High-Q two-dimensional photonic crystal nanocavity on glass with an upper glass thin film.

We numerically analyze two-dimensional photonic crystal (PhC) nanocavities on glass with a thin glass film on top of the structure. We investigated a multistep heterostructure GaAs PhC nanocavity located on glass. We found that covering the structure even with a very thin glass film efficiently suppresses unwanted polarization mode conversion occurring due to the asymmetric refractive index environment around the PhC. We also uncovered that the glass-covered structure can exhibit a higher Q factor than that observed in the structure symmetrically cladded with thick glass. We point out that the mode mismatch between the PhC nanocavity and modes in the upper glass film largely contributed to the observed Q-factor enhancement. These observations were further analyzed through the comparison among different types of on-glass PhC nanocavities covered with thin glass films. We also discuss that the in-plane structure of the upper glass film is important for additionally enhancing the Q factor of the nanocavity.

Efficient light couplers to topological slow light waveguides in valley photonic crystals.

We numerically and experimentally demonstrate efficient light couplers between topological slow light waveguides in valley photonic crystals (VPhCs) and wire waveguides. By numerical simulations, we obtained a high coupling efficiency of -0.84 dB/coupler on average in the slow light regime of a group index ng = 10 - 30. Experimentally, we fabricated the couplers in a Si slab and measured the transmitted power of the devices. We realized a high coupling efficiency of approximately -1.2 dB/coupler in the slow light region of ng = 10 - 30, which is close to the result from the numerical simulations. These demonstrations will lay the groundwork for low-loss photonic integrated circuits using topological slow light waveguides.

Descemet stripping automated endothelial keratoplasty via a frown incision.

PURPOSE: To assess the outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) via a sclerocorneal frown incision. STUDY DESIGN: Retrospective comparative study. METHODS: The outcomes of Descement stripping endothelial keratoplasty (DSAEK) were retrospectively compared between 36 patients (36 eyes) who underwent surgery via a 3.8-mm frown incision (frown incision group) and 20 patients (20 eyes) who underwent surgery via a 4.6-mm straight incision (straight incision group). In all patients, an NS Endo-Inserter was used as the graft inserter and the incision for a frown incision was via the superior sclerocorneal site and for the straight incision via the temporal cornea. DSAEK was performed by the standard technique, except for the incision. At 1 year after surgery, the two groups were compared with respect to the visual acuity, decrease of corneal endothelial cell density, the severity of corneal astigmatism (diopters), the number of sutures for wound closure, and intraoperative/postoperative complications. RESULTS: There was no significant difference between the two groups in terms of postoperative visual acuity, corneal astigmatism, and intraoperative/postoperative complications one year after surgery. On the other hand, the number of sutures required for wound closure was 1.13 ± 0.42 in the frown incision group, whereas in the straight incision group, it was 3.20 ± 0.40, showing a significant difference (P<0.001). In addition, there was no decreased corneal endothelial cell density associated with the reduction in incision width. CONCLUSIONS: A sclerocorneal frown incision is useful for performing DSAEK with an NS Endo-Inserter as it does not affect endothelial cell loss despite its short incision width.

Effects of truncations in the N- and C-terminal domains of filensin on filament formation with phakinin in cell-free conditions and cultured cells.

Filensin and phakinin are lens fiber cell-specific proteins that constitute the beaded filaments (BFs) that are critical for maintaining lens transparency. In the Shumiya cataract rat, filensin 94 kDa undergoes N- and C-terminal proteolytic processing to give a transient 50 kDa fragment and a final 38 kDa fragment, just before opacification. To characterize the effects of this processing on filensin function, recombinant proteins representing the two filensin fragments, termed Fil(30-416) and Fil(30-369), respectively, were examined. Fil(30-416) lacks the N-terminal 29 amino acids and the C-terminal 248 amino acids. Fil(30-369) lacks the N-terminal 29 residues and the C-terminal 295 residues. In cell-free assembly characterized by electron microscopy, filensin and Fil(30-416) co-polymerized with phakinin and formed rugged, entangled filaments, whereas Fil(30-369) formed only aggregates. In cultured SW-13 and MCF-7 cells expressing fluorescent fusion proteins, filensin and Fil(30-416) co-polymerized with phakinin and formed cytoplasmic sinuous filaments with different widths, while Fil(30-369) gave aggregates. Therefore, while truncation of the N-terminal 29 amino acids did not affect filament formation, truncation of the C-terminal 295 but not the 248 residues resulted in failure of filament formation. These results indicate that the tail B region (residues 370-416) of rat filensin is essential for filament formation with phakinin. Truncation of the tail B region by proteolytic processing in the cataract rat lens might interfere with BF formation and thereby contribute to opacification.

Influence of blending and layer-by-layer assembly methods on chitosan-gelatin composite films enriched with curcumin nanoemulsion.

In this study, gelatin (GE) was composited with chitosan films (CH) and chitosan films incorporated with curcumin nanoemulsion (CH-CNE) through blending and layer-by-layer (LbL) assembly in order to overcome the physical limitations of the chitosan and its incorporated films. Furthermore, the distinctive effects of blending and LbL assembly on the physicochemical parameters of the composite films were assessed. The composite LbL films incorporated with GE exhibited improvement of water vapor barrier, tensile strength, solubility, which contributed to the enhanced antioxidant activity from the single components. By contrast, the composite films of the blending method exhibited greater elongation at break and increased swelling degree. Additionally, the films containing the nanoemulsion exhibited reduced light transmission and increased opacity. The thermal properties indicating the thermal stability and compatibility interactions of the composite films were examined by the glass transition temperature (Tg). Results revealed that the distinctive behavior of the Tg was affected by the compositing method. The LbL films exhibited substantially increased Tg, indicating enhanced thermal stability. The results indicated that the composited films formed via the LbL assembly attained better physicochemical properties and thermal stability, implying higher compatible film than the blending.

Optimizing the optical and magneto-optical response of all-dielectric metasurfaces with tilted side walls.

All-dielectric metasurfaces based on ferrimagnetic iron garnets are a promising platform for realizing ultra-compact magneto-optical (MO) devices with low loss. However, ferrimagnetic iron garnets are notorious for being intractable on fine nanopatterning, hindering the faithful fabrication of designed nanostructures. In this regard, it is important to assess the influence of fabrication imperfections on the performance of MO metasurfaces. Here, we investigate the optical properties of a MO metasurface with structural imperfections. As the most typical fabrication error, we studied the impact of the tilted side walls of cylindrical garnet disks that constitute the metasurfaces. We found that tilting the side walls drastically degrades the MO response and light transmittance of the device. Nevertheless, it was also found that the performance can be recovered by optimizing the refractive index of the material covering the upper half of the nanodisks.

Synthetic dimension band structures on a Si CMOS photonic platform.

Synthetic dimensions, which simulate spatial coordinates using nonspatial degrees of freedom, are drawing interest in topological science and other fields for modeling higher-dimensional phenomena on simple structures. We present the first realization of a synthetic frequency dimension on a silicon ring resonator integrated photonic device fabricated using a CMOS process. We confirm that its coupled modes correspond to a one-dimensional tight-binding model through acquisition of up to 280-GHz bandwidth optical frequency comb-like spectra and by measuring synthetic band structures. Furthermore, we realized two types of gauge potentials along the frequency dimension and probed their effects through the associated band structures. An electric field analog was produced via modulation detuning, whereas effective magnetic fields were induced using synchronized nearest- and second nearest-neighbor couplings. Creation of coupled mode lattices and two effective forces on a monolithic Si CMOS device represents a key step toward wider adoption of topological principles.

Unidirectional output from a quantum-dot single-photon source hybrid integrated on silicon.

We report a quantum-dot single-photon source (QD SPS) hybrid integrated on a silicon waveguide embedding a photonic crystal mirror, which reflects photons and enables efficient unidirectional output from the waveguide. The silicon waveguide is constituted of a subwavelength grating so as to maintain the high efficiency even under the presence of stacking misalignment accompanied by hybrid integration processes. Experimentally, we assembled the hybrid photonic structure by transfer printing and demonstrated single-photon generation from a QD and its unidirectional output from the waveguide. These results point out a promising approach toward scalable integration of SPSs on silicon quantum photonics platforms.

Transmission properties of microwaves at an optical Weyl point in a three-dimensional chiral photonic crystal.

Microwave transmission measurements were performed for a three-dimensional (3D) layer-by-layer chiral photonic crystal (PhC), whose photonic band structure contains 3D singular points, Weyl points. For the frequency and wavevector in the vicinity of a Weyl point, the transmitted intensity was found to be inversely proportional to the square of the propagation length. In addition, the transmitted wave was well-collimated in the plane parallel to the PhC layers, even for point-source incidence. When a plane wave was incident on the PhC containing metal scatters, the planar wavefront was reconstructed after the transmission, indicating a cloaking effect.

Change in Contralateral Muscle Blood Volume During Passive Unilateral Muscle Stretching Before and After Surgery.

OBJECTIVE: Passive muscle stretching is a common physical therapy for critically ill patients in the intensive care units. This study aimed to evaluate the effects of unilateral passive stretching of the gastrocnemius muscle (GM) before and after surgery on blood volume (BV) in the contralateral (non-stretched) GM in patients who are sedated after surgery. METHODS: We enrolled eight patients with esophageal cancer. The patients completed two sessions of passive cyclical stretching (20-s hold, 10-s release, 10 cycles) of the right GM: one before surgery (awake) and one after (under sedation). We used near-infrared spectroscopy to measure the BV in the stretched and contralateral GM. BV kinetics were compared between the ipsilateral and contralateral GM. RESULTS: In seven of the eight patients, BV in the stretched GM decreased during stretching and increased during the stretch-relaxation phase, both before and after surgery. Both before and after surgery, the change in the BV in the contralateral GM was inversely synchronized to the stretching cycle. CONCLUSIONS: Unilateral passive stretching of the GM influenced the microcirculation of the contralateral GM. The mechanism underlying the synchronous change in the BV in the contralateral GM remains to be clarified.

Experimental demonstration of topological slow light waveguides in valley photonic crystals.

We experimentally demonstrate topological slow light waveguides in valley photonic crystals (VPhCs). We employed a bearded interface formed between two topologically-distinct VPhCs patterned in an air-bridged silicon slab. The interface supports both topological and non-topological slow light modes below the light line. By means of optical microscopy, we observed light propagation in the topological mode in the slow light regime with a group index ng over 30. Furthermore, we confirmed light transmission via the slow light mode even under the presence of sharp waveguide bends. In comparison between the topological and non-topological modes, we found that the topological mode exhibits much more efficient waveguiding than the trivial one, demonstrating topological protection in the slow light regime. This work paves the way for exploring topological slow-light devices compatible with existing photonics technologies.

All-dielectric chiral-field-enhanced Raman optical activity.

Raman optical activity (ROA) is effective for studying the conformational structure and behavior of chiral molecules in aqueous solutions and is advantageous over X-ray crystallography and nuclear magnetic resonance spectroscopy in sample preparation and cost performance. However, ROA signals are inherently minuscule; 3-5 orders of magnitude weaker than spontaneous Raman scattering due to the weak chiral light-matter interaction. Localized surface plasmon resonance on metallic nanoparticles has been employed to enhance ROA signals, but suffers from detrimental spectral artifacts due to its photothermal heat generation and inability to efficiently transfer and enhance optical chirality from the far field to the near field. Here we demonstrate all-dielectric chiral-field-enhanced ROA by devising a silicon nanodisk array and exploiting its dark mode to overcome these limitations. Specifically, we use it with pairs of chemical and biological enantiomers to show >100x enhanced chiral light-molecule interaction with negligible artifacts for ROA measurements.

Bioaccessibility and antioxidant activity of phenolic acids, flavonoids, and anthocyanins of encapsulated Thai rice bran extracts during in vitro gastrointestinal digestion.

Encapsulation technique was applied to improve the stability of bioactive compounds in bran extracts from Thai rice cultivars (Khao Dawk Mali 105, Kiaw Ngu, Hom Nil, and Leum Pua), using three carriers including gelatin, gum Arabic, and the mixture of gelatin and gum Arabic. The microcapsules obtained using gelatin provided a higher production yield of 76.08, 85.63, 85.63 and 85.59%, respectively. A greater encapsulation efficiency was also observed in the extracts encapsulated with gelatin (93.45, 95.91, 91.19 and 95.09%, respectively). After simulated gastric and intestinal digestion, the microcapsules formed by using gelatin exhibited the higher release of bioactive compounds and antioxidant activity than unencapsulated extracts. However, the extracts encapsulated using gelatin and gum Arabic complex yielded the lowest release of bioactive compounds and their antioxidant activity after simulated digestion. The overall results showed that gelatin was an appropriate carrier that could protect bioactive compounds from the digestion conditions.

Operative Complications of Glaucoma Drainage Implant Tube Insertion Through the Sulcus for Pseudophakic Eye.

PRECIS: Malposition of the tube through the ciliary sulcus is more frequently observed with the Ahmed glaucoma valve (AGV) than the Baerveldt drainage implant (BDI) due to the weaker rigidity of the Ahmed tube. PURPOSE: To report intraoperative and early postoperative complications of ciliary sulcus tube insertion of glaucoma drainage implants (GDIs). PATIENTS AND METHODS: We performed retrospective analysis of 104 eyes of 94 patients with GDI tube insertion through the ciliary sulcus were performed. The rigidities of tubes were also examined using a microcompression tester. RESULTS: The mean observation period was 20.0 (range, 6 to 60) months. Thirteen eyes were treated with the BDI and 91 were with the AGV. The mean age of the patients was 69.3 (34 to 90) years. The mean intraocular pressure was 27.9 mm Hg before surgery and 12.9 mm Hg after surgery (P<0.01). Upon tube insertion 42/91 eyes (46%) with the AGV required reinsertion of the tube due to malpositioning, whereas only 1/13 (8%) eyes with BDI did (P<0.01). Transient hyphema (12 eyes) and hypotony (12 eyes) were observed as early postoperative complications with the AGV. Seven eyes with hypotony were treated by proline stenting of the tube. We could not accomplish sulcus insertions in 4 eyes. Microcompression analysis of the tubes showed that the BGI tube was more rigid than that of the AGV. CONCLUSIONS: Ciliary sulcus insertion of the tube is an effective method to control intraocular pressure. The tube of the AGV was more difficult to insert through the sulcus than the BDI due to its weaker rigidity.

Expression of leukotriene B4 receptor 1 defines functionally distinct DCs that control allergic skin inflammation.

Leukotriene B4 (LTB4) receptor 1 (BLT1) is a chemotactic G protein-coupled receptor expressed by leukocytes, such as granulocytes, macrophages, and activated T cells. Although there is growing evidence that BLT1 plays crucial roles in immune responses, its role in dendritic cells remains largely unknown. Here, we identified novel DC subsets defined by the expression of BLT1, namely, BLT1hi and BLT1lo DCs. We also found that BLT1hi and BLT1lo DCs differentially migrated toward LTB4 and CCL21, a lymph node-homing chemoattractant, respectively. By generating LTB4-producing enzyme LTA4H knockout mice and CD11c promoter-driven Cre recombinase-expressing BLT1 conditional knockout (BLT1 cKO) mice, we showed that the migration of BLT1hi DCs exacerbated allergic contact dermatitis. Comprehensive transcriptome analysis revealed that BLT1hi DCs preferentially induced Th1 differentiation by upregulating IL-12p35 expression, whereas BLT1lo DCs accelerated T cell proliferation by producing IL-2. Collectively, the data reveal an unexpected role for BLT1 as a novel DC subset marker and provide novel insights into the role of the LTB4-BLT1 axis in the spatiotemporal regulation of distinct DC subsets.

Alteration of gene expression in mice after glaucoma filtration surgery.

To clarify the early alterations of gene expression using a mouse model of glaucoma filtration surgery, we carried out microarray expression analysis. Using BALB/c mice, a filtration surgery model was made by incision of the limbal conjunctiva, followed by the insertion of a 33G needle tip into the anterior chamber, and 11-0 nylon sutures. Subgroups of mice were treated intraoperatively with 0.4 mg/ml mitomycin-C (MMC). At day 3 after surgery the bleb was maintained. The bleb region tissue was sampled 3 days after the filtration surgery, and gene expression analysis was carried out using a mouse Agilent 8 × 60 K array. We found 755 hyperexpressed transcripts in the bleb region compared to control conjunctiva. The hyperexpressed transcripts included epithelial cell metaplasia-related (Il1b, Krt16, Sprr1b), inflammation-related (Ccl2, Il6) and wound healing-related (Lox, Timp1) genes. We also found downregulation of a goblet cell marker gene (Gp2) in the bleb conjunctiva. MMC treatment suppressed elastin (Eln) gene expression and enhanced keratinization-related gene expression (Krt1, Lor) in the bleb region. Our results suggest the importance of epithelial wound healing after filtration surgery, and this filtration surgery model will be a useful tool for further pathophysiological analysis.

Proline-assisted Tube Insertion Through Sulcus in Ahmed Valve.

To prevent corneal endothelial cell loss, ciliary sulcus tube insertion is preferred for the pseudophakic eye. However, we sometimes encounter technical difficulties when inserting the tube through the sulcus. Even in cases in which we are able to insert a 23-G needle through the sulcus into the space between the iris and intraocular lens, the tube of Ahmed valve may stray into the vitreous cavity or under Elschnig pearls. To remedy such conditions, we developed a new tube insertion method using a 4-0 proline stent as a guide to insert the tube in the appropriate position.

Physicochemical stability and in vitro bioaccessibility of phenolic compounds and anthocyanins from Thai rice bran extracts.

The processing and digestive stability of ethanolic extracts from four Thai rice bran varieties, namely Khao Dawk Mali 105, Hom Nil, Kiaw Ngu, and Leum Pua, were assessed by applying different thermal and pH conditions, as well as in vitro gastrointestinal digestion models. High-performance liquid chromatography, Folin-Ciocalteu analysis, as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP) assays were used to determine the chemical composition, total phenolic content (TPC), and antioxidant activity. Thermal treatment at 100 °C for 15 min induced the degradation of phenolic components and TPC, whereas the antioxidant activities measured by DPPH and FRAP assays remained stable after the heat treatment. Higher phenolic content and antioxidant activity values were observed in the extracts incubated at acidic pH levels of 3 and 5. After simulated digestion, all extracts exhibited the decrease of phenolic compounds and anthocyanin contents, as well as antioxidant activities.