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Journal of Anatomy Dec 2013Although the plantar fascia (PF) has been studied quite well from a biomechanical viewpoint, its microscopic properties have been overlooked: nothing is known about its...
Although the plantar fascia (PF) has been studied quite well from a biomechanical viewpoint, its microscopic properties have been overlooked: nothing is known about its content of elastic fibers, the features of the extracellular matrix or the extent of innervation. From a functional and clinical standpoint, the PF is often correlated with the triceps surae muscle, but the anatomical grounds for this link are not clear. The aim of this work was to focus on the PF macroscopic and microscopic properties and study how Achilles tendon diseases might affect it. Twelve feet from unembalmed human cadavers were dissected to isolate the PF. Specimens from each PF were tested with various histological and immunohistochemical stains. In a second stage, 52 magnetic resonance images (MRI) obtained from patients complaining of aspecific ankle or foot pain were analyzed, dividing the cases into two groups based on the presence or absence of signs of degeneration and/or inflammation of the Achilles tendon. The thickness of PF and paratenon was assessed in the two groups and statistical analyses were conducted. The PF is a tissue firmly joined to plantar muscles and skin. Analyzing its possible connections to the sural structures showed that this fascia is more closely connected to the paratenon of Achilles tendon than to the Achilles tendon, through the periosteum of the heel. The PF extended medially and laterally, continuing into the deep fasciae enveloping the abductor hallucis and abductor digiti minimi muscles, respectively. The PF was rich in hyaluronan, probably produced by fibroblastic-like cells described as 'fasciacytes'. Nerve endings and Pacini and Ruffini corpuscles were present, particularly in the medial and lateral portions, and on the surface of the muscles, suggesting a role for the PF in the proprioception of foot. In the radiological study, 27 of the 52 MRI showed signs of Achilles tendon inflammation and/or degeneration, and the PF was 3.43 ± 0.48 mm thick (99%CI and SD = 0.95), as opposed to 2.09 ± 0.24 mm (99%CI, SD = 0.47) in the patients in which the MRI revealed no Achilles tendon diseases; this difference in thickness of 1.29 ± 0.57 mm (99%CI) was statistically significant (P < 0.001). In the group of 27/52 patients with tendinopathies, the PF was more than 4.5 mm thick in 5, i.e. they exceeded the threshold for a diagnosis of plantar fasciitis. None of the other 25/52 paitents had a PF more than 4 mm thick. There was a statistically significant correlation between the thicknesses of the PF and the paratenon. These findings suggest that the plantar fascia has a role not only in supporting the longitudinal arch of the foot, but also in its proprioception and peripheral motor coordination. Its relationship with the paratenon of the Achilles tendon is consistent with the idea of triceps surae structures being involved in the PF pathology, so their rehabilitation can be considered appropriate. Finally, the high concentration of hyaluronan in the PF points to the feasibility of using hyaluronan injections in the fascia to treat plantar fasciitis.
Topics: Achilles Tendon; Aged; Aged, 80 and over; Cadaver; Fascia; Female; Foot; Humans; Immunohistochemistry; Magnetic Resonance Imaging; Male; Tendinopathy
PubMed: 24028383
DOI: 10.1111/joa.12111 -
Materials (Basel, Switzerland) Sep 2021The possibility of producing stable thin films, only a few atomic layers thick, from a variety of materials beyond graphene has led to two-dimensional (2D) materials... (Review)
Review
The possibility of producing stable thin films, only a few atomic layers thick, from a variety of materials beyond graphene has led to two-dimensional (2D) materials being studied intensively in recent years. By reducing the layer thickness and approaching the crystallographic monolayer limit, a variety of unexpected and technologically relevant property phenomena were observed, which also depend on the subsequent arrangement and possible combination of individual layers to form heterostructures. These properties can be specifically used for the development of multifunctional devices, meeting the requirements of the advancing miniaturization of modern manufacturing technologies and the associated need to stabilize physical states even below critical layer thicknesses of conventional materials in the fields of electronics, magnetism and energy conversion. Differences in the structure of potential two-dimensional materials result in decisive influences on possible growth methods and possibilities for subsequent transfer of the thin films. In this review, we focus on recent advances in the rapidly growing field of two-dimensional materials, highlighting those with oxidic crystal structure like perovskites, garnets and spinels. In addition to a selection of well-established growth techniques and approaches for thin film transfer, we evaluate in detail their application potential as free-standing monolayers, bilayers and multilayers in a wide range of advanced technological applications. Finally, we provide suggestions for future developments of this promising research field in consideration of current challenges regarding scalability and structural stability of ultra-thin films.
PubMed: 34576436
DOI: 10.3390/ma14185213 -
Optics Express May 2022This study utilized thin p-GaN, indium tin oxide (ITO), and a reflective passivation layer (RPL) to improve the performance of deep ultra-violet light-emitting diodes...
This study utilized thin p-GaN, indium tin oxide (ITO), and a reflective passivation layer (RPL) to improve the performance of deep ultra-violet light-emitting diodes (DUV-LEDs). RPL reflectors, which comprise HfO/SiO stacks of different thickness to maintain high reflectance, were deposited on the DUV-LEDs with 40 nm-thick p-GaN and 12 nm-thick ITO thin films. Although the thin p-GaN and ITO films affect the operation voltage of DUV-LEDs, the highly reflective RPL structure improved the WPE and light extraction efficiency (LEE) of the DUV-LEDs, yielding the best WPE and LEE of 2.59% and 7.57%, respectively. The junction temperature of DUV-LEDs with thick p-GaN increased linearly with the injection current, while that of DUV-LEDs with thin p-GaN, thin ITO, and RPL was lower than that of the Ref-LED under high injection currents (> 500 mA). This influenced the temperature sensitive coefficients (dV/dT, dLOP/dT, and dWLP/dT). The thermal behavior of DUV-LEDs with p-GaN and ITO layers of different thicknesses with/without the RPL was discussed in detail.
PubMed: 36221517
DOI: 10.1364/OE.457740 -
Journal of Ophthalmic & Vision Research 2020To investigate the effects of refraction on retinal thickness measurements at different locations and layers in healthy eyes of Saudi participants. (Review)
Review
PURPOSE
To investigate the effects of refraction on retinal thickness measurements at different locations and layers in healthy eyes of Saudi participants.
METHODS
Thirty-six randomly selected adults aged 27.0 5.7 years who attended a Riyadh hospital from 2016 to 2017 were categorized into three groups: non-myopic (spherical equivalent refraction [SER], +1.00 to -0.50 diopters [D]), low myopic (SER, -0.75 to -3.00D), and moderate to high myopic (SER -3.25D). Full, inner, and outer retinal thicknesses were measured at nine locations by spectral-domain stratus optical coherence tomography (Optovue Inc., Fremont, CA, USA) and were compared according to refractive group and sex.
RESULTS
The mean SERs for the non-myopia, low myopia, and moderate to high myopia groups were 0.2 0.6, -1.5 0.5, and -7.5 1.9 D, respectively. Refractive error, but not sex, had significant effects on the retinal layer thickness measurements at different locations ( 0.05). The parafoveal and outer retinal layers were significantly thicker than the perifoveal and inner retina layers in all groups ( 0.05). The full foveal thickness was higher and the full parafoveal and perifoveal regions were thinner in moderate to high myopic eyes than in the non-myopic eyes ( 0.05), but were similar to those in the low myopic eyes ( 0.05). The foveal thicknesses measured in the inner and outer layers of the retina were higher but the thicknesses measured at the inner and outer layers of the parafoveal and perifoveal regions were lower in moderate to high myopic eyes.
CONCLUSION
There were regional differences in the retinal layer thicknesses of healthy Saudi eyes, which was dependent on the central refractions. This is important when interpreting retinal nerve fiber layer thicknesses in myopia and disease management in Saudi participants.
PubMed: 32308952
DOI: 10.18502/jovr.v15i2.6735 -
International Journal of Clinical... 2016To evaluate the prevalence of various gingival biotypes and to corroborate gingival thickness and gingival biotypes across tooth type, site, and gender. (Review)
Review
AIM
To evaluate the prevalence of various gingival biotypes and to corroborate gingival thickness and gingival biotypes across tooth type, site, and gender.
MATERIALS AND METHODS
A cross-sectional study was conducted across systemically healthy subjects. A systematic clinical evaluation for gingival biotypes and gingival thicknesses was recorded by modified Iwanson's gauge, to the nearest 0.1 mm, probing the gingival sulcus at the midfacial aspect of maxillary and mandibular central incisors and first molars. All measurements were made across a total of 920 sites in 115 subjects (69 female and 46 male) based on gingival transparency and were statistically analyzed.
RESULTS
A significant agreement on the reproducibility of the measurements was noted. The median overall gingival thickness was recorded at 0.75 mm with interquantile difference of 0.39 mm. The thin biotype variant showed across the ranges of 0.3 to 0.6 mm of gingival thicknesses and thick biotype variant across the ranges of 1.0 to 1.2 mm, with more prevalence in anterior and posterior site respectively. Moreover, for gingi-val thickness of 0.7 mm, the probe visibility showed tendency toward both thin/thick biotype variant in both anterior and posterior segments. The disposition of male participants toward thick biotype and female participants toward the thin biotype variant has been noted.
CONCLUSION
Within the limitations of the current study, our data support the traditional hypothesis of two main gingival biotypes as distinguishable by gingival transparency. In addition, we provide evidence of existence of intermediate biotypes with respect to gingival thickness. These findings can be utilized as objective guidelines for determination of biotype and can be implicated in many dental operative procedures. How to cite this article: Rathee M, Rao PL, Bhoria M. Prevalence of Gingival Biotypes among Young Dentate North Indian Population: A Biometric Approach. Int J Clin Pediatr Dent 2016;9(2):104-108.
PubMed: 27365928
DOI: 10.5005/jp-journals-10005-1343 -
Clinical Oral Investigations Sep 2021To compare gingival phenotype assessment methods based on soft tissue transparency on different backgrounds and assessor experience levels.
OBJECTIVE
To compare gingival phenotype assessment methods based on soft tissue transparency on different backgrounds and assessor experience levels.
METHODS
For this purpose, 24 gingival specimens were retrieved from pig jaws with tissue thicknesses from 0.2 to 1.25 mm. Three methods were assessed: periodontal probe PCP12 (thin/thick), double-ended periodontal probe DBS12 (thin/moderate/thick) and colour-based phenotype probe CBP (thin/moderate/thick/very thick). Each sample was photographed with each probe underneath and categorized whether the probe was visible or not using different coloured backgrounds. To measure experience level influence, dentists, dental undergraduate students and laypersons (n = 10/group) performed the evaluation.
RESULTS
PCP12 probe showed a threshold between 0.4 and 0.5 mm. To distinct between thin and moderate thick gingiva, a comparable range for DBS12 was found while moderate thickness was between 0.5 and 0.8 mm and for thick above 0.8 mm. CBP also showed a comparable threshold of 0.5 mm for thin versus moderate as compared with the other methods; above 0.8 mm, predominantly a very thick tissue was measured. In general, the background colour had a minor impact on PCP12 and DBS12, and investigator experience showed no clear influence on GP assessment.
CONCLUSION
Based on probe transparency and within the limitation of a preclinical study, we suggest GP differentiation into three entities: thin (< 0.5 mm; high risk), moderate (0.5-0.8 mm; medium risk) and thick (> 0.8 mm; low risk).
CLINICAL RELEVANCE
All three GP assessment methods are easy to perform and seem to have a high predictive value with a three entities classification for DBS12 and CBP.
Topics: Animals; Cell Differentiation; Gingiva; Humans; Maxilla; Microsurgery; Phenotype; Swine
PubMed: 33725167
DOI: 10.1007/s00784-021-03860-5 -
The Ocular Surface Apr 2019The outer surface layer of tears is presumably composed of lipid. The thickness of this layer is considered critical to retard evaporation. Prior thickness measurements... (Comparative Study)
Comparative Study
PURPOSE
The outer surface layer of tears is presumably composed of lipid. The thickness of this layer is considered critical to retard evaporation. Prior thickness measurements differ widely. Advances in ellipsometry have availed more precise and accurate measurements for thin films. The range in thickness of the surface layer of tears was studied by ellipsometry to uncover the source of prior discrepancies.
METHODS
Tear surface layers of normal and dry eye subjects were measured by in-vitro ellipsometry. Lateral and Z resolutions of ∼1 μm and 0.1 nm, were achieved respectively. Thicknesses were derived from matrices and a Levenberg-Marquardt multivariate regression algorithm to Fresnel equations for multi-layered films.
RESULTS
Ellipsometric measurements of pooled and individual human tears in-vitro revealed a larger overall range (0-500 nm) of surface film thicknesses than previously reported by any one study. Each sample showed thin areas (0-2.6 nm) with interspersed thicker regions (∼200-500 nm). Repeat measurements of a single donor collected at weekly intervals showed a broad range of surface thicknesses within and between samples. Thickness measurements from a dry eye subject overlapped that of normal subjects.
CONCLUSION
The data show that published disparity in surface film thickness may be attributable to limitations of prior methodologies. The range and overlap of surface film thicknesses challenge less rigorous methodologies that claim to segregate normal and dry eye.
Topics: Dry Eye Syndromes; Humans; Interferometry; Lipid Metabolism; Meibomian Glands; Tears
PubMed: 30818036
DOI: 10.1016/j.jtos.2019.02.008 -
Therapeutic Advances in Ophthalmology 2022The distance between the optic disc center and the fovea is a biometric parameter; however, it is unclear whether DFD (disc-fovea distance) affects the choroidal...
BACKGROUND
The distance between the optic disc center and the fovea is a biometric parameter; however, it is unclear whether DFD (disc-fovea distance) affects the choroidal thickness.
OBJECTIVE
The aim of this study is to investigate the association between DFD and choroidal thickness.
DESIGN
This is a prospective, and cross-sectional study.
METHODS
Two hundred fifty eyes of 250 healthy participants were examined in terms of DFD, age, axial length, spherical equivalent, and choroidal thickness. Inclusion criteria included aged between 20-40 years, no posterior segment disorders, and participants with best-corrected visual acuity (10/10 according to Snellen's chart). Participants with high hypermetropia (>4 diopter) or myopia (>6 diopter) or any systemic disease likely to affect choroidal thickness were excluded. Choroidal thickness measurements were performed at subfoveal, 1.0 mm temporal, and 1.0 mm nasal using the enhanced-depth imaging optical coherence tomography.
RESULTS
The mean age of all the participants was 26.21 ± 5.73 years, mean DFD was 4634.29 ± 274.70 µm, mean axial length was 23.62 ± 0.83 mm, and mean spherical equivalent was -0.61 ± 1.06 diopter. The mean subfoveal, nasal, and temporal choroidal thicknesses were 388.73 ± 90.15 µm, 351.26 ± 88.09 µm, and 366.50 ± 79.56 µm, respectively. A negative correlation was found between subfoveal, nasal, and temporal choroidal thicknesses and axial length ( = -0.157, = 0.013; = -0.168, = 0.008; = -0.174, = 0.006, respectively). Insignificant correlation was found between choroidal thicknesses and spherical equivalent ( > 0.05). There was not a statistically significant correlation between DFD and subfoveal, nasal, and temporal choroidal thicknesses ( = -0.028, = 0.655; = 0.030, = 0.641; = -0.025, = 0.699, respectively). In addition, there was not a statistically significant correlation between age and choroidal thickness.
CONCLUSION
This study shows that DFD and spherical equivalent do not affect choroidal thickness; axial length negatively affects choroidal thickness. In addition, age does not affect choroidal thickness between 20 and 40 years.
PubMed: 35602660
DOI: 10.1177/25158414221096062 -
Indian Journal of Ophthalmology Feb 2022To analyze the early changes in host and donor lenticule thickness after Descemet Stripping Endothelial Keratoplasty (DSEK).
PURPOSE
To analyze the early changes in host and donor lenticule thickness after Descemet Stripping Endothelial Keratoplasty (DSEK).
METHODS
DSEK was performed on 32 eyes of 31 patients. Pre- and post- operative slit lamp examination and anterior segment Optical Coherence Tomography (OCT) was done on day-1, day-7, 1 month, and 3 months.
RESULTS
There were significant changes in host, lenticule, and total corneal thicknesses between day-1 and day-7, and day-7 and 1 month. There were significant changes in host thickness and total corneal thickness between 1 month and 3 months. Thickness changes were significant between day-1 and day-7, and 1 month and 3 months for thick and thin host, respectively, whereas these changes were observed both for thick and thin host between day-7 and 1 month. Similarly, significant changes were observed between day-7 and 1 month, and day-7 and 1 month in thin lenticule whereas in case of thick lenticule, it was observed till the 3 months follow-up period. There was a significant improvement in visual acuity till the 3 months follow-up period. No significant correlation was observed between visual acuity and host and lenticule thickness.
CONCLUSION
The thicknesses of host and lenticule decrease continuously. Lenticule thickness stabilizes before host. Thinner cornea stabilizes earlier compared to thicker cornea.
Topics: Cornea; Descemet Stripping Endothelial Keratoplasty; Endothelium, Corneal; Humans; Tissue Donors; Tomography, Optical Coherence; Visual Acuity
PubMed: 35086231
DOI: 10.4103/ijo.IJO_746_21