Increase In Mean Thickness Research Articles

Thermodynamic and dynamic contributions to seasonal Arctic sea ice thickness distributions from airborne observations

Sea ice thickness is a key parameter in the polar climate and ecosystem. Thermodynamic and dynamic processes alter the sea ice thickness. The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition provided a unique opportunity to study seasonal sea ice thickness changes of the same sea ice. We analyzed 11 large-scale (∼50 km) airborne electromagnetic sea thickness and surface roughness surveys from October 2019 to September 2020. Data from ice mass balance and position buoys provided additional information. We found that thermodynamic growth and decay dominated the seasonal cycle with a total mean sea ice thickness increase of 1.4 m (October 2019 to June 2020) and decay of 1.2 m (June 2020 to September 2020). Ice dynamics and deformation-related processes, such as thin ice formation in leads and subsequent ridging, broadened the ice thickness distribution and contributed 30% to the increase in mean thickness. These processes caused a 1-month delay between maximum thermodynamic sea ice thickness and maximum mean ice thickness. The airborne EM measurements bridged the scales from local floe-scale measurements to Arctic-wide satellite observations and model grid cells. The spatial differences in mean sea ice thickness between the Central Observatory (<10 km) of MOSAiC and the Distributed Network (<50 km) were negligible in fall and only 0.2 m in late winter, but the relative abundance of thin and thick ice varied. One unexpected outcome was the large dynamic thickening in a regime where divergence prevailed on average in the western Nansen Basin in spring. We suggest that the large dynamic thickening was due to the mobile, unconsolidated sea ice pack and periodic, sub-daily motion. We demonstrate that this Lagrangian sea ice thickness data set is well suited for validating the existing redistribution theory in sea ice models. Our comprehensive description of seasonal changes of the sea ice thickness distribution is valuable for interpreting MOSAiC time series across disciplines and can be used as a reference to advance sea ice thickness modeling.

Effect of Diazepam on Proliferation of Chondrocytes in Intermediate and Deep Zones of Patellar Articular Cartilage in Adult Male Mice.

To determine the effect of diazepam on proliferation of chondrocytes in intermediate and deep zones of degenerating patellar articular cartilage in Balb/c mice. Experimental study. Department of Anatomy, College of Physicians and Surgeons Pakistan, Regional Centre, Islamabad, Pakistan, from June 2015 to May 2016. There were two groups of adult male mice as control group A and experimental group B. Group A having 90 mice was further divided into three subgroups having 30 mice in each subgroups. In subgroup A1 having 30 mice were treated normally. Subgroup A2 mice were kept immobilised for 20 days. Mice in subgroup A3 were given normal saline intraperitoneally during next 30 days of remobilisation and sacrificed. Among the mice in group B, normal saline was replaced with diazepam at the dose of 4 mg/kg for 30 days. Control subgroups and experimental group were compared. Data was analysed quantitatively using SPSS Version 16. Significant decrease in mean thickness of combined zone (66.69 ± 2.77μm) and chondrocytes count (5.61±0.76) were seen in subgroup A2 mice than subgroup A1 (77.54 ± 3.4μm) and (5.61 ± 0.76), respectively (p<0.001). Subgroup A3 showed significantly increased mean thickness (95.45 ± 5.17μm) and chondrocytes count (7.31 ± 0.44) than subgroup A2 (P<0.001). No significant increase in mean thickness (96.46 ± 4.94μm) and chondrocytes count (7.35 ± 0.41) of group B were seen than subgroup A3 (p=0.01). Diazepam administration does not stimulate proliferation of chondrocytes of combined intermediate and deep zones of degenerating articular cartilage by acting on GABA A receptors.

Changes in epidermal morphology associated with dandruff.

Dandruff is a very common scalp condition characterized by flaking and pruritus usually with no visible signs of inflammation, such as redness and erythema. Dandruff is considered a multifactorial condition with both microbial colonization and host factors such as sebum production thought to play a role. There is evidence of changes in epidermal morphology in the scalp skin of dandruff sufferers, with reports of an increase in mean thickness and more nucleated cell layers. The underlying mechanisms driving these morphological changes are currently unclear. The objective of this study was to fully characterize epidermal morphology in dandruff compared to healthy scalp skin and to evaluate potential mechanisms underlying any changes observed. Scalp skin biopsies were taken from 22 healthy female subjects and 21 dandruff sufferers, from both lesional and non-lesional sites. Samples were processed, sectioned and stained using haematoxylin and eosin (H&E). To fully characterize epidermal morphology, measurements were taken of epidermal thickness, the convolution of the dermal-epidermal junction and the depth of epidermal rete ridges. To analyse changes in epidermal proliferation immunohistochemical staining was performed using Ki67, a well-established marker of cell proliferation, and quantified using image analysis. Histochemical analysis of skin sections revealed that in dandruff lesional samples, the epidermis was thicker, had a more convoluted dermal epidermal junction and the rete ridges were elongated, compared to healthy scalp skin. Similar directional changes in epidermal morphology, were observed in non-lesional dandruff samples, albeit to a lesser extent. Image analysis of Ki67 expression in the epidermis revealed dandruff lesional skin contained significantly more Ki67-positive proliferating keratinocytes than healthy controls samples. This suggests dandruff scalp skin epidermal keratinocytes are in a hyper-proliferative state. There were significant changes in epidermal morphology in dandruff lesional skin compared to healthy scalp skin including increased epidermal thickness, a more convoluted dermal-epidermal junction and elongation of rete ridges. Interestingly, we found there was evidence of an increase in the percentage of epidermal Ki67-positive cells, which has not been reported previously, and demonstrates dandruff is a condition displaying epidermal hyper-proliferation.

Preparation and Thickness Profile of Endothelial Keratoplasty Lenticules from Donated Whole Eyes with Previous Photorefractive Keratectomy.

Purpose:To describe the preparation and thickness profiles of endothelial keratoplasty lenticules harvested from eyes with previous photorefractive keratectomy (PRK).Methods:Donor whole eyes that underwent PRK were subjected to microkeratome-assisted dissection for Descemet stripping automated endothelial keratoplasty. Specular microscopy and Visante optical coherence tomography were performed on precut corneas. Endothelial cell indices and thickness profiles of endothelial keratoplasty lenticules were statistically analyzed. Postoperative reports for transplanted lenticules were recorded.Results:Over a 6-month period, 2,929 whole eyes from 1,471 donors were screened for PRK. Twenty-five (0.85%) eyes from 14 donors were diagnosed with disciform haziness due to prior PRK and were used uneventfully for preparation of endothelial keratoplasty lenticules. Mean endothelial cell count was 3164.6 ± 311.0/mm2 and mean central posterior lenticule thickness was 128 ± 34 μm. Posterior lenticules revealed an increase in thickness from the central to peripheral cornea (mean increase of 26.2 μm at pericentral and 90.4 μm at peripheral locations). Mean increase in thickness was statistically different between two peripheral locations (74.5 μm vs. 108.1 μm, P = 0.047). Postoperative reports of transplanted lenticules revealed no posterior flap detachment or loss of clarity at least three months after the surgery.Conclusion:PRK donor whole eyes are potential sources for preparation of microkeratome-assisted thin endothelial keratoplasty lenticules with a high endothelial cell count. Although an asymmetric and significant increase in thickness was present at the peripheral cornea, neither attachment nor clarity of transplanted lenticules was affected by variations in thickness of precut corneas.

Choroidal thickness in diabetic patients without diabetic retinopathy

PurposeCompare choroidal thickness (CT) between diabetic patients without diabetic retinopathy (DR) and a non‐diabetic group. Explore how CT relates to disease duration, mean arterial pressure (MAP), glycaemia, glycosylated haemoglobin (HbA1c), intraocular pressure and ocular pulse amplitude (OPA).MethodsIn this cross‐sectional study, CT was assessed using SD‐OCT (Spectral Domain Optical Coherence Tomography) and enhanced depth mode at 13 different locations (subfoveal and 3 measurements 500 μm apart in all 4 directions – nasal, temporal, superior and inferior). Linear regression models were used to analyse the data.Results175 patients were recruited (125 diabetic patients without DR and 50 non‐diabetics patients). In diabetic patients, CT was significantly thicker than in non‐diabetic group in two locations: 1,500 μm nasal (p = 0.036) and 1,500 μm superior to the fovea (p = 0.021). CT was negatively associated with age (p &lt; 0.001) in both groups, but only in the diabetic group was it positively associated to OPA (with a mean increase in thickness between 8.5 and 11.6 μm for each increase of one OPA's unit). CT values seem to stabilize after 150 months of diabetes, with patients presenting higher glycaemia levels (&gt;160 mg/dl) while showing no fluctuation in neither HbA1c nor MAP.ConclusionsThere appears to be a thickening of the choroid in diabetic patients without DR. Moreover, this tissue may be functionally different in diabetic patients, as the pattern of associations seems to differ between groups.

Effect of Temporomandibular Joint Bony Ankylosis on Maxillary Sinus Wall Thickness

<i><span>Objectives:</span></i><span> </span><span>This study was designed to clarify the changes that might be induced in the maxillary sinus walls thickness in response to TMJ bony ankylosis</span><span> </span><i><span>Subjects and methods:</span></i><span> </span><span>Forty five </span><span>(45</span><span>) subjects were included in the study. They were divided into two groups Group I, (patients group) comprised</span><span> fifteen 15</span><span> patients were suffering from temporomandibular joint bony ankylosis (26 maxillary sinuses involved) and Group II, (control group) contained thirty (30) healthy volunteer.</span><span> Maxillary sinus walls thickness</span><span> has been measured by computerized tomography scan for both groups and was compared. </span><i><span>Results:</span></i><span> </span><span>There was significant increase in mean thickness of all walls of maxillary sinus in patients group. The thickness of lateral wall of recurrent cases of TMJ ankylosis showed significant de</span><span>crease when compared with the non-recurrent cases.</span><span> </span><i><span>Conclusion:</span></i><span> </span><span>Observable Increase in the thickness of maxillary sinus walls. This may be attributed to bone apposition from outer side without resorption from inner side. This explanation is ascribed to lack of pneumatization associated with hindrance of upper air way that usually existing with cases of TMJ bony ankylosis

Effect of Angle of Incidence on Macular Thickness and Volume Measurements Obtained by Spectral-Domain Optical Coherence Tomography

Evaluation of the effect of angle of incidence on macular thickness and volume measurements obtained by spectral-domain optical coherence tomography (OCT). A total of 30 eyes from 15 healthy young subjects underwent macular cube volume scans (512 × 128 protocol) following dilation using the Cirrus spectral domain OCT. For each eye, scans were obtained by positioning the scanning beam in the center of the dilated pupil, as well as in four eccentric positions (approximately 3 mm from the center), superior, inferior, nasal, and temporal to the pupillary center, to create oblique angles of incidence between the light beam and retina. In all cases, the region scanned by the volume cube was centered on the fovea. Macular thickness and volume measurements were computed for volume scan acquisitions, and differences in values between eccentric scans and the central scan were analyzed. Retinal thickness and volume values were observed to increase significantly in all subfields for all eccentrically-obtained scans compared to scans obtained through the center of the pupil. The mean increase in thickness for the various scan positions and subfields ranged from 3.76 to 11.38. Scans that were displaced temporally consistently showed the greatest increase in thickness and volume, whereas nasally positioned scans showed the least increase. The increase in retinal thickness for all subfields correlated significantly with angle of inclination or tilting of the retina. Macular thickness and volume measurement results may be affected significantly by positioning of the scanning beam in the pupil and resultant angle of incidence on the retina. These findings suggest that care should be taken to position the scanning beam consistently in the center of the pupil to achieve reliable measurements.

Clinical and histological evaluation of subepithelial connective tissue after collagen sponge implantation in the human palate

Successful root-coverage treatment depends on the thickness of the donor tissue. This study aimed to evaluate the thickness of donor tissue after augmentation of the connective tissue in the palatal area by implantation of lyophilized collagen sponge (Hemospon(®) ). Ten patients with an indication for root coverage, whose palate was deficient in adequate connective tissue, were recruited. The procedure was carried out in two stages. In the first stage, the palatal thickness in the donor site was measured at three standardized points (points 1, 2 and 3), from the distal of the canine to the distal of the first molar, and the lyophilized collagen sponge was inserted. In the second stage, the palatal thickness over the implant was measured (at points 1, 2 and 3), two biopsies of the palatal mucosa were collected - one over the implant (experimental sample) and the other on the contralateral side (control sample) - and then root-coverage treatment was performed. Analyses consisted of clinical assessment of the palatal measurements before and after sponge implantation, and histological assessment of the experimental and control biopsy samples. Data were analyzed using the Wilcoxon test. Both analyses showed a significant increase in mean thickness, of 1.08 mm of neoformed tissue in the clinical analysis (the tissue at point 2 was the thickest of the three points) and of 0.53 mm in the histological analysis. The insertion of lyophilized collagen sponge induced a significant increase in the thickness of palatal connective tissue.

Correlation of leaking microaneurysms with retinal thickening in diabetic retinopathy.

To investigate the contribution of fluorescein angiographic leaking microaneurysms (leak-MA) versus non-leaking microaneurysms (non-leak-MA) to retinal thickening in diabetic retinopathy. A consecutive series of 38 eyes from 24 patients with diabetic retinopathy was included. Leak-MA and non-leak-MA in each eye were selected in pairs at corresponding topographic location. Leaking was defined by late phase fluorescein angiograms compared to early phase. Retinal thickness was measured with Heidelberg Spectralis OCT topographically aligned on early phase angiograms at the MA site and within a 1 mm circle. In all eyes, significant retinal thickening at the site of leaking compared to non-leaking microaneurysms was observed (356±69µm vs 318±56µm, P<0.001), showing a mean increase in thickness in the areas of leak-MA vs non-leak-MA of 38±39µm (95% confidence interval 25-51µm, P<0.001). All 1mm area measurements also showed significant (P<0.001) thickening of the leak-MA with average thickness of leak-MA vs non-leak-MA as 351±67µm vs 319±59µm; minimum thickness 311±62µm vs 284±60µm; maximum thickness 389±78µm vs 352±66µm; and retina volume 26.4±6.0mm vs 23.6±3.7mm(3), respectively. Leaking of microaneurysms on fluorescein angiography appears to cause focal thickening of retina, which can be measured with high-resolution OCT. Therefore, targeting leaking microaneursyms in diabetic retinopathy has the potential to reduce retinal thickening.

Lipoprotein(a) predicts progression of carotid artery intima-media thickening in patients with type 2 diabetes: A four-year follow-up

The aim of the study was to establish whether increased levels of serum lipoprotein(a) significantly contribute to an increase in intima-media thickness and the number of carotid artery plaques, and consequently to cardiovascular risk in patients with type 2 diabetes mellitus. Lipoprotein(a) levels, intima-media thickness and the number of carotid artery plaques were determined at the beginning of the study in 146 patients with type 2 diabetes. Patients were divided into two groups according to serum lipoprotein(a) levels (> or <or=30 mg/dl). Intima-media thickness and the number of plaques were again determined after four years of follow-up. Intima-media thickness was assessed using high-resolution B-mode ultrasound. The two groups of patients revealed no significant differences in baseline intima-media thickness (P = 0.112) in relation to lipoprotein(a) level. After follow-up, intima-media thickness was significantly greater in patients with higher lipoprotein(a) levels (1.24 + 0.22 vs. 1.15 + 0.17 mm, respectively; P = 0.005). The mean increase in thickness over four years was 0.12 mm (0.030 mm/year) in the group with low lipoprotein(a) levels and 0.17 mm (0.043 mm/year) in the group with high lipoprotein(a). Multivariate analysis indicated that intima-media thickness depended on lipoprotein(a), and not on triglyceride, HDL-cholesterol levels or waist-to-hip ratio. No significant difference in baseline and follow-up number of plaques was observed between the study groups (P = 0.276 vs. P = 0.355, respectively). Although the group with lipoprotein(a) >30 mg/dl had more cardiovascular events, the difference was not statistically significant. These results indicate that lipoprotein(a) is an independent, genetically determined risk factor closely associated with progression of intima-media thickness in type 2 diabetes.

Effects of age on the thickness of myelin sheaths in monkey primary visual cortex.

The effect of age on myelin sheath thickness was determined by an electron microscopic examination of cross sections of the vertical bundles of nerve fibers that pass through primary visual cortex of the rhesus monkey. The tissue was taken from the cortices of young (4-9 years of age) and old (over 24 years of age) monkeys, and the sections were taken at the level of layer 4Cbeta. From the electron photomicrographs, the diameters of axons and the numbers of lamellae in their myelin sheaths were determined. No change was found in the diameters of axons with age, although the mean numbers of myelin lamellae in the sheaths increased from 5.6 in the young monkeys to 7.0 in the old monkeys. Much of this increase in mean thickness was due to the fact that, in the old monkeys, thick myelin sheaths with more than ten lamellae are more common than in the young monkeys. While this increase in the thickness of myelin sheaths is occurring in old monkeys, there are also age-related changes in some of the sheaths. Consequently, it seems that, with age, there is some degeneration of myelin but, at the same time, a continued production of lamellae.

An intermediate (1.0–1.5 monolayers) stage of heteroepitaxial growth of InAs on GaAs(100) during submonolayer molecular beam epitaxy

Intermediate (1–1.5 monolayer) stage of InAs deposition on the GaAs(100) singular and vicinal (3° towards [011] direction) surfaces results in the formation of different InAs surface arrangements. The formation of few monolayer-height quantum wires along [001] direction occurs immediately after 1 monolayer InAs deposition on the singular surface. The characteristic period equals ∼ 30 nm. Increase in mean thickness of InAs to 1.5 monolayer results in a less pronounced surface corrugation (“parquet” like structures) and the characteristic period increases to 50–60 nm. The wire-like structures on vicinal surfaces occurs independently of the mean thickness of InAs (within the region 1–1.5 monolayers).

焼結タングステン線材の再結晶過程

The time law of primary grain growth and the effect of doping agent, annealing temperature and heating rate on the shape of secondary recrystallized grains and the orientation distribution of the wire axis for them are investigated using sintered tungsten wires. The rate of primary grain growth is obtained from an increase in mean thickness of fibers, showing that the rate is fairly smaller in the doped wire than in the non-doped wire. Doping has another effect on retarding the start of secondary recrystallization from the surface and also its completion at the central part of the wire. The grains of the doped wire are much more elongated in a longitudinal direction than those of the non-doped wire after a complete secondary recrystallization. However, there is the tendency that the grains of both materials become more equiaxed in shape and are distributed near 〈011〉 in the wire axis as the annealing temperature and the rate of heating increase. It is concluded that the appearance of large elongated secondary recrystallized grains with a wire axis near 〈011〉-〈135〉 is directly due to the bubble effect and the large driving force of grain growth inherent in their orientations.

A morphometric study of vein graft intimal hyperplasia.

The extent of intimal hyperplasia in veins grafted into arteries is a major determinant of graft survival. The development of intimal hyperplasia in experimental iliolumbar vein grafts in iliac arteries of 36 rats was followed by light microscopy between 2 and 140 days after grafting. The increase in mean thickness of the graft intima was most rapid from 2 to 21 days and then more gradual to reach a maximum at 140 days, when the graft intima was the same thickness as the combined intima and media of the control artery. Grafts aged between 15 and 28 days showed a significant thickening at the anastomosis, but this was not evident in older grafts. Our results quantitate the arterialization of a vein graft and show that there is no significant anastomotic intimal hyperplasia in mature grafts in this model.

Relationship of prospective diabetes control in pregnancy to neonatal cardiorespiratory function

We evaluated two groups of diabetic women in pregnancy who differed primarily in the time of initiation of careful diabetes management. Group A (early) were entered in the first trimester (n = 35); group B (late) were entered in the late second or early third trimester (n = 28). Normal women delivering at the same period were used as controls (n = 23). All infants were evaluated by a thorough clinical and echocardiographic examination between 24 and 72 hours of life. Both groups of infants of diabetic mothers had mild increase in mean thickness of ventricular and septal walls compared with those of normal newborn infants, and both had a significant percentage with septal hypertrophy (43% vs 39%). None of the infants in the early group had respiratory symptoms requiring oxygen therapy, compared with 19% in the late group. The early group had significantly fewer infants with elevated right ventricular systolic time interval ratios than did the late group (20% vs 50%); none of the normal infants had elevated ratios. We conclude that careful management of diabetes in pregnancy reduces the severity of hypertrophic cardiomyopathy, although no advantage of early vs late management was obvious. Early management does significantly reduce the number of infants of diabetic mothers who develop respiratory symptoms requiring oxygen therapy.

A morphometric analysis of isolated perfused dog lungs after acute oncotic edema

Established stereologic techniques were used to evaluate morphologic changes in isolated-perfused dog lungs after induction of severe, acute oncotic edema. Lung volumes that were occupied by the connective tissue spaces surrounding extraalveolar vessels and airways were increased. Likewise, thickness of the parenchymal interstitium (interstitial compartment of the air-blood barrier) was increased, which created an overall increase in mean thickness of the barrier. In the cellular compartment of the air-blood barrier, cytoplasmic volumes of the endothelial and type I epithelial cells occupied by pinocytotic vesicles were increased. In addition, the number of vesicles opening directly onto the luminal and abluminal cellular surfaces was increased. Thus, transendothelial and transepithelial vesicular transport may contribute to edema formation in isolated perfused dog lungs. The production of oncotic edema was also associated with an increase in alveolar surface density while the proportion of the alveolar septa occupied by capillary contents was decreased.

Effect of cup geometry on ear height and thickening in cylindrical flatbottomed steel cups

AbstractAn investigation of the effect of cup geometry on ear height and wall thickening in cylindrical flat-bottom cups made from various mild steels has been carried out, and empirical relationships relating these factors have been established. The work has shown that, with reasonable accuracy, the ear height E is given by:E=MP (B2–P2/P)(B–P/P)1·5where B is the blank diameter, P is the punch diameter, and MP is a dimensionless earing parameter of the steel which may vary substantially between different steels. The mean increase in thickness at the top of the cup is given by:(Tm–To)=KPTo (B–P/P)where Tm is the mean final thickness at the top of the cup, To is the starting sheet thickness, and KP is a parameter which varies from steel to steel. The variation in thickness at the top of a cup due to earing ∆Te is given by:∆Te=2·66 MPTo (B2–P2/P2)(B–P/P)1·5Equations similar in form were found to hold when P was replaced by the die diameter D and these were about as accurate as those involving P. The empirica...

Initial Stage of Epitaxial Growth of Evaporated Gold Films on Sodium Chloride

The initial stage of the formation of evaporated gold films from 0.5 Å to 100 Å in mean thickness on cleavage surfaces of sodium chloride was studied by means of a transmission electron microscope. Above the epitaxial temperature, 330°C, gold particles have the so-called parallel orientation. Twin orientations are introduced by coalescence of particles initially formed, with the increase in mean thickness. Below the epitaxial temperature, compound particles are formed at a very early stage of deposition corresponding to the mean thickness of 2 Å. With the increase in mean thickness, their structure is modified by coalescence of particles. An essential difference in the size distribution and the crystallographic orientation of gold particles is found between the step-free and step-rich regions of the cleavage surface. Surface migration of gold atoms on the substrate surface is also studied in connection with the difference of amounts of gold between the step-free and step-rich regions.