a visually observable rotation of the spatial pattern emerging from the fiber when imaged through a linear polarizer. A dielectric metasurface q-plate was designed and fabricated to excite the desired mode combination in a hollow ring-core fiber that supports stable propagation of OAM modes. The observed spatial patterns show strong agreement with numerical simulations of the vector coupled nonlinear Schrödinger equations. These results constitute the first measurements of what can be described as the spin-orbit coupled generalization of the nonlinear polarization rotation effect.

Treatment decision and estimation of growth of head and neck paragangliomas.

PURPOSE: Head and neck paragangliomas are slow growing tumors where observation has become more widely accepted. Tumor growth rate as well as predictors of increased tumor growth were analyzed with the goal to identify factors to better predict disease progression and counsel patients. MATERIALS AND METHODS: Multi-institutional retrospective cohort study from 2011 to 2020. RESULTS: 130 head and neck paragangliomas in 125 patients were analyzed. 38 were observed (30.4%), 16 radiated (12.8%), and 71 underwent surgery (56.8%). Surgical patients were significantly younger (p = 0.038) and with more genetically mediated paragangliomas (p = 0.026). Significantly more patients were asymptomatic in the observation group (p = 0.005). Of the 39 observed tumors, 43.6% (n = 17) grew with a tumor doubling time of 5.67 years. More than half of the observed paragangliomas had no growth. When examining symptoms postoperatively and at follow-up, the surgical cohort had significantly more worsening symptoms (p = 0.007) and new cranial neuropathies (p = 0.031). CONCLUSIONS: Head and neck paragangliomas have slow growth rates if they grow at all. Patients in the surgical cohort had more clinical symptoms at presentation and worsening postoperative symptoms.

Effect of Helicopter Transportation of Acute Ischemic Stroke Patients on Mortality and Functional Outcomes: A Systematic Review and Meta-Analysis.

OBJECTIVE: The "time is brain" concept denotes the importance of the expedited transfer of patients to stroke care centers. Helicopter emergency medical services (HEMS) can reduce the time to definitive care, which could improve neurologic prognosis and reduce mortality. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a search for randomized controlled trials, nonrandomized controlled trials, and prospective and retrospective cohort studies was performed through specific databases from inception to February 2020. Helicopter, acute stroke, and their synonyms (according to Medical Subject Headings) were included in this search. The Newcastle-Ottawa Scale was used to assess the quality of the included studies, and the Egger test was used to assess for publication bias. RESULTS: A total of 8 studies matched the inclusion criteria and were included for meta-analysis. The overall number recruited for helicopter transportation was 1,372, and for emergency standard transportation, it was 8,587. The association among HEMS and mortality was not statistically significant (odds ratio [OR] = 0.7; 95% confidence interval [CI], 0.60-1.06; P = .12). There was a significant association between good outcomes and HEMS (OR = 2; 95% CI, 1.79-2.34; P ≤ .001), and the overall poor neurologic outcome was reduced (OR = 0.52; 95% CI, 0.46-0.60; P ≤ .001). CONCLUSION: A good neurologic outcome was higher with HEMS compared with emergency standard transportation. The mortality rate was less in the emergency standard transportation group after pooled analysis but was not significant; the reduction in a poor outcome was statistically significant.

Intracranial hypertension in patients with aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis.

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating and life-threatening condition with high mortality and morbidity. Even though there is an association with intracranial pressure (ICP) raise and aSAH, there is a lack of recommendations regarding the indications for ICP monitoring in patients with aSAH. Defining what patients are at a higher risk to develop intracranial hypertension and its role in the functional outcome and mortality in patients with aSAH will be the purpose of the following systematic review and meta-analysis. The primary endpoint is to determine the prevalence and impact on mortality of ICP in patients with aSAH. Secondary endpoints aim to describe the variables related to the development of ICP and the relationship between traumatic and aneurysmal etiology of intracranial hypertension. PubMed, Embase, Central Cochrane Registry of Controlled Trials, and research meeting abstracts were searched up to August 2019 for studies that performed ICP monitoring, assessed the prevalence of intracranial hypertension and the mortality, in adults. Newcastle Ottawa scale (NOS) was used to assess study quality. The statistical analysis was performed using the Mantel-Haenszel methodology for the prevalence and mortality of intracranial hypertension for reasons with a randomized effect analysis model. Heterogeneity was assessed by I2. A total of 110 bibliographic citations were identified, 20 were considered potentially eligible, and after a review of the full text, 12 studies were considered eligible and 5 met the inclusion criteria for this review. One study obtained 7 points in the NOS, another obtained 6 points, and the rest obtained 5 points. Five studies were chosen for the final analysis, involving 793 patients. The rate of intracranial hypertension secondary to aSAH was 70.69% (95% CI 56.79-82.84%) showing high heterogeneity (I2 = 92.48%, p = < 0.0001). The results of the meta-analysis of mortality rate associated with intracranial hypertension after aSAH found a total of four studies, which involved 385 patients. The mortality rate was 30.3% (95% CI: 14.79-48.57%). Heterogeneity was statistically significant (I2 = 90.36%; p value for heterogeneity < 0.001). We found that in several studies, they reported that a high degree of clinical severity scale (Hunt and Hess or WNFS) and tomographic (Fisher) were significantly correlated with the increase in ICP above 20 mmHg (P < 0.05). The interpretation of the results could be underestimated for the design heterogeneity of the included studies. New protocols establishing the indications for ICP monitoring in aSAH are needed. Given the high heterogeneity of the studies included, we cannot provide clinical recommendations regarding this issue.

Hemoglobin levels as a transfusion criterion in moderate to severe traumatic brain injury: a systematic review and meta-analysis.

BACKGROUND: Several factors can influence the outcome of severe head injuries including the patient's hemoglobin levels. There has often been a dilemma regarding levels of hemoglobin at which red cell blood transfusion (RCBT) should be performed. OBJECTIVE: To systematically review the literature to determine the usefulness of management protocols that have hemoglobin levels <10 g/dL vs <7 g/dL as an RCBT criterion. METHODS: Following the PRISMA statement, the search was constructed using terms and descriptors of the Medical Subject Heading (MeSH), combined with Boolean operators. Full text of these articles was studied, and outcome measures at 3-6 months were considered for patients who were given a RCBT at <10 g/dL or at 7 g/dL hemoglobin levels. RESULTS: A total of 4 articles were found suitable for inclusion in the meta-analysis. RCBT below 7 g/dL was not associated with an increased risk of mortality as compared to RCBT using the value of less than 10 g/dL. RCBT at lower levels of hemoglobin was also not associated with a poor neurological outcome (GOS 4-5) but rather RCBT at lower levels lead to better outcomes (GOS 1-3) and the association was significant. CONCLUSION: Allogenic RCBT was associated with poorer neurological outcomes, within a wide range of reported differences in the hemoglobin threshold to decide for RCBT in TBI patients. Restrictive RCBT strategy may be useful in moderate to severe TBI cases although the risk of anemia-induced cerebral injury needs further investigation regarding the risks and complications inherent to RCBT.

Chiroptical Response of Aluminum Nanocrescents at Ultraviolet Wavelengths.

Manipulation of plasmon modes at ultraviolet wavelengths using engineered nanophotonic devices allows for the development of high-sensitivity chiroptical spectroscopy systems. We present here an experimental framework based on aluminum-based crescent-shaped nanostructures that exhibit a strong chiroptical response at ultraviolet wavelengths. Through utilization of higher-order plasmon modes in wavelength-scale nanostructures, we address the inherent fabrication challenges in scaling the response to higher frequencies. Additionally, the distinct far-field spectral response types are analyzed within a coupled-oscillator model framework. We find two competing chiroptical response types that contribute toward potential ambiguity in the interpretation of the circular dichroism spectra. The first, optical activity, originates from the interaction between hybridized eigenmodes, whereas the second manifests as a response superficially similar to optical activity but originating instead from differential near-field absorption modes. The study of the chiroptical response from nanoplasmonic devices presented here is expected to aid the development of next-generation chiroptical spectroscopy systems.

Photonic Spin-Multiplexing Metasurface for Switchable Spiral Phase Contrast Imaging.

As the two most representative operation modes in an optical imaging system, bright-field imaging and phase contrast imaging can extract different morphological information on an object. Developing a miniature and low-cost system capable of switching between these two imaging modes is thus very attractive for a number of applications, such as biomedical imaging. Here, we propose and demonstrate that a Fourier transform setup incorporating an all-dielectric metasurface can perform a two-dimensional spatial differentiation operation and thus achieve isotropic edge detection. In addition, the metasurface can provide two spin-dependent, uncorrelated phase profiles across the entire visible spectrum. Therefore, based on the spin-state of incident light, the system can be used for either diffraction-limited bright-field imaging or isotropic edge-enhanced phase contrast imaging. Combined with the advantages of planar architecture and ultrathin thickness of the metasurface, we envision this approach may open new vistas in the very interdisciplinary field of imaging and microscopy.