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Functionalization of micro-size garnet at the end of optical fiber for magneto-optical applications.Optics Express Feb 2024We utilized a metal propionate solution to prepare polycrystalline bismuth-substituted yttrium iron garnets through the metal-organic decomposition process. After...
We utilized a metal propionate solution to prepare polycrystalline bismuth-substituted yttrium iron garnets through the metal-organic decomposition process. After conducting thorough optimization, we successfully synthesized a garnet that exhibited a high magneto-optic response directly at the end of an optical fiber. A notable achievement of our work lies in the ability to restrict the size and position of the garnet to match the dimensions of the fiber's core. The functionalized fiber was integrated into a magneto-optical sensor setup, offering the flexibility to operate either in the Faraday rotation or magnetic circular dichroism mode.
PubMed: 38439442
DOI: 10.1364/OE.503864 -
Optics Express Feb 2024In this work, we employ Rb atoms as rotation media to manipulate the polarization of optical fields in both magnetic and magnetic-free environments. Employing the...
In this work, we employ Rb atoms as rotation media to manipulate the polarization of optical fields in both magnetic and magnetic-free environments. Employing the nonlinear magneto-optical rotation mechanism, we achieve a state-of-the-art magneto-optical rotation coefficient of 1.74×10 rad⋅T⋅m which is four orders of magnitude higher than commonly employed materials. Additionally, in a magnetic-free environment, we achieve all-optical cross-polarization modulation between the pump and probe light via Rb atoms. The nonlinear magneto-optical rotation configuration introduces inventive techniques for a new type of magneto-optical modulator while the all-optical configuration paves the way for exploring photonic integrated circuit (PIC) devices free from disruptions caused by electrical or magnetic crosstalk.
PubMed: 38439436
DOI: 10.1364/OE.514173 -
Optics Express Feb 2024Coherent superposition has been proposed to synthesize high-order quadrature amplitude modulation (QAM) by coherently superposing low-order QAMs in the optical domain....
Coherent superposition has been proposed to synthesize high-order quadrature amplitude modulation (QAM) by coherently superposing low-order QAMs in the optical domain. These approaches could effectively relax the digital-to-analog converter resolution and reduce the complexity of the driving electronics. However, in the superposition process, imperfect phase rotations (IPRs) in low-order QAMs will be transferred to the resultant high-order QAM. Importantly, the induced IPR cannot be compensated for by conventional linear equalizers and carrier recovery methods. To combat the induced IPR, herein, we propose a hierarchical blind phase search (HBPS) algorithm to compensate for the IPRs in synthesized high-order QAMs. The proposed HBPS can match the generation mechanism of the IPRs in coherent superposition, by tracing back and estimating the IPR in the QPSK-like constellation of each hierarchy and finally correcting the induced IPRs. Simulation and experimental results verify that this algorithm could effectively compensate for the IPR in the resultant 16-QAMs synthesized using coherent superposition approaches. The proposed HBPS shows significant optical signal-to-noise ratio (OSNR) gains compared to the conventional blind phase search (BPS) method for high-order QAMs coherently superposed using optical signal processing (OSP) and tandem modulators (TMs). Specifically, at the BER of 2.4e-2, the HBPS achieves a 1.5-dB OSNR sensitivity enhancement over the BPS in either OSP or TMs-based schemes, even with an imperfection rotation of up to 20.
PubMed: 38439417
DOI: 10.1364/OE.509523 -
Scientific Reports Feb 2024Colonoscopy and endoscopic ultrasound play pivotal roles in the assessment of rectal diseases, especially rectal cancer and inflammatory bowel diseases. Optical...
Colonoscopy and endoscopic ultrasound play pivotal roles in the assessment of rectal diseases, especially rectal cancer and inflammatory bowel diseases. Optical coherence tomography (OCT) offers a superior depth resolution, which is a critical factor for individualizing the therapeutic concept and evaluating the therapy response. We developed two distinct rectoscope prototypes, which were integrated into a 1300 nm MHz-OCT system constructed at our facility. The rapid rotation of the distal scanning probe at 40,000 revolutions per minute facilitates a 667 Hz OCT frame rate, enabling real-time endoscopic imaging of large areas. The performance of these OCT-rectoscopes was assessed in an ex vivo porcine colon and a post mortem human in-situ colon. The OCT-rectoscope consistently distinguished various layers of the intestinal wall, identified gut-associated lymphatic tissue, and visualized a rectal polyp during the imaging procedure with 3D-reconstruction in real time. Subsequent histological examination confirmed these findings. The body donor was preserved using an ethanol-glycerol-lysoformin-based technique for true-to-life tissue consistency. We could demonstrate that the novel MHZ-OCT-rectoscope effectively discriminates rectal wall layers and crucial tissue characteristics in a post mortem human colon in-situ. This real-time-3D-OCT holds promise as a valuable future diagnostic tool for assessing disease state and therapy response on-site in rectal diseases.
Topics: Animals; Swine; Humans; Tomography, Optical Coherence; Proctoscopy; Endoscopy, Gastrointestinal; Rectum; Rectal Diseases; Rectal Neoplasms
PubMed: 38409328
DOI: 10.1038/s41598-024-55338-5 -
Translational Vision Science &... Feb 2024This study aimed to determine the influence of decentration, rotation, and tilt on objective optical quality of plate haptic toric intraocular lenses (tIOLs).
PURPOSE
This study aimed to determine the influence of decentration, rotation, and tilt on objective optical quality of plate haptic toric intraocular lenses (tIOLs).
METHODS
The area ratio of modulation transfer function (MTF), strehl ratio of point spread function (PSF), and higher order aberrations (HOAs) for 3 mm and 5 mm pupil diameter (PD) were evaluated at postoperative 1 month. The retroillumination images pictured by OPD-scan III were used to quantify the degree of decentration and rotation, whereas the tIOL tilt was directly obtained by the tilt aberration. Patients were separated into two subgroups based on tIOL misalignment cutoff values.
RESULTS
There were 29 eyes (24 patients) in the study. The decentration of more than 0.25 mm did not substantially differ from those less than or equal to 0.25 mm. PSF of 3 mm PD and MTF, intraocular HOAs, and trefoil aberration for 3 mm and 5 mm PD significantly deteriorated with a rotation of more than 3 degrees, whereas only intraocular HOAs for 5 mm PD and coma for 3 mm and 5 mm PD were significantly severe with a tilt of more than 0.1 µm and 0.25 µm in corresponding PD. Furthermore, tIOL rotation and tilt were highly correlated with intraocular trefoil aberration and coma, respectively.
CONCLUSIONS
The decentration of the monofocal bitoric IOLs is more tolerant to optical quality degradation after 1 month of surgery but more sensitive to intraocular trefoil aberration caused by rotation and coma aberration induced by tilt.
TRANSLATIONAL RELEVANCE
As far as we know, this is the first study to investigate the relationship between the plate haptic bitoric IOL misalignment and objective optical quality measured by OPD-scan III in the real world, which may provide reference information for IOL selection to improve surgical outcomes.
Topics: Humans; Coma; Haptic Technology; Rotation; Lenses, Intraocular; Postoperative Period
PubMed: 38407885
DOI: 10.1167/tvst.13.2.19 -
ACS Omega Feb 2024The phytochemical investigation of the whole plants of Lindl. var. led to the discovery of three new phenolic glycosides, i.e., coelofusides A-C () and 12 known...
The phytochemical investigation of the whole plants of Lindl. var. led to the discovery of three new phenolic glycosides, i.e., coelofusides A-C () and 12 known compounds (). For the first time, we reported the nuclear magnetic resonance (NMR) data of 4--(6'--glucosyl-4″-hydroxybenzoyl)-4-hydroxybenzyl alcohol () in this study. The identification of the structures of newly discovered compounds was done through the analysis of their spectroscopic data [NMR, mass spectrometry, ultraviolet, Fourier transform infrared, optical rotation, and circular dichroism (CD)]. In comparison to anticancer drugs (i.e., etoposide and carboplatin), we evaluated anticancer potential of the isolated compounds on two different breast cancer cell lines, namely, T47D and MDA-MB-231. Human fibroblast HaCaT cells were used as the control cells. After a 48 h incubation, flavidin (), coelonin (), 3,4-dihydroxybenzaldehyde (), and oxoflavidin () showed significant cytotoxic effects against breast cancer cells. Among them, oxoflavidin () exhibited the most potent cytotoxicity on MDA-MB-231 with an IC value of 26.26 ± 4.33 μM. In the nuclear staining assay, oxoflavidin induced apoptosis after 48 h in both T47D and MDA-MB-231 cells in a dose-dependent manner. Furthermore, oxoflavidin upregulated the expression of apoptotic genes, such as p53, Bax, poly(ADP-ribose) polymerase, caspase-3, and caspase-9 genes while significantly decreasing antiapoptotic protein (Bcl-2) expression levels.
PubMed: 38405545
DOI: 10.1021/acsomega.3c07048 -
ACS Omega Feb 2024Synthesis of both enantiomers of guaipyridine alkaloid cananodine was achieved. The stereocenter at C8 was set through an Evans alkylation, and the seven-membered...
Synthesis of both enantiomers of guaipyridine alkaloid cananodine was achieved. The stereocenter at C8 was set through an Evans alkylation, and the seven-membered carbocycle was constructed using an intramolecular Mizoroki-Heck reaction. Hydrogenation of an exomethylene set the C5 stereocenter. The optical rotation of each enantiomer matched the literature. The synthetic scheme is amenable to analogue preparation. (+)- and (-)-Rupestine G were also prepared.
PubMed: 38405498
DOI: 10.1021/acsomega.3c07735 -
Sensors (Basel, Switzerland) Feb 2024The attainment of a substantial aperture in the rotating synthetic aperture imaging system involves the rotation of a slender rectangular primary mirror. This...
The attainment of a substantial aperture in the rotating synthetic aperture imaging system involves the rotation of a slender rectangular primary mirror. This constitutes a pivotal avenue of exploration in space telescope research. Due to the considerable aspect ratio of the primary mirror, environmental disturbances can significantly impact its surface shape. Active optical technology can rectify surface shape irregularities through the detection of wavefront information. The Phase Diversity (PD) method utilizes images captured by the imaging system to compute wavefront information. In this study, the PD method is applied to rotating synthetic and other rectangular aperture imaging systems, employing Legendre polynomials to model the wavefront. The study delved into the ramifications stemming from the aperture aspect ratio and aberration size.
PubMed: 38400349
DOI: 10.3390/s24041191 -
Biomolecules Jan 2024Three new bibenzochromenones named phanogracilins A-C (-) were isolated from the crinoid . The structure of was established using X-ray crystallography as...
Three new bibenzochromenones named phanogracilins A-C (-) were isolated from the crinoid . The structure of was established using X-ray crystallography as 5,5',6,6',8,8'-hexahydroxy-2,2'-dipropyl-4H,4'H-[7,9'-bibenzo[g]chromene]-4,4'-dione. This allowed us to assign reliably 2D NMR signals for compound and subsequently for its isomer that differed in the connecting position of two benzochromenone moieties (7,10' instead of 7,9'), and compound for that differed in the length of the aliphatic chain of one of the fragments. Compound was derived from in alkaline conditions, and its structure was elucidated as 5,5',6',8,8'-pentahydroxy-2,2'-dipropyl-4H,4'H-[7,9'-bibenzo[g]chromene]-4,4',6,9-tetraone. Even though compounds - did not contain stereo centers, they possessed notable optical activity due to sterical hindrances, which limited the internal rotation of two benzochromenone fragments around C(7)-C(9'/10') bonds. Isolated bibenzochromenones - were tested for their antiradical, neuroprotective and antimicrobial activities. Compounds , and demonstrated significant antiradical properties towards ABTS radicals higher than the positive control trolox. Compounds and exhibited moderate neuroprotective activity, increasing the viability of rotenone-treated Neuro-2a cells at a concentration of 1 µM by 9.8% and 11.8%, respectively. Compounds and at concentrations from 25 to 100 μM dose-dependently inhibited the growth of Gram-positive bacteria and yeast-like fungi , and they also prevented the formation of their biofilms. Compounds and exhibited low antimicrobial activity.
Topics: Animals; Staphylococcus aureus; Echinodermata; Anti-Infective Agents; Benzopyrans; Bacteria; Microbial Sensitivity Tests; Anti-Bacterial Agents
PubMed: 38397388
DOI: 10.3390/biom14020151 -
Biophysics and Physicobiology 2023A small and flexible molecule, ribocil A (non-binder) or B (binder), binds to the deep pocket of the aptamer domain of the FMN riboswitch, which is an RNA molecule. This...
A small and flexible molecule, ribocil A (non-binder) or B (binder), binds to the deep pocket of the aptamer domain of the FMN riboswitch, which is an RNA molecule. This binding was studied by mD-VcMD, which is a generalized-ensemble simulation method. Ribocil A and B are structurally similar because they are optical isomers to each other. In the initial conformation of simulation, the ligands and the aptamer were completely dissociated in explicit solvent. The aptamer-ribocil B binding was stronger than the aptamer-ribocil A binding, which agrees with experiments. The computed free-energy landscape for the aptamer-ribocil B binding was funnel-like, whereas that for the aptamer-ribocil A binding was rugged. When passing through the gate (named "front gate") of the binding pocket, each ligand interacted with bases of the riboswitch by non-native π-π stackings, and the stackings restrained the ligand's orientation to be advantageous to reach the binding site smoothly. When the ligands reached the binding site in the pocket, the non-native stackings were replaced by the native stackings. The ligand's orientation restriction is discussed referring to a selection mechanism reported in an earlier work on a drug-GPCR interaction. The present simulation showed another pathway leading the ligands to the binding site. The gate ("rear gate") for this pathway was located completely opposite to the front gate on the aptamer's surface. However, the approach from the rear gate required overcoming a free-energy barrier regarding ligand's rotation before reaching the binding site.
PubMed: 38344029
DOI: 10.2142/biophysico.bppb-v20.0047