Reliability and reproducibility of spectral and time domain optical coherence tomography images before and after correction for patients with age-related macular degeneration.

PURPOSE: To evaluate the reproducibility and reliability of optical coherence tomography scans obtained using the time domain (TD-OCT) Stratus (TM) OCT, and the Spectral Domain (SD-OCT) Spectralis (TM) and Cirrus (TM) OCT devices before and after manual correction in eyes with either Neovascular (NV-AMD) or Non-Neovascular (NNV-AMD) age-related macular degeneration. DESIGN: Prospective observational study. SETTING: University-based retina practice. PATIENTS: Thirty-six patients (50 eyes) with NV-AMD or NNV-AMD. PROCEDURE: OCT scans were taken simultaneously using one TD-OCT and two SD-OCT devices. MAIN OUTCOME MEASURES: Macular thickness measurements were assessed before and after correction of the algorithm by constructing Bland-Altman plots for agreement and calculating intraclass correlation coefficients (ICCs) and coefficients of repeatability (COR) to evaluate intraclass repeatability. RESULTS: Spectralis had the highest number of images needing manual correction. All machines had high ICCs, with Spectralis having the highest. Also, Bland-Altman plots indicated that there was low agreement between Cirrus™ and Stratus™, Spectralis™ and Stratus™, while there was good agreement between the Cirrus™ and Spectralis™. The CORs were lowest for Spectralis (TM) and similar and higher for Cirrus (TM) and Stratus (TM). Agreement, CORs, and ICCs generally improved after manual correction, but only minimally. CONCLUSION: Agreement is low between devices, except between both SD-OCT machines. Manual correction tends to improve results

Development of quantitative competitive PCR for determination of copy number and expression level of the synthetic glyphosate oxidoreductase gene in transgenic canola plants

Background: For successful in vitro plant regeneration, plant cell lines with multiple transgene integration and low transgene expression levels need to be ruled out. Although real-time polymerase chain reaction (real-time PCR) is a rapid way to accomplish this, it is also expensive and typically limits the size of the target sequence. Quantitative competitive PCR (QC-PCR) is proven to be a safe and accurate method for determination of both copy number and quantification of transcript levels of synthetic transgenes in transformed plants.Results: The glyphosate oxidoreductase gene was chemically synthesized and used to transform Brassica napus L. via Agrobactrium -mediated transformation. A construct containing the mutated form of a synthetic glyphosate oxidoreductase (gox) gene (internal standard) was prepared. Gene copy number was estimated in nine independent transgenic lines using QC-PCR as well as the standard method of Southern blot analysis. By quantitative competitive reverse transcriptase PCR (QC-RT-PCR), transcript levels were also determined in these lines. High (> 3), medium to high (2.2-3), medium to low (1-2.2), and low (< 1) levels of transcript were detected. Conclusions: No direct relationship was found between copy number and transgene expression levels. QC-PCR method could be implemented to screen putative transgenic plants and quickly select single T-DNA inserts. QC-PCR methods and the prepared competitor construct may be useful for future quantification of commercial transgenic food and feed

Characterization of macular lesions in punctate inner choroidopathy with spectral domain optical coherence tomography.

PURPOSE: Punctate inner choroidopathy (PIC) is an ocular inflammatory disease. Spectral domain optical coherence tomography (SD-OCT) allows detailed visualization of retinal and choroidal structures. We aimed to describe the retinal changes on SD-OCT associated with PIC lesions localized in the macula. METHODS: Retrospective case series: PIC lesions not associated with choroidal neovascularization (CNV) and captured by macular SD-OCT scans were identified and characterized. RESULTS: Twenty-seven PIC lesions from seven patients (eight eyes) were identified and classified into four categories according to disease activity and temporal changes. Among clinically inactive patients, two main patterns were noted on OCT: (1) retinal pigment epithelium (RPE) elevation with sub-RPE hyper-reflective signals and (2) localized disruption of outer retinal layers with choroid and Bruch\u27s membrane (BM) generally spared. Clinically active patients demonstrated lesions with intact BM with RPE elevation that fluctuated with disease activity and sub-RPE hyper-reflective signals. Photoreceptor-associated bands on SD-OCT (PRs) were not visible during active disease, but returned to normal visibility when lesions were clinically stable. Seven lesions in patients without clinically detected activity demonstrated alteration of RPE elevation. CONCLUSION: SD-OCT can provide detailed structural characteristics of PIC lesions. RPE elevation is noted in many lesions while BM and choroid are spared. Photoreceptor-associated bands on SD-OCT appear compressed during clinically active stages and are visible during stabilization. OCT may provide information on activity not detected clinically

Ultra-wide-field retinal imaging in the management of non-infectious retinal vasculitis.

BACKGROUND: The purpose of this study is to describe and quantify the benefit of ultra-wide-field imaging and fluorescein angiography (FA) in the management of non-infectious retinal vasculitis. In this prospective observational cohort series, patients with non-infectious retinal vasculitis were evaluated and enrolled by four investigators from the Divisions of Retina and Ocular Immunology at the Wilmer Eye Institute. In each patient, disease activity and the need for management changes were assessed, based on clinical examination with or without standard (60°) imaging and then with the addition of ultra-wide-field pseudo-color scanning laser ophthalmoscope (SLO) images and FA using the Optos ultra-wide-field SLO (Optos Panoramic 200MA™, Optos PLC, Dunfermline, Scotland, UK). A standardized questionnaire was completed by each investigator at the time of the clinical evaluation.The primary outcome was the percentage of patients whose management was changed by clinical examination and standard FA, compared with clinical examination plus ultra-wide-field imaging. The secondary outcome was the percentage of patients whose disease was determined to be active based on each modality. RESULTS: Seventy-one visits from 23 patients were reviewed and analyzed. Based on examination plus ultra-wide-field imaging and ultra-wide-field angiography, disease activity was detected in 48/71 (68%) compared with 32/71 (45%) based on examination and standard FA (P = 0.0095). Based on the clinical examination alone, the decision to alter management was made in 4 of 71 visits (6%), and an additional 3 of 71 (4%) based on simulated standard FA. The addition of ultra-wide-field SLO pseudo-color images altered management in an additional 10/71 visits (14%), and 36/71 (51%) with the addition of ultra-wide-field FA. CONCLUSIONS: Ultra-wide-field fluorescein imaging and angiography can provide additional information that may be important and relevant in the management of retinal vasculitis

Importance of proper diagnosis for management: multifocal choroiditis mimicking ocular histoplasmosis syndrome

PURPOSE: The study aims to evaluate a series of patients with initial diagnosis of ocular histoplasmosis syndrome (OHS) with progression and response to treatments consistent with multifocal choroiditis (MFC). METHODS: Retrospective review of nine patients referred for management of recurrent OHS lesions. Serology panel was conducted to rule out autoimmune and infectious causes. RESULTS: Clinical examination revealed multiple small, punched-out peripheral chorioretinal scars, and peripapillary atrophy. Histoplasma antigen/antibody was negative in all patients. Fluorescein angiography and optical coherence tomography confirmed active inflammation in five patients. Immunomodulatory therapy (IMT) was initiated to control active inflammation. While on IMT, visual acuity stabilized or improved in three patients with no recurrence of CNV or lesion activities over the follow-up period. CONCLUSIONS: MFC may initially masquerade as OHS. Clinical characteristics of recurrent MFC and absence of histoplasma titer may lead to consideration of IMT and other proper treatments for MFC

Comparison of time domain and spectral domain optical coherence tomography in measurement of macular thickness in macular edema secondary to diabetic retinopathy and retinal vein occlusion.

Purpose. To evaluate macular thickness, agreement, and intraclass repeatability in three optical coherence tomography (OCT) devices: the time domain (TD) Stratus OCT and two spectral domain (SD) OCTs, Spectralis and Cirrus SD-OCT, in eyes with macular edema secondary to diabetic retinopathy (DR) and retinal vein occlusion (VO). Methods. In a prospective observational study at a university-based retina practice, retinal thickness tomography was performed simultaneously for fifty-eight patients (91 eyes) with DR and VO employing a time domain and two spectral domain OCTs. Agreement in macular measurements was assessed by constructing Bland-Altman plots. Intraclass repeatability was assessed by intraclass correlation coefficients (ICCs). Results. Based on the Bland-Altman plots for central macular thickness, there was low agreement between the measurements of Cirrus SD-OCT and Stratus OCT, Spectralis OCT and Stratus OCT, as well as Spectralis OCT and Cirrus SD-OCT among DR and RVO patients. All three devices demonstrated high intraclass repeatability, with ICC of 98% for Stratus OCT, 97% for Cirrus SD-OCT, and 100% for Spectralis OCT among DR patients. The ICC was 97% for Stratus OCT, 79% for Cirrus SD-OCT, and 91% for Spectralis OCT among RVO patients. Conclusion. There are low agreements among interdevice measurements. However, intraclass repeatability is high in both TD and SD-OCT devices

Insight into impact of carbon nanotubes on Li-ion cathode materials

Materials that are one-dimensional (1D) exhibit unique properties which cannot be found in 2D and 3D materials. Obviously, Carbon nanotube (CNT) and its variants are among the most significant 1D materials (e.g. SWCNT, MWCNT, etc.). The CNT materials are potentially effective additives to change the electrode characteristics of Li-ion batteries due to the requirement of electron conductivity. To comprehend the impact of these additives on the electrode behaviors and their origins, a comprehensive analytical assessment is mandatory. Charge-discharge data of the many cathode materials modified with CNT additives in various conditions and different labs are gathered from literature for this purpose. To evaluate the impact of the additives on performance, rate-capability, activating particle, and goodness of the activated particles, the results are applied to three type diagrams (ordinary, standardization, and normalization). These evaluations are novel, since, the resulted final conclusions cannot be derived without normalization/standardization of the data. This study gathered many data from literature and make comparison between them to shed light to understand the mechanisms and effectiveness of the additives. Our evaluations show that the effectiveness highly depends on the nature of electrode and synthesis method. Also, preparation parameters play roles in effectiveness of the additives

Evaluation of Ti3C2 as electrode material for Li, Na, Mg, Al, K, Ca, and Zn -ion intercalation batteries: A DFT study

Layered structures attracts attention as the intercalation host structures. MAX-phases are a family of ternary layered carbides and nitrides, with general formula Mn+1AXn. By etching the A parameter out of MAX-phase layers, MXene uses as electrode material in different intercalation batteries. In the present work, we use noble approaches for density functional theory (DFT) calculations to evaluate Ti3C2 MXene as an intercalation electrode for Li-ion, Na-ion, Mg-ion, Al-ion, K-ion, Ca-ion, and Zn-ion batteries. The evaluated electrode materials are Ti3LiC2, Ti3NaC2, Ti3MgC2, Ti3AlC2, Ti3KC2, Ti3CaC2, and Ti3ZnC2, respectively. The structural, electrical, electrochemical, and bonding properties of the Ti3C2-MXene with and without the intercalating ion are studied. Two deintercalated structures are investigated, called 1st and 2nd deintercalated structures. Consequently, we conclude that Ti3C2 MXene is a superior electrode material for the intercalation batteries at least regarding to its structural (2nd deint. st.) and electrical properties. However, Ca, K, and Na -ion cells may have a problem for their 1st (de)intercalation cycle. This study helps future investigations for MXene electrode materials. Also, it provides an appropriate methodology to study analogous materials

Differential impact of mitigation policies and socioeconomic status on COVID-19 prevalence and social distancing in the United States

Abstract Background The spread of COVID-19 has highlighted the long-standing health inequalities across the U.S. as neighborhoods with fewer resources were associated with higher rates of COVID-19 transmission. Although the stay-at-home order was one of the most effective methods to contain its spread, residents in lower-income neighborhoods faced barriers to practicing social distancing. We aimed to quantify the differential impact of stay-at-home policy on COVID-19 transmission and residents’ mobility across neighborhoods of different levels of socioeconomic disadvantage. Methods This was a comparative interrupted time-series analysis at the county level. We included 2087 counties from 38 states which both implemented and lifted the state-wide stay-at-home order. Every county was assigned to one of four equally-sized groups based on its levels of disadvantage, represented by the Area Deprivation Index. Prevalence of COVID-19 was calculated by dividing the daily number of cumulative confirmed COVID-19 cases by the number of residents from the 2010 Census. We used the Social Distancing Index (SDI), derived from the COVID-19 Impact Analysis Platform, to measure the mobility. For the evaluation of implementation, the observation started from Mar 1st 2020 to 1 day before lifting; and, for lifting, it ranged from 1 day after implementation to Jul 5th 2020. We calculated a comparative change of daily trends in COVID-19 prevalence and Social Distancing Index between counties with three highest disadvantage levels and those with the least level before and after the implementation and lifting of the stay-at-home order, separately. Results On both stay-at-home implementation and lifting dates, COVID-19 prevalence was much higher among counties with the highest or lowest disadvantage level, while mobility decreased as the disadvantage level increased. Mobility of the most disadvantaged counties was least impacted by stay-at-home implementation and relaxation compared to counties with the most resources; however, disadvantaged counties experienced the largest relative increase in COVID-19 infection after both stay-at-home implementation and relaxation. Conclusions Neighborhoods with varying levels of socioeconomic disadvantage reacted differently to the implementation and relaxation of COVID-19 mitigation policies. Policymakers should consider investing more resources in disadvantaged counties as the pandemic may not stop until most neighborhoods have it under control