Background: One of the major causes of reversible visual impairment is a refractive error, which can be corrected through refractive surgery. Data regarding the outcomes and complications of these procedures exist; however, there is a notable gap in understanding the factors leading to patient rejection, particularly in diverse populations like Israel.
Objectives: To detect clinical risk factors of patients who intend to undergo LASIK procedure and to improve the conversion rates of LASIK procedure in this population.
Objectives: Detecting premalignant lesions for pancreatic ductal adenocarcinoma, mainly pancreatic intraepithelial neoplasia (PanIN), is critical for early diagnosis and for understanding PanIN biology. Based on PanIN's histology, we hypothesized that diffusion tensor imaging (DTI) and T2* could detect PanIN.
Materials And Methods: DTI was explored for the detection and characterization of PanIN in genetically engineered mice (KC, KPC).
Introduction: In this case report, we demonstrate the application of an aspheric macular lens (Grieshaber, Alcon) for conducting posterior segment procedures after a posterior capsular rupture (PCR) occurrence during cataract surgery.
Case Presentation: During a cataract surgery on a 70-year-old female patient, a PCR was identified, accompanied by the descent of the lens into the vitreous, and prompted subsequent interventions. This involved performing posterior-assisted levitation, anterior segment phacoemulsification, and anterior segment vitrectomy.
Introduction: The study aimed to compare postoperative pain between alcohol-assisted and transepithelial photorefractive keratectomy in patients who received the novel analgesic preoperative nepafenac treatment 2 days preoperatively and 3 days postoperatively. Pain, stinging, tearing, light sensitivity, and stress levels were evaluated.
Methods: The study included a retrospective analysis of 55 patients divided into two groups: bilateral alcohol-assisted photorefractive keratectomy (aa-PRK) and transepithelial photorefractive keratectomy (transepithelial-PRK).
Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas (CRISPR-associated proteins) systems provide acquired heritable protection to bacteria and archaea against selfish DNA elements, such as viruses. These systems must be tightly regulated because they can capture DNA fragments from foreign selfish elements, and also occasionally from self-chromosomes, resulting in autoimmunity. Most known species from the halophilic archaeal genus contain type I-B CRISPR-Cas systems, and the strongest hotspot for self-spacer acquisition by was a locus that contained a putative transposable element, as well as the gene , which was a very frequent target for self-targeting spacers.
View Article and Find Full Text PDFCase Rep Ophthalmol
August 2024
Introduction: In this case study, we present the "Ballerina" sign as a potentially valuable clinical indicator for detecting posterior capsular rupture (PCR) during cataract surgery. The purpose of this study is to highlight the significance of PCR in the context of cataract surgery and introduce this novel sign.
Case Presentation: During the cataract operation on a 70-year-old patient, we observed a spiraling fragment of the nucleus attached to a vitreous string.
Magnetic susceptibility imaging may provide valuable information about chemical composition and microstructural organization of tissue. However, its estimation from the MRI signal phase is particularly difficult as it is sensitive to magnetic tissue properties ranging from the molecular to the macroscopic scale. The MRI Larmor frequency shift measured in white matter (WM) tissue depends on the myelinated axons and other magnetizable sources such as iron-filled ferritin.
View Article and Find Full Text PDFThe visual continuity illusion involves a shift in visual perception from static to dynamic vision modes when the stimuli arrive at high temporal frequency, and is critical for recognizing objects moving in the environment. However, how this illusion is encoded across the visual pathway remains poorly understood, with disparate frequency thresholds at retinal, cortical, and behavioural levels suggesting the involvement of other brain areas. Here, we employ a multimodal approach encompassing behaviour, whole-brain functional MRI, and electrophysiological measurements, for investigating the encoding of the continuity illusion in rats.
View Article and Find Full Text PDFPurpose: To extend quantitative susceptibility mapping to account for microstructure of white matter (WM) and demonstrate its effect on ex vivo mouse brain at 16.4T.
Theory And Methods: Previous studies have shown that the MRI measured Larmor frequency also depends on local magnetic microstructure at the mesoscopic scale.
Trauma Violence Abuse
July 2024
Extensive research has been conducted on the link between trauma, child maltreatment (CM), and chronic pain. Although the risk of suffering from chronic pain among CM survivors has been established, much less is known about the experience of pain during CM incidents or whether such peritraumatic pain sensations are associated with later chronic pain. This scoping review was conducted to synthesize the existing literature on pain during and a short time following CM (i.
View Article and Find Full Text PDFUnderstanding the dynamics of stability/plasticity balances during adulthood is pivotal for learning, disease, and recovery from injury. However, the brain-wide topography of sensory remapping remains unknown. Here, using a first-of-its-kind setup for delivering patterned visual stimuli in a rodent magnetic resonance imaging (MRI) scanner, coupled with biologically inspired computational models, we noninvasively mapped brain-wide properties-receptive fields (RFs) and spatial frequency (SF) tuning curves-that were insofar only available from invasive electrophysiology or optical imaging.
View Article and Find Full Text PDFMyopia, short-sightedness, is the most frequent cause of vision difficulty and its prevalence is expected to rise. Nowadays, the usage of atropine drops is effective for myopia progression control. Studies on the Asian population showed that atropine 0.
View Article and Find Full Text PDFMP-PCA denoising has become the method of choice for denoising MRI data since it provides an objective threshold to separate the signal components from unwanted thermal noise components. In rodents, thermal noise in the coils is an important source of noise that can reduce the accuracy of activation mapping in fMRI. Further confounding this problem, vendor data often contains zero-filling and other post-processing steps that may violate MP-PCA assumptions.
View Article and Find Full Text PDFPurpose: Estimating magnetic susceptibility using MRI depends on inverting a forward relationship between the susceptibility and measured Larmor frequency. However, an often-overlooked constraint in susceptibility fitting is that the Larmor frequency is only measured inside the sample, and after successful background field removal, susceptibility sources should only reside inside the same sample. Here, we test the impact of accounting for these constraints in susceptibility fitting.
View Article and Find Full Text PDFTemporal Diffusion Ratio (TDR) is a recently proposed dMRI technique (Dell'Acqua et al., proc. ISMRM 2019) which provides contrast between areas with restricted diffusion and areas either without restricted diffusion or with length scales too small for characterisation.
View Article and Find Full Text PDFSpontaneous fluctuations in functional magnetic resonance imaging (fMRI) signals correlate across distant brain areas, shaping functionally relevant intrinsic networks. However, the generative mechanism of fMRI signal correlations, and in particular the link with locally-detected ultra-slow oscillations, are not fully understood. To investigate this link, we record ultrafast ultrahigh field fMRI signals (9.
View Article and Find Full Text PDFThe magnetic susceptibility of tissue can provide valuable information about its chemical composition and microstructural organization. However, the relation between the magnetic microstructure and the measurable Larmor frequency shift is understood only for a few idealized cases. Here we analyze the microstructure formed by magnetized, NMR-invisible infinite cylinders suspended in an NMR-reporting fluid.
View Article and Find Full Text PDFPurpose: To develop a denoising strategy leveraging redundancy in high-dimensional data.
Theory And Methods: The SNR fundamentally limits the information accessible by MRI. This limitation has been addressed by a host of denoising techniques, recently including the so-called MPPCA: principal component analysis of the signal followed by automated rank estimation, exploiting the Marchenko-Pastur distribution of noise singular values.
Whole-brain radiotherapy (WBRT) is the treatment backbone for many patients with brain metastasis; however, its efficacy in preventing disease progression and the associated toxicity have questioned the clinical impact of this approach and emphasized the need for alternative treatments. Given the limited therapeutic options available for these patients and the poor understanding of the molecular mechanisms underlying the resistance of metastatic lesions to WBRT, we sought to uncover actionable targets and biomarkers that could help to refine patient selection. Through an unbiased analysis of experimental in vivo models of brain metastasis resistant to WBRT, we identified activation of the S100A9-RAGE-NF-κB-JunB pathway in brain metastases as a potential mediator of resistance in this organ.
View Article and Find Full Text PDFDiffusion MRI (dMRI) provides unique insights into the neural tissue milieu by probing interactions between diffusing molecules and tissue microstructure. Most dMRI techniques focus on white matter (WM) tissues, nevertheless, interest in gray matter characterizations is growing. The Soma and Neurite Density MRI (SANDI) methodology harnesses a model incorporating water diffusion in spherical objects (assumed to be associated with cell bodies) and in impermeable "sticks" (assumed to represent neurites), which potentially enables the characterization of cellular and neurite densities.
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