203 research outputs found
High Sensitivity Sensors Made of Perforated Waveguides
Sensors based on surface plasmons or waveguide modes are at the focus of interest for applications in biological or environmental chemistry. Waveguide-mode spectra of 1 μm-thick pure and perforated silica films comprising isolated nanometric holes with great aspect ratio were measured before and after adhesion of streptavidin at concentrations of 500 nM. The shift of the angular position for guided modes was nine times higher in perforated films than in bulk films. Capturing of streptavidin in the nanoholes is at the origin of that largely enhanced shift in the angular position as the amplitude of the guided mode in the waveguide perfectly overlaps with the perturbation caused by the molecules. Hence, the device allows for strongly confined modes and their strong perturbation to enable ultra-sensitive sensor applications
PREFRONTAL ACTIVATION DURING EMOTIONAL EXPERIENCE AS MEASURED BY NIRS
To investigate brain activation in the prefrontal cortex (PFC) during emotional
experiences, we examined blood oxygenation changes of healthy female volunteers by
using multi-channel Near Infrared Spectroscopy (NIRS). Results directly confirmed
that the PFC was activated during emotional tasks suggesting that the levels of oxy-Hb
increased significantly larger in negative periods compared with positive or neutral in
the bilateral dorsolateral PFC. There is a possibility that this brain area is associated
with the regulation of negative emotion. Our results suggest that it may be possible to
evaluate emotional changes using NIRS sensitively
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Polyethylene Glycol-Based Synthetic Hydrogel Sealant for Closing Vitrectomy Wounds: An In Vivo and Histological Study
Purpose We conducted an in vivo study using Dutch pigmented rabbit eyes to test the usefulness of polyethylene glycol (PEG) sealant for the closure of sutureless sclerotomies in microincisional vitrectomy surgery (MIVS). Methods: Three-port, 23-gauge vitrectomy was performed on rabbit eyes. After air leakage was confirmed by the application of 0.625% povidone–iodine at the sclerotomy site, PEG sealant was subconjunctivally injected using a 27-gauge needle through conjunctival incisions to cover the sclerotomy wounds, following which it was polymerized by the application of xenon light for 60 seconds. Ophthalmological examinations and intraocular pressure measurements were conducted the day before and 1, 3, 5, and 7 days after surgery. The eyes were enucleated for histological evaluation 7 days after surgery. Results: PEG sealant was rapidly polymerized by the application of xenon light after subconjunctival injection, and it firmly sealed the sclerotomies without air leakage, as confirmed by povidone–iodine dropping, in all cases. Conjunctival and scleral wounds closed with PEG sealant were successfully attached and remained intact till the end of the follow-up period. There was no sign of postoperative hypotony or infection in any eye, and no adverse effects of PEG sealant were found. In histological examination, linear scar formation and eosinophilic staining of collagen fibers were observed at the sclerotomy sites, while the sclerotomy tunnels appeared tightly closed. Conclusions: PEG sealant can be useful for the closure of sutureless 23-gauge vitrectomy incisions in rabbits. Translational Relevance The PEG sealant may become an effective option for closing vitrectomy incisions including pediatric cases
Label-free metabolic imaging of non-alcoholic-fatty-liver-disease (NAFLD) liver by volumetric dynamic optical coherence tomography
Label-free metabolic imaging of non-alcoholic fatty liver disease (NAFLD)
mouse liver is demonstrated ex vivo by dynamic optical coherence tomography
(OCT). The NAFLD mouse is a methionine choline-deficient (MCD)-diet model, and
two mice fed MCD diet for 1 and 2 weeks are involved in addition to a
normal-diet mouse. The dynamic OCT is based on repeating raster scan and
logarithmic intensity variance (LIV) analysis which enables volumetric
metabolic imaging with a standard-speed (50,000 A-lines/s) OCT system.
Metabolic domains associated with lipid droplet accumulation and inflammation
are clearly visualized three-dimensionally. Particularly, the normal-diet liver
exhibits highly metabolic vessel-like structures of peri-vascular hepatic
zones. The 1-week MCD-diet liver shows ring-shaped highly metabolic structures
formed with lipid droplets. The 2-week MCD-diet liver exhibits fragmented
vessel-like structures associated with inflammation. These results imply that
volumetric LIV imaging is useful for visualizing and assessing NAFLD
abnormalities
Plasma Thrombopoietin Levels are Unlikely to Account for the Platelet-sparing Effect of Paclitaxel in Lung Cancer Patients
Purpose: The present study was designed to determine whether the combination of carboplatin (CBDCA) with paclitaxel (PTX) spared CBDCA-induced thrombocytopenia by increased plasma thrombopoietin (TPO) levels. Methods: Patients with non-small-cell and small-cell lung cancer were consecutively assigned to CBDCA with PTX regimen (CBDCA/PTX) and CBDCA with irinotecan (CPT-11) regimen (CBDCA/CPT-11), respectively. Results: Ten patients were entered into either CBDCA/PTX (n=5) or CBDCA/CPT-11 (n=5). CBDCA/PTX showed a lesser reduction of platelet counts than CBDCA/CPT-11 (p<0.05), although more severe neutropenia was observed in CBDCA/PTX (p<0.01). The plasma TPO levels were inversely correlated with circulating platelet counts in CBDCA/PTX and CBDCA/CPT-11. However, the increased rate of plasma TPO levels in CBDCA/PTX was not significantly different from that in CBDCA/CPT-11. Conclusions: These findings suggest that the increased plasma TPO levels in CBDCA/PTX result secondarily from thrombocytopenia, and that circulating TPO is probably not involved in the platelet-sparing effect of PTX
Combined transabdominal and transperineal endoscopic pelvic exenteration for colorectal cancer: feasibility and safety of a two-team approach
Purpose: Pelvic exenteration (PE) is a highly invasive procedure with high morbidity and mortality rates. Promising options to reduce this invasiveness have included laparoscopic and transperineal approaches. The aim of this study was to identify the safety of combined transabdominal and transperineal endoscopic PE for colorectal malignancies.Methods: Fourteen patients who underwent combined transabdominal and transperineal PE (T group: 2-team approach, n = 7; O group: 1-team approach, n = 7) for colorectal malignancies between April 2016 and March 2020 in our institutions were included in this study. Clinicopathological features and perioperative outcomes were compared between groups.Results: All patients successfully underwent R0 resection. Operation time tended to be shorter in the T group (463 minutes) than in the O group (636 minutes, P = 0.080). Time to specimen removal was significantly shorter (258 minutes vs. 423 minutes, P = 0.006), blood loss was lower (343 mL vs. 867 mL, P = 0.042), and volume of blood transfusion was less (0 mL vs. 560 mL, P = 0.063) in the T group, respectively. Postoperative complications were similar between groups.Conclusion: Combined transabdominal and transperineal PE under a synchronous 2-team approach was feasible and safe, with the potential to reduce operation time, blood loss, and surgeon stress
Scleral birefringence as measured by polarization-sensitive optical coherence tomography and ocular biometric parameters of human eyes in vivo
The relationship between scleral birefringence and biometric parameters of human eyes in vivo is investigated. Scleral birefringence near the limbus of 21 healthy human eyes was measured using polarization-sensitive optical coherence tomography. Spherical equivalent refractive error, axial eye length, and intraocular pressure (IOP) were measured in all subjects. IOP and scleral birefringence of human eyes in vivo was found to have statistically significant correlations (r = −0.63, P = 0.002). The slope of linear regression was −2.4 × 10−2 deg/μm/mmHg. Neither spherical equivalent refractive error nor axial eye length had significant correlations with scleral birefringence. To evaluate the direct influence of IOP to scleral birefringence, scleral birefringence of 16 ex vivo porcine eyes was measured under controlled IOP of 5−60 mmHg. In these ex vivo porcine eyes, the mean linear regression slope between controlled IOP and scleral birefringence was −9.9 × 10−4 deg/μm/mmHg. In addition, porcine scleral collagen fibers were observed with second-harmonic-generation (SHG) microscopy. SHG images of porcine sclera, measured on the external surface at the superior side to the cornea, showed highly aligned collagen fibers parallel to the limbus. In conclusion, scleral birefringence of healthy human eyes was correlated with IOP, indicating that the ultrastructure of scleral collagen was correlated with IOP. It remains to show whether scleral collagen ultrastructure of human eyes is affected by IOP as a long-term effect
cGAS Drives Noncanonical-Inflammasome Activation in Age-Related Macular Degeneration
Geographic atrophy is a blinding form of age-related macular degeneration characterized by retinal pigmented epithelium (RPE) death; the RPE also exhibits DICER1 deficiency, resultant accumulation of endogenous Alu-retroelement RNA, and NLRP3-inflammasome activation. How the inflammasome is activated in this untreatable disease is largely unknown. Here we demonstrate that RPE degeneration in human-cell-culture and mouse models is driven by a noncanonical-inflammasome pathway that activates caspase-4 (caspase-11 in mice) and caspase-1, and requires cyclic GMP-AMP synthase (cGAS)-dependent interferon-β production and gasdermin D-dependent interleukin-18 secretion. Decreased DICER1 levels or Alu-RNA accumulation triggers cytosolic escape of mitochondrial DNA, which engages cGAS. Moreover, caspase-4, gasdermin D, interferon-β, and cGAS levels were elevated in the RPE in human eyes with geographic atrophy. Collectively, these data highlight an unexpected role of cGAS in responding to mobile-element transcripts, reveal cGAS-driven interferon signaling as a conduit for mitochondrial-damage-induced inflammasome activation, expand the immune-sensing repertoire of cGAS and caspase-4 to noninfectious human disease, and identify new potential targets for treatment of a major cause of blindness
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