Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Psychol Sci ; 35(6): 597-612, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38648277

RESUMEN

This study investigated how relocation patterns affect disaster survivors' psychological stress on the diverse durations and spaces of relocation. It analyzed a 10-year data set of 1,236 families affected by 2009's Typhoon Morakot in Taiwan, identifying six relocation patterns through dynamic time warping (DTW). A hierarchical linear model was utilized, revealing the discernible impacts of environmental factors, sociocultural factors, and family-level socioeconomic factors on psychological stress. The study revealed that survivors who quickly found stable residences after the disaster initially experienced lower stress levels, but in the long term, their stress increased. Conversely, those with unstable residences experienced higher initial stress but lower long-term stress. Comparing similar patterns, we found that survivors who had more time for preparation and who sought opportunities, coped, or adapted to secondary stressors before long-distance relocation faced lower stress levels. These findings suggest that relocation patterns have a greater impact on the psychosocial stress of disaster survivors than time or relocation distance.


Asunto(s)
Tormentas Ciclónicas , Desastres , Estrés Psicológico , Sobrevivientes , Humanos , Estrés Psicológico/psicología , Femenino , Masculino , Adulto , Taiwán , Sobrevivientes/psicología , Adaptación Psicológica , Factores Socioeconómicos
2.
Cancer Sci ; 114(10): 3957-3971, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37496288

RESUMEN

Lysyl oxidase-like 2 (LOXL2) is a matrix-remodeling enzyme that has recently been identified as an important regulator of tumor progression and metastasis. This study discovered that LOXL2 expression in oral squamous cell carcinoma (OSCC) tissues was significantly associated with tumor clinical stage, lymph node metastasis and patients' overall survival time. LOXL2-overexpressing human buccal SCC TW2.6 (TW2.6/LOXL2) and hypopharyngeal SCC FaDu (FaDu/LOXL2) cells exhibited enhanced migration, invasion, epithelial-mesenchymal transition (EMT), and cancer stem cell (CSC) phenotypes, independently of its enzymatic activity. Moreover, TW2.6/LOXL2 significantly increased tumor-initiating frequency in SCID mice. We further demonstrated that LOXL2 increased the levels of interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) and IFIT3 in TW2.6/LOXL2 and FaDu/LOXL2 cells. We also identified IFIT1 and IFIT3 as key downstream components of LOXL2 action in migration, invasion, EMT, and CSC phenotypes in TW2.6 and FaDu cells. Furthermore, a significant positive correlation between LOXL2 expression and IFIT1 and IFIT3 overexpression in human OSCC tissues was observed. In addition, TW2.6/LOXL2 and FaDu/LOXL2 cells were 3.3- to 3.6-fold more susceptible to the epidermal growth factor receptor (EGFR) inhibitor gefitinib than were their respective control cells. The antitumor effect of gefitinib on orthotopic TW2.6/LOXL2 xenograft tumor was fourfold higher than that on controls. Our results indicate that LOXL2 expression is a strong prognostic factor for OSCC and may be used as a marker to identify patients most likely to respond to EGFR-targeted therapy.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Animales , Ratones , Humanos , Gefitinib/farmacología , Carcinoma de Células Escamosas/patología , Proteína-Lisina 6-Oxidasa , Ratones SCID , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológico , Proteínas de Unión al ARN/genética , Receptores ErbB , Regulación Neoplásica de la Expresión Génica , Transición Epitelial-Mesenquimal , Línea Celular Tumoral , Péptidos y Proteínas de Señalización Intracelular
3.
Oral Dis ; 28(6): 1484-1495, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33655573

RESUMEN

OBJECTIVES: The myeloid-derived suppressor cells (MDSCs) frequently have a high expansion in cancer patients. This research explored whether administration of ß-glucan could increase anti-tumor immunity in oral squamous cell carcinoma (OSCC) patients. MATERIALS AND METHODS: This study evaluated the MDSC level of circulating blood as CD33+ /CD11b+ /HLA-DR-/low by flow cytometry in 30 healthy donors (HDs, group I), in 48 oral squamous cell carcinoma (OSCC) patients before and after 14-day preoperative administration of ß-glucan (group II), and in 52 OSCC patients without taking ß-glucan (group III). RESULTS: A significantly higher mean MDSC level was observed in 100 OSCC patients than in 30 HDs (p < .001). There was a significant reduction of the mean MDSC level in group II patients after taking ß-glucan (p < .001). Moreover, we discovered a significantly higher recurrence-free survival (RFS) in group II than in group III patients (p = .026). Finally, the multivariate Cox regression further identified the MDSC level ≤1% and administration of ß-glucan as more favorable prognostic factors for OSCC patients. CONCLUSION: Preoperative administration of ß-glucan can augment anti-tumor immunity and increase RFS rate via subversion of suppressive function of MDSC in OSCC patients.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Células Supresoras de Origen Mieloide , beta-Glucanos , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/patología , Neoplasias de Cabeza y Cuello/patología , Humanos , Células Supresoras de Origen Mieloide/patología , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , beta-Glucanos/farmacología , beta-Glucanos/uso terapéutico
4.
Nanotechnology ; 31(32): 324002, 2020 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-32453710

RESUMEN

Inorganic perovskite quantum dots (IPQDs) such as cesium lead halide (CsPbX3, X = Cl, Br and I) quantum dots have attracted much attention for developing cadmium-free quantum light-emitting displays (QLEDs) based on outstanding light emission properties including narrow full width at half maximum (FWHM), tunable bandgap and ultrahigh (>90%) photoluminescence quantum yield (PLQY). Nevertheless, their poor stability under ambient conditions, at high temperature or under continuous light irradiation is the main problem for practical applications. In this study, a new method is proposed to effectively stabilize CsPbBr3 IPQDs by synthesizing them with sulfate-functionalized cellulose nanocrystals (CNCs) at room temperature without using traditional quantum dot stabilizers such as oleylamine (OLA) and oleic acid (OA). The as-prepared CsPbBr3 IPQD/CNC hybrid paper-like films are highly stable and the relative photoluminescence (PL) intensity can be maintained at 92% under continuous UV light (306 nm, 15 W) illumination for 130 h, >99% at high temperature (100 °C) for 130 h, and >99% in ambient conditions for 15 d. Additionally, the PLQY and FWHM of IPQD/CNC are 45.69% and 22 nm, respectively. The ultrahigh stability and narrow FWHM characteristics proposed here for IPQD/CNC hybrid films can provide new possibilities for practical applications in the future development of IPQD-related devices.

5.
Endoscopy ; 51(4): 355-359, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30261534

RESUMEN

BACKGROUND: This study aimed to evaluate the use of ultrahigh-speed volumetric en face and cross-sectional optical coherence tomography (OCT) with micromotor catheters for the in vivo assessment of Barrett's esophagus and dysplasia. METHODS: 74 OCT datasets with correlated biopsy/endoscopic mucosal resection histology (49 nondysplastic Barrett's esophagus [NDBE], 25 neoplasia) were obtained from 14 patients with Barrett's esophagus and a history of dysplasia and 30 with NDBE. The associations between irregular mucosal patterns on en face OCT, absence of mucosal layering, surface signal > subsurface, and > 5 atypical glands on cross-sectional OCT vs. histology and treatment history were assessed by three blinded readers. RESULTS: Atypical glands under irregular mucosal patterns occurred in 75 % of neoplasia (96 % of treatment-naïve neoplasia) vs. 30 % of NDBE datasets (43 % of short- and 18 % of long-segment NDBE). Mucosal layering was absent in 35 % of neoplasia and 50 % of NDBE datasets, and surface signal > subsurface occurred in 29 % of neoplasia and 30 % of NDBE datasets. CONCLUSIONS: Atypical glands under irregular mucosal patterns are strongly associated with neoplasia, suggesting potential markers for dysplasia and a role in pathogenesis.


Asunto(s)
Esófago de Barrett , Mucosa Esofágica , Neoplasias Esofágicas , Lesiones Precancerosas , Tomografía de Coherencia Óptica/métodos , Esófago de Barrett/diagnóstico , Esófago de Barrett/patología , Biopsia/métodos , Mucosa Esofágica/diagnóstico por imagen , Mucosa Esofágica/patología , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/patología , Esofagoscopía/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Lesiones Precancerosas/diagnóstico por imagen , Lesiones Precancerosas/patología , Reproducibilidad de los Resultados
6.
Opt Lett ; 42(16): 3193-3196, 2017 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-28809905

RESUMEN

Endoscopic optical coherence tomography (OCT) instruments are mostly side viewing and rely on at least one proximal scan, thus limiting accuracy of volumetric imaging and en face visualization. Previous forward-viewing OCT devices had limited axial scan speeds. We report a forward-viewing fiber scanning 3D-OCT probe with 900 µm field of view and 5 µm transverse resolution, imaging at 1 MHz axial scan rate in the human gastrointestinal tract. The probe is 3.3 mm diameter and 20 mm rigid length, thus enabling passage through the endoscopic channel. The scanner has 1.8 kHz resonant frequency, and each volumetric acquisition takes 0.17 s with 2 volumes/s display. 3D-OCT and angiography imaging of the colon was performed during surveillance colonoscopy.

7.
Gastrointest Endosc ; 86(3): 476-484.e3, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28167119

RESUMEN

BACKGROUND AND AIMS: Angiogenesis is associated with neoplastic progression of Barrett's esophagus (BE). Volumetric optical coherence tomography angiography (OCTA) visualizes subsurface microvasculature without exogenous contrast agents. We investigated the association of OCTA microvascular features with low-grade dysplasia (LGD) and high-grade dysplasia (HGD). METHODS: Fifty-two patients undergoing BE surveillance or endoscopic eradication therapies for dysplasia were imaged using volumetric OCTA and corresponding histologic diagnoses wre obtained to yield 97 data sets (nondysplastic BE [NDBE], 74; LGD, 10; HGD, 13). After evaluating OCTA image quality, 54 datasets (NDBE, 35; LGD, 8; HGD, 11) from 32 patients were used to develop a training and reading protocol. The association of abnormal vessel branching and heterogeneous vessel size with LGD/HGD and a regular honeycomb vessel pattern with NDBE were investigated. RESULTS: Blinded OCTA reading of 41 OCTA datasets (NDBE, 27; LGD, 7; HGD, 7) was performed by readers with various levels of OCT/OCTA experience including 3 OCT trainees, 1 gastroenterologist, and 2 gastroenterology fellows. Among the 6 readers, OCTA features of abnormal vessel branching and heterogeneous vessel size had an overall 94% sensitivity (95% CI, 89-99) and 69% specificity (95% CI, 62-76) for differentiating LGD/HGD versus NDBE with a mean reading time of 45 seconds per data set and moderate (kappa = .58) interobserver agreement. CONCLUSIONS: Volumetric en face OCTA imaging enables rapid examination of depth resolved microvascular features with near-microscopic resolution. OCTA can visualize microvascular features associated with LGD/HGD with high accuracy, which motivates new technologic advances and future studies investigating the diagnostic performance of OCTA.


Asunto(s)
Adenocarcinoma/diagnóstico por imagen , Esófago de Barrett/diagnóstico por imagen , Neoplasias Esofágicas/diagnóstico por imagen , Microvasos/diagnóstico por imagen , Anciano , Angiografía/métodos , Progresión de la Enfermedad , Esofagoscopía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Tomografía de Coherencia Óptica/métodos
8.
Opt Lett ; 39(20): 5973-6, 2014 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-25361133

RESUMEN

We demonstrate a computationally efficient method for correcting the nonuniform rotational distortion (NURD) in catheter-based imaging systems to improve endoscopic en face optical coherence tomography (OCT) and OCT angiography. The method performs nonrigid registration using fiducial markers on the catheter to correct rotational speed variations. Algorithm performance is investigated with an ultrahigh-speed endoscopic OCT system and micromotor catheter. Scan nonuniformity is quantitatively characterized, and artifacts from rotational speed variations are significantly reduced. Furthermore, we present endoscopic en face OCT and OCT angiography images of human gastrointestinal tract in vivo to demonstrate the image quality improvement using the correction algorithm.


Asunto(s)
Angiografía/instrumentación , Artefactos , Catéteres , Procesamiento de Imagen Asistido por Computador/métodos , Rotación , Tomografía de Coherencia Óptica/instrumentación , Algoritmos , Angiografía/normas , Marcadores Fiduciales , Tracto Gastrointestinal/diagnóstico por imagen , Humanos , Tomografía de Coherencia Óptica/normas
9.
Opt Lett ; 39(2): 186-8, 2014 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-24562102

RESUMEN

We developed a compact, optical fiber scanning piezoelectric transducer (PZT) probe for endoscopic and minimally invasive optical coherence tomography (OCT). Compared with previous forward-mount fiber designs, we present a reverse-mount design that achieves a shorter rigid length. The fiber was mounted at the proximal end of a quadruple PZT tube and scanned inside the hollow PZT tube to reduce the probe length. The fiber resonant frequency was 338 Hz using a 17-mm-long fiber. A 0.9 mm fiber deflection was achieved with a driving amplitude of 35 V. Using a GRIN lens-based optical design with a 1.3× magnification, a ∼6 µm spot was scanned over a 1.2 mm diameter field. The probe was encased in a metal hypodermic tube with a ∼25 mm rigid length and covered with a 3.2 mm outer diameter (OD) plastic sheath. Imaging was performed with a swept source OCT system based on a Fourier domain modelocked laser (FDML) light source at a 240 kHz axial scan rate and 8 µm axial resolution (in air). En face OCT imaging of skin in vivo and human colon ex vivo was demonstrated.


Asunto(s)
Fibras Ópticas , Tomografía de Coherencia Óptica/instrumentación , Transductores , Colon , Diseño de Equipo , Humanos
10.
Bioengineering (Basel) ; 10(11)2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-38002442

RESUMEN

Dental caries on the crown's surface is caused by the interaction of bacteria and carbohydrates, which then gradually alter the tooth's structure. In addition, calculus is the root of periodontal disease. Optical coherence tomography (OCT) has been considered to be a promising tool for identifying dental caries; however, diagnosing dental caries in the early stage still remains challenging. In this study, we proposed an ultrahigh-resolution OCT (UHR-OCT) system with axial and transverse resolutions of 2.6 and 1.8 µm for differentiating the early-stage dental caries and calculus. The same teeth were also scanned by a conventional spectral-domain OCT (SD-OCT) system with an axial resolution of 7 µm. The results indicated that early-stage carious structures such as small cavities can be observed using UHR-OCT; however, the SD-OCT system with a lower resolution had difficulty identifying it. Moreover, the estimated surface roughness and the scattering coefficient of enamel were proposed for quantitatively differentiating the different stages of caries. Furthermore, the thickness of the calculus can be estimated from the UHR-OCT results. The results have demonstrated that UHR-OCT can detect caries and calculus in their early stages, showing that the proposed method for the quantitative evaluation of caries and calculus is potentially promising.

11.
J Urol ; 187(2): 691-9, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22177199

RESUMEN

PURPOSE: We evaluated the feasibility of using optical coherence tomography and optical coherence microscopy technology to assess human kidney morphology. MATERIALS AND METHODS: A total of 35 renal specimens from 19 patients, consisting of 12 normal tissues and 23 tumors (16 clear cell renal cell carcinomas, 5 papillary renal cell carcinomas and 2 oncocytomas) were imaged ex vivo after surgical resection. Optical coherence tomography and optical coherence microscopy images were compared to corresponding hematoxylin and eosin histology to identify characteristic features of normal and pathological renal tissues. Three pathologists blinded to histology evaluated the sensitivity and specificity of optical coherence microscopy images to differentiate normal from neoplastic renal tissues. RESULTS: Optical coherence tomography and optical coherence microscopy images of normal kidney revealed architectural features, including glomeruli, convoluted tubules, collecting tubules and loops of Henle. Each method of imaging renal tumors clearly demonstrated morphological changes and decreased imaging depth. Optical coherence tomography and microscopy features matched well with the corresponding histology. Three observers achieved 88%, 100% and 100% sensitivity, and 100%, 88% and 100% specificity, respectively, when evaluating normal vs neoplastic specimens using optical coherence microscopy images with substantial interobserver agreement (κ = 0.82, p <0.01). CONCLUSIONS: Integrated optical coherence tomography and optical coherence microscopy imaging provides coregistered, multiscale images of renal pathology in real time without exogenous contrast medium or histological processing. High sensitivity and specificity were achieved using optical coherence microscopy to differentiate normal from neoplastic renal tissues, suggesting possible applications for guiding renal mass biopsy or evaluating surgical margins.


Asunto(s)
Adenoma Oxifílico/patología , Carcinoma de Células Renales/patología , Neoplasias Renales/patología , Tomografía de Coherencia Óptica/métodos , Adulto , Anciano , Humanos , Persona de Mediana Edad
12.
Gastrointest Endosc ; 76(6): 1104-12, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22831857

RESUMEN

BACKGROUND: Radiofrequency ablation (RFA) is effective for treating Barrett's esophagus (BE) but often involves multiple endoscopy sessions over several months to achieve complete response. OBJECTIVE: Identify structural markers that correlate with treatment response by using 3-dimensional (3-D) optical coherence tomography (OCT; 3-D OCT). DESIGN: Cross-sectional. SETTING: Single teaching hospital. PATIENTS: Thirty-three patients, 32 male and 1 female, with short-segment (<3 cm) BE undergoing RFA treatment. INTERVENTION: Patients were treated with focal RFA, and 3-D OCT was performed at the gastroesophageal junction before and immediately after the RFA treatment. Patients were re-examined with standard endoscopy 6 to 8 weeks later and had biopsies to rule out BE if not visibly evident. MAIN OUTCOME MEASUREMENTS: The thickness of BE epithelium before RFA and the presence of residual gland-like structures immediately after RFA were determined by using 3-D OCT. The presence of BE at follow-up was assessed endoscopically. RESULTS: BE mucosa was significantly thinner in patients who achieved complete eradication of intestinal metaplasia than in patients who did not achieve complete eradication of intestinal metaplasia at follow-up (257 ± 60 µm vs 403 ± 86 µm; P < .0001). A threshold thickness of 333 µm derived from receiver operating characteristic curves corresponded to a 92.3% sensitivity, 85% specificity, and 87.9% accuracy in predicting the presence of BE at follow-up. The presence of OCT-visible glands immediately after RFA also correlated with the presence of residual BE at follow-up (83.3% sensitivity, 95% specificity, 90.6% accuracy). LIMITATIONS: Single center, cross-sectional study in which only patients with short-segment BE were examined. CONCLUSION: Three-dimensional OCT assessment of BE thickness and residual glands during RFA sessions correlated with treatment response. Three-dimensional OCT may predict responses to RFA or aid in making real-time RFA retreatment decisions in the future.


Asunto(s)
Esófago de Barrett/cirugía , Ablación por Catéter , Esofagoscopía , Esófago/patología , Tomografía de Coherencia Óptica/métodos , Adulto , Anciano , Anciano de 80 o más Años , Esófago de Barrett/patología , Estudios Transversales , Esófago/cirugía , Femenino , Estudios de Seguimiento , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Resultado del Tratamiento
13.
Gastrointest Endosc ; 76(1): 32-40, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22482920

RESUMEN

BACKGROUND: Radiofrequency ablation (RFA) is an endoscopic technique used to eradicate Barrett's esophagus (BE). However, such ablation can commonly lead to neosquamous epithelium overlying residual BE glands not visible by conventional endoscopy and may evade detection on random biopsy samples. OBJECTIVE: To demonstrate the capability of endoscopic 3-dimensional optical coherence tomography (3D-OCT) for the identification and characterization of buried glands before and after RFA therapy. DESIGN: Cross-sectional study. SETTING: Single teaching hospital. PATIENTS: Twenty-six male and 1 female white patients with BE undergoing RFA treatment. INTERVENTIONS: 3D-OCT was performed at the gastroesophageal junction in 18 patients before attaining complete eradication of intestinal metaplasia (pre-CE-IM group) and in 16 patients after CE-IM (post-CE-IM group). MAIN OUTCOME MEASUREMENTS: Prevalence, size, and location of buried glands relative to the squamocolumnar junction. RESULTS: 3D-OCT provided an approximately 30 to 60 times larger field of view compared with jumbo and standard biopsy and sufficient imaging depth for detecting buried glands. Based on 3D-OCT results, buried glands were found in 72% of patients (13/18) in the pre-CE-IM group and 63% of patients (10/16) in the post-CE-IM group. The number (mean [standard deviation]) of buried glands per patient in the post-CE-IM group (7.1 [9.3]) was significantly lower compared with the pre-CE-IM group (34.4 [44.6]; P = .02). The buried gland size (P = .69) and distribution (P = .54) were not significantly different before and after CE-IM. LIMITATIONS: A single-center, cross-sectional study comparing patients at different time points in treatment. Lack of 1-to-1 coregistered histology for all OCT data sets obtained in vivo. CONCLUSION: Buried glands were frequently detected with 3D-OCT near the gastroesophageal junction before and after radiofrequency ablation.


Asunto(s)
Esófago de Barrett/patología , Unión Esofagogástrica/patología , Tomografía de Coherencia Óptica , Adulto , Anciano , Anciano de 80 o más Años , Esófago de Barrett/cirugía , Ablación por Catéter , Estudios Transversales , Esofagoscopía , Femenino , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad
14.
Diagnostics (Basel) ; 12(4)2022 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-35453872

RESUMEN

Fractional laser treatment is commonly used for dermatological applications, enabling effective induction of collagen regeneration and significantly reducing recovery time. However, it is challenging to observe laser-induced photodamage beneath the tissue surface in vivo, making the non-invasive evaluation of treatment outcomes difficult. For in vivo real-time study of the photodamage induced by fractional pulsed CO2 and Nd:YAG lasers commonly utilized for clinical therapy, a portable spectral-domain optical coherence tomography (SD-OCT) system was implemented for clinical studies. The photodamage caused by two lasers, including photothermal and photoacoustic effects, was investigated using OCT, together with the correlation between photodamage and exposure energy. Additionally, to investigate the change in the optical properties of tissue due to photodamage, the attenuation coefficients and damaged areas of normal skin and laser-treated skin were estimated for comparison. Finally, the recovery of the exposed skin with both lasers was also compared using OCT. The results show that OCT can be a potential solution for in vivo investigation of laser-induced tissue damage and quantitative evaluation.

15.
Small Methods ; 6(4): e2101228, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35212186

RESUMEN

Manipulation and precise delivery of optical energies in the regions of interest within specimens require different strategies. Hence, proper control of input beam parameters is a prerequisite. One of the prominent methods is metasurface optics, capable of crafting properties of light at nanoscales. Here, the generation of an abrupt autofocusing (AAF) beam by a nanophotonic metasurface for biomedical applications is demonstrated. Fluorescence guided laser microprofiling of mouse cardiac samples is experimentally investigated, using the AAF beam to deliver optical energy selectively to specific locations. In addition, photocoagulation of ex vivo swine skin tissue is performed and observed through optical coherence tomography. The results show great potentials for integrating metasurface optics to realize miniature laser surgery instruments for wide applications in biomedicine.


Asunto(s)
Rayos Láser , Óptica y Fotónica , Animales , Ratones , Porcinos
17.
Biomed Opt Express ; 12(8): 5139-5158, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-34513247

RESUMEN

A technique using Linnik-based optical coherence microscopy (OCM), with built-in fluorescence microscopy (FM), is demonstrated here to describe cellular-level morphology for fresh porcine and biobank tissue specimens. The proposed method utilizes color-coding to generate digital pseudo-H&E (p-H&E) images. Using the same camera, colocalized FM images are merged with corresponding morphological OCM images using a 24-bit RGB composition process to generate position-matched p-H&E images. From receipt of dissected fresh tissue piece to generation of stitched images, the total processing time is <15 min for a 1-cm2 specimen, which is on average two times faster than frozen-section H&E process for fatty or water-rich fresh tissue specimens. This technique was successfully used to scan human and animal fresh tissue pieces, demonstrating its applicability for both biobank and veterinary purposes. We provide an in-depth comparison between p-H&E and human frozen-section H&E images acquired from the same metastatic sentinel lymph node slice (∼10 µm thick), and show the differences, like elastic fibers of a tiny blood vessel and cytoplasm of tumor cells. This optical sectioning technique provides histopathologists with a convenient assessment method that outputs large-field H&E-like images of fresh tissue pieces without requiring any physical embedment.

18.
Biomed Opt Express ; 12(2): 722-736, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33680538

RESUMEN

Optical coherence tomography angiography (OCTA) can provide rapid, volumetric, and noninvasive imaging of tissue microvasculature without the requirement of exogenous contrast agents. To investigate how A-scan rate and interscan time affected the contrast and dynamic range of OCTA, we developed a 1.06-µm swept-source OCT system enabling 100-kHz or 200-kHz OCT using two light sources. After system settings were carefully adjusted, almost the same detection sensitivity was achieved between the 100-kHz and 200-kHz modalities. OCTA of ear skin was performed on five mice. We used the variable interscan time analysis algorithm (VISTA) and the designated scanning protocol with OCTA images reconstructed through the correlation mapping method. With a relatively long interscan time (e.g., 12.5 ms vs. 6.25 ms for 200-kHz OCT), OCTA can identify more intricate microvascular networks. OCTA image sets with the same interscan time (e.g., 12.5 ms) were compared. OCTA images acquired with a 100-kHz A-scan rate showed finer microvasculature than did other imaging modalities. We performed quantitative analysis on the contrast from OCTA images reconstructed with different A-scan rates and interscan time intervals in terms of vessel area, total vessel length, and junction density.

19.
Biomed Opt Express ; 12(4): 2339-2352, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33996233

RESUMEN

Currently, the cochlear implantation procedure mainly relies on using a hand lens or surgical microscope, where the success rate and surgery time strongly depend on the surgeon's experience. Therefore, a real-time image guidance tool may facilitate the implantation procedure. In this study, we performed a systematic and quantitative analysis on the optical characterization of ex vivo mouse cochlear samples using two swept-source optical coherence tomography (OCT) systems operating at the 1.06-µm and 1.3-µm wavelengths. The analysis results demonstrated that the 1.06-µm OCT imaging system performed better than the 1.3-µm OCT imaging system in terms of the image contrast between the cochlear conduits and the neighboring cochlear bony wall structure. However, the 1.3-µm OCT imaging system allowed for greater imaging depth of the cochlear samples because of decreased tissue scattering. In addition, we have investigated the feasibility of identifying the electrode of the cochlear implant within the ex vivo cochlear sample with the 1.06-µm OCT imaging. The study results demonstrated the potential of developing an image guidance tool for the cochlea implantation procedure as well as other otorhinolaryngology applications.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA