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Ultrasound in Obstetrics & Gynecology :... Sep 2013To determine the pathological basis and clinical associations of excessively thick placentae observed at second-trimester ultrasound examination.
OBJECTIVES
To determine the pathological basis and clinical associations of excessively thick placentae observed at second-trimester ultrasound examination.
METHODS
In a retrospective cohort of 19 singleton high-risk second-trimester pregnancies noted to have a placental length-to-maximum thickness ratio ≤ 2.0, maximum sonographic placental thickness was correlated with clinical outcome, maximum placental thickness after delivery and placental pathological findings. Results were compared with those of an intermediate group of 21 high-risk pregnancies with normal placental dimensions and a control group of 18 low-risk pregnancies also with normal placental dimensions. Increased maximum placental thickness (> 28 mm) and abnormal placental deflation following delivery (pathology - sonography difference in maximum placental thickness < -2 mm) were defined by the upper and lower quartile values, respectively, in the control group.
RESULTS
The study group exhibited significantly more adverse outcomes and gross pathological placental features compared with both intermediate and control groups. Despite increased sonographic maximum placental thickness in the study group (median, 55 (range, 40-75) mm compared with both the intermediate group (median, 27 (range, 22-41) mm, P < 0.0001) and the control group (median 26 (range, 23-36) mm, P < 0.0001)), all three groups had similar maximal placental thickness following delivery (study group: median, 24 (range, 10-50) mm vs intermediate group: median, 27 (range, 15-40) mm, P = 0.82 and vs control group: median, 28.5 (range, 18-44), P = 0.42). Pathology-sonography difference in maximum placental thickness in the study group (median, -30 (range, -42 to 0) mm) was significantly greater than that in either the intermediate (median, -2 (range, -11 to 9) mm, P < 0.0001) or the control (median, 1.5 (range, -10 to 18) mm, P < 0.0001) group and was significantly associated with abnormal development of the gas-exchanging placental villi (distal villous hypoplasia) (P = 0.0001).
CONCLUSIONS
Increased second-trimester sonographic maximum placental thickness represents a pathological finding associated with severe adverse perinatal outcome. This observation is due to overinflation of the intervillous space by maternal blood rather than to adaptive formation of functional placental tissue.
Topics: Adolescent; Adult; Case-Control Studies; Female; Fetal Growth Retardation; Humans; Middle Aged; Placenta; Pregnancy; Pregnancy Outcome; Pregnancy Trimester, Second; Pregnancy, High-Risk; Premature Birth; Retrospective Studies; Ultrasonography, Prenatal; Young Adult
PubMed: 23288860
DOI: 10.1002/uog.12386 -
Dental Research Journal 2023Similarity in the appearance of a monolithic restoration with the adjacent teeth is necessary. This study aims to influence the foundation material type and ceramic...
BACKGROUND
Similarity in the appearance of a monolithic restoration with the adjacent teeth is necessary. This study aims to influence the foundation material type and ceramic thickness on the final color of zirconia-reinforced lithium silicate (ZLS) ceramic.
MATERIALS AND METHODS
In this experimental study, the A2 translucent blocks of ZLS were sectioned into rectangular specimens with thicknesses 1, 1.5, and 2 mm ( = 15). Substructure materials include resin composite (B1, D2, A2, A3, and C3), nickel chrome alloy, amalgam, and white and black substrate. Substructure material of resin composite with A2 color was proposed as the control group. The value of the color difference (ΔE) is calculated by the CIEDE2000 formula. Data analysis was accomplished by two-factor repeated measures ANOVA and one-sample -test (α =0.05).
RESULTS
The mean value of maximum ΔE with a black substrate (12.13 ± 0.17) at 1 mm ceramic thickness and the mean value of minimum ΔE with B1 resin composite foundation material (0.02 ± 0.17) at 2 mm ceramic thickness are visible. The significant effect of the foundation restoration type, thickness, and interaction between them is visible on ΔE ( < 0.001).
CONCLUSION
Different thickness is required to meet ideal esthetic outcomes with different substrates. Under the conditions of this investigation, zirconia-reinforced lithium silicate over black, white, nickel-chromium, and amalgam did not meet acceptable outcomes.
PubMed: 38020248
DOI: No ID Found -
Arquivos Brasileiros de Oftalmologia Jun 2020To measure the central-to-peripheral corneal thickness and its volume according to age and gender in 10-30-year-old patients with Down syndrome (DS) and in matched...
PURPOSE
To measure the central-to-peripheral corneal thickness and its volume according to age and gender in 10-30-year-old patients with Down syndrome (DS) and in matched individuals without DS.
METHODS
In the report, 202 normal pattern right eyes of patients with Down syndrome and 190 right eyes of individuals without Down syndrome and compared averages using independent sample t-tests and multiple linear regression models. The measured variables included the apical corneal thickness; the minimum corneal thickness; the average thickness on rings at 2 mm (R2), 3 mm (R3), and 4 mm (R4); the corneal volume in the central zones at 2-, 3-, 4-, and 10-mm diameters; Ambrosio's relational thickness; and the pachymetric progression indices.
RESULTS
The mean age of the participants was 16.99 ± 4.70 and 17.22 ± 4.54 years (p=0.636). The means ± SD were 516.7 ± 33.0 and 555.7 ± 33.1 µm for apical corneal thicknesses, 508.0 ± 33.5 and 549.0 ± 40.6 µm for minimum corneal thicknesses, 543.0 ± and 588.4 ± 33.8 µm for R2s, 584.9 ± 35.6 and 637.0 ± µm for R3s, 646.9 ± 38.5 and 707.6 ± 37.1 µm for R4s, 396.4 ± 102.3 and 462.7 ± 96.2 µm for Ambrosio's relational thicknesses, 1.36 ± 0.37 and 1.22 ± 0.18 for pachymetric progression index maximums, 1.62 ± 0.11 and 1.74 ± 0.11 mm3 for corneal volume at 2 mm, 3.73 ± 0.24 and 4.01 ± 0.24 mm3 for corneal volume at 3 mm, 6.76 ± 0.44 and 7.30 ± 0.43 mm3 for corneal volume at 4 mm, and 57.03 ± 3.44 and 61.51 ± 3.40 mm3 for total corneal volume in the Down syndrome and control groups, respectively (all p<0.001). All the above indices were inversely related to age, but not to gender. Ambrosio's relational thickness maximum and the pachymetric progression index maximum were independent of age and gender.
CONCLUSION
Non-keratoconic patients with Down syndrome had thin corneas with a homogeneous distribution. Therefore, the reference ranges of cornea thickness and volume should be re-defined for this patient population.
Topics: Adolescent; Adult; Child; Cornea; Corneal Topography; Cross-Sectional Studies; Down Syndrome; Humans; Keratoconus; Reference Values; Young Adult
PubMed: 32490977
DOI: 10.5935/0004-2749.20200058 -
Veterinary World Sep 2017The aim of the successful incubation period is to achieve maximum health chicks in each batch. Therefore, all factors affecting incubation have to be investigated in...
BACKGROUND AND AIM
The aim of the successful incubation period is to achieve maximum health chicks in each batch. Therefore, all factors affecting incubation have to be investigated in detail. This study investigated the effect of eggshell thickness on hatchability of quail eggs.
MATERIALS AND METHODS
A total of 1415 eggs were collected from the same flock at the ages of 23 and 41 weeks. Two different incubations were performed at these eggs. Eggshell thicknesses of all eggs were determined with an ultrasonic gauge before incubation. Incubation period was applied as for 18 days. After 15 days of incubation, eggs were transferred to hatching machine. Eggs were classified as thin-, medium-, and thick-shelled according to eggshell thickness values.
RESULTS
Eggshell thicknesses were ranged between 0.24 and 0.36 mm, and the differences between the hatching rates of thickness values were not found significant. Hatchability of thin-, medium-, and thick-shelled eggs was found as 69.2%, 69.4%, and 82.4% for Experiment 1. These values were as 87.8%, 89.2%, and 91.9% for Experiment 2, respectively. Similar to eggshell thickness frequencies, the differences between hatching rates of eggshell thickness groups were found insignificant.
CONCLUSION
Results of this study showed that eggshell thickness does not affect hatchability.
PubMed: 29062202
DOI: 10.14202/vetworld.2017.1114-1117 -
Nanomaterials (Basel, Switzerland) Aug 2022Perovskite solar cells (PSCs) are a promising area of research among different new generations of photovoltaic technologies. Their manufacturing costs make them...
Perovskite solar cells (PSCs) are a promising area of research among different new generations of photovoltaic technologies. Their manufacturing costs make them appealing in the PV industry compared to their alternatives. Although PSCs offer high efficiency in thin layers, they are still in the development phase. Hence, optimizing the thickness of each of their layers is a challenging research area. In this paper, we investigate the effect of the thickness of each layer on the photoelectric parameters of solar cell through various simulations. Using the Sol-Gel method, PSC structure can be formed in different thicknesses. Our aim is to identify a functional connection between those thicknesses and the optimum open-circuit voltage and short-circuit current. Simulation results show that the maximum efficiency is obtained using a perovskite layer thickness of 200 nm, an electronic transport layer (ETL) thickness of 60 nm, and a hole transport layer (HTL) thickness of 20 nm. Furthermore, the output power, fill factor, open-circuit voltage, and short-circuit current of this structure are 18.9 mW/cm, 76.94%, 1.188 V, and 20.677 mA/cm, respectively. The maximum open-circuit voltage achieved by a solar cell with perovskite, ETL and HTL layer thicknesses of (200 nm, 60 nm, and 60 nm) is 1.2 V. On the other hand, solar cells with the following thicknesses, 800 nm, 80 nm, and 40 nm, and 600 nm, 80 nm, and 80 nm, achieved a maximum short-circuit current density of 21.46 mA/cm and a fill factor of 83.35%. As a result, the maximum value of each of the photoelectric parameters is found in structures of different thicknesses. These encouraging results are another step further in the design and manufacturing journey of PSCs as a promising alternative to silicon PV.
PubMed: 35957123
DOI: 10.3390/nano12152692 -
Journal of Current Ophthalmology 2015To evaluate the macular thickness changes in diabetic macular edema after meal.
PURPOSE
To evaluate the macular thickness changes in diabetic macular edema after meal.
METHODS
In this prospective case series, macular thicknesses of diabetic patients with clinically significant macular edema (CSME) were measured after 7 h of fasting and repeated 2 h after breakfast.
RESULTS
Thirty six eyes of 20 diabetic patients were evaluated. The mean central subfield thickness (CST) and maximum retinal thickness (MRT) significantly decreased after meal (mean change of -10.3 ± 14.3 μm and -13.1 ± 12.7 μm, respectively, both P < 0.001). A decrease in CST and MRT values was found in 23 (63.8%) and 28 (77.7%) eyes, respectively, and no eye had an increase in retinal thickness measurements. Significant correlation was found between CST and MRT change and fasting thickness measurements (P = 0.001 and P = 0.01, respectively) and intraretinal cystic spaces (P = 0.001 and P = 0.03, respectively). Mean MRT change was significantly higher in the presence of subretinal fluid (P = 0.01).
CONCLUSION
Retinal thickness measurements may change after meal. So, fasting state of diabetic patient should be considered in measurement of macular thickness of patients with CSME.
PubMed: 27239590
DOI: 10.1016/j.joco.2015.11.005 -
Scientific Reports Feb 2022Optimisation and reproducibility of beams of protons accelerated from laser-solid interactions require accurate control of a wide set of variables, concerning both the...
Optimisation and reproducibility of beams of protons accelerated from laser-solid interactions require accurate control of a wide set of variables, concerning both the laser pulse and the target. Among the former ones, the chirp and temporal shape of the pulse reaching the experimental area may vary because of spectral phase modulations acquired along the laser system and beam transport. Here, we present an experimental study where we investigate the influence of the laser pulse chirp on proton acceleration from ultrathin flat foils (10 and 100 nm thickness), while minimising any asymmetry in the pulse temporal shape. The results show a [Formula: see text] change in the maximum proton energy depending on the sign of the chirp. This effect is most noticeable from 10 nm-thick target foils, suggesting a chirp-dependent influence of relativistic transparency.
PubMed: 35194105
DOI: 10.1038/s41598-022-07019-4 -
Medicine Mar 2023Given that there are controversial findings regarding vessel density in amblyopia, we quantified retinal microcirculation using optical coherence tomography angiography...
Given that there are controversial findings regarding vessel density in amblyopia, we quantified retinal microcirculation using optical coherence tomography angiography and compared it between hyperopic ametropic amblyopia eyes and age-matched control eyes. This case-control study was conducted from March 2021 to March 2022 at the Affiliated Eye Hospital of Nanchang University, Nanchang, China. Both groups included 72 eyes. Foveal avascular zone area, circularity and perimeter, perfusion density and vessel density of macular superficial retinal capillary plexus, macular thickness, macular volume, peripapillary retinal nerve fiber layer thickness, and ganglion cell-inner plexiform layer thickness were compared between hyperopia ametropic amblyopia eyes and age-matched control eyes. Additionally, best-corrected visual acuity, maximum corneal curvature, minimum corneal curvature, and anterior chamber depth were measured. In the hyperopia ametropic amblyopia eyes and control eyes, vessel density was 7.51 ± 2.13 and 9.91 ± 2.71 mm-1 in the central, 17.20 ± 1.38 and 18.25 ± 1.37 mm-1 in the inner, and 17.90 ± 0.88 and 18.43 ± 0.97 mm-1 in the full regions, respectively. The perfusion densities were 0.17 ± 0.06 and 0.23 ± 0.07 in the central, 0.41 ± 0.05 and 0.44 ± 0.03 in the inner, and 0.44 ± 0.03 and 0.46 ± 0.02 in the full regions, respectively. The central macular thicknesses of hyperopia ametropic amblyopia and control eyes were 240.04 ± 20.11 and 235.08 ± 24.41 µm, respectively. Foveal avascular zone perimeter and circularity (P < .043 and P = .001) significantly differed between the 2 groups. Hyperopia ametropic amblyopia eyes showed lower appreciably in vessel and perfusion densities, which could be one of the major pathophysiological mechanisms of hyperopia ametropic amblyopia and provide a new direction for the diagnosis and treatment of amblyopia.
Topics: Humans; Amblyopia; Tomography, Optical Coherence; Case-Control Studies; Hyperopia; Microcirculation; Visual Acuity; Retina; Retinal Vessels; Fluorescein Angiography
PubMed: 36897692
DOI: 10.1097/MD.0000000000033196 -
Experimental Eye Research Apr 2021There have been many studies on lens properties in specific populations (e.g. in China, Europe, Singapore, etc.) some of which suggest there may be differences between... (Comparative Study)
Comparative Study
There have been many studies on lens properties in specific populations (e.g. in China, Europe, Singapore, etc.) some of which suggest there may be differences between populations. Differences could be caused by ethnic or environmental influences or experimental procedures. The purpose of this study is to evaluate if any differences exist between Indian and European populations in the central geometric and full shape properties of human lenses. Two custom-developed spectral domain optical coherence tomography systems were used to acquire the crystalline lens geometry: one in India (69 lenses from 59 donors) and the other in Spain (24 lenses from 19 donors). The steps for obtaining accurate 3-D models from optical coherence tomography raw images comprised of image segmentation, fan and optical distortion correction, tilt removal and registration. The outcome variables were lens equatorial diameter, lens thickness, anterior and posterior lens thicknesses and their ratio, central radius of curvature of the anterior and posterior lens surfaces, lens volume and lens surface area. A mixed effects model by maximum likelihood estimation was used to evaluate the effect of age, population and their interaction (age*population) on lens parameters. After adjusting for age, there were no population differences observed in anterior and posterior radii of curvature, equatorial diameter, lens thickness, anterior and posterior lens thicknesses and their ratio, volume and surface area (all p ≥ 0.08). There was also no effect of the interaction term on anterior and posterior radii of curvature, equatorial diameter, lens thickness, anterior and posterior lens thicknesses and their ratio, volume and surface area (all p ≥ 0.06). All central geometric and full shape parameters appeared to be comparable between the European and Indian populations. This is the first study to compare geometric and full shape lens parameters between different populations in vitro.
Topics: Adult; Asian People; Biometry; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; India; Lens, Crystalline; Likelihood Functions; Middle Aged; Models, Statistical; Organelle Shape; Tomography, Optical Coherence; White People; Young Adult
PubMed: 33545121
DOI: 10.1016/j.exer.2021.108481 -
Journal of Dental Sciences Oct 2023Overlay restorations can be used clinically as a treatment option to preserve natural dentine. However, whether the residual enamel thickness and overlay thickness...
ABSTRACT
Overlay restorations can be used clinically as a treatment option to preserve natural dentine. However, whether the residual enamel thickness and overlay thickness affect the adhesion between the restoration and tooth is still unknown. This study was to investigate effects of the overlay thickness and residual enamel thickness on bonding strength.
MATERIALS AND METHODS
Overlays of different thicknesses were prepared with natural teeth which had 2, 4, and 6 mm of occlusal reduction (n = 10). Specimens were subjected to 10,000 cycles in water at 5-55 °C, and finally compressive strength tests were used to evaluate the bonding strength.
RESULTS
All groups showed good bond strength ( > 0.05). The overlay restorations of different thicknesses reduced the preparation amount by 30.3%-7.2% and significantly preserved more of the tooth structure ( < 0.005). Compared to the control group, the overlay restoration increased the marginal fitness by about 0.67-0.88 times. The thermal cycling indicated that the decrease in the maximum bearing stress was due to the aging of the ceramic itself. Therefore, the thickness of the overlay had a greater influence on the compressive strength than the bond strength.
CONCLUSION
Based on the above this study recommends an overlay thickness of at least 2 mm in clinical practice. The aging test confirmed that adhesion between the overlay and teeth was quite firm and stable. This shows that a stable adhesive effect of the overlay can be used as a treatment option for preserving a greater amount of a tooth's structure.
PubMed: 37799901
DOI: 10.1016/j.jds.2023.06.011