Absolute Thickness Research Articles

1298P - Discovery of KIRREL as a biomarker for prognostic stratification of patients with thin melanoma

Background: There is a great unmet clinical need to identify patients with thin primary cutaneous melanomas (T1, Breslow thickness ≤ 1 mm) who have a high risk for tumor recurrence and death from melanoma. Kin of IRRE-like protein 1 (KIRREL/NEPH1) is expressed in podocytes and involved in glomerular filtration, but its expression in human cancer has not yet been reported. Screening in the Human Protein Atlas portal revealed a particularly high expression of KIRREL in melanoma, both at the mRNA and protein levels. In this study, we followed up on these findings and examined the prognostic value of KIRREL in a population-based cohort of melanoma. Methods: Immunohistochemical analysis of KIRREL was performed on tissue microarrays with a subset of primary tumors and paired lymph node metastases from an original cohort of 268 incident cases of melanoma in the Malmo Diet and Cancer study. Kaplan Meier analysis and Cox proportional hazards modelling were used to assess the relationship between KIRREL expression and time to recurrence (TTR) and melanoma-specific survival (MSS). The prognostic value of KIRREL mRNA expression was examined in 102 melanoma cases in The Cancer Genome Atlas (TCGA). Results: Membranous/cytoplasmic expression of KIRREL was detected in 158/185 (85.4%) primary tumours and 18/19 (94.7%) metastases, in various fractions and intensities. High expression of KIRREL was significantly associated with several unfavourable clinicopathological factors. KIRREL expression was not prognostic in tumours >1 mm thickness, but in T1 tumours (n = 106, median thickness 0.58, range 0.08-1.00), high expression of KIRREL was significantly associated with a reduced TTR, independent of and outperforming absolute thickness in mm and ulceration (HR = 4.54, 95% CI 1.01-20.45), and borderline significantly associated with MSS. High mRNA levels of KIRREL were associated with a significantly reduced overall survival in the TCGA (p = 0.028). Conclusions: KIRREL is not only a novel potential diagnostic marker for melanoma, but may also be a useful prognostic biomarker for improved stratification of patients with thin melanoma. These findings may be of high clinical relevance and therefore merit further validation. (Less)

Why large seeds with physical dormancy become nondormant earlier than small ones.

Under natural conditions, large seeds with physical dormancy (PY) may become water permeable earlier than small ones. However, the mechanism for this difference has not been elucidated. Thus, our aim was to evaluate the traits associated with PY in seeds of Senna multijuga (Fabaceae) and to propose a mechanism for earlier dormancy-break in large than in small seeds. Two seedlots were collected and each separated into large and small seeds. Seed dry mass, water content, thickness of palisade layer in the hilar and distal regions and the ratio between palisade layer thickness (P) in the lens fissure and seed mass (M) were evaluated. Further, the correlation between seed mass and seed dimensions was investigated. Large seeds had higher dry mass and water content than small seeds. The absolute thickness of the palisade layer in the different regions did not show any trend with seed size; however, large seeds had a lower P:M ratio than small seeds. Seed mass correlated positively with all seed dimensions, providing evidence for a substantially higher volume in large seeds. Since wet, but not dry, high temperatures break PY in sensitive seeds of S. multijuga, the data support our prediction that internal pressure potential in the seed and palisade layer thickness in the water gap (lens), which is related to seed mass (i.e. P:M ratio), act together to modulate the second step (dormancy break) of the two-stage sensitivity cycling model for PY break. In which case, large seeds are predetermined to become water-permeable earlier than small ones.

Effects of Deformation Conditions on the Rolling Force during Variable Gauge Rolling

In this study, effects of different deformation conditions on the rolling force were studied during variable gauge rolling processes. To this end, variations of rolling forces with rolling times were analyzed at different roll diameters, absolute thickness reductions and friction coefficients. Considering the rolling force variations, an abrupt change in the outlet section of downward and outward rolling was observed at all deformation conditions. The experimental data, along with the results obtained from finite element method (FEM) simulations, revealed that this drop in the rolling force (DRF) is strongly dependent on the deformation conditions. It was found that the DRF value increases with increasing absolute thickness reduction, roll diameter and friction coefficient. Furthermore, dependency of contact length on the roll radius and wedge angle (slope of the thickness transition zone) was investigated. Accordingly, it was concluded that the variations of the DRF value can be mainly attributed to the changes in the contact length during variable gauge rolling. Moreover, slab method analysis was used to model the effects of deformation conditions on DRF.

Single point Linnik white-light spectral microscopic interferometer for surface measurement

According to the requirement for high precision surface measurement in complex situations, a single point Linnik type measuring system with long working distance is built based on white-light spectral interferometry. Five-step phase-shifting algorithm is used to extract accurate phase information in the measuring system. Several experiments are conducted to measure the absolute distance and film thickness, verifying the feasibility of the system. It has been achieved that the system can measure the surface form and film thickness with nanoscale accuracy.

A digital, constant-frequency pulsed phase-locked-loop instrument for real-time, absolute ultrasonic phase measurements.

A digitally controlled instrument for conducting single-frequency and swept-frequency ultrasonic phase measurements has been developed based on a constant-frequency pulsed phase-locked-loop (CFPPLL) design. This instrument uses a pair of direct digital synthesizers to generate an ultrasonically transceived tone-burst and an internal reference wave for phase comparison. Real-time, constant-frequency phase tracking in an interrogated specimen is possible with a resolution of 0.000 38 rad (0.022°), and swept-frequency phase measurements can be obtained. Using phase measurements, an absolute thickness in borosilicate glass is presented to show the instrument's efficacy, and these results are compared to conventional ultrasonic pulse-echo time-of-flight (ToF) measurements. The newly developed instrument predicted the thickness with a mean error of -0.04 μm and a standard deviation of error of 1.35 μm. Additionally, the CFPPLL instrument shows a lower measured phase error in the absence of changing temperature and couplant thickness than high-resolution cross-correlation ToF measurements at a similar signal-to-noise ratio. By showing higher accuracy and precision than conventional pulse-echo ToF measurements and lower phase errors than cross-correlation ToF measurements, the new digitally controlled CFPPLL instrument provides high-resolution absolute ultrasonic velocity or path-length measurements in solids or liquids, as well as tracking of material property changes with high sensitivity. The ability to obtain absolute phase measurements allows for many new applications than possible with previous ultrasonic pulsed phase-locked loop instruments. In addition to improved resolution, swept-frequency phase measurements add useful capability in measuring properties of layered structures, such as bonded joints, or materials which exhibit non-linear frequency-dependent behavior, such as dispersive media.

CONTRAST-EHANCED MRI IN TIME-STRUCTURE ANALYSIS OF MYOCARDIAL DAMAGE IN ACUTE INFARCTION AND EARLY PREHOSPITAL THROMBOLYTIC THERAPY

Purpose:to evaluate the dependence of absolute and relative thickness of damaged myocardium in the acute myocardial infarction (AMI) area from the time interval between oncet of pain and start of intravenous thrombolysis (so-called “pain–needle time”), in AMI patients treated with prehospital intravenous thrombolysis and also later on with subsequent percutaneous coronary angiplasty (PCA) and stenting, using contrast-enhanced MRI of the heart Materials and methods. The study comprised data of CE-MRI studies in 25 patients with theyr first acute myocardial infarction, in whom the pre-hospital thrombolytic therapy (TLT) was carried out in the course of 35–300 min after onset of chest pain, with coronarography and percutaneous coronary angioplasty and stenting after admission to the institute of cardiology. In six patients the TLT was not success ful and in these the restoration of coronary blood flow was obtained only at PCA. In all patients in terms 18–34 hours after TLT the CE-MRI of the heart was carried out using gadobutrol or gadoversetamid, as 0.1 mM per kg of BW, in T1-weighted mode with fat suppression and as inversion-recovery with inversion time adjusted to get the normal myocardium “nulled”. We calculated the segmental extension of damage, the thickness of infarcted irreversibly damaged myocardium and of non-damaged myocardium in the same locations, the index of transmurality, as ratio of thickness of damaged myocardium to the overall wall thickness. We analyzed the dependence of these indices of damage from the time interval between pain oncet and beginning of intravenous thrombolytic therapy (or PCA – when TLT was unsuccessful).Results.The dependence of thickness of non-damaged myocardium from the “pain-needle” time was as exponential as Y = 2.08 + 17.11 · exp(−t/42.4), r = 0.843, p < 0.002. Index of transmurality did depend on the time interval “pain – needle” as Boltzmann function, pretty closely to reverse exponential one: No-reflow zone with absent blood flow in the infarcted area was present only in cases with the “pain–needle” time interval over 70 min. Later on the full or partial restoration of contractility in infarcted segments was observed only if the IT was below 0.55–0.6.Conclusion.CE-MRI delivers adequate quantitative estimates of anatomic transmural extent of myocardial infarction from early acute period of the AMI. The depth of myocardial damage is a function of “pain–needle” time and approaches the half of wall thickness for as short as 55–65 min, determining by this the future prognosis of the mechanical restitution of contractility in the infarcted region. It is suggested the CE-MRI of the heart must be carried out in every patient in whom due to AMI the thrombolytic therapy and/or percutaneous coronary angioplasty has been done, for unbiased myocardium-focused control of efficiency of restoration of coronary arterial patency.

Using modern human cortical bone distribution to test the systemic robusticity hypothesis

The systemic robusticity hypothesis links the thickness of cortical bone in both the cranium and limb bones. This hypothesis posits that thick cortical bone is in part a systemic response to circulating hormones, such as growth hormone and thyroid hormone, possibly related to physical activity or cold climates. Although this hypothesis has gained popular traction, only rarely has robusticity of the cranium and postcranial skeleton been considered jointly. We acquired computed tomographic scans from associated crania, femora and humeri from single individuals representing 11 populations in Africa and North America (n = 228). Cortical thickness in the parietal, frontal and occipital bones and cortical bone area in limb bone diaphyses were analyzed using correlation, multiple regression and general linear models to test the hypothesis. Absolute thickness values from the crania were not correlated with cortical bone area of the femur or humerus, which is at odds with the systemic robusticity hypothesis. However, measures of cortical bone scaled by total vault thickness and limb cross-sectional area were positively correlated between the cranium and postcranium. When accounting for a range of potential confounding variables, including sex, age and body mass, variation in relative postcranial cortical bone area explained ∼20% of variation in the proportion of cortical cranial bone thickness. While these findings provide limited support for the systemic robusticity hypothesis, cranial cortical thickness did not track climate or physical activity across populations. Thus, some of the variation in cranial cortical bone thickness in modern humans is attributable to systemic effects, but the driving force behind this effect remains obscure. Moreover, neither absolute nor proportional measures of cranial cortical bone thickness are positively correlated with total cranial bone thickness, complicating the extrapolation of these findings to extinct species where only cranial vault thickness has been measured.

Large-scale hollow nanoparticle identification by X-ray absorption spectroscopy

Large-scale SiO2 hollow nanoparticles were synthesized by a sol-gel method. The composition, morphology, and chemical bonding information of SiO2 hollow nanoparticles were studied by X-ray absorption near edge structure (XANES) and scanning transmission X-ray microscopy (STXM). XANES at the Si L-edge and K-edge reveal the characteristics of hollow nanoparticles, which are essentially amorphous SiO2 with a slightly longer Si–O bond than SiO2 nanoparticles on average and deficiencies in oxygen. Individual SiO2 hollow spheres were also examined using STXM, which provides spectromicroscopic information, as well as the absolute thickness, of the sample.

Side differences of the lateral abdominal wall in supine rest position in mild adolescent idiopathic thoracolumbar scoliosis.

This study aims to evaluate the thickness of the abdominal muscles on both sides in patients with mild adolescent idiopathic scoliosis (AIS) and to assess the absolute and relative thickness of oblique external (OE), oblique internal (OI), and transversus abdominis (TrA). A total of 84 participants underwent ultrasonographic examination of the abdominal muscles in the supine resting position. All participants were divided into two groups including AIS group (n=42) and control group (n=42). The absolute and relative thicknesses of OE, OI, and TrA were recorded. In the AIS group, the TrA on the left side was significantly thicker by 0.30 mm (95% CI 0.01-0.7) than the right side. For relative values, the percentage contribution to the structure of the lateral abdominal wall of the OE on the right and the TrA on the left was significantly higher by 3.2% (95% CI 0.9-5.5) and 3.1% (95% CI 1.1-5.0), respectively, in the AIS group. Our study results show that, in the supine resting position, the muscles of the lateral abdominal wall are thinner in AIS patients. In addition, side-to-side differences in the percentage contribution of the OE and TrA to the structure of the lateral abdominal wall are seen in this patient population, although these differences are independent of the direction of the scoliosis.

Can resistance training impact MRI outcomes in relapsing-remitting multiple sclerosis?

Background: Multiple sclerosis (MS) is characterised by accelerated brain atrophy, which relates to disease progression. Previous research shows that progressive resistance training (PRT) can counteract brain atrophy in other populations. Objective: To evaluate the effects of PRT by magnetic resonance imaging (MRI) and clinical measures of disease progression in people with MS. Methods: This study was a 24-week randomised controlled cross-over trial, including a Training (n = 18, 24 weeks of PRT followed by self-guided physical activity) and Waitlist group (n = 17, 24 weeks of habitual lifestyle followed by PRT). Assessments included disability measures and MRI (lesion load, global brain volume, percentage brain volume change (PBVC) and cortical thickness). Results: While the MS Functional Composite score improved, Expanded Disability Status Scale, lesion load and global brain volumes did not differ between groups. PBVC tended to differ between groups and higher absolute cortical thickness values were observed in 19 of 74 investigated cortical regions after PRT. Observed changes were confirmed and reproduced when comparing relative cortical thickness changes between groups for four areas: anterior cingulate gyrus, temporal pole, orbital sulcus and inferior temporal sulcus. Conclusion: PRT seem to induce an increase in cortical thickness, indicating that PRT have a neuroprotective or even neuroregenerative effect in relapsing-remitting MS.

Ultrastructure of Skeletal Muscles in Mice Lacking Muscle-Specific VEGF Expression.

Vascular endothelial growth factor-A (VEGF) influences several physiological processes including endothelial cell function, angiogenesis and maintenance of organ/tissue capillarity. While the functional aspects of VEGF were vigorously investigated, only little detail is known on structural integrity of skeletal muscle fibers and capillaries in mice lacking VEGF expression in their muscles. Therefore, we assessed systematically the architecture of the glycolytic plantaris and the oxidative soleus muscles obtained from muscle-specific VEGF knockout (mVEGF-KO, n = 7) mice and their wild-type (WT, n = 7) littermates by morphometry after transmission electron microscopy. The capillary/fiber ratio was lower (plantaris: -63.5%; soleus: -54.8%; P ≤ 0.05) in mVEGF-KO mice than in WT mice. In plantaris, quantification of volume density (Vv) of compartments revealed higher Vv of total mitochondria (+56.5%, P ≤ 0.05) as well as higher Vv-values for both intrafibrillar (+39%; P ≤ 0.05) and subsarcolemmal (+220%; P ≤ 0.05) mitochondrial pools in mVEGF-KO mice than WT mice. The capillary phenotype also differed (P ≤ 0.05) between the two mouse-strains: Vv (-17.4%), absolute area size (-19.1%) and thickness (-19.6%) of the endothelium layer were lower and Vv of capillary lumen (+15.1%) was higher in mVEGF-KO mice than in WT littermates. In soleus, mitochondrial Vv in fibers and the structural indicators specific to the capillary phenotype exhibited the same tendency in differences between the mouse strains without reaching statistical significance. Our morphometric analysis demonstrates that the lower capillary supply in plantaris of mVEGF-KO mice is accompanied by higher mitochondrial Vv in muscle fibers as well as lumen dilation and endothelium thinning of capillaries. These structural alterations were more pronounced in a glycolytic than an oxidative muscle. Anat Rec, 300:2239-2249, 2017. © 2017 Wiley Periodicals, Inc.

Measurement of Thickness of High-Resistivity Substrate by Photoconduction Enhanced Capacitance Displacement Sensor

Capacitive displacement sensors provide non-contact, extreme resolution, and absolute accuracy thickness measurements. However, if the resistivity of a target substrate is within 105-107 ohm-cm, an uncertainty will appear in the thickness measurement. The common solution is to adjust the resistivity to be outside the range that causes the measurement uncertainty by implanting dopants and followed by an activation anneal, but this will unavoidably lead to changes in the material properties and morphology. Here, we exploit the photoconductive effect to generate sufficient high amount of electron-hole pairs, thereby temporarily decreasing the resistivity and thus enabling the capacitive displacement sensor to accurately measure the thickness at nanoscale resolution. After the measurement is complete, the resistivity of the substrate will return to its original status. The photoconductive effect can be simply induced via laser irradiation at the sensing point, which narrows or eliminates the gap in the measurement range of capacitive sensors to include high-resistivity substrate.

Specific Lp(a) apheresis: A tool to prove lipoprotein(a) atherogenicity

BackgroundAn elevated lipoprotein(a) (Lp(a)) level is observed in more than 30% of patients with stable ischemic heart disease (SIHD). We conducted an investigation of the effects of specific Lp(a) apheresis on the progression of atherosclerosis in SIHD patients with Lp(a) levels greater than 50 mg/dL. MethodsWe prospectively enrolled 15 patients diagnosed with SIHD based on symptom-driven coronary angiography findings, with Lp(a) ≥50 mg/dL and a low density lipoprotein cholesterol (LDL-C) ≤2.5 mmol/L, who were on long-term statin therapy. They underwent weekly Lp(a) apheresis using Lp(a) Lipopak® adsorption columns which contain monospecific sheep polyclonal antibodies against human Lp(a). Fifteen age and gender matched SIHD patients receiving atorvastatin monotherapy served as controls. At baseline and 18 months post-treatment, quantitative coronary angiography, intracoronary ultrasound with virtual histology and carotid ultrasound were performed. Lipid profile, including Lp(a), was measured at the scheduled visits, and before and after each apheresis procedure. Levels of high-sensitivity C-reactive protein (hsCRP), matrix metalloproteinases (MMP)-7 and 9, and tissue inhibitor of matrix metalloproteinases (TIMP)-1 and 2 were determined at baseline and at the end of the study period. ResultsEach specific Lp(a) apheresis procedure was carried out with two adsorption columns resulting in an average acute decrease in Lp(a) levels of 75% (from 110 ± 22 to 29 ± 16 mg/dL) without significant changes in other plasma components. Lp(a) reduction over the course of 18 months was associated with a decrease in the mean percent diameter stenosis of 5.05% and an increase in minimal lumen diameter of 14%; the mean total atheroma volume was reduced by 4.60 mm3 (p < 0.05 for all). There was a decrease in absolute common carotid intima-media thickness in the Lp(a) apheresis group of 0.07 ± 0.15 mm both from baseline and compared with the control group (p = 0.01). Levels of hsCRP were reduced by 40% in patients on Lp(a) apheresis without significant changes in the levels of other biomarkers at the end of the study. ConclusionReduction of the atherosclerotic burden in coronary and carotid arteries was observed in patients treated with specific Lp(a) apheresis and statin over 18 months compared with statin therapy alone. These findings support the atherogenic role of Lp(a) and reinforce the need to assess the effects of Lp(a)-lowering on cardiovascular events and mortality.Trial Registration Clinicaltrials.gov (NCT02133807).

Measurement of Thickness of High-Resistivity Substrate By Photoconduction Enhanced Capacitance Displacement Sensor

Capacitive displacement sensors can offer non-contact, extreme resolution, and absolute accuracy thickness measurements. However, for general capacitive displacenent sensors, if the resistivity of a target substrate is within 105-107 ohm-cm, a measurement uncertainty will occur in the thickness measurement. The measnurement uncentration may be several microon meters. The common solution is to adjust the resistivity to be outside the range that causes the measurement uncertainty by implanting dopants and followed by an activation anneal, but this will unavoidably lead to changes in the material properties and morphology. Here, we exploit the photoconductive effect to generate sufficient high amount of electron-hole pairs, thereby temporarily decreasing the resistivity and thus enabling the capacitive displacement sensor to accurately measure the thickness at nanoscale resolution. After the measurement is complete, the resistivity of the substrate will return to its original status. The photoconductive effect can be simply induced via laser irradiation at the sensing point, which narrows or eliminates the gap in the measurement range of capacitive sensors to include high-resistivity substrates.

Definition of common carotid wall thickness affects risk classification in relation to degree of internal carotid artery stenosis: the Plaque At RISK (PARISK) study

BackgroundMean or maximal intima-media thickness (IMT) is commonly used as surrogate endpoint in intervention studies. However, the effect of normalization by surrounding or median IMT or by diameter is unknown. In addition, it is unclear whether IMT inhomogeneity is a useful predictor beyond common wall parameters like maximal wall thickness, either absolute or normalized to IMT or lumen size. We investigated the interrelationship of common carotid artery (CCA) thickness parameters and their association with the ipsilateral internal carotid artery (ICA) stenosis degree.MethodsCCA thickness parameters were extracted by edge detection applied to ultrasound B-mode recordings of 240 patients. Degree of ICA stenosis was determined from CT angiography.ResultsNormalization of maximal CCA wall thickness to median IMT leads to large variations. Higher CCA thickness parameter values are associated with a higher degree of ipsilateral ICA stenosis (p < 0.001), though IMT inhomogeneity does not provide extra information. When the ratio of wall thickness and diameter instead of absolute maximal wall thickness is used as risk marker for having moderate ipsilateral ICA stenosis (>50%), 55 arteries (15%) are reclassified to another risk category.ConclusionsIt is more reasonable to normalize maximal wall thickness to end-diastolic diameter rather than to IMT, affecting risk classification and suggesting modification of the Mannheim criteria.Trial registrationClinical trials.gov NCT01208025.

Structural Changes in Acetophenone Fluid Films as a Function of Nanoscale Thickness

We report experimental observations of a developing fluid/solid interface by examining acetophenone films of varying thicknesses, supported on solid silver substrates. A dynamic wetting technique provides experimental control of fluid film thickness, as a function of rotational velocity. Ellipsometry and infrared reflection absorption spectroscopy data are analyzed to provide absolute film thickness and details of the changing chemical environment for varying film thickness. These data are compared to theoretical models that predict fluid film thicknesses, based on physical-chemical properties of the acetophenone/silver pair. As the velocity of the substrate is varied from 0.003 cm s-1 to 1.872 cm s-1, the fluid film's thickness changes from a ca. 200 nm to 2 μm. This increase in film thickness with increasing velocity follows a Landau trend, which is linear with respect to velocity2/3. Our data also show clear evidence of molecular orientation changes, as a function of film thickness, which occur as the thinner films are increasingly comprised of acetophenone molecules within a confined, interfacial environment. The spectral changes for the thinnest fluid films (<100 nm) are shown to exhibit features similar to transmission Fourier transform infrared (FTIR) data of frozen acetophenone, suggesting that these films are highly ordered, as a result of their nanometer-scale confinement.

Reliability and Precision of Sonography of the Lumbar Multifidus and Transversus Abdominis During Dynamic Activities.

To determine the intrarater reliability and precision of lumbar multifidus and transversus abdominis thickness measurements using freehand sonography in a range of static and dynamic conditions. Fifteen asymptomatic participants performed a range of exercises while sonography was used to measure absolute muscle thickness and changes in muscle thickness from rest. Exercise conditions included the abdominal drawing-in maneuver, active straight leg raise, contralateral arm lift, both unloaded and loaded, treadmill walking, and using the Functional Readaptive Exercise Device. Intraday and interday reliability was assessed by intraclass correlation coefficients, and the standard error of measurement was used to assess measurement precision. Good to excellent reliability was achieved for absolute transversus abdominis and lumbar multifidus thickness in all conditions. Measurement precision for absolute lumbar multifidus thickness was ≤2.8 mm for the unloaded contralateral arm lift, ≤1.8 mm for the loaded contralateral arm lift, ≤3.1 mm for treadmill walking, and ≤3.8 mm for the Functional Readaptive Exercise Device; for absolute transversus abdominis thickness, precision was ≤0.6 mm for the abdominal drawing-in maneuver, ≤0.5 mm for the active straight leg raise, ≤0.7 mm for treadmill walking, and ≤0.5 mm for the Functional Readaptive Exercise Device. Good to excellent reliability was achieved for relative transversus abdominis and lumbar multifidus thickness in all conditions. Measurement precision for relative lumbar multifidus thickness was ≤3.7% for the unloaded contralateral arm lift, ≤3.8% for the loaded contralateral arm lift, ≤6.3% for treadmill walking, and ≤7.6% for the Functional Readaptive Exercise Device; for relative transversus abdominis thickness, precision was ≤13.6% for the abdominal drawing-in maneuver, ≤6.9% for the active straight leg raise, ≤11.1% for treadmill walking, and ≤7.2% for the Functional Readaptive Exercise Device. Acceptable reliability and precision of measurement is achieved for absolute and relative measures of deep spinal muscle thickness using freehand sonography in relatively static and dynamic exercises.

Simultaneous interferometric measurement of the absolute thickness and surface shape of a transparent plate using wavelength tuning Fourier analysis and phase shifting

The absolute optical thickness and surface shape of optical devices are considered as the fundamental characteristics when designing optical equipment. The thickness and surface shape should be measured simultaneously to reduce cost. In this research, the absolute optical thickness and surface shape of a 6–mm-thick fused silica transparent plate of diameter 100mm was measured simultaneously by a three-surface Fizeau interferometer. A measurement method combining the wavelength tuning Fourier and phase shifting technique was proposed. The absolute optical thickness that corresponds to the group refractive index was determined by wavelength tuning Fourier analysis. At the beginning and end of the wavelength tuning, the fractional phases of the interference fringes were measured by the phase shifting technique and optical thickness deviations with respect to the ordinary refractive index and surface shape were determined. These two kinds of optical thicknesses were synthesized using the Sellmeier equation for the refractive index of fused silica glass, and the least square fitting method was used to determine the final absolute optical thickness distribution. The experimental results indicate that the all the measurement uncertainties for the absolute optical thickness and surface shape were approximately 3nm and 35nm, respectively.

Communication—Eliminating Thickness Measurement Uncertainty of Capacitive Displacement Sensor in High Resistivity Substrate by Photoconduction

Capacitive displacement sensors provide non-contact and absolute accuracy thickness measurements. However, if the resistivity of a target substrate is within 105–107 Ω-cm, a measurement uncertainty will occur. Incorporating dopants in the substrate can adjust the resistivity to be outside the range that causes the measurement uncertainty, but also permanently changes the electronic properties. Here, we exploit the photoconductive effect to generate an adequate amount of electron-hole pairs, thereby temporarily decreasing the resistivity and thus enabling the capacitive displacement sensor to accurately measure the thickness at nanoscale resolution. After the measurement is completed, the resistivity of the substrate will return to its original value.

Sacrotuberous Ligament Healing following Surgical Division during Transgluteal Pudendal Nerve Decompression: A 3-Tesla MR Neurography Study.

Pelvic pain due to chronic pudendal nerve (PN) compression, when treated surgically, is approached with a transgluteal division of the sacrotuberous ligament (STL). Controversy exists as to whether the STL heals spontaneously or requires grafting. Therefore, the aim of this study was to determine how surgically divided and unrepaired STL heal. A retrospective evaluation of 10 patients who had high spatial resolution 3-Tesla magnetic resonance imaging (3T MRI) exams of the pelvis was done using an IRB-approved protocol. Each patient was referred for residual pelvic pain after a transgluteal STL division for chronic pudendal nerve pain. Of the 10 patients, 8 had the STL divided and not repaired, while 2 had the STL divided and reconstructed with an allograft tendon. Of the 8 that were left unrepaired, 6 had bilateral surgery. Outcome variables included STL integrity and thickness. Normative data for the STL were obtained through a control group of 20 subjects. STL integrity and thickness were measured directly on 3 T MR Neurography images, by two independent Radiologists. The integrity and thickness of the post-surgical STL was evaluated 39 months (range, 9–55) after surgery. Comparison was made with the native contra-lateral STL in those who had unilateral STL division, and with normal, non-divided STL of subjects of the control group. The normal STL measured 3 mm (minimum and maximum of absolute STL thickness, 2–3 mm). All post-operative STL were found to be continuous regardless of the surgical technique used. Measured at level of Alcock’s canal in the same plane as the obturator internus tendon posterior to the ischium, the mean anteroposterior STL diameter was 5 mm (range, 4–5 mm) in the group of prior STL division without repair and 8 mm (range, 8–9 mm) in the group with the STL reconstructed with grafts (p<0.05). The group of healed STLs were significantly thicker than the normal STL (p<0.05). We conclude that a surgically divided STL will heal spontaneously and will be significantly thicker after healing.