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Consciousness and Cognition Apr 2021Humans can perceive a coherent visual scene despite a low spatial resolution in peripheral vision. How does the visual system determine whether an object exists in the...
Humans can perceive a coherent visual scene despite a low spatial resolution in peripheral vision. How does the visual system determine whether an object exists in the periphery? We addressed this question by focusing on the extinction illusion in which a disk becomes subjectively invisible when presented at the intersection of grids. We hypothesized that the disk would go unnoticed when the stimuli with and without the disk produced the same strength of visual signals. The visual system would miss the disk by confounding the target signals with the intersection signals that should be discounted. Computational analysis revealed that the energy ratio between the stimuli with and without the disk decreased with stimulus eccentricity and such energy ratio could successfully explain the observer's d' to detect the disk. These results indicate that the discounting mechanism relying on stimulus energy determines the awareness toward a peripheral object.
Topics: Humans; Illusions; Visual Perception
PubMed: 33640785
DOI: 10.1016/j.concog.2021.103100 -
Survey of Ophthalmology 2019Optic disk pit, one of the optic disk cavitary anomalies, is generally congenital and unilateral and occurs equally in males and females. Optic disk pit maculopathy is... (Review)
Review
Optic disk pit, one of the optic disk cavitary anomalies, is generally congenital and unilateral and occurs equally in males and females. Optic disk pit maculopathy is characterized by intraretinal and subretinal fluid at the macula, causing visual deterioration. The origin of the macular fluid and the mechanism of transition to the subretinal space in optic disk pit maculopathy pathophysiology are not yet fully understood. With the evolution of imaging modalities, especially optic coherence tomography, our knowledge of this disorder continues to increase. Although many different treatments have been tried, there is no consensus on the most effective.
Topics: Eye Diseases, Hereditary; Humans; Macula Lutea; Macular Degeneration; Optic Disk; Tomography, Optical Coherence; Visual Acuity
PubMed: 30797884
DOI: 10.1016/j.survophthal.2019.02.006 -
Indian Journal of Ophthalmology Dec 2019Melanocytoma is a deeply pigmented variant of melanocytic nevus that classically occurs in the optic disk, sometimes with contiguous involvement of the adjacent retina... (Review)
Review
Melanocytoma is a deeply pigmented variant of melanocytic nevus that classically occurs in the optic disk, sometimes with contiguous involvement of the adjacent retina or choroid. Historically, this tumor was often confused with malignant melanoma both clinically and histopathologically. Today, however, it is generally recognized by its typical clinical features that differ from most melanomas and erroneous enucleation is rarely done. Histopathologically, melanocytoma is composed of intensely pigmented round to oval nevus cells with benign features. Although traditionally believed to be a relatively stationary lesion, it is now known to exhibit minor enlargement in 10--15% of cases and can cause minor visual loss by a variety of mechanisms. In rare instance, it can induce severe visual loss due to spontaneous necrosis of the lesion or compressive optic neuropathy. More importantly, it can exhibit malignant transformation into melanoma in 1--2% of cases. Ophthalmologists should be familiar with melanocytoma of the optic disk and affected patients should be followed periodically.
Topics: Cell Transformation, Neoplastic; Humans; Melanoma; Nevus, Pigmented; Optic Disk; Optic Nerve Neoplasms
PubMed: 31755427
DOI: 10.4103/ijo.IJO_2039_19 -
Clinics in Sports Medicine Jul 2021Lumbar disk herniation is the most common surgical condition of the spine. High-level athletes participate in activities that place extreme loads on the intervertebral... (Review)
Review
Lumbar disk herniation is the most common surgical condition of the spine. High-level athletes participate in activities that place extreme loads on the intervertebral disks. These repetitive loads may lead to an elevated risk for degenerative disk disease, which in turn predisposes to disk herniations. Treatment algorithms for athletes with disk herniations are similar to those in the nonathletic population; however, success in the athletic population is often measured in the ability to return to play. Both nonoperative and operative treatment show a high success rate in return to play in athletes treated for disk herniations.
Topics: Athletic Injuries; Humans; Intervertebral Disc Displacement; Lumbar Vertebrae; Radiculopathy; Return to Sport
PubMed: 34051943
DOI: 10.1016/j.csm.2021.04.001 -
Ophthalmology Dec 2022
Topics: Humans; Optic Disk Drusen
PubMed: 35773065
DOI: 10.1016/j.ophtha.2022.03.008 -
Ophthalmology Jul 2023
Topics: Humans; Optic Disk; Intraocular Pressure
PubMed: 36229273
DOI: 10.1016/j.ophtha.2022.08.016 -
Frontiers in Bioengineering and... 2021Low-back and neck-shoulder pains caused by intervertebral disk degeneration are highly prevalent among middle-aged and elderly people globally. The main therapy method... (Review)
Review
Low-back and neck-shoulder pains caused by intervertebral disk degeneration are highly prevalent among middle-aged and elderly people globally. The main therapy method for intervertebral disk degeneration is surgical intervention, including interbody fusion, disk replacement, and diskectomy. However, the stress changes caused by traditional fusion surgery are prone to degeneration of adjacent segments, while non-fusion surgery has problems, such as ossification of artificial intervertebral disks. To overcome these drawbacks, biomaterials that could endogenously regenerate the intervertebral disk and restore the biomechanical function of the intervertebral disk is imperative. Intervertebral disk is a fibrocartilaginous tissue, primarily comprising nucleus pulposus and annulus fibrosus. Nucleus pulposus (NP) contains high water and proteoglycan, and its main function is absorbing compressive forces and dispersing loads from physical activities to other body parts. Annulus fibrosus (AF) is a multilamellar structure that encloses the NP, comprises water and collagen, and supports compressive and shear stress during complex motion. Therefore, different biomaterials and tissue engineering strategies are required for the functional recovery of NP and AF based on their structures and function. Recently, great progress has been achieved on biomaterials for NP and AF made of functional polymers, such as chitosan, collagen, polylactic acid, and polycaprolactone. However, scaffolds regenerating intervertebral disk remain unexplored. Hence, several tissue engineering strategies based on cell transplantation and growth factors have been extensively researched. In this review, we summarized the functional polymers and tissue engineering strategies of NP and AF to endogenously regenerate degenerative intervertebral disk. The perspective and challenges of tissue engineering strategies using functional polymers, cell transplantation, and growth factor for generating degenerative intervertebral disks were also discussed.
PubMed: 34746112
DOI: 10.3389/fbioe.2021.766087 -
Advanced Materials (Deerfield Beach,... Sep 2023Using ions in aqueous milieu for signal processing, like in biological circuits, may potentially lead to a bioinspired information processing platform. Studies, however,...
Using ions in aqueous milieu for signal processing, like in biological circuits, may potentially lead to a bioinspired information processing platform. Studies, however, have focused on individual ionic diodes and transistors rather than circuits comprising many such devices. Here a 16 × 16 array of new ionic transistors is developed in an aqueous quinone solution. Each transistor features a concentric ring electrode pair with a disk electrode at the center. The electrochemistry of these electrodes in the solution provides the basis for the transistor operation. The ring pair electrochemically tunes the local electrolytic concentration to modulate the disk's Faradaic reaction rate. Thus, the disk current as a Faradaic reaction to the disk voltage is gated by the ring pair. The 16 × 16 array of these transistors performs analog multiply-accumulate (MAC) operations, a computing modality hotly pursued for low-power artificial neural networks. This exploits the transistor's operating regime where the disk current is a multiplication of the disk voltage and a weight parameter tuned by the ring pair gating. Such disk currents from multiple transistors are summated in a global reference electrode to complete a MAC task. This ionic circuit demonstrating analog computing is a step toward sophisticated aqueous ionics.
PubMed: 35998945
DOI: 10.1002/adma.202205096 -
Spine Surgery and Related Research 2022Intervertebral disk degeneration is a universal and natural process. However, no reports have summarized anatomical age-related intervertebral disk height and disk...
INTRODUCTION
Intervertebral disk degeneration is a universal and natural process. However, no reports have summarized anatomical age-related intervertebral disk height and disk degenerative changes in the thoracolumbar spine or examined sex-specific differences. This study aimed to establish age-related changes and gender-specific differences of intervertebral disk height and disk degeneration of the thoracolumbar spine in a large cohort of relatively healthy subjects and also to evaluate the relationship between the degree of thoracolumbar disk height and disk degeneration.
METHODS
Six hundred and twenty-seven relatively healthy subjects (307 males and 320 females; average age, 49.6±16.5 years) were enrolled. We included at least 50 males and 50 females in each decade of life between the 20s and the 70s. We measured intervertebral disk height from T10/T11 to L5/S1, vertebral body height from T10 to S1 on lateral neutral radiographs. Lumbar disk degeneration was defined according to the Pfirrmann classification in sagittal plane magnetic resonance imaging.
RESULTS
Age-related decreases in intervertebral disk height were most prominent at L4/L5 in middle-aged and elderly individuals of both sexes. The grade of disk degeneration significantly increased with age in both genders at every level. Mild disk degeneration was observed even in the 20s. The disk degeneration occurred around the L4/L5 level. Although grade V disk degeneration was not identified for males in the 20s and the 30s, it appeared after the 40s and then increased further with age. The intervertebral disk height at the lower lumbar disks decreased with a progression in the disk degeneration grade in both genders.
CONCLUSIONS
This large-scale cross-sectional analysis of the thoracolumbar spine in relatively healthy subjects demonstrated that lumbar disk height narrowing progresses with age and is correlated with the progression of disk degeneration.
PubMed: 36051683
DOI: 10.22603/ssrr.2021-0187 -
European Journal of Gastroenterology &... Dec 2021The aim of this study was to validate the IBD-Disk in a Portuguese cohort according to the COnsensus-based Standards for the selection of the health Measurement...
OBJECTIVE
The aim of this study was to validate the IBD-Disk in a Portuguese cohort according to the COnsensus-based Standards for the selection of the health Measurement INstruments (COSMIN) recommendations.
METHODS
After translation of the original IBD-Disk to Portuguese, a group of IBD patients was invited to complete the IBD-Disk at baseline (T0), after 1-4 weeks (T1) and after more than 3 months (T2), from July 2020 to February 2021. At T0 and T2, the patients also completed the IBD Disability Index. We evaluated reliability (internal consistency, test-retest, interrater reliability and measurement error), construct validity, responsiveness, interpretability of IBD-Disk, sociodemographic and clinical factors associated with IBD-Disk.
RESULTS
At T0, 154 patients (107 - Crohn's disease; 46 - ulcerative colitis) completed the IBD-Disk; 1 - IBD-unclassified). At T1 and T2, 64 and 114 patients repeated the questionnaire, respectively. Factor analysis confirmed the unidimensionality of the scale and reduced the final version to 10 items. Internal consistency was excellent with a Cronbach's α of 0.916. The intraclass correlation coefficient was 0.95 for test-retest (T0 and T1). To evaluate construct validity, the IBD-Disk was compared with the IBD Disability Index and Manitoba IBD Index with a significative positive correlation (r = 0.850 and r = 0.459, respectively; P < 0.001 for both). IBD-Disk scores ranged from 0 to 93 with a mean of 38.18 ± 25.39. Female sex, professional inactivity, longer IBD duration and clinical activity were associated with significantly higher IBD-Disk scores.
CONCLUSION
The Portuguese version of IBD-Disk is a reliable and valid tool to assess disability in Portuguese IBD patients.
Topics: Colitis, Ulcerative; Female; Humans; Portugal; Reproducibility of Results; Severity of Illness Index; Translations
PubMed: 34907981
DOI: 10.1097/MEG.0000000000002330