Dynamic Ultrastrong Coupling in a 2 nm Gap Plasmonic Cavity at the Sub-Picosecond Scale.

Localized surface plasmon resonances (LSPRs) can enhance the electromagnetic fields on metallic nanostructures upon light illumination, providing an approach for manipulating light-matter interactions at the sub-wavelength scale. However, currently, there is no thorough investigation of the physical mechanism in the dynamic formation of the strongly coupled LSPRs on sub-5 nm plasmonic cavities at the sub-picosecond scale. In this work, through femtosecond broadband transient absorption spectroscopy, we reveal the dynamic ultrastrong coupling processes in a nanoparticle-in-trench (NPiT) structure containing 2 nm gap cavities, and demonstrate a coherent motional coupling between vibrating AuNPs and the nanogaps. We achieve a maximum Rabi splitting energy of ∼660 meV in the sub-picosecond hot-electron relaxation time scale under the resonant excitation of the nanogap cavity's LSPR, reaching the ultrastrong coupling regime. This leads to a change of global vibration modes for the 2 nm gap cavity, potentially related to the dynamical Casimir effect with nanogap resonators.

XPS Depth-Profiling Studies of Chlorophyll Binding to Poly(cysteine methacrylate) Scaffolds in Pigment-Polymer Antenna Complexes Using a Gas Cluster Ion Source.

X-ray photoelectron spectroscopy (XPS) depth-profiling with an argon gas cluster ion source (GCIS) was used to characterize the spatial distribution of chlorophyll a (Chl) within a poly(cysteine methacrylate) (PCysMA) brush grown by surface-initiated atom-transfer radical polymerization (ATRP) from a planar surface. The organization of Chl is controlled by adjusting the brush grafting density and polymerization time. For dense brushes, the C, N, S elemental composition remains constant throughout the 36 nm brush layer until the underlying gold substrate is approached. However, for either reduced density brushes (mean thickness ∼20 nm) or mushrooms grown with reduced grafting densities (mean thickness 6-9 nm), elemental intensities decrease continuously throughout the brush layer, because photoelectrons are less strongly attenuated for such systems. For all brushes, the fraction of positively charged nitrogen atoms (N+/N0) decreases with increasing depth. Chl binding causes a marked reduction in N+/N0 within the brushes and produces a new feature at 398.1 eV in the N1s core-line spectrum assigned to tetrapyrrole ring nitrogen atoms coordinated to Zn2+. For all grafting densities, the N/S atomic ratio remains approximately constant as a function of brush depth, which indicates a uniform distribution of Chl throughout the brush layer. However, a larger fraction of repeat units bound to Chl is observed at lower grafting densities, reflecting a progressive reduction in steric congestion that enables more uniform distribution of the bulky Chl units throughout the brush layer. In summary, XPS depth-profiling using a GCIS is a powerful tool for characterization of these complex materials.

Metasurface-Driven Optically Variable Devices.

Optically variable devices (OVDs) are in tremendous demand as optical indicators against the increasing threat of counterfeiting. Conventional OVDs are exposed to the danger of fraudulent replication with advances in printing technology and widespread copying methods of security features. Metasurfaces, two-dimensional arrays of subwavelength structures known as meta-atoms, have been nominated as a candidate for a new generation of OVDs as they exhibit exceptional behaviors that can provide a more robust solution for optical anti-counterfeiting. Unlike conventional OVDs, metasurface-driven OVDs (mOVDs) can contain multiple optical responses in a single device, making them difficult to reverse engineered. Well-known examples of mOVDs include ultrahigh-resolution structural color printing, various types of holography, and polarization encoding. In this review, we discuss the new generation of mOVDs. The fundamentals of plasmonic and dielectric metasurfaces are presented to explain how the optical responses of metasurfaces can be manipulated. Then, examples of monofunctional, tunable, and multifunctional mOVDs are discussed. We follow up with a discussion of the fabrication methods needed to realize these mOVDs, classified into prototyping and manufacturing techniques. Finally, we provide an outlook and classification of mOVDs with respect to their capacity and security level. We believe this newly proposed concept of OVDs may bring about a new era of optical anticounterfeit technology leveraging the novel concepts of nano-optics and nanotechnology.

Translating and Adapting the DISCERN Instrument Into a Simplified Chinese Version and Validating Its Reliability: Development and Usability Study.

BACKGROUND: There is a wide variation in the quality of information available to patients on the treatment of the diseases afflicting them. To help patients find clear and accessible information, many scales have been designed to evaluate the quality of health information, including the Patient Education Materials Assessment Tool; the Suitability Assessment of Materials for evaluation of health-related information for adults; and DISCERN, an instrument for judging the quality of written consumer health information on treatment choices. These instruments are primarily in English. Few of them have been translated and adapted into simplified Chinese tools for health information assessment in China. OBJECTIVE: This study aimed to translate and adapt DISCERN into the first simplified Chinese version and validate the psychometric properties of this newly developed scale for judging the quality of patient-oriented health information on treatment choices. METHODS: First, we translated DISCERN into simplified Chinese using rigorous guidelines for translation and validation studies. We tested the translation equivalence and measured the content validity index. We then presented the simplified Chinese instrument to 3 health educators and asked them to use it to assess the quality of 15 lung cancer-related materials. We calculated the Cohen κ coefficient and Cronbach α for all items and for the entire scale to determine the reliability of the new tool. RESULTS: We decided on the simplified Chinese version of the DISCERN instrument (C-DISCERN) after resolving all problems in translation, adaptation, and content validation. The C-DISCERN was valid and reliable: the content validity index was 0.98 (47/48, 98% of the items) for clarity and 0.94 (45/48, 94% of the items) for relevance, the Cronbach α for internal consistency was .93 (95% CI 0.699-1.428) for the whole translated scale, and the Cohen κ coefficient for internal consistency was 0.53 (95% CI 0.417-0.698). CONCLUSIONS: C-DISCERN is the first simplified Chinese version of the DISCERN instrument. Its validity and reliability have been attested to assess the quality of patient-targeted information for treatment choices.

The Chinese Version of the Patient Education Materials Assessment Tool for Printable Materials: Translation, Adaptation, and Validation Study.

BACKGROUND: Providing people with understandable and actionable health information can considerably promote healthy behaviors and outcomes. To this end, some valid and reliable scales assessing the patient-friendliness of health education materials, like the PEMAT-P (Patient Education Materials Assessment Tool for printable materials), have been well developed in English-speaking countries. However, the English version of the PEMAT-P has not been translated and adapted into simplified Chinese and validated in mainland China. OBJECTIVE: This study sought to translate the PEMAT-P tool into a simplified Chinese (Mandarin) version (C-PEMAT-P, a Chinese version of the Patient Education Materials Assessment Tool for printable materials) and verify its validity and reliability for assessing the comprehensibility and actionability of health education resources written in simplified Chinese. As a result, the validated C-PEMAT-P could be used to guide health researchers and educators to design more comprehensible and actionable materials for more tailored and targeted health education and interventions. METHODS: We translated the PEMAT-P into simplified Chinese in the following three steps: (1) forward-translating the PEMAT-P into simplified Chinese, (2) back-translating the simplified Chinese version into English, and (3) testing translation equivalence linguistically and culturally by examining the original English version of the PEMAT-P and the back-translated English version of the tool. Any discrepancies between the original English tool and the back-translated English tool were resolved through a panel discussion among the research team of all authors to produce a revised forward-translated Chinese version (C-PEMAT-P). We then evaluated the clarity of construction and wording as well as the content relevance of the C-PEMAT-P using a 4-point ordinal scale to determine its content validity. After that, 2 native Chinese speakers (health educators) used the C-PEMAT-P to rate 15 health education handouts concerning air pollution and health to validate their reliability. We calculated the Cohen coefficient and Cronbach α to determine the interrater agreement and internal consistency of the C-PEMAT-P, respectively. RESULTS: We finalized the translated Chinese tool after discussing the differences between the 2 English versions (original and back-translated) of the PEMAT-P, producing the final Chinese version of the PEMAT-P (C-PEMAT-P). The content validity index of the C-PEMAT-P version was 0.969, the Cohen coefficient for the interrater scoring agreement was 0.928, and the Cronbach α for internal consistency was .897. These values indicated the high validity and reliability of the C-PEMAT-P. CONCLUSIONS: The C-PEMAT-P has been proven valid and reliable. It is the first Chinese scale for assessing the comprehensibility and actionability of Chinese health education materials. It can be used as an assessment tool to evaluate health education materials currently available and a guide to help health researchers and educators design more comprehensible and actionable materials for more tailored and targeted health education and interventions.

Assessing Patients' Critical Health Literacy and Identifying Associated Factors: Cross-sectional Study.

BACKGROUND: Previous studies have revealed that functional health literacy plays a less important role than communicative and critical health literacy (CRHL) and that communicative literacy and CRHL contribute more to better patient self-management. Although improving health literacy has been identified as an approach to fostering community involvement and empowerment, CRHL may be regarded as the neglected domain of health literacy, rarely achieving any focus or interventions that claim to be working toward this outcome. Considering this research background, close scholarly attention needs to be paid to CRHL and its associated factors. OBJECTIVE: This study aimed to assess CRHL and identify essential factors closely associated with the status of CRHL among Chinese patients and to provide some implications for clinical practice, health education, medical research, and public health policy making. METHODS: We conducted this cross-sectional study, which lasted from April 8, 2022, to September 23, 2022, following the steps below. We first designed a 4-section survey questionnaire and then recruited Mandarin Chinese-speaking patients from Qilu Hospital of Shandong University, China, using randomized sampling. Subsequently, we administered the questionnaire via wenjuanxing, the most popular web-based survey platform in China, between July 20, 2022, and August 19, 2022. Finally, we used latent class modeling to analyze the valid data collected to classify the patient participants and identify the factors potentially associated with different CRHL levels. RESULTS: All data in the 588 returned questionnaires were valid. On the basis of the collected data, we classified the patient participants into 3 latent classes of limited, moderate, and adequate CRHL and identified 4 factors associated with limited CRHL, including middle and old age, male sex, lower educational attainment, and low internal drive to maintain one's health. CONCLUSIONS: Using latent class modeling, we identified 3 classes of CRHL and 4 factors associated with limited CRHL among the Chinese study participants. These literacy classes and the predicting factors ascertained in this study can provide some implications for clinical practice, health education, medical research, and health policy making.

Silicon Nanoantenna Mix Arrays for a Trifecta of Quantum Emitter Enhancements.

Dielectric nanostructures have demonstrated optical antenna effects due to Mie resonances. Previous work has exhibited enhancements in absorption, emission rates and directionality with practical limitations. In this paper, we present a Si mix antenna array to achieve a trifecta enhancement of ∼1200-fold with a Purcell factor of ∼47. The antenna design incorporates ∼10 nm gaps, within which fluorescent molecules strongly absorb the pump laser energy through a resonant mode. In the emission process, the antenna array increases the radiative decay rates of the fluorescence molecules via a Purcell effect and provides directional emission through a separate mode. This work could lead to novel CMOS-compatible platforms to enhance fluorescence for biological and chemical applications.

Multiphoton Upconversion Enhanced by Deep Subwavelength Near-Field Confinement.

Efficient generation of anti-Stokes emission within nanometric volumes enables the design of ultracompact, miniaturized photonic devices for a host of applications. Many subwavelength crystals, such as metal nanoparticles and two-dimensional layered semiconductors, have been coupled with plasmonic nanostructures for augmented anti-Stokes luminescence through multiple-harmonic generation. However, their upconversion process remains inefficient due to their intrinsic low absorption coefficients. Here, we demonstrate on-chip, site-specific integration of lanthanide-activated nanocrystals within gold nanotrenches of sub-25 nm gaps via bottom-up self-assembly. Coupling of upconversion nanoparticles to subwavelength gap-plasmon modes boosts 3.7-fold spontaneous emission rates and enhances upconversion by a factor of 100 000. Numerical investigations reveal that the gap-mode nanocavity confines incident excitation radiation into nanometric photonic hotspots with extremely high field intensity, accelerating multiphoton upconversion processes. The ability to design lateral gap-plasmon modes for enhanced frequency conversion may hold the potential to develop on-chip, background-free molecular sensors and low-threshold upconversion lasers.

High-efficiency holographic metacoder for optical masquerade.

Optical masquerades are a low-cost camouflage strategy that avoids the hidden objects to be recognized despite being detected. Here, we demonstrate an optical holography-based masquerade that could encode the camouflaged object ("bomb") into another uncorrelated phase object ("dog") by using transmissive dielectric metasurfaces with the total efficiency as high as 78% at visible wavelengths. The phase modulation in the encoded "dog" is realized by changing the inplane orientation of nanostructures. Illuminated by the circularly polarized light, the experimental hologram fabricated by using electron-beam lithography exhibits only the "dog" pattern when observing the surface of sample. To recover the hidden "bomb," one can observe the holographic image reconstructed at the Fresnel region, which works at the broadband spectrum from 540 nm to 680 nm. Such a technique might find potential applications in information security and military affairs.

The Effects of High-Salt Gastric Intake on the Composition of the Intestinal Microbiota in Wistar Rats.

BACKGROUND A high-salt diet may result in chronic disease and changes in the intestinal microbiota. This pilot study aimed to investigate the microbial composition of the intestine in Wistar rats given intragastric high-salt infusions for four weeks. MATERIAL AND METHODS Six 4-week-old male Wistar rats were fed standard chow and divided into the high-salt group (n=3) and the control study group (n=3). Rats in the high-salt group were given 1 ml of 10% NaCl solution intragastrically three times per week for four weeks. The fecal pellets were collected, and the microbiota was characterized using 16S rRNA gene sequencing that targeted the V4 region. The relative abundance of microbial populations was compared using linear discriminant analysis effect size (LEfSe) statistical analysis for the identification of biomarkers between two or more groups, principal component analysis (PCA), and linear discriminant analysis (LDA). Microbial genome prediction was performed using the phylogenetic investigation of communities by reconstructing the unobserved states (PICRUSt) bioinformatics software. RESULTS There was no significant difference in the alpha diversity of the fecal microbiota between the high-salt group and the control group. However, PCA showed structural segregation between the two groups. Further analysis using LEfSe showed that the intestinal contents in the high-salt group had significantly reduced populations of Lactobacillus and Prevotella NK3B31, and a significant increase in Alloprevotella and Prevotella 9, without physiological or pathological changes. CONCLUSIONS A pilot study in Wistar rats showed that high-salt intake was associated with a change in the composition of the intestinal microbiota.

Ultraviolet Interband Plasmonics With Si Nanostructures.

Although Si acts as an electrical semiconductor, it has properties of an optical dielectric. Here, we revisit the behavior of Si as a plasmonic metal. This behavior was previously shown to arise from strong interband transitions that lead to negative permittivity of Si across the ultraviolet spectral range. However, few have studied the plasmonic characteristics of Si, particularly in its nanostructures. In this paper, we report localized plasmon resonances of Si nanostructures and the observation of plasmon hybridization in the UV (∼250 nm wavelength). In addition, simulation results show that Si nanodisk dimers can achieve a local intensity enhancement greater than ∼500-fold in a 1 nm gap. Lastly, we investigate hybrid Si-Al nanostructures to achieve sharp resonances in the UV, due to the coupling between plasmon resonances supported by Si and Al nanostructures. These results will have potential applications in the UV range, such as nanostructured devices for spectral filtering, plasmon-enhanced Si photodetectors, interrogation of molecular chirality, and catalysis. It could have significant impact on UV photolithography on patterned Si structures.

MicroRNA-125a suppresses cell migration, invasion, and regulates hyaluronic acid synthase 1 expression by targeting signal transducers and activators of transcription 3 in renal cell carcinoma cells.

Renal cell carcinoma (RCC) is one of the most common cancers in urology. MicroRNA-125a (miR-125a) has been demonstrated to be implicated in various cancers. However, the functional role of miR-125a in RCC remains largely unclear. This study was aimed to investigate the functional role of miR-125a and the expression relevance of signal transducers and activators of transcription 3 (STAT3) with hyaluronic acid synthase 1 (HAS1) in RCC. We revealed that miR-125a was downexpressed in 786-O cells, and examined transfected efficiency. According to functional assay, overexpression of miR-125a inhibited cell migration and cell invasion, but no obvious effect was observed on cell proliferation. The luciferase activity assay showed that miR-125a could directly target STAT3 3'-untranslated regions. Meanwhile, quantitative polymerase chain reaction (qPCR) assay and Western blot analysis demonstrated that miR-125a could inhibit STAT3 expression at both messenger RNA and protein levels. Furthermore, the combination sites between STAT3 and HAS1 were predicted by prediction of transcription factor binding sites database analysis. The expression of STAT3 was correlated with HAS1 expression, exemplified by the same tendency detected by qPCR assay. Taken together, our results preliminarily demonstrate that miR-125a could constrain cell migration, invasion, and regulate HAS1 expression in RCC cells by targeting STAT3. It is likely to facilitate a better understanding of the regulation mechanisms of miR-125a in RCC.

Serum Membrane Type 1-Matrix Metalloproteinase (MT1-MMP) mRNA Protected by Exosomes as a Potential Biomarker for Gastric Cancer.

BACKGROUND Our previous research revealed that membrane type 1-matrix metalloproteinase (MT1-MMP) is overexpressed and plays a crucial role in gastric cancer (GC) progression. Exosomes are important for GC carcinogenesis, and the exosomal contents are ideal biomarkers. However, the expression of exosomal MT1-MMP mRNA in serum and its potential significance in GC remains unclear. MATERIAL AND METHODS The expression of exosomal MT1-MMP mRNA in serum of patients with GC, chronic gastritis, or atypical hyperplasia, and healthy controls was detected using real-time quantitative RT-PCR. Serum CEA, CA19-9, and CA72-4 were also measured by electrochemiluminescence assay. RESULTS Exosomes were isolated and identified in serum, and serum exosomal MT1-MMP mRNA was found to be higher in patients with GC compared with healthy controls and patients with chronic gastritis or atypical hyperplasia (all P<0.05). Serum exosomal MT1-MMP mRNA was significantly correlated with tumor diameter, differentiation, Borrmann type, invasion depth, lymphatic metastasis, distal metastasis, and TNM stage. The AUC of exosomal MT1-MMP mRNA was 0.788 (95% CI: 0.714-0.850) with 63.9% sensitivity and 87.1% specificity, and was higher than that of CEA (0.655 (95% CI: 0.573-0.730)). The combination of 2 markers gave an AUC of 0.821 (95% CI: 0.750-0.878), which was better than with the individual marker. The sensitivity, specificity, and positive and negative predictive values were 75.6%, 83.9%, 94.7%, and 47.3%, respectively. Moreover, the multiple logistic regression model showed that tumor diameter, differentiation, invasion depth, and exosomal MT1-MMP mRNA were the risk factors for lymphatic metastasis in GC. CONCLUSIONS Our results characterized serum exosomal MT1-MMP mRNA in GC, providing a foundation for discovering serum exosomes-targeted biomarkers for GC diagnosis.

Noninterleaved Metasurface for (26-1) Spin- and Wavelength-Encoded Holograms.

Nanostructured metasurfaces demonstrate extraordinary capabilities to control light at the subwavelength scale, emerging as key optical components to physical realization of multitasked devices. Progress in multitasked metasurfaces has been witnessed in making a single metasurface multitasked by mainly resorting to extra spatial freedom, for example, interleaved subarrays, different angles. However, it imposes a challenge of suppressing the cross-talk among multiwavelength without the help of extra spatial freedom. Here, we introduce an entirely novel strategy of multitasked metasurfaces with noninterleaved single-size Si nanobrick arrays and minimalist spatial freedom demonstrating massive information on 6-bit encoded color holograms. The interference between electric dipole and magnetic dipole in individual Si nanobricks with in-plane orientation enables manipulating six bases of incident photons simultaneously to reconstructed 6-bit wavelength- and spin-dependent multicolor images. Those massively reconstructed images can be distinguished by pattern recognition. It opens an alternative route for integrated optics, data encoding, security encryption, and information engineering.

After neoadjuvant chemotherapy platelet/lymphocyte ratios negatively correlate with prognosis in gastric cancer patients.

INTRODUCTION: Circulating predictors prognostic factors of neoadjuvant chemotherapy, which identify the patients who are potential possibly to benefit from it are limited at present. In this research, we aimed to compare the prognostic significance of neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) in patients with locally advance gastric carcinoma who were treated with neoadjuvant chemotherapy (NAC) followed by D2 gastrectomy. MATERIALS AND METHODS: From 2007 to 2015, 91 patients with locally advanced gastric cancer treated with NAC followed by D2 gastrectomy included in this retrospective cohort study. The correlation of clinical data, including tumor regression, response evaluation, tumor location, pathological type, systemic therapy, tumor size (cm), neural invasion, lymphatic-vascular invasion, ypTNM stage, and survival prognosis were analyzed. RESULTS: Platelet/lymphocyte ratio and neutrophil/lymphocyte ratio in gastric cancer patients were higher than in matched normal volunteers. PLR levels higher after neoadjuvant chemotherapy are associated with worse OS. Multivariate Cox proportional analysis showed that pre-neoadjuvant chemotherapy PLR was an independent prognostic factor. CONCLUSIONS: Pre-neoadjuvant chemotherapy PLR may be a feasible biomarker for survival prognosis in patients with locally advanced gastric cancer. PLR and NLR were reduced after neoadjuvant chemotherapy. After neoadjuvant chemotherapy, PLR level was negatively correlated with survival prognosis.

Printing Beyond sRGB Color Gamut by Mimicking Silicon Nanostructures in Free-Space.

Localized optical resonances in metallic nanostructures have been increasingly used in color printing, demonstrating unprecedented resolution but limited in color gamut. Here, we introduce a new nanostructure design, which broadens the gamut while retaining print resolution. Instead of metals, silicon nanostructures that exhibit localized magnetic and electric dipole resonances were fabricated on a silicon substrate coated with a Si3N4 index matching layer. Index matching allows a suppression of substrate effects, thus enabling Kerker's conditions to be met, that is, sharpened transitions in the reflectance spectra leading to saturated colors. This nanostructure design achieves a color gamut superior to sRGB, and is compatible with CMOS processes. The presented design could enable compact high-resolution color displays and filters, and the use of a Si3N4 antireflection coating can be readily extended to designs with nanostructures fabricated using other high-index materials.

Directed self-assembly of sub-10 nm particle clusters using topographical templates.

Directed self-assembly of nanoparticles (DSA-n) is an approach that creates suitable conditions to capture nanoparticles randomly dispersed in a liquid and position them into predefined locations on a solid template. Although DSA-n is emerging as a potential bottom-up patterning technique to build nanostructures using nanoparticles of various sizes, geometries and material compositions, there are still several outstanding challenges. In this paper, we focus on the DSA-n of sub-10 nm particles using topographical templates to guide them into 1D and 2D ordered arrays. The process mechanism leading DSA-n at sub-10 nm size scale has been reviewed and experimental evidence of the impact of the template on the positioning both individual and clusters of particles with low level of structure defects have also been demonstrated. Furthermore, by controlling the drying direction of the liquid within polygonal traps, we are also able to tune the spacing between the trapped nanoparticle clusters. This self-structuring phenomenon is of crucial importance for various applications such as plasmonics and charge transport within quantum circuits, whereby the coupling effects are highly dependent on the size of the nanoparticles and their separation.

Second-Harmonic Generation from Sub-5 nm Gaps by Directed Self-Assembly of Nanoparticles onto Template-Stripped Gold Substrates.

Strong field enhancement and confinement in plasmonic nanostructures provide suitable conditions for nonlinear optics in ultracompact dimensions. Despite these enhancements, second-harmonic generation (SHG) is still inefficient due to the centrosymmetric crystal structure of the bulk metals used, e.g., Au and Ag. Taking advantage of symmetry breaking at the metal surface, one could greatly enhance SHG by engineering these metal surfaces in regions where the strong electric fields are localized. Here, we combine top-down lithography and bottom-up self-assembly to lodge single rows of 8 nm diameter Au nanoparticles into trenches in a Au film. The resultant "double gap" structures increase the surface-to-volume ratio of Au colocated with the strong fields in ∼2 nm gaps to fully exploit the surface SHG of Au. Compared to a densely packed arrangement of AuNPs on a smooth Au film, the double gaps enhance SHG emission by 4200-fold to achieve an effective second-order susceptibility χ((2)) of 6.1 pm/V, making it comparable with typical nonlinear crystals. This patterning approach also allows for the scalable fabrication of smooth gold surfaces with sub-5 nm gaps and presents opportunities for optical frequency up-conversion in applications that require extreme miniaturization.

Plasmon excitation on flat graphene by s-polarized beams using four-wave mixing.

Graphene plasmons have received significant attention recently due to its attractive properties such as high spatial confinement and tunability. However, exciting plasmons on graphene effectively still remains a challenge owing to the large wave-vector mismatch between the optical beam in air and graphene plasmon. In this paper, we present a novel scheme capable of exciting graphene surface plasmons (GSPs) on a flat suspended graphene by using only s-polarized optical beams through four-wave mixing (FWM) process, where the GSPs fields were derived analytically based on the Green's function analysis, under the basis of momentum conservation. By incorporating the merits of nonlinear optics, the presented scheme avoids any patterning of either graphene or substrate. We believe that the proposed scheme potentially paves the way towards an efficient pure optical excitation, switching and modulation of GSPs for realizing graphene-based nano-photonic and optoelectronic integrated circuits.

Downregulation of urinary cell-free microRNA-214 as a diagnostic and prognostic biomarker in bladder cancer.

BACKGROUND AND OBJECTIVES: We aimed to investigate potential of urinary cell-free microRNA-214 (miR-214) as a noninvasive biomarker for bladder cancer in this report. METHODS: We screened miR-214 expression in medium from 2 bladder cancer cell lines to determine whether it is secretory. Then we validated expression of cell-free miR-214 in urine samples from an independent set of 192 preoperative bladder cancer patients, 80 matching postoperative patients and 169 healthy controls. RESULTS: miR-214 was secreted from bladder cancer cell lines. Cell-free miR-214 levels were significantly attenuated in preoperative urine from bladder cancer patients, whereas its expression significantly increased in matched postoperative urine. Underexpressed extracellular miR-214 in urine was significantly associated with higher tumor stage, higher lymph node status, higher grade, age and history of non-muscle-invasive bladder cancer (NMIBC). Urinary cell-free miR-214 could forcefully differentiate bladder cancer (area under the curve; AUC = 0.838; 95% CI = 0.796-0.875) patients from healthy controls. Additionally, miR-214 in urine supernatant could serve as an independent prognostic predicator of recurrence-free survival (RFS) and overall survival (OS) for patients with muscle-invasive bladder cancer (MIBC). CONCLUSIONS: Urinary cell-free miR-214 is a hopeful biomarker for tumor stratification, early diagnosis and prognostic assessment of bladder cancer.