890 research outputs found

    Longitudinal Changes in Retinal Nerve Fiber Layer Thickness after Acute Primary Angle Closure Measured with Optical Coherence Tomography

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    PURPOSE. Longitudinal follow-up of peripapillary retinal nerve fiber layer (RNFL) thickness after an episode of acute primary angle closure (APAC) using Stratus optical coherence tomography (OCT). METHODS. Seventeen patients who had experienced a single unilateral APAC episode (intraocular pressure, Ͼ50 mm Hg) were enrolled. The average and superior, temporal, inferior, and nasal quadrant RNFL thicknesses of the affected and fellow eyes at 1, 4, and 12 weeks after remission were compared by using StratusOCT. The relationship between average RNFL thickness and interval of follow-up were evaluated with regression analysis. RESULTS. The mean duration of the APAC episode was 13.8 hours (range, 3-40). Comparison of the average and four quadrant RNFL thicknesses in the affected eyes longitudinally showed significant differences between 1 and 4, and 1 and 12 weeks, but not between 4 and 12 weeks. The average and four-quadrant RNFL thicknesses for the affected eyes were greater than the analogous values for fellow eyes at 1 week. In contrast, the inferior-and superior-quadrant RNFL thicknesses for the affected eyes were lower at 4 and 12 weeks, whereas the average and nasal quadrant values for the affected eyes were lower than those in fellow eyes at 12 weeks. Average RNFL thickness for the affected eyes was correlated with the interval of follow-up by using inverse regression analysis (P Ͻ 0.001; R 2 ϭ 0.60). Controlling for duration of APAC episode, the interval of follow-up on RNFL thickness reduction remained significant (P Ͻ 0.001, r ϭ Ϫ0.69). CONCLUSIONS. This study demonstrated an initial increase in diffuse RNFL thickness after a single APAC episode, followed by a subsequent decrease. (Invest Ophthalmol Vis Sci. 2007; 48:1659 -1664) DOI:10.1167/iovs.06-0950 A cute primary angle closure (APAC) is an ophthalmic emergency and a potentially blinding disease. Optic nerve damage can occur after the sudden rise in intraocular pressure (IOP) associated with an APAC episode. The optic disc appears edematous during this episode, and pallor with or without cupping may develop after remission. When treatment is delayed, vision may be markedly reduced to hand movement or light perception. 1 Perimetric examination during acute episodes is difficult and usually unreliable. After remission, visual field defects vary greatly in severity and type. 2 Measurement of retinal nerve fiber layer (RNFL) thickness loss after APAC is very important, as it is both objective and sensitive in terms of detection of the optic disc damage with either normal or unreliable visual fields. Scanning laser polarimetry with fixed corneal compensator (SLP-FCC) has been used for quantification of RNFL thickness change after APAC in cross-sectional study, 5 However, the latter investigation included several patients with poor IOP control after an APAC episode, as determined by RNFL measurement at follow-up. Moreover, SLP-FCC has limited functionality in measurement of RNFL thickness because of the lack of correction for variation in corneal polarization axis and corneal curvature. StratusOCT is a powerful imaging technology that can measure RNFL thickness and image tissue structure to an axial resolution of Ͻ10 m. 7 The stronger association with function in StratusOCT RNFL measurement compared with SLP-VCC suggests that the former may be superior for evaluation of glaucoma progression. 8 Therefore, the purpose of this study was to use StratusOCT to detect longitudinal change (1-12 weeks) in RNFL thickness after remission from a single APAC episode. MATERIALS AND METHODS In this prospective study, longitudinal observations were made using RNFL measurements obtained from StratusOCT at 1, 4, and 12 weeks after a single episode of unilateral APAC. Seventeen consecutive patients were recruited while undergoing treatment in the emergency or the ophthalmology outpatient departments of the Chang Gung Memorial Hospital-Kaohsiung Medical Center over a 1-year period. The study and data accumulation were in conformity with all relevant Taiwanese laws, and the investigation was conducted in accordance with the tenets of the Declaration of Helsinki. The APAC definition used for the study consisted of: The inclusion criteria were: (1) duration of episode less than 48 hours (interval from onset of acute symptoms to first hospital presentation); (2) resolution of acute episode and IOP control (Ͻ21 mm Hg) after antiglaucoma medication prescribed on first presentation, with interval between presentation and resolution under 2 hours (patients were treated with intravenous mannitol drip, oral acetazolamide, topical ␤-blocker and pilocarpine; the IOP was then rechecked 30 to 60 minutes after treatment); (3) subsequent laser iridotomy (LI) performed within 2 days of presentation on both affected and fellow eyes; and, (4) IOP Ͻ 21 mm Hg in both eyes for up to 12 weeks after treatment. Antiglaucoma medication was used to control IOP before and after LI in both eyes to prevent elevation (IOP Ͼ 21 mm Hg). The exclusion criteria were: (1) history of previous APAC in the affected or fellow eyes; (2) previous intraocular surgery, coexisting From th

    BANet: Blur-aware Attention Networks for Dynamic Scene Deblurring

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    Image motion blur usually results from moving objects or camera shakes. Such blur is generally directional and non-uniform. Previous research efforts attempt to solve non-uniform blur by using self-recurrent multi-scale or multi-patch architectures accompanying with self-attention. However, using self-recurrent frameworks typically leads to a longer inference time, while inter-pixel or inter-channel self-attention may cause excessive memory usage. This paper proposes blur-aware attention networks (BANet) that accomplish accurate and efficient deblurring via a single forward pass. Our BANet utilizes region-based self-attention with multi-kernel strip pooling to disentangle blur patterns of different degrees and with cascaded parallel dilated convolution to aggregate multi-scale content features. Extensive experimental results on the GoPro and HIDE benchmarks demonstrate that the proposed BANet performs favorably against the state-of-the-art in blurred image restoration and can provide deblurred results in real-time

    Electrochemical impedimetric biosensor based on a nanostructured polycarbonate substrate

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    This study integrates the techniques of nanoelectroforming, hot-embossing, and electrochemical deposition to develop a disposable, low-cost, and high sensitivity nanostructure biosensor. A modified anodic aluminum oxide barrier-layer surface was used as the template for thin nickel film deposition. After etching the anodic aluminum oxide template off, a three-dimensional mold of the concave nanostructure array was created. The fabricated three-dimensional nickel mold was further used for replica molding of a nanostructure polycarbonate substrate by hot-embossing. A thin gold film was then sputtered onto the polycarbonate substrate to form the electrode, followed by deposition of an orderly and uniform gold nanoparticle layer on the three-dimensional gold electrode using electrochemical deposition. Finally, silver nanoparticles were deposited on the uniformly deposited gold nanoparticles to enhance the conductivity of the sensor. Electrochemical impedance spectroscopy analysis was then used to detect the concentration of the target element. The sensitivity of the proposed scheme on the detection of the dust mite antigen, Der p2, reached 0.1 pg/mL

    Methyl (2′S,3′S)-3,4-O-(2′,3′-dimethoxy­butane-2′,3′-di­yl)-α-l-rhamnopyran­oside: a glycosyl acceptor

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    The title compound, C13H24O7, is the product of the ketalization of methyl l-(+)-rhamnopyran­oside with 2,3-butane­dione. It crystallizes with two mol­ecules in the asymmetric unit, which are connected by O—H⋯O hydrogen bonds. The C-3,4 diequatorial hydroxy groups of the methyl l-(+)-rhamnopyran­oside were protected, leaving the C-2 hydroxy group free. The l-(+)-rhamnopyran­oside and 2′,3′-dimethoxy­butane-2′,3′-diyl rings adopt chair conformations and all meth­oxy groups are in axial positions. The absolute configuration was assumed from the synthesis

    Deranged Bioenergetics and Defective Redox Capacity in T Lymphocytes and Neutrophils Are Related to Cellular Dysfunction and Increased Oxidative Stress in Patients with Active Systemic Lupus Erythematosus

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    Urinary excretion of N-benzoyl-glycyl-Nε-(hexanonyl)lysine, a biomarker of oxidative stress, was higher in 26 patients with active systemic lupus erythematosus (SLE) than in 11 non-SLE patients with connective tissue diseases and in 14 healthy volunteers. We hypothesized that increased oxidative stress in active SLE might be attributable to deranged bioenergetics, defective reduction-oxidation (redox) capacity, or other factors. We demonstrated that, compared to normal cells, T lymphocytes (T) and polymorphonuclear neutrophils (PMN) of active SLE showed defective expression of facilitative glucose transporters GLUT-3 and GLUT-6, which led to increased intracellular basal lactate and decreased ATP production. In addition, the redox capacity, including intracellular GSH levels and the enzyme activity of glutathione peroxidase (GSH-Px) and γ-glutamyl-transpeptidase (GGT), was decreased in SLE-T. Compared to normal cells, SLE-PMN showed decreased intracellular GSH levels, and GGT enzyme activity was found in SLE-PMN and enhanced expression of CD53, a coprecipitating molecule for GGT. We conclude that deranged cellular bioenergetics and defective redox capacity in T and PMN are responsible for cellular immune dysfunction and are related to increased oxidative stress in active SLE patients

    Diagnosis of Polypoidal Choroidal Vasculopathy from Fluorescein Angiography Using Deep Learning

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    Purpose: To differentiate polypoidal choroidal vasculopathy (PCV) from choroidal neovascularization (CNV) and to determine the extent of PCV from fluorescein angiography (FA) using attention-based deep learning networks. Methods: We build two deep learning networks for diagnosis of PCV using FA, one for detection and one for segmentation. Attention-gated convolutional neural network (AG-CNN) differentiates PCV from other types of wet age-related macular degeneration. Gradient-weighted class activation map (Grad-CAM) is generated to highlight important regions in the image for making the prediction, which offers explainability of the network. Attention-gated recurrent neural network (AG-PCVNet) for spatiotemporal prediction is applied for segmentation of PCV. Results: AG-CNN is validated with a dataset containing 167 FA sequences of PCV and 70 FA sequences of CNV. AG-CNN achieves a classification accuracy of 82.80% at image-level, and 86.21% at patient-level for PCV. Grad-CAM shows that regions contributing to decision-making have on average 21.91% agreement with pathological regions identified by experts. AG-PCVNet is validated with 56 PCV sequences from the EVEREST-I study and achieves a balanced accuracy of 81.132% and dice score of 0.54. Conclusions: The developed software provides a means of performing detection and segmentation of PCV on FA images for the first time. This study is a promising step in changing the diagnostic procedure of PCV and therefore improving the detection rate of PCV using FA alone. Translational Relevance: The developed deep learning system enables early diagnosis of PCV using FA to assist the physician in choosing the best treatment for optimal visual prognosis

    Diagnosis of Polypoidal Choroidal Vasculopathy From Fluorescein Angiography Using Deep Learning

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    Purpose: To differentiate polypoidal choroidal vasculopathy (PCV) from choroidal neovascularization (CNV) and to determine the extent of PCV from fluorescein angiography (FA) using attention-based deep learning networks. Methods: We build two deep learning networks for diagnosis of PCV using FA, one for detection and one for segmentation. Attention-gated convolutional neural network (AG-CNN) differentiates PCV from other types of wet age-related macular degeneration. Gradient-weighted class activation map (Grad-CAM) is generated to highlight important regions in the image for making the prediction, which offers explainability of the network. Attention-gated recurrent neural network (AG-PCVNet) for spatiotemporal prediction is applied for segmentation of PCV. Results: AG-CNN is validated with a dataset containing 167 FA sequences of PCV and 70 FA sequences of CNV. AG-CNN achieves a classification accuracy of 82.80% at image level, and 86.21% at patient-level for PCV. Grad-CAM shows that regions contributing to decision-making have on average 21.91% agreement with pathological regions identified by experts. AG-PCVNet is validatedwith56PCV sequences from the EVEREST-I study and achieves a balanced accuracy of 81.132% and dice score of 0.54. Conclusions: The developed software provides a means of performing detection and segmentation of PCV on FA images for the first time. This study is a promising step in changing the diagnostic procedure of PCV and therefore improving the detection rate of PCV using FA alone. Translational Relevance: The developed deep learning system enables early diagnosis of PCV using FA to assist the physician in choosing the best treatment for optimal visual prognosis. Introductio

    A pre-S gene chip to detect pre-S deletions in hepatitis B virus large surface antigen as a predictive marker for hepatoma risk in chronic hepatitis B virus carriers

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    <p>Abstract</p> <p>Background</p> <p>Chronic hepatitis B virus (HBV) infection is an important cause of hepatocellular carcinoma (HCC) worldwide. The pre-S<sub>1 </sub>and -S<sub>2 </sub>mutant large HBV surface antigen (LHBS), in which the pre-S<sub>1 </sub>and -S<sub>2 </sub>regions of the LHBS gene are partially deleted, are highly associated with HBV-related HCC.</p> <p>Methods</p> <p>The pre-S region of the LHBS gene in two hundred and one HBV-positive serum samples was PCR-amplified and sequenced. A pre-S oligonucleotide gene chip was developed to efficiently detect pre-S deletions in chronic HBV carriers. Twenty serum samples from chronic HBV carriers were analyzed using the chip.</p> <p>Results</p> <p>The pre-S deletion rates were relatively low (7%) in the sera of patients with acute HBV infection. They gradually increased in periods of persistent HBV infection: pre-S mutation rates were 37% in chronic HBV carriers, and as high as 60% in HCC patients. The Pre-S Gene Chip offers a highly sensitive and specific method for pre-S deletion detection and is less expensive and more efficient (turnaround time 3 days) than DNA sequencing analysis.</p> <p>Conclusion</p> <p>The pre-S<sub>1/2 </sub>mutants may emerge during the long-term persistence of the HBV genome in carriers and facilitate HCC development. Combined detection of pre-S mutations, other markers of HBV replication, and viral titers, offers a reliable predictive method for HCC risks in chronic HBV carriers.</p

    The Relationship between Qi Deficiency, Cancer-related Fatigue and Quality of Life in Cancer Patients

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    AbstractBackgroundQi (氣 qì) refers to the vital energy of the body in Traditional Chinese medicines (TCM). Qi deficiency (氣虛 qì xū) is the most common symptom in cancer patients according to the concept of TCM. We hypothesized that cancer patients with Qi deficiency suffer from poor quality of life (QOL) and fatigue.MethodAmong the 256 registered cancer patients screened at our outpatient clinic, a total of 198 were enrolled. The inclusion criteria were (1) age between 18 and 70years, (2) cancer diagnosis confirmed by the professional physician, (3) being Chinese, and (4) Eastern Cooperative Oncology Group (ECOG) performance status rating (PSR)≤3. The major outcome is the difference in QOL score in cancer patients with and without Qi deficiency.ResultsThe initial results showed statistically significant differences in WHO-QOL scores in physical, psychological, and social domains between the groups with and without Qi deficiency as well as the groups with and without cancerrelated fatigue (CRF). All patients with CRF present were also diagnosed as Qi deficient. In addition, among the patients with no CRF, 39.9% (69/173) were diagnosed as suffering from Qi deficiency, which led to poor QOL.ConclusionsThe present study showed statistically significant difference in WHO-QOL scores in physical, psychological, and social domains between the groups with and without Qi deficiency as well as the groups with and without CRF. Cancer patients diagnosed with Qi deficiency or CRF have poor QOL. The concept of Qi deficiency in TCM might be applied to cancer health care
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