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1.
BMC Geriatr ; 23(1): 346, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37264334

RESUMO

PURPOSE: Spinal sarcopenia is a multifactorial disorder associated with atrophy and fatty changes in paraspinal muscles. Interventional studies for spinal sarcopenia are limited. We aimed to evaluate the effectiveness of a combined exercise and nutrition intervention for the treatment of spinal sarcopenia. METHODS: 35 community-dwelling older women diagnosed with spinal sarcopenia in a previous cohort study were included. The 12-week combined intervention consisted of back extensor strengthening exercises and protein supplementation. The following outcomes were measured at baseline (week 0), after the intervention (week 12), and follow-up (week 24): conventional variables of sarcopenia (appendicular skeletal muscle mass, handgrip strength, 6-meter gait speed, and short physical performance battery); lumbar extensor muscle mass; lumbar extensor muscle volume and signal intensity; back extensor isokinetic strength; and back performance scale. We used the intention-to-treat analysis method, and repeated measures analysis of variance was used to analyze the data. RESULTS: Of the total 35 potential participants, 26 older women participated in the study (mean age 72.5 ± 4.0 years old). After 12 weeks of combined exercise and nutrition intervention, there were no changes in the appendicular skeletal muscle mass, lumbar extensor muscle mass, volume, or signal intensity. Handgrip strength and back extensor isokinetic strength did not change significantly. Short physical performance battery significantly increased (P = 0.042) from 11.46 ± 0.86 to 11.77 ± 0.53 at week 12 and 11.82 ± 0.40 at week 24. The back performance scale sum score also significantly improved (P = 0.034) from 2.68 ± 1.81 to 1.95 ± 1.21 at week 12 and 2.09 ± 1.34 at week 24. CONCLUSION: The combined exercise and nutrition intervention for community-dwelling older women with spinal sarcopenia could be feasible and helpful in improving the physical performance as well as back performance.


Assuntos
Sarcopenia , Idoso , Feminino , Humanos , Exercício Físico , Terapia por Exercício , Força da Mão , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Sarcopenia/diagnóstico
2.
J Korean Med Sci ; 36(38): e241, 2021 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-34609091

RESUMO

BACKGROUND: To assess the rate of germline BRCA gene tests in epithelial ovarian cancer (EOC) patients and uptake of post-test risk management strategies in BRCA1/2-mutated patients. METHODS: Institutional databases were searched to identify patients who were diagnosed with epithelial ovarian, fallopian tube, or primary peritoneal cancer (EOC) between 2009 and 2019 in two academic hospitals. Retrospective review on medical records was performed to collect clinico-pathologic variables, including performance of germline BRCA gene test and its results, as well as conduct of breast cancer screening tests and cascade testing. If annual mammography +/- breast ultrasonography was performed, it was considered that regular breast cancer surveillance was done. RESULTS: A total of 840 women with EOC were identified during the study period. Of these, 454 patients (54.0%) received BRCA gene testing and 106 patients (106/454, 23.3%) were positive for BRCA1/2 mutations. The rate of BRCA tests has markedly increased from 25.8% in 2009-2012 to 62.7% in 2017-2019. Among the 93 patients with BRCA1/2 mutation without previous personal breast cancer history, 20 patients (21.5%) received annual mammography with or without breast ultrasonography for regular surveillance. Among the 106 BRCA1/2-mutated EOC patients, cascade testing on family members was performed only in 13 patients (12.3%). CONCLUSION: Although BRCA1/2 gene tests have been substantially expanded, the uptake of post-test risk management strategies, including breast cancer screening for BRCA1/2-mutated patients and cascade testing for family members, has remained low. Strategies to increase its uptake and education about the importance of post-test risk managements are needed.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias das Tubas Uterinas/patologia , Neoplasias Ovarianas/patologia , Neoplasias Peritoneais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Quimioterapia Adjuvante , Bases de Dados Factuais , Neoplasias das Tubas Uterinas/tratamento farmacológico , Neoplasias das Tubas Uterinas/genética , Feminino , Células Germinativas/citologia , Células Germinativas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Peritoneais/genética , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
3.
Opt Express ; 24(8): 8718-34, 2016 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-27137306

RESUMO

A new slim-type electro-floating display system based on the polarization-controlled optical path is proposed. In the proposed system, the optical path between the input plane and Fresnel lens can be made recursive by repetitive transmission and reflection of the input beam by employing a new polarization-based optical path controller (P-OPC), which is composed of two quaterwave plates, a half mirror and a reflective polarizer. Based on this P-OPC, the absolute optical path between the input plane and Fresnel lens, virtually representing the physical depth of the display system, can be reduced down to one third of its original path, which results in the same rate of decrease in the volume size of the display system. The operational principle of the proposed system is analyzed with the Jones matrix. In addition, to confirm the feasibility of the proposed system, experiments with test prototypes are carried out, and the results are comparatively discussed with those of the conventional system.

4.
Appl Opt ; 55(3): A22-31, 2016 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-26835954

RESUMO

A three-directional motion-compensation mask-based novel look-up table method is proposed and implemented on graphics processing units (GPUs) for video-rate generation of digital holographic videos of three-dimensional (3D) scenes. Since the proposed method is designed to be well matched with the software and memory structures of GPUs, the number of compute-unified-device-architecture kernel function calls can be significantly reduced. This results in a great increase of the computational speed of the proposed method, allowing video-rate generation of the computer-generated hologram (CGH) patterns of 3D scenes. Experimental results reveal that the proposed method can generate 39.8 frames of Fresnel CGH patterns with 1920×1080 pixels per second for the test 3D video scenario with 12,088 object points on dual GPU boards of NVIDIA GTX TITANs, and they confirm the feasibility of the proposed method in the practical application fields of electroholographic 3D displays.

5.
Opt Express ; 22(19): 22513-27, 2014 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-25321721

RESUMO

As a new approach for rapid generation of holographic videos, a so-called compressed novel-look-up-table(C-NLUT), which is composed of only two principal fringe patterns (PFPs) of baseline and depth-compensating PFPs (B-PFP, DC-PFP), is proposed. Here, the hologram pattern for a 3-D video frame are generated by calculating the fringe patterns for all depth layers only by using the B-PFP, and then transforming them into those for their depth layers by being multiplied with corresponding DC-PFPs. With this one-step calculation process, the computational speed (CS) of the proposed method can be greatly enhanced. Experimental results show that the CS of the proposed method has been improved by 30.2% on the average compared to that of the conventional method. Furthermore, the average calculation time of a new hybrid MC/C-NLUT method, in which both of motion-compensation (MC) and one-step calculation schemes are employed, has been reduced by 99.7%, 65.4%, 60.2% and 30.2%, respectively compared to each of the conventional ray-tracing, LUT, NLUT, and MC-NLUT methods. In addition, the memory size of the proposed method has been also reduced by 82 × 10(6)-fold and 128-fold compared to those of the conventional LUT and NLUT methods, respectively.


Assuntos
Algoritmos , Holografia , Imageamento Tridimensional/instrumentação
6.
Opt Express ; 22(14): 16925-44, 2014 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-25090509

RESUMO

A new three-directional motion compensation-based novel-look-up-table (3DMC-NLUT) based on its shift-invariance and thin-lens properties, is proposed for video hologram generation of three-dimensional (3-D) objects moving with large depth variations in space. The input 3-D video frames are grouped into a set of eight in sequence, where the first and remaining seven frames in each set become the reference frame (RF) and general frames (GFs), respectively. Hence, each 3-D video frame is segmented into a set of depth-sliced object images (DOIs). Then x, y, and z-directional motion vectors are estimated from blocks and DOIs between the RF and each of the GFs, respectively. With these motion vectors, object motions in space are compensated. Then, only the difference images between the 3-directionally motion-compensated RF and each of the GFs are applied to the NLUT for hologram calculation. Experimental results reveal that the average number of calculated object points and the average calculation time of the proposed method have been reduced compared to those of the conventional NLUT, TR-NLUT and MPEG-NLUT by 38.14%, 69.48%, and 67.41% and 35.30%, 66.39%, and 64.46%, respectively.

7.
Opt Express ; 22(7): 8047-67, 2014 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-24718180

RESUMO

A new robust MPEG-based novel look-up table (MPEG-NLUT) is proposed for accelerated computation of video holograms of fast-moving three-dimensional (3-D) objects in space. Here, the input 3-D video frames are sequentially grouped into sets of four, in which the first and remaining three frames in each set become the reference (RF) and general frames (GFs). Then, the frame images are divided into blocks, from which motion vectors are estimated between the RF and each of the GFs, and with these estimated motion vectors, object motions in all blocks are compensated. Subsequently, only the difference images between the motion-compensated RF and each of the GFs are applied to the NLUT for CGH calculation based on its unique property of shift-invariance. Experiments with three types of test 3-D video scenarios confirm that the average number of calculated object points and the average calculation time of the proposed method, have found to be reduced down to 27.34%, 55.46%, 45.70% and 19.88%, 44.98%, 30.72%, respectively compared to those of the conventional NLUT, temporal redundancy-based NLUT (TR-NLUT) and motion compensation-based NLUT (MC-NLUT) methods.

8.
Opt Express ; 22(8): 9820-38, 2014 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-24787867

RESUMO

A novel directional backlight system based on volume-holographic optical elements (VHOEs) is demonstrated for time-sequential autostereoscopic three-dimensional (3-D) flat-panel displays. Here, VHOEs are employed to control the direction of light for a time-multiplexed display for each of the left and the right view. Those VHOEs are fabricated by recording interference patterns between collimated reference beams and diverging object beams for each of the left and right eyes on the volume holographic recording material. For this, self-developing photopolymer films (Bayfol® HX) were used, since those simplify the manufacturing process of VHOEs substantially. Here, the directional lights are similar to the collimated reference beams that were used to record the VHOEs and create two diffracted beams similar to the object beams used for recording the VHOEs. Then, those diffracted beams read the left and right images alternately shown on the LCD panel and form two converging viewing zones in front of the user's eyes. By this he can perceive the 3-D image. Theoretical predictions and experimental results are presented and the performance of the developed prototype is shown.

9.
Opt Express ; 21(9): 11568-84, 2013 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-23670014

RESUMO

A novel approach for fast generation of video holograms of three-dimensional (3-D) moving objects using a motion compensation-based novel-look-up-table (MC-N-LUT) method is proposed. Motion compensation has been widely employed in compression of conventional 2-D video data because of its ability to exploit high temporal correlation between successive video frames. Here, this concept of motion-compensation is firstly applied to the N-LUT based on its inherent property of shift-invariance. That is, motion vectors of 3-D moving objects are extracted between the two consecutive video frames, and with them motions of the 3-D objects at each frame are compensated. Then, through this process, 3-D object data to be calculated for its video holograms are massively reduced, which results in a dramatic increase of the computational speed of the proposed method. Experimental results with three kinds of 3-D video scenarios reveal that the average number of calculated object points and the average calculation time for one object point of the proposed method, have found to be reduced down to 86.95%, 86.53% and 34.99%, 32.30%, respectively compared to those of the conventional N-LUT and temporal redundancy-based N-LUT (TR-N-LUT) methods.


Assuntos
Algoritmos , Holografia/métodos , Aumento da Imagem/métodos , Imageamento Tridimensional/métodos , Armazenamento e Recuperação da Informação/métodos , Gravação em Vídeo/métodos , Retroalimentação , Movimento (Física)
10.
Gynecol Oncol ; 131(2): 336-40, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23954903

RESUMO

OBJECTIVES: We aimed to develop a risk model to predict a risk of suboptimal cytoreduction in primary surgery of ovarian cancer. METHODS: The clinical records and computed tomography (CT) data of 358 patients with stages II-IV epithelial ovarian cancer were reviewed. Tumor spread patterns identified by principal component analysis, CA-125, and a newly developed surgical skill index were integrated into a logistic model along with other variables. Internal validation was performed using bootstrapped re-sampling and calibration was assessed by goodness-of-fit test. RESULTS: Among the 358 patients, optimal cytoreduction, which was defined as no residual tumor, was achieved in 145 patients (40.5%). The surgical capacity of an individual institution was estimated by a surgical skill index, which was the frequency of complex surgeries in patients with advanced disease. In a multivariate model, two distinctive CT patterns of tumor spread (diffuse spread pattern and upper abdominal extension pattern), a surgical skill index, and serum CA-125 independently predicted a risk of suboptimal cytoreduction (P=0.006, P=0.013, P=0.031, and P=0.001, respectively). The model showed a C-statistic of .73 (95% confidence interval .67 to .79), which was significantly higher than tumor stage or ascites. Rigorous internal validation by bootstrapped re-sampling successfully confirmed the model. CONCLUSIONS: We identified two distinct tumor spread patterns of ovarian cancer, which can be integrated to improve a prediction model. Our model may be useful in patient referral or clinical trials for patient stratification.


Assuntos
Modelos Estatísticos , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Epiteliais e Glandulares/cirurgia , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/cirurgia , Adulto , Idoso , Antígeno Ca-125/sangue , Carcinoma Epitelial do Ovário , Feminino , Procedimentos Cirúrgicos em Ginecologia/métodos , Procedimentos Cirúrgicos em Ginecologia/normas , Humanos , Modelos Logísticos , Proteínas de Membrana/sangue , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Epiteliais e Glandulares/sangue , Neoplasias Ovarianas/sangue , Análise de Componente Principal , Reprodutibilidade dos Testes , Risco , Tomografia Computadorizada por Raios X , Adulto Jovem
11.
Opt Express ; 20(11): 12021-34, 2012 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-22714188

RESUMO

We propose a novel approach to massively reduce the memory of the novel look-up table (N-LUT) for computer-generated holograms by employing one-dimensional (1-D) sub-principle fringe patterns (sub-PFPs). Two-dimensional (2-D) PFPs used in the conventional N-LUT method are decomposed into a pair of 1-D sub-PFPs through a trigonometric relation. Then, these 1-D sub-PFPs are pre-calculated and stored in the proposed method, which results in a remarkable reduction of the memory of the N-LUT. Experimental results reveal that the memory capacity of the LUT, N-LUT and proposed methods have been calculated to be 149.01 TB, 2.29 GB and 1.51 MB, respectively for the 3-D object having image points of 500 × 500 × 256, which means the memory of the proposed method could be reduced by 103 × 10(6) fold and 1.55 × 10(3) fold compared to those of the conventional LUT and N-LUT methods, respectively.


Assuntos
Algoritmos , Holografia/instrumentação , Armazenamento e Recuperação da Informação/métodos , Refratometria/métodos
12.
Appl Opt ; 50(19): 3375-82, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21743543

RESUMO

In this paper, we propose an approach, new to our knowledge, to effectively generate and reconstruct the resolution-enhanced computer-generated hologram (CGH) of three-dimensional (3-D) objects with a significantly reduced in memory size novel look-up table (N-LUT) by taking into account a relationship between the pixel pitch and reconstruction distance of the hologram pattern. In the proposed method, a CGH pattern composed of shifted versions of the principal fringe patterns (PFPs) with a short pixel pitch can be reconstructed just by using the CGH generated with a much longer pixel pitch by controlling the hologram reconstruction distance. Accordingly, the corresponding N-LUT memory size required for resolution-enhanced hologram patterns can be significantly reduced in the proposed method. To confirm the feasibility of the proposed method, experiments are carried out and the results are discussed.

13.
J Vet Diagn Invest ; 22(4): 524-30, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20622221

RESUMO

Brucella abortus is a bacterium of brucellosis causing abortion in cattle. The diagnosis of bovine brucellosis mainly relies on serologic tests using smooth lipopolysaccharide (S-LPS) from B. abortus. However, the usefulness of this method is limited by false-positive reactions due to cross-reaction with other Gram-negative bacteria. In the present study, the eryC gene encoding B. abortus d-erythrulose 1-phosphate dehydrogenase, which is involved in the erythritol metabolism in virulent B. abortus strain but is absent from a B. abortus vaccine strain (S19), was cloned. Recombinant EryC was expressed and purified for the evaluation as a diagnostic reagent for bovine brucellosis. Other B. abortus proteins, Omp16, PP26, and CP39 were also purified and their seroreactivities were compared. Recombinant EryC, Omp16, PP26, and PP39 were all reactive to B. abortus-positive serum. The specificity of recombinant Omp16, PP26, CP39, and EryC, were shown to be approximately 98%, whereas that of B. abortus whole cell lysates was shown to be 95%. The sensitivity of Omp16, PP26, CP39, and EryC were 10%, 51%, 64%, and 43%, respectively, whereas that of B. abortus whole cell lysates was 53%. These results suggested that B. abortus EryC would be a potential reagent for diagnosis for bovine brucellosis as a single protein antigen.


Assuntos
Proteínas de Bactérias/metabolismo , Brucella/enzimologia , Brucelose Bovina/diagnóstico , Oxirredutases/metabolismo , Animais , Proteínas de Bactérias/genética , Western Blotting/métodos , Western Blotting/veterinária , Bovinos , Clonagem Molecular , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Oxirredutases/genética , Proteínas Recombinantes , Reprodutibilidade dos Testes
14.
Sci Rep ; 10(1): 22158, 2020 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-33335164

RESUMO

Recent technical advances related to the CRISPR/Cas9-based genome editing system have enabled sophisticated genome editing in microalgae. Although the demand for research on genome editing in microalgae has increased over time, methodological research has not been established to date for the delivery of a ribonucleoprotein (Cas9/sgRNA complex) using a cell penetrating peptide into microalgal cell lines. Here, we present a ribonucleoprotein delivery system for Chlamydomonas reinhardtii mediated by the cell penetrating peptide pVEC (LLIILRRRIRKQAHAHSK) which is in a non-covalent form. Using this technically simple method, the ribonucleoprotein was successfully delivered into C. reinhardtii. Gene Maa7 and FKB12 were disrupted, and their distinguishing patterns of Indel mutations were analyzed with the observation of several insertions of sequences not originating from the genome DNA, such as chloroplast DNA, into the expected loci. In addition, the cytotoxicity of Cas9 and the ribonucleoprotein was investigated according to the concentration and time in the algal cells. It was observed that Cas9 alone without the sgRNA induces a more severe cytotoxicity compared to the ribonucleoprotein. Our study will not only contribute to algal cell biology and its genetic engineering for further applications involving various organisms but will also provide a deeper understating of the basic science of the CRISPR/Cas9 system.


Assuntos
Sistemas CRISPR-Cas , Chlamydomonas reinhardtii/genética , Edição de Genes , Técnicas de Transferência de Genes , Peptídeos , Ribonucleoproteínas/genética , Linhagem Celular , DNA de Cloroplastos , Marcação de Genes , Engenharia Genética , Mutagênese , Peptídeos/química , RNA Guia de Cinetoplastídeos/genética
15.
Appl Opt ; 48(34): H95-104, 2009 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-19956307

RESUMO

In this paper, we propose a novel computational integral-imaging reconstruction (CIIR)-based three-dimensional (3-D) image correlator system for the recognition of 3-D volumetric objects by employing a 3-D reference object. That is, a number of plane object images (POIs) computationally reconstructed from the 3-D reference object are used for the 3-D volumetric target recognition. In other words, simultaneous 3-D image correlations between two sets of target and reference POIs, which are depth-dependently reconstructed by using the CIIR method, are performed for effective recognition of 3-D volumetric objects in the proposed system. Successful experiments with this CIIR-based 3-D image correlator confirmed the feasibility of the proposed method.

16.
Opt Express ; 16(6): 3623-35, 2008 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-18542455

RESUMO

In this paper, a novel approach to effectively extract location coordinates of 3-D objects employing a blur metric has been proposed. With elemental images of 3-D objects, plane object images (POIs) were reconstructed along the output plane using the CIIR (computational integral imaging reconstruction) algorithm, in which only the POIs reconstructed on the output planes where 3-D objects were originally located are focused whereas the other ones are blurred. Therefore, by calculating these blur metrics of the reconstructed POIs depth data of 3-D objects could be extracted. That is, the blur metric is the lowest on the focused point, but it starts to increase as (fill in the blank) moves away from that point. Accordingly, by finding out the points of inflection in the map of blur metric variation, the output planes where the objects were located were finally detected. To show the feasibility of our proposed scheme, some experiments were carried out and its results are presented as well.


Assuntos
Algoritmos , Inteligência Artificial , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Reconhecimento Automatizado de Padrão/métodos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
Respiration ; 76(3): 331-7, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18212516

RESUMO

BACKGROUND: Cytokine production profiles may reflect the clinical pictures of patients with tuberculosis (TB). OBJECTIVE: We examined the relationship between cytokine levels and clinical parameters indicating the state of disease in active pulmonary TB patients. METHODS: We measured interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha and interleukin (IL)-10 levels in whole blood after stimulation with culture filtrate protein of Mycobacterium tuberculosis in 33 multi-drug resistant (MDR)-TB and 51 non-MDR-TB patients. RESULTS: No significant difference was found in IFN-gamma production between non-MDR-TB and MDR-TB patients, but there was a marked reduction in TNF-alpha production in MDR-TB patients accompanied by a moderate increase in IL-10 levels. In contrast, the presence of cavity was associated with a significant increase in IFN-gamma, whereas no difference in TNF-alpha between the cavity and non-cavity group was observed. Those who have TB lesions in the left lung showed lower levels of IFN-gamma and TNF-alpha and higher IL-10 levels than the patients with lesions on the right side. IFN-gamma levels were significantly increased in those with moderate or advanced lesions compared with patients with mild lesions. TNF-alpha and IL-10 levels did not change with disease severity. The number of M. tuberculosis bacilli in sputum was closely associated with TNF-alpha levels. The patient group with high value (+++) of sputum culture acid-fast bacilli produced significantly reduced levels of TNF-alpha compared with medium (++) and low (+) values. CONCLUSION: These findings suggest that IFN-gamma, TNF-alpha or IL-10 production patterns in whole blood are associated with disease progression in active pulmonary TB.


Assuntos
Progressão da Doença , Interleucina-10/sangue , Tuberculose Resistente a Múltiplos Medicamentos/sangue , Fator de Necrose Tumoral alfa/sangue , Adulto , Idoso , Feminino , Humanos , Interferon gama/sangue , Pulmão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Radiografia , Índice de Gravidade de Doença , Escarro/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico por imagem
18.
Appl Opt ; 47(32): 5986-95, 2008 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-19002222

RESUMO

Even though there are many types of methods to generate CGH (computer-generated hologram) patterns of three-dimensional (3D) objects, most of them have been applied to still images but not to video images due to their computational complexity in applications of 3D video holograms. A new method for fast computation of CGH patterns for 3D video images is proposed by combined use of data compression and lookup table techniques. Temporally redundant data of the 3D video images are removed with the differential pulse code modulation (DPCM) algorithm, and then the CGH patterns for these compressed videos are generated with the novel lookup table (N-LUT) technique. To confirm the feasibility of the proposed method, some experiments with test 3D videos are carried out, and the results are comparatively discussed with the conventional methods in terms of the number of object points and computation time.

19.
Appl Opt ; 47(21): 3901-8, 2008 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-18641760

RESUMO

We present a novel approach for generating three-dimensional (3-D) integral images from a fringe pattern of 3-D objects. A recorded hologram of 3-D objects is segmented into a number of subholograms. Then, different views of 3-D objects are reconstructed from them because each subhologram has its own perspective of 3-D objects in the recording process. These locally reconstructed images can be rearranged as the same subimage array of the conventional integral-imaging system and transformed into virtually picked-up elemental images of 3-D objects. From this newly generated elemental image array, 3-D images could easily be reconstructed by using a white light. Experiments with a 3-D test object have been performed and the results have been presented.

20.
Appl Opt ; 47(31): 5784-9, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-19122720

RESUMO

We have implemented experimental code to compute a compensated phase-added stereogram (CPAS), which was proposed in a previous paper, on a graphic processing unit (GPU). In this paper, we show an acceleration method for CPAS computation by means of the GPU and compare the computation time between CPU-based and GPU-based calculations, which are programmed in our laboratories. In addition, we demonstrate their reconstructed images. As a result, we could achieve a performance gain of a factor of over 33 compared with a CPU-based computing environment and digital holograms can be displayed at 30 frames per second with 15,000 points.

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