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1.
Anaesthesia ; 78(1): 64-72, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36198200

RESUMEN

Unanticipated difficult laryngoscopy is associated with serious airway-related complications. We aimed to develop and test a convolutional neural network-based deep-learning model that uses lateral cervical spine radiographs to predict Cormack-Lehane grade 3 or 4 direct laryngoscopy views of the glottis. We analysed the radiographs of 5939 thyroid surgery patients at our hospital, 253 (4%) of whom had grade 3 or 4 glottic views. We used 10 randomly sampled datasets to train a model. We compared the new model with six similar models (VGG, ResNet, Xception, ResNext, DenseNet and SENet). The Brier score (95%CI) of the new model, 0.023 (0.021-0.025), was lower ('better') than the other models: VGG, 0.034 (0.034-0.035); ResNet, 0.033 (0.033-0.035); Xception, 0.032 (0.031-0.033); ResNext, 0.033 (0.032-0.033); DenseNet, 0.030 (0.029-0.032); SENet, 0.031 (0.029-0.032), all p < 0.001. We calculated mean (95%CI) of the new model for: R2 , 0.428 (0.388-0.468); mean squared error, 0.023 (0.021-0.025); mean absolute error, 0.048 (0.046-0.049); balanced accuracy, 0.713 (0.684-0.742); and area under the receiver operating characteristic curve, 0.965 (0.962-0.969). Radiographic features around the hyoid bone, pharynx and cervical spine were associated with grade 3 and 4 glottic views.


Asunto(s)
Aprendizaje Profundo , Humanos
2.
Zhonghua Fu Chan Ke Za Zhi ; 56(7): 482-488, 2021 Jul 25.
Artículo en Chino | MEDLINE | ID: mdl-34304440

RESUMEN

Objective: To investigate the influence of age on the fresh cycle live birth rate in patients with poor ovarian response in different controlled ovarian hyperstimulation groups. Methods: The clinical data of 3 342 patients in The First Affiliated Hospital of Zhengzhou University from February 2014 to November 2018 were retrospectively collected, including early-follicular phase long-acting gonadotropin-releasing hormone (GnRH) agonist long protocol group (1 375 cases), mid-luteal phase short-acting GnRH agonist long protocol group (1 161 cases) and GnRH antagonist protocol group (806 cases); each group was divided into 4 subgroups according to age: ≤30 years, 31-35 years, 36-40 years and >40 years, the pregnancy outcomes in each age subgroup were analyzed under different controlled ovarian hyperstimulation protocols. Results: In early-follicular phase long-acting GnRH agonist long protocol group, the final live birth rates of each age subgroup were 39.4% (228/579), 36.1% (135/374), 16.6% (48/290) and 3.0% (4/132); in mid-luteal phase short-acting GnRH agonist long protocol group, live birth rates of each age subgroup were 32.1% (99/308), 20.8% (55/264), 13.0% (45/346) and 7.0% (17/243); in GnRH antagonist protocol group, live birth rates of each age subgroup were 22.8% (26/114), 16.3% (25/153), 11.2% (31/278), and 3.8% (10/261); the live birth rate of each group decreased significantly with the increase of age (all P<0.01). When the age≤35 years old, the fresh cycle live birth rate of the early-follicular phase long-acting GnRH agonist long protocol group was significantly better than those of the other two groups (all P<0.01). The multivariate logistic regression analysis of age and live birth rate of the three controlled ovarian hyperstimulation groups showed age was the independent influence factor (OR=0.898, 95%CI: 0.873-0.916, P<0.01; OR=0.926, 95%CI: 0.890-0.996, P<0.01; OR=0.901, 95%CI: 0.863-0.960, P<0.01). Conclusions: Age is an independent influencing factor for the prediction of fresh cycle live birth rate in low ovarian response patients. No matter which controlled ovarian hyperstimulation protocol is adopted, the final live birth rate decreases significantly with the increase of women's age. In addition, the early-follicular phase long-acting GnRH agonist long protocol has the highest fresh cycle live birth rate among all controlled ovarian hyperstimulation groups.


Asunto(s)
Tasa de Natalidad , Inducción de la Ovulación , Adulto , Femenino , Fertilización In Vitro , Hormona Liberadora de Gonadotropina , Humanos , Nacimiento Vivo/epidemiología , Embarazo , Índice de Embarazo , Estudios Retrospectivos
3.
J Dent Res ; 98(3): 363-367, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30412680

RESUMEN

The extent of dental tissue destruction during the treatment of white spot lesions (WSLs) increases with the severity of the lesion. If the depth and shape of WSLs can be predicted with a noninvasive diagnostic method before dental caries treatment, more conservative interventions can be planned. Given the superiority of high-frequency ultrasound (HFUS) imaging in observing the internal structures of the body, the present study aimed to verify the possibility of HFUS imaging to examine the depth and shape of WSLs. We prepared tooth samples and developed a biomicroscopic system with a HFUS transducer to obtain images of normal and WSL regions. HFUS images were compared with conventional ultrasound images and micro-computed tomography images. HFUS distinctly differentiated demineralization within WSL and normal regions. WSL depth calculated in the micro-computed tomography image was similar to that in HFUS. This study revealed that HFUS imaging has the potential to detect early dental caries and offer information on the invasion depth of early dental caries quantitatively.


Asunto(s)
Caries Dental , Ultrasonografía , Algoritmos , Humanos , Microtomografía por Rayos X
4.
Genet Mol Res ; 13(4): 8147-52, 2014 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-25299199

RESUMEN

Korean rose bitterling (Rhodeus uyekii) is a freshwater fish endemic to Korea. Natural populations of this species have experienced severe declines as a result of habitat fragmentation and water pollution. To conserve and restore R. uyekii, the genetic diversity of this species needs to be assessed at the population level. Eighteen novel polymorphic microsatellite loci for R. uyekii were developed using an enriched partial genomic library. Polymorphisms at these loci were studied in 150 individuals collected from three populations. The number of alleles at each locus ranged from 3 to 47 (mean = 17.1). Within the populations, the observed heterozygosity ranged from 0.032 to 1.000, expected heterozygosity from 0.082 to 0.967, and polymorphism information content from 0.078 to 0.950. Six loci showed significant deviation from Hardy-Weinberg equilibrium after Bonferroni's correction, and no significant linkage disequilibrium was detected between most locus pairs, except in three cases. These highly informative microsatellite markers should be useful for genetic population structure analyses of R. uyekii.


Asunto(s)
Peces/genética , Biblioteca Genómica , Repeticiones de Microsatélite , Alelos , Animales , Genotipo , Polimorfismo Genético
5.
Appl Opt ; 53(10): 1983-9, 2014 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-24787150

RESUMEN

An initial optical design method based on an iterative calculation of third-order aberration is presented to overcome the problems of the conventional method. The aberrations of each lens group in the optical system are calculated individually and iteratively under the constraint that aberrations of one group compensate for those of the other groups. The stabilities of initial design results have been confirmed and the iterative design method has been applied for the design of optical system with an external entrance pupil for imaging spectrometer. The designed lens corresponds to an objective lens with the aperture of F/1.5 and the focal length of 30 mm.

6.
Oral Dis ; 20(8): 773-9, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24735459

RESUMEN

OBJECTIVE: This study assessed trends in the incidence of and survival rates for oral cavity cancer in the Korean population. MATERIALS AND METHODS: Data from the Korea Central Cancer Registry were extracted for 10,282 patients diagnosed with oral cavity cancer (C01-C06) between 1999 and 2010 to evaluate the age-standardised incidence rate, annual percentage change (APC) and 5-year relative survival rate (RSR) according to gender and age. RESULTS: In males, the incidence rate slightly decreased [APC of -0.2% (P = 0.6427)]; in females, the incidence rate increased [APC of 3.1% (P < 0.05)]. In males and females, the incidence of oral tongue cancer (C02) significantly increased [APC of 2.2% and 4.1%, respectively (P < 0.05)]. This increase in oral tongue cancer incidence was most prominent in the younger age group (<40 years, APC = 6.1%, P < 0.05). The incidence of buccal cheek cancer increased only among males [APC of 4.8% (P < 0.05)]. The 5-year RSR improved from 42.7% (1993-1995) to 59.5% (2006-2010), corresponding to an increase of 16.8% from 1993 to 2010 (P < 0.05). CONCLUSION: The incidence of oral cavity cancer in females increased, whereas it stabilised or decreased in males. However, the incidence of oral tongue cancer increased in both males and females, especially in the younger age group.


Asunto(s)
Neoplasias de la Boca/mortalidad , Adulto , Anciano , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/fisiopatología , República de Corea/epidemiología , Tasa de Supervivencia
7.
Artículo en Inglés | MEDLINE | ID: mdl-24109687

RESUMEN

Cell-based biological machines can be defined as a set of sub-components consisting of living cells and cell-instructive micro-environments that interact to perform a range of prescribed tasks. The realization of biological machines and their sub-components will require a number of suitable cell sources, biomaterials, and enabling technologies. Here, we review our group's recent accomplishments and continuing efforts toward the development of building biological machines.


Asunto(s)
Materiales Biocompatibles/síntesis química , Materiales Biomiméticos/síntesis química , Biomimética , Humanos , Impresión Tridimensional , Andamios del Tejido
8.
IARC Sci Publ ; (162): 155-62, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21675419

RESUMEN

The Busan cancer registry was established in 1996; cancer registration is done by passive and active methods. The registry contributed survival data for 48 cancer sites or types registered during 1996-2001. Follow-up information has been gleaned predominantly by passive methods with median follow-up ranging between 1-57 months for various cancers. The proportion with histologically verified diagnosis for different cancers ranged between 20-100%; death certificates only (DCOs) comprised 0-53%; 47-100% of total registered cases were included for survival analysis. The top-ranking cancers on 5-year age-standardized relative survival rates were penis (94%), thyroid (91%), non-melanoma skin (89%), placenta (86%), breast (76%), Hodgkin lymphoma (75%) and testis (72%). Five-year relative survival by age group showed a decreasing trend with increasing age groups for cancers of the nasopharynx, gall bladder, lung, bone, soft tissue, breast, cervix, corpus uteri, thyroid, multiple myeloma, lymphoid leukaemia and myeloid leukaemia or was fluctuating for other cancers.


Asunto(s)
Neoplasias/mortalidad , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Sistema de Registros , República de Corea/epidemiología , Factores de Tiempo
9.
J Fish Biol ; 76(8): 1958-71, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20557649

RESUMEN

The population structure of olive flounder Paralichthys olivaceus was estimated using nine polymorphic microsatellite (MS) loci in 459 individuals collected from eight populations, including five wild and three hatchery populations in Korea. Genetic variation in hatchery (mean number of alleles per locus, A = 10.2-12.1; allelic richness, A(R) = 9.3-10.1; observed heterozygosity, H(O) = 0.766-0.805) and wild (mean number of alleles per locus, A = 11.8-19.6; allelic richness, A(R) = 10.9-16.1; observed heterozygosity, H(O) = 0.820-0.888) samples did not differ significantly, suggesting a sufficient level of genetic variation in these well-managed hatchery populations, which have not lost a substantial amount of genetic diversity. Neighbour-joining tree and principal component analyses showed that genetic separation between eastern and pooled western and southern wild populations in Korea was probably influenced by restricted gene flow between regional populations due to the barrier effects of sea currents. The pooled western and southern populations are genetically close, perhaps because larval dispersal may depend on warm currents. One wild population (sample from Wando) was genetically divergent from the main distribution, but it was genetically close to hatchery populations, indicating that the genetic composition of the studied populations may be affected by hydrographic conditions and the release of fish stocks. The estimated genetic population structure and potential applications of MS markers may aid in the proper management of P. olivaceus populations.


Asunto(s)
Lenguado/genética , Variación Genética , Genética de Población , Alelos , Animales , Explotaciones Pesqueras , Flujo Génico , Geografía , Repeticiones de Microsatélite , Análisis de Componente Principal , República de Corea , Análisis de Secuencia de ADN
10.
J Appl Genet ; 50(3): 245-50, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19638679

RESUMEN

We isolated and characterized the profilin (FcPFN) cDNA from hemocytes of Fenneropenaeus chinensis, a unique shrimp species from the Yellow Sea. The FcPFN cDNA consists of 830 bp and encodes a polypeptide of 125 amino acids, having a predicted isoelectric point of 5.06. The deduced amino acid sequence of FcPFN shows 36% and 90% amino acid sequence identity to the profilin genes of Pacific white shrimp Litopenaeus vannamei and black tiger shrimp Penaeus monodon, respectively. The FcPFN mRNA was highly expressed in hemocytes and hepatopancreas and moderately in muscle of normal shrimp. The higher expression of FcPFN mRNA is observed in shrimp infected with the white spot syndrome virus (WSSV), which is a major concern in all shrimp-growing regions of the world. These results suggest a potential role for FcPFN in viral host defense mechanisms.


Asunto(s)
Penaeidae/genética , Penaeidae/virología , Profilinas/genética , Virus del Síndrome de la Mancha Blanca 1 , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Hemocitos/metabolismo , Hemocitos/virología , Datos de Secuencia Molecular , Filogenia , Profilinas/química , Profilinas/clasificación , Alineación de Secuencia
11.
Appl Opt ; 45(15): 3430-41, 2006 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-16708087

RESUMEN

A novel imaging spectrometer can individually control spatial and spectral resolution by using zoom lenses as the foreoptics of the system and a focusing lens. By varying the focal length we can use the focusing lens to change the spatial and spectral dimensions; with the foreoptics, however, we can change only the spatial dimension. Therefore the spectral resolution and the spectral range are affected by the zoom ratio of the focusing lens, whereas the spatial resolution and the field of view are affected by the multiplication of the zoom ratios of the foreoptics and the focusing lens. By properly combining two zoom ratios, we can control the spectral resolution with a fixed spatial resolution or the spatial resolution with a fixed spectral resolution. For an imaging spectrometer with this novel zooming function, we used the lens module method and third-order aberration theory to design an initial four-group zoom system with an external entrance pupil for the focusing lens. Furthermore, using the optical design software CODE V, we obtained an optimized zoom lens with a focal-length range of 50 to 150 mm. Finally, the zoom system with its transmission grating in the Littrow configuration performs satisfactorily as the focusing lens of an imaging spectrometer in the wavelength range 450-900 nm.

12.
Conf Proc IEEE Eng Med Biol Soc ; 2004: 1229-32, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-17271910

RESUMEN

Stereo disc photograph was analyzed and reconstructed as 3 dimensional contour image to evaluate the status of the optic nerve head for the early detection of glaucoma and the evaluation of the efficacy of treatment. Stepwise preprocessing was introduced to detect the edge of the optic nerve head and retinal vessels and reduce noises. Paired images were registered by power cepstrum method and zero-mean normalized cross-correlation. After Gaussian blurring, median filter application and disparity pair searching, depth information in the 3 dimensionally reconstructed image was calculated by the simple triangulation formula. Calculated depth maps were smoothed through cubic B-spline interpolation and retinal vessels were visualized more clearly by adding reference image. Resulted 3 dimensional contour image showed optic cups, retinal vessels and the notching of the neural rim of the optic disc clearly and intuitively, helping physicians in understanding and interpreting the stereo disc photograph.

13.
J Dent Res ; 82(11): 903-8, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14578503

RESUMEN

It is widely assumed that coupling the degradation rate of polymers used as cell transplantation carriers to the growth rate of the developing tissue will improve its quantity or quality. To test this hypothesis, we developed alginate hydrogels with a range of degradation rates by gamma-irradiating high-molecular-weight alginate to yield polymers of various molecular weights and structures. Decreasing the size of the polymer chains increased the degradation rate in vivo, as measured by implant retrieval rates, masses, and elastic moduli. Rapidly and slowly degrading alginates, covalently modified with RGD-containing peptides to control cell behavior, were then used to investigate the effect of biodegradation rate on bone tissue development in vivo. The more rapidly degrading gels led to dramatic increases in the extent and quality of bone formation. These results indicate that biomaterial degradability is a critical design criterion for achieving optimal tissue regeneration with cell transplantation.


Asunto(s)
Implantes Absorbibles , Osteoblastos/trasplante , Osteogénesis/fisiología , Ingeniería de Tejidos , Alginatos/efectos de la radiación , Animales , Biodegradación Ambiental/efectos de la radiación , Elasticidad , Rayos gamma , Hidrogeles , Ratones , Peso Molecular , Polímeros/química , Ratas
14.
Phys Rev E Stat Nonlin Soft Matter Phys ; 64(4 Pt 2): 047402, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11690182

RESUMEN

We present x-ray shadowgraphs from a high Mach number ( approximately 20) laboratory environment that simulate outward flowing ejecta matter from supernovae that interact with ambient cloud matter. Using a laser-plastic foil interaction, we generate a "complex" blast wave (a supersonic flow containing forward and reverse shock waves and a contact discontinuity between them) that interacts with a high-density (100 times ambient) sphere. The experimental results, including vorticity localization, compare favorably with two-dimensional axisymmetric hydrodynamic simulations.

15.
J Biol Chem ; 276(30): 28098-105, 2001 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-11356826

RESUMEN

The transcription factor CCAAT/enhancer-binding protein-alpha (C/EBPalpha) has a vital role in cell growth and differentiation. To delineate further a mechanism for C/EBPalpha-mediated differentiation, we screened C/EBPalpha-interacting proteins through far-Western screening. One of the strongest interactions was with RFC140, the large subunit of the replication factor C complex. C/EBPalpha specifically interacted with RFC140 from rat liver nuclear extract as determined by a combination of affinity chromatography and co-immunoprecipitation. Subsequent far-Western blotting showed that the bZIP domain of C/EBPalpha interacted with the DNA-binding region of RFC140. Overexpression of RFC140 in mammalian cells increased the transactivation activity of C/EBPalpha on both minimal and native promoters. Consistent with the enhanced transactivation, a complex of C/EBPalpha and RFC140 proteins with the cognate DNA element was detected in vitro. The specific interaction between C/EBPalpha and RFC140 was detected in the terminal differentiation of 3T3-L1 preadipocytes to adipocytes. The synergistic transcription effect of these two proteins increased the promoter activity and protein expression of peroxisome proliferator-activated receptor-gamma, which is a main regulator of adipocyte differentiation. Our results demonstrate that the specific transcription factor C/EBPalpha and the general DNA replication factor RFC140 interact functionally and physically. This observation highlights a unique mechanism by which the levels of the general replication factor can strongly modulate the functional activity of the specific transcription factor as a coactivator.


Asunto(s)
Tejido Adiposo/metabolismo , Proteínas de Unión al ADN/química , Hígado/metabolismo , Proteínas Nucleares , Proteínas de Unión al ARN , Factores de Transcripción/química , Adipocitos/metabolismo , Tejido Adiposo/citología , Animales , Western Blotting , Diferenciación Celular , Cromatografía de Afinidad , Clonación Molecular , ADN/metabolismo , ADN Complementario/metabolismo , Fibroblastos/metabolismo , Glutatión Transferasa/metabolismo , Ratones , Pruebas de Precipitina , Unión Proteica , Estructura Terciaria de Proteína , Ratas , Receptores Citoplasmáticos y Nucleares/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Proteína de Replicación C , Factores de Transcripción/metabolismo , Transcripción Genética , Activación Transcripcional , Transfección
16.
Biochem Biophys Res Commun ; 281(5): 1241-7, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11243868

RESUMEN

p38beta mitogen-activated protein kinase activity is required for the differentiation of 3T3-L1 fibroblasts into adipocytes. Activating transcription factor-2 (ATF-2) is efficiently phosphorylated and activated by p38beta kinase. These findings led us to examine a regulatory role of ATF-2 in adipocyte differentiation. The induction of ATF-2 protein precedes the expression of the transcription factors, peroxisome proliferator-activated receptor (PPAR) gamma and CCAAT/enhancer-binding protein (C/EBP) alpha. Consistent with early activation of p38beta kinase, the phosphorylation of ATF-2 was also detected in early stage of adipocyte differentiation. ATF-2 regulated gene transcription of PPARgamma, which was synergistically enhanced by p38beta kinase and C/EBPbeta proteins expression. Ectopic expression of ATF-2 in 3T3-L1 cells induced the endogenous PPARgamma protein levels. These results suggest that ATF-2 plays a role in a primary regulator of adipocyte differentiation with C/EBPbeta through promoting adipogenesis-inducing transcription factors including PPARgamma and becomes associated earlier in the differentiation program as mitotic clonal expansion proceeds and the cells become initially differentiated.


Asunto(s)
Adipocitos/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Factores de Transcripción/metabolismo , Factor de Transcripción Activador 2 , Adipocitos/citología , Animales , Proteína beta Potenciadora de Unión a CCAAT/metabolismo , Diferenciación Celular , Línea Celular , Ratones , Proteína Quinasa 11 Activada por Mitógenos , Proteínas Quinasas Activadas por Mitógenos/genética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fosforilación , Regiones Promotoras Genéticas , Receptores Citoplasmáticos y Nucleares/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Factores de Transcripción/genética , Activación Transcripcional , Transfección
17.
FEBS Lett ; 483(2-3): 114-8, 2000 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-11042264

RESUMEN

The X gene product of the human hepatitis B virus (HBx), a major factor responsible for hepatitis and hepatocellular carcinoma, modulates transactivation by a variety of transcription factors. Herein, expression of the phosphoenolpyruvate carboxykinase (PEPCK) gene was found to be regulated transcriptionally by HBx through two distinct promoter regions. The cAMP response element (CRE)-1 site within the proximal promoter region mediated the HBx-induced transactivation of the PEPCK gene through C/EBP alpha and ATF-2. A retinoid X receptor (RXR) response element within the distal promoter region also contributed to the HBx-induced transactivation. Consistent with these results, HBx directly interacted with RXR, and the interaction interfaces were localized to the transactivation domain of HBx and the ligand binding domain of RXR.


Asunto(s)
Fosfoenolpiruvato Carboxiquinasa (GTP)/genética , Receptores de Ácido Retinoico/metabolismo , Transactivadores/metabolismo , Factores de Transcripción/metabolismo , Factor de Transcripción Activador 2 , Alitretinoína , Sitios de Unión , Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Células HeLa , Humanos , Regiones Promotoras Genéticas/genética , Unión Proteica , Receptores de Ácido Retinoico/genética , Receptores X Retinoide , Transactivadores/genética , Factores de Transcripción/genética , Transcripción Genética/efectos de los fármacos , Activación Transcripcional/efectos de los fármacos , Tretinoina/farmacología , Células Tumorales Cultivadas , Técnicas del Sistema de Dos Híbridos , Proteínas Reguladoras y Accesorias Virales
18.
Opt Lett ; 24(2): 107-9, 1999 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-18071423

RESUMEN

We propose one- and two-wavelength methods of absolute measurement of diffraction-grating spacings based on the Littman configuration for autocollimation. The one-wavelength method has been applied to measure the spacing of a grating with a nominal value of 2160grooves/mm . The grating spacing was measured to be 463.16 nm, with an experimental standard deviation of 0.24 nm. It has been demonstrated that the both methods can provide direct traceability in the submicrometer region in terms of wavelength standards for applications in the field of nanometrology.

19.
Appl Opt ; 38(9): 1742-5, 1999 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-18305798

RESUMEN

We introduce a Fabry-Perot cavity-length modulation technique for measuring the linewidth of a continuous wave (cw) laser. We calculate the peak intensity of a cw laser transmitted through a Fabry-Perot cavity as a function of mirror speed. By fitting the experimental data to the results of the calculation, we determine the linewidth of a frequency-stabilized cw laser. The linewidth of a cw ring dye laser measured in the 570-590-nm wavelength range is approximately 170 +/- 20 kHz. We also demonstrate the use of this technique to measure the reflectivity of a high-reflectance mirror.

20.
Appl Opt ; 36(24): 6009-10, 1997 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-18259444

RESUMEN

We experimentally determine a geometric form factor for an inhomogeneous atmosphere by using the polynomial regression method in a lidar equation.

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