Publications by authors named "Gregori G"

We present two methods for computing the dynamic structure factor for warm dense hydrogen without invoking either the Born-Oppenheimer approximation or the Chihara decomposition, by employing a wave-packet description that resolves the electron dynamics during ion evolution. First, a semiclassical method is discussed, which is corrected based on known quantum constraints, and second, a direct computation of the density response function within the molecular dynamics. The wave-packet models are compared to PIMC and DFT-MD for the static and low-frequency behavior.

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  • This study aimed to confirm the reliability of measuring choriocapillaris flow deficit (CCFD) within a specific macular grid and to track these measurements over time.
  • Researchers utilized advanced imaging technology to gather data, excluding certain areas in the scans to accurately calculate CCFD percentages in both normal eyes and those with eye conditions.
  • The findings showed that the methodology is effective for monitoring changes in CCFD, particularly in cases where drusen (eye abnormalities) resolved, demonstrating the practicality of the grid strategy for longitudinal studies.
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  • The study investigated choroidal vascular responses in chronic central serous chorioretinopathy (CSCR) patients using optical coherence tomography (OCT) during temporary blood pressure increases from physical stress.
  • It compared CSCR patients with age-matched healthy individuals, measuring parameters like mean ocular perfusion pressure (MOPP) and choroidal thickness at rest and during hand-grip exercises.
  • Results showed CSCR patients had higher MOPP and choroidal thickness compared to controls, but unlike healthy subjects, they did not exhibit a vasoconstrictive response to stress, indicating possible impairment in their choroidal blood flow regulation.
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Objectives: Chagas disease (CD), or American trypanosomiasis, is a parasitic disease caused by Trypanosoma cruzi, primarily transmitted by triatomine bugs. Increased travels and migrations introduced CD to non-endemic regions, including Europe. In Italy, the disease has raised public attention mainly in northern regions, where Latin American migrant population is larger.

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  • The study compares the grading of two types of retinal atrophy (complete and incomplete) using two different imaging techniques: spectral domain optical coherence tomography (SD-OCT) and swept-source OCT angiography (SS-OCTA).
  • Findings reveal a 99.6% agreement in grading complete retinal lesions between the two methods, but a notable discrepancy in the assessment of incomplete retinal atrophy, where 27.4% of these lesions were found within areas of persistent choroidal hypertransmission defects.
  • The study emphasizes the importance of using high-quality B-scans and en face OCT imaging to improve the accuracy of diagnosing retinal conditions and understanding the extent of retinal damage.
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  • - The study aims to quantify uncertainty in deep learning segmentation of geographic atrophy (GA) using retrospective OCT image analysis from the SWAGGER cohort.
  • - Two Bayesian deep learning techniques, Monte Carlo dropout and ensemble methods, were developed and compared against a traditional model, focusing on segmenting GA lesions and evaluating their performance with Dice scores and Shannon Entropy.
  • - Results showed that the Bayesian models had higher Dice scores (0.90 and 0.88) and greater pixel-level uncertainty compared to the traditional model (0.82), suggesting that these techniques may enhance model reliability and assist clinicians in their decision-making for GA.
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  • Age-related macular degeneration (AMD) features large choroidal hypertransmission defects (hyperTDs), which are bright lesions detected via optical coherence tomography (OCT) and indicate loss of retinal pigment epithelium (RPE).
  • Large hyperTDs tend to persist over time, making them critical for understanding the progression from intermediate to late-stage atrophic AMD and useful as endpoints in clinical trials for potential therapies.
  • In a study monitoring 202 AMD eyes for nearly 47 months, a vast majority (99.6%) of the large hyperTDs remained persistent, while only a few showed non-persistence, mainly due to changes in the RPE and retinal area where the hyperTDs were present.
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  • The study aimed to compare the effectiveness of spectral-domain OCT angiography (SD-OCTA) and swept-source OCT angiography (SS-OCTA) in detecting and measuring persistent choroidal hypertransmission defects (hyperTDs) in patients with advanced age-related macular degeneration (AMD).
  • A total of 32 patients underwent both imaging techniques, and the results showed a high level of agreement in the number and size of hyperTDs, with correlation coefficients of 0.969 and 0.999.
  • While there were some statistically significant differences in measurements, these differences were not clinically meaningful, indicating that SD-OCTA can serve as a reliable alternative to SS-OCTA for evaluating hyperTDs.
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Purpose: To report longitudinal changes in choroidal thickness and the choroidal vasculature using SS-OCT imaging in a patient with superior ophthalmic vein thrombosis (SOVT).

Observations: In a 93-year-old woman with a left-sided SOVT, the choroid in the left eye was thickened and the choroidal vessels were dilated both superiorly and inferiorly, with greater changes evident in the inferotemporal region of the choroid. After the superior ophthalmic vein was decompressed, a decrease in the choroidal thickness and choroidal vessel dilatation was observed both superiorly and inferiorly.

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Unlabelled: Associations between different sarcopenia definitions and the risk of injurious falls were investigated in 75-80-year-old women in the Swedish SUPERB cohort. Only sarcopenia according to the Sarcopenia Definitions and Outcomes Consortium (SDOC) definition was associated with incident injurious falls with and without fractures in older women.

Purpose: To investigate the association between three commonly used sarcopenia definitions and the risk of injurious falls in a population of older Swedish women.

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Purpose: The association between the total macular burden of hyperreflective foci (HRF) in eyes with intermediate AMD (iAMD) and the onset of persistent choroidal hypertransmission defects (hyperTDs) was studied using swept-source optical coherence tomography (SS-OCT).

Design: Post hoc subgroup analysis of a prospective study.

Methods: A retrospective review of iAMD eyes from subjects enrolled in a prospective SS-OCT study was performed.

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Background: Physical function is an important risk factor for fracture. Previous studies found that different physical tests (e.g.

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Purpose: In age-related macular degeneration (AMD), choriocapillaris flow deficits (CCFDs) under soft drusen can be measured using established compensation strategies. This study investigated whether CCFDs can be quantified under calcified drusen (CaD).

Methods: CCFDs were measured in normal eyes (n = 30) and AMD eyes with soft drusen (n = 30) or CaD (n = 30).

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Relativistic electron-positron plasmas are ubiquitous in extreme astrophysical environments such as black-hole and neutron-star magnetospheres, where accretion-powered jets and pulsar winds are expected to be enriched with electron-positron pairs. Their role in the dynamics of such environments is in many cases believed to be fundamental, but their behavior differs significantly from typical electron-ion plasmas due to the matter-antimatter symmetry of the charged components. So far, our experimental inability to produce large yields of positrons in quasi-neutral beams has restricted the understanding of electron-positron pair plasmas to simple numerical and analytical studies, which are rather limited.

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Importance: Daily supplementation with the probiotic Limosilactobacillus reuteri ATCC PTA 6475 (L reuteri) vs placebo has previously been demonstrated to reduce bone loss in an estrogen deficiency mice model and older women, although the magnitude of the effect was small. We hypothesized that long-term treatment with L reuteri could result in clinically relevant skeletal benefits in postmenopausal osteoporosis.

Objective: To evaluate whether daily supplementation with L reuteri vs placebo could reduce early postmenopausal bone loss and whether the effects remained or increased over time during 2 years of treatment.

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This study aims to report the efficacy of a combined intrastromal injection in optimizing the outcome of severe mycotic keratitis. Herein, we report a case series of 20 consecutive patients with positive fungal cultures not responding to topical antifungal treatment. Patients received cycles of intrastromal injections of voriconazole (50 µg/0.

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Purpose: Swept-source OCT angiography (SS-OCTA) scans of eyes with age-related macular degeneration (AMD) were used to replace color, autofluorescence, infrared reflectance, and dye-based fundus angiographic imaging for the diagnosis and staging of AMD. Through the use of different algorithms with the SS-OCTA scans, both structural and angiographic information can be viewed and assessed using both cross sectional and en face imaging strategies.

Design: Presented at the 2022 Charles L.

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The purpose of this study was to investigate the prevalence of three sarcopenia definitions and their associations with fracture risk in older Swedish women when adjusted for fracture risk assessment (FRAX)-based risk factors; 2,883 women with a mean age of 77.8 years were included. Sarcopenia was defined based on the Sarcopenia Definitions and Outcomes Consortium (SDOC; low handgrip strength [kg] and gait speed (m/s)), revised European Working Group on Sarcopenia in Older People (EWGSOP2; low appendicular lean mass index, appendicular lean mass [ALM]/height; kg/m2], and hand grip strength [kg]), and Asian Working Group for Sarcopenia (AWGS; low ALM (kg), and hand grip strength [kg]) definitions.

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  • * This experiment produced 2.05 MJ of laser energy, resulting in 3.1 MJ of total fusion yield, which exceeds the Lawson criterion for ignition, demonstrating a key milestone in fusion research.
  • * The report details the advancements in target design, laser technology, and experimental methods that contributed to this historic achievement, validating over five decades of research in laboratory fusion.
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Purpose: An algorithm developed to obtain drusen area and volume measurements using swept-source OCT angiography (SS-OCTA) scans was tested on spectral-domain OCT angiography (SD-OCTA) scans.

Design: Retrospective study.

Participants: Forty pairs of scans from 27 eyes with intermediate age-related macular degeneration and drusen.

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Effective biomarkers are required for assessing the progression of age-related macular degeneration (AMD), a prevalent and progressive eye disease. This paper presents a deep learning-based automated algorithm, applicable to both swept-source OCT (SS-OCT) and spectral-domain OCT (SD-OCT) scans, for measuring outer retinal layer (ORL) thickness as a surrogate biomarker for outer retinal degeneration, e.g.

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Objectives: Corporate health programs (CHPs) aim to improve employees' health through health promotion strategies at the workplace. Physical activity (PA) plays a crucial role in primary prevention, leading many companies to implement PA-based CHPs. However, there is limited examination in the scientific literature on whether PA-based CHPs (PA-CHPs) lead to economic benefits.

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Purpose: The impact of carotid endarterectomy (CEA) on choriocapillaris (CC) perfusion was investigated using swept-source optical coherence tomography angiography (SS-OCTA) imaging before and after surgery in patients with clinically significant carotid artery stenosis (CAS).

Methods: In this prospective observational study, patients with clinically significant CAS undergoing unilateral CEA had SS-OCTA imaging performed in both eyes before and within 1 week after surgery. The percent CC flow deficits (CC FD%) and CC thickness were assessed using previously validated algorithms.

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Background: The expanding population of older adults with obesity is a public health challenge, in part, because of the increased risk of fractures despite normal or high bone mineral density. Potential factors predisposing to fractures in this group include sarcopenia associated with obesity and impaired bone quality. We aimed to determine the contribution of sarcopenic obesity (SO) indices to bone strength as assessed by microfinite element analysis (μFEA) of high-resolution peripheral quantitative computed tomography (HR-pQCT).

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