Micrometer Caliper Research Articles

Hair diameter measurement methods: micrometer caliper versus phototrichogram

Background Hair diameter is a crucial element in deciding the treatment and predicting the prognosis of hair transplantation in patients with hair loss.Methods Ten female volunteers participated in this study. Three sites at different horizontal positions of the scalp were chosen for measurement: midoccipital, mastoid, and temporal. Three boxes of 1 cm2 were marked from superior to inferior along the midline of each site, and five anagen hairs ≥10 cm long were randomly sampled from each box. The thickness of each collected hair was measured at three positions along the hair length: 1 cm, 5 cm, and 10 cm from the surface of the skin. The diameters of the hairs were measured using a micrometer caliper and a Folliscope phototrichogram, and the measurements were compared.Results The average thickness of all hairs was 76.90±12.29 μm when measured with the caliper and 108.78±19.97 μm when measured with the phototrichogram. There was a statistically significant difference between the two measurement methods (P<0.001). The average hair thickness from the three areas (midoccipital, mastoid, and temporal) showed a significant difference between the caliper and the Folliscope hair measurements (P<0.001): midoccipital area (caliper, 74.46±9.71 μm; Folliscope, 109.03±19.59 μm), mastoid area (caliper, 76.36±10.67 μm; Folliscope, 103.73±18.67 μm), and temporal area (caliper, 79.89±15.18 μm; Folliscope, 113.59±20.43 μm).Conclusions Measuring hair thickness using a phototrichogram, which generates a measurement of the long-axis dimension, is clinically useful in the treatment of patients with hair loss and patients undergoing hair transplantation.

Hair diameter measurements for planning follicular unit extraction surgery (FUE): Is there a correlation between the micrometer caliper and scanning electron microscopy (SEM) findings?

Hair shaft diameter is one of the most important factors for the outcome of follicular unit extraction (FUE) surgery. In fact, the hair shaft is elliptical. Therefore, it has a long and short axis. Many hair transplantation surgeons use manual micrometer caliper for gauging hair diameter and use the results in the management of recipient and donor area. In this study, we aimed to identify the dependability of micrometer caliper and also the hair diameter diversity pattern in the donor area. Two hundred and seventy hairs were collected from three males with androgenetic alopecia. Hair samples were obtained from the 1cm2 boxes from superior to inferior at the mid-point of temporal, parietal, and occipital donor areas. The diameter of each hair was measured both with a micrometer caliper and scanning electron microscopy (SEM). Average diameter measured by scanning electron microscopy was 83.01µm for the long axis and 51.51µm for the short axis. The average value for the micrometer caliper measurement was 53.32µm. Comparison of micrometer caliper results with the short-axis measurements of SEM revealed a strong significant correlation. The hair diameters from superior, middle, and inferior boxes revealed a tendency to decrease toward the inferior regions. A manual micrometer caliper is a dependable tool for planning FUE surgery, and it measures the short axis of the elliptical hair shaft. Hair diameter tends to decrease toward the inferior regions of the donor area.

Amelioration of CIA by Asarinin Is Associated to a Downregulation of TLR9/NF-κB and Regulation of Th1/Th2/Treg Expression.

To study the role of asarinin on collagen-induced arthritis (CIA) and its treatment mechanism on dendritic cells (DCs) and T cells. Before the onset of arthritis, asarinin were given orally to CIA mouse. Macroscopic scoring and micrometer caliper measurement were used to assess arthritis. The occurrence of cartilage destruction and bone erosion were assessed by histology of knee. Sandwich enzyme-linked immunosorbent assay (ELISA) and PCR were used to assess the level of cytokines in hindpaw and arthritic joint. The CD11c MicroBeads were employed to isolate CD11c+ cells from the spleen. Quantitative PCR was used to determine DCs surface molecules of spleen. Macroscopic score and the frequency of arthritis were inhibited by asarinin. Swelling of hindpaws, inflammatory cell infiltration in the synovium, cartilage destruction, and bone erosion were delayed with asarinin. Asarinin treatment suppressed the expression of T helper type 1 (Th1) cytokines and increased the levels of Th2 cytokines (interleukin (IL)-10), transforming growth factor (TGF)-β and Foxp3 in the synovium and hindpaw, however T-bet mRNA levels in synovium decreased. Lower expression of toll-like receptor 9 (TLR9) and nuclear factor-kappaB (NF-κB) were found in DCs after asarinin treatment. There was no difference in the expression of intercellular cell adhesion molecule-1(ICAM-1), OX40-L, and 4-1BBL in spleen DCs between the asarinin group and model control group. Asarinin can treat CIA. TLR9/NF-κB pathway may be involved in the asarinin treatment of CIA by skewing the balance of Th1/Th2/regulatory T (Treg) to a Th2 type.

Flexible Strain Sensor Based on Layer-by-Layer Self-Assembled Graphene/Polymer Nanocomposite Membrane and Its Sensing Properties

Graphene is a potential building block for next generation electronic devices including field-effect transistors, chemical sensors, and radio frequency switches. Investigations of strain application of graphene-based films have emerged in recent years, but the challenges in synthesis and processing achieving control over its fabrication constitute the main obstacles towards device applications. This work presents an alternative approach, layer-by-layer self-assembly, allowing a controllable fabrication of graphene/polymer film strain sensor on flexible substrates of polyimide with interdigital electrodes. Carboxylated graphene and poly (diallyldimethylammonium chloride) (PDDA) were exploited to form hierarchical nanostructure due to electrostatic action. The morphology and structure of the film were inspected by using scanning electron microscopy, x-ray diffraction and Fourier transform infrared spectroscopy. The strain-sensing properties of the graphene/PDDA film sensor were investigated through tuning micrometer caliper exertion and a PC-assisted piezoresistive measurement system. Experimental result shows that the sensor exhibited not only excellent response and reversibility behavior as a function of deflection, but also good repeatability and acceptable linearity. The strain-sensing mechanism of the proposed sensor was attributed to the electrical resistance change resulted from piezoresistive effect.

Wall thickness measurement using resonant phenomena of circumferential Lamb waves generated by plural transducer elements located evenly on girth

We present a novel method of measuring the pipe wall thickness using the resonance of the circumferential (C-) Lamb wave generated by a piezoelectric ring-shaped sensor (PS). The PS is a special device for an axially propagating torsional wave; however, the C-Lamb waves are generated simultaneously as spurious signals owing to the structure of the PS. Particularly under resonant conditions, the C-Lamb waves are dominantly generated, distorting the axially propagating wave. In this method, these troublesome spurious signals are used effectively for the measurement of the wall thickness under the PS location that is a dead zone of the PS itself. The method can compensate for its drawback, namely, the dead zone problem, without using additional instruments. In this study, the mechanisms of the generation and resonance of the C-Lamb waves were first explained. Secondly, the principle of the wall thickness estimation utilizing the resonance of the C-Lamb waves was proposed. Finally, experimental verifications were carried out. The estimated wall thicknesses agreed very well (maximum 1.5% error) with those measured by a micrometer caliper under suitable resonant conditions.

Lymph Node Size Alone is Not an Accurate Predictor of Metastases in Rectal Cancer: A Node-for-Node Comparative Study of Specimens and Histology

Although size criteria have been proposed to identify lymph node metastases in patients with rectal cancer, size may not be an accurate predictor. Specimens from consecutive rectal cancer patients who underwent curative-intent radical surgery were examined. The long and short axes of lymph nodes were measured on the glass slides using micrometer calipers. The pathologic diagnosis was used as the reference. The diagnostic accuracy of metastatic status according to lymph node size was evaluated. Overall, 1283 lymph nodes from 78 patients were reviewed. The metastatic rate correlates with the length of both the long and short axes. However, metastases were present even in 1-mm lymph nodes, and the metastatic rate exceeds 5 per cent in lymph nodes measuring 3 mm along both axes. Cutoff values of ≥4 mm and ≥3 mm for the long and short axes result in a sensitivity of 76 per cent and 79 per cent, and a specificity of 36 per cent and 33 per cent, respectively, for each axis. Size criteria alone do not accurately predict the N-stage of rectal cancer. Diminutive lymph nodes, which are not seen on imaging studies, can contain metastatic disease.

Scleral cross-linking by riboflavin and blue light application in young rabbits: damage threshold and eye growth inhibition.

Scleral cross-linking (SXL) by riboflavin and light application has been introduced as a possible treatment to increase scleral tissue stiffness and to inhibit excessive axial elongation of highly myopic eyes. We evaluated an ocular tissue damage threshold for blue light irradiation, and used SXL treatment to induce eye growth inhibition. The sclera of 3-week-old rabbits (39 pigmented and 15 albino rabbits) were treated with different blue light intensities (450 ± 50 nm) and riboflavin. Alterations and a damage threshold were detected in ocular tissues by means of light microscopy and immunohistochemistry. The influence of SXL on the eye growth was examined in 21 young rabbits and was measured by using A-scan ultrasonography, micrometer caliper, and for selected eyes additionally by MR imaging. Light microscopic examinations demonstrated degenerative changes in ocular tissue after irradiation with blue light intensities above 400 mW/cm(2) (with and without riboflavin application). Therefore, that light intensity was defined as the damage threshold. Tissue alteration in retina, choroid, and sclera and activation of retinal microglia cells and Müller cells could be earlier observed at blue light intensities of 150 and 200 mW/cm(2). Albino rabbits were less sensitive to this SXL treatment. A significant reduction of the eye growth could be detected by SXL treatment with the minimal efficient blue light intensity of 15 mW/cm(2) and maintained stable for 24 weeks. SXL with riboflavin and blue light intensities below a defined damage threshold can induce a long lasting growth inhibitory effect on young rabbit eyes. Therefore, SXL might be a realistic approach to inhibit eye elongation in highly myopic eyes.

Dimedone Derivative {2-[(4-Hydroxy-phenylamino)- methylene]-5,5-dimethyl-cyclohexane-1,3-dione} Plays an Important Role in Breast Cancer Treatment

Purpose: To investigate the effect of 2-[(4-hydroxy-phenylamino)-methylene]-5,5-dimethyl-cyclohex (HPDH) on mammary carcinogenesis induced by 7,12-dimethylbenz(a)anthracene in female Sprague Dawley rats.Methods: Among three groups of rats (50 each) used in the study, the control group was fed standard diet alone, ibuprofen group received standard diet containing 1200 mg/kg ibuprofen while HPDH group was administered standard diet containing 1200 mg/kg HPDH. The treatment was for 10 days for all the groups. All the animals received 20 mg of DMBA intragastrically by gavage. Clinical parameters for the rats were recorded weekly. Micrometer caliper was used to measure the diameter of all the tumors at the end of the experiment and tumor volume calculated. Histological evaluation was performed using hematoxylin and eosin (H&E) staining. High performance liquid chromatography (HPLC) was used to determine the level of HPDH and ibuprofen in the serum of the animals.Results: The data revealed a significant decrease in the number of rats with mammary tumor, number of tumors/rat and tumor volume by 54, 72 and 75 %, respectively, in HPDH group compared to control group. The ibuprofen- treated rats also showed significant decrease in the number of rats with tumor, number of tumors/rat and tumor volume by 43, 55, and 59 %, respectively. Treatment of rats with HPDH increased the latency period of tumor induction significantly (p < 0.005). Median detection period (50 % of tumors) was 92, 83 and 56 days, respectively, in HPDH, ibuprofen and control groups, respectively, after DMBA induction.Conclusion: These results demonstrate that HPDH possesses strong chemopreventive activity against mammary carcinogenesis.Keywords: Carcinogenesis, Mammary tumor, Median detection period, Tumor, Latency period, Chemopreventive activity, Ibuprofen

Association of the nipple-areola complexes with age, parity, and breastfeeding in Korean premenopausal women.

There is no standard method of measuring the nipple-areola complex or defining the normal range and the changes seen in this complex. Numerous factors are involved in the anthropometric characteristics of the nipple-areola complex. The purpose of this study was to evaluate the anthropometric characteristics of the nipple-areola complex related to age, parity, and breastfeeding in 234 premenopausal Korean women (468 breasts). This cross-sectional study was conducted from May 2011 to June 2012. Five parameters of both nipple-areola complexes were measured in volunteers who were placed in a supine position. The diameters of the nipple-areola complex and the nipple projection were measured using micrometer calipers. The size of the nipple-areola complex increased according to age (P < .05). The measurements of the right nipple and the vertical diameter of the right areola were larger than those of the left sides in all age groups. There were no differences in the horizontal areola diameter and nipple projection between the 2 sides. The left horizontal areola diameter in breastfeeding parous women was larger than that in the non-breastfeeding parous women group (P = .011). The nipple projection was associated with the duration of breastfeeding (especially more than 12 months). The percentage of women with retracted nipples was 11.2%. Our study may be helpful in understanding nipple-areola complex changes related to age, parity, and breastfeeding. These results should be evaluated with larger study cohorts and more longitudinal studies to better understand factors related to changes of the nipple-areola complex.

Fully Automated Biometry of In Situ Intraocular Lenses Using Long Scan Depth Spectral-Domain Optical Coherence Tomography

Spectral-domain optical coherence tomography (SD-OCT) was used to automatically measure accommodative biometric changes in the anterior segment of eyes implanted with an intraocular lens (IOL). The repeatability and reliability of the automated measurements were also evaluated. Long scan depth SD-OCT was used to image the anterior segment of eyes implanted with IOLs. A fully automated algorithm was used to detect the boundaries of the cornea and IOL and yielded the measurements. The results included anterior segment dimensions in IOL eyes and the deflection of the IOLs. Automated measurements were validated in vitro and compared with the manual results in vivo on 15 cross-sectional images from patients with IOLs. Five eyes with five different types of IOLs, respectively, were enrolled to test the repeatability of the automated measurements during accommodation. Intraocular lens central thickness and anterior and posterior curvature radii measured by long scan depth SD-OCT in vitro and in a model eye matched well with those determined by a micrometer caliper and interferometer. In vivo, there was good correlation of the biometric data determined by automated and manual segmentations (P<0.05, r-value range: 0.635-0.997). There were no significant differences for any variable between the two measurements at each accommodative state (P>0.05). Anterior chamber depth and pupil diameter showed significant changes between the nonaccommodative and 2.5-D accommodative states (P<0.05), whereas the shape of the IOLs did not change significantly (P>0.05). The long scan depth SD-OCT with the automated algorithm was verified to have a great potential in studying accommodative biometric changes of the anterior segment in eyes with IOLs and IOL deflections.

Assessment of iatrogenic damage to proximal surfaces of adjacent teeth following crown preparation by final year dental students in Saudi Arabia

Aim: The purpose of the following study is to measure the amount and frequency of iatrogenic damage to inter-proximal surfaces of adjacent teeth, following crown preparation, among undergraduate dental students in Riyadh Colleges of Dentistry and Pharmacy. Materials and Methods: Teeth surfaces were examined on master casts, using ×2.5 magnifying loupes. The damage depth of the injured teeth was measured, with - a modified digital micrometer caliper (Whitworth's 6 inch Digital Caliper). To ensure that examined teeth surfaces were intact pre-operatively, they were confirmed with pretreatment radiographs. Results: A sample of 180 teeth surfaces chosen randomly was examined of which only 111 samples done by undergraduate students with intact teeth surfaces were included. The 69 excluded samples either had carious or restored teeth surfaces or were done by practitioners other than dental students. Over Nearly 98% of examined teeth surfaces, adjacent to crown prepared teeth, were proximally injured. Through using specific measuring parameters, the most frequent type of damage was abrasion (58.7%). The most commonly damaged area found was the middle-third of the proximal surface. The damage extended to more than 50% of the proximal surface, in 63% of the total sample. The depth of the injury was more than 0.1 mm in 58% of the total sample. Damage was more frequent in maxillary teeth (60.4%), than mandibular teeth (39.6%).Conclusion: Conventional crown preparation methods appear to result in significant damage to adjacent teeth surfaces; increasing caries risk potential, thermal sensitivity and periodontal disease. Therefore, protection of these surfaces and selection of the most appropriate instruments and preparation techniques are important.

Phase retrieval in lens-based Fresnel wave propagation model

The goal of phase retrieval is to extract the phase of an optical wave field from intensity measurements. The transport-of-intensity equation (TIE)-based method is a popular deterministic solution and has been applied in various fields such as optical microscopy, electron microscopy, and x-ray imaging. For macro-imaging, a camera is often used to capture the images, and thus the phase modulation of the lens should be considered. A new formulation is proposed to extend TIE for phase retrieval in a lens-based wave propagation model. To obtain the defocus step, a data-collection-reading device is designed by equipping a camera with a micrometer caliper. Simulation and real experiments are conducted to test the proposed method.

Design and analysis of a head-mounted parallel kinematic device for skull surgery

Precision skull surgery requires specialized instrumentation to satisfy demanding requirements in cochlear array implantation, deep brain stimulation electrode placement, and related applications. A miniaturized reconfigurable parallel kinematic mechanism which can be directly mounted on a patient's skull was designed, built, and tested for precision skull surgery. A Stewart-Gough platform is attached to a patient's skull so no optical tracking affecting the overall accuracy in keyhole surgery is required. Six bone anchors comprising the mechanism base joints are implanted at positions with sufficient skull thickness. Since no fixation frame is required, intervention planning flexibility is increased. The centers of the spherical shaped bone anchors can be localized accurately in the image space. An implicit registration to the physical space is performed by assembling the kinematics. Registration error is minimized compared to common optical tracker-based approaches. Due to the reconfigurable mechanism, an optimization of the hexapod's configuration is needed to maximize accuracy and mechanical stability during the incision. Mathematical simulation was conducted to estimate system performance. Simulation results revealed significant improvement in accuracy and stability when exploiting the redundant degrees of freedom and the implemented reconfigurability. Inaccurate localization of base points in the image data set was identified as the main source of error. A first prototype with passive prismatic actuators, i.e. micrometer calipers, was successfully built. A head-mounted parallel kinematic device for high precision skull surgery was developed that provides submillimetric accuracy in straight-line incisions. The system offers enhanced flexibility due to the absence of a rigid fixation frame.

Analysis and test of modified turn-buckles for measuring tensile force

A turn-buckle inserted between tension members is a device capable of adjusting tensile force. However, the measurement of tensile force is practically difficult, and tensile force is roughly estimated by the experience of field workers. The conventional turn-buckle may be used without any adjustment even though the tensile force has changed with time. Thus, a new measurable turn-buckle was developed to deal with the disadvantages of conventional turn-buckles in this study. The straight elements of a conventional turn-buckle were slightly bent in advance to induce lateral displacement. The change of gap between curved elements due to applied load is measured with a micrometer or vernier calipers in the field construction site. The measured displacement of the gap is then converted to the load of the tension member. A theoretical analysis and FEA were performed to investigate the applicability of the measurable turn-buckle developed in this study. The results of loading and unloading tests showed acceptable linearity and precision of the new turn-buckle for the field application. Additionally, two measurable turn-buckles with different measuring capacity were installed for six-month long-term measurements. The results of this test indicated that the recovery of measuring performance of the measurable turn-buckles was acceptable for long-term usage.

Measurement of Skull Bone Thickness for Bone-Anchored Hearing Aids

A-mode ultrasound scanning with coded signals allows bone thickness measurements at the site of bone-anchored hearing aid surgery as compared to computed tomographic scanning and mechanical measurements. Adequate bone thickness is a prerequisite for successful, long-lasting osseointegration of titanium fixtures for bone-anchored hearing aids. Computed tomography can be used to measure bone thickness but has several drawbacks. Bone thickness was measured at the site of bone-anchored hearing aids surgery in 28 formaldehyde-preserved human cadaver temporoparietal bones. Four blinded investigators used a hand-held, A-mode ultrasound system with direct coupling at 2.25 MHz transducer using coded signals (SonoPointer) and repeated the measurements twice. Comparisons were made with high-resolution computed tomographic scanning and mechanical micrometer caliper measurements. There was significant anatomical variation in the temporoparietal bones. Computed tomography was in good agreement with the mechanical reference. All specimens could be measured by the SonoPointer. The mean difference between the mechanical control and ultrasound scanning averaged for all measurements by all investigators was 0.3 mm (standard deviation, 1.2 mm). Trained ultrasound experts yielded better results (mean difference, 0.3 mm; standard deviation, 1.0 mm). Agreement was best for bone thickness up to 5 mm. Outliers occurred in bones thicker than 7.5 mm. The SonoPointer is a promising, noninvasive, hand-held tool for real-time measurement of bone thickness in bone-anchored hearing aid surgery, especially for children. Even disregarding the absolute thickness reading, the SonoPointer could be used to search intraoperatively for a local maximum of bone thickness.

Extraction of geometrical information for fiber pull-out using 3D image processing

A method to measure the deformation and fracture of fibers on the fracture surfaces of fiber reinforced composite (FRC) is developed by reconstructing a 3-D image from a stereograph. The method proposed in this article integrates image processing techniques of thresholding, vectorization, matching, and 3-D analysis. The accuracy of the measured result obtained by this method is evaluated by the comparison between the calculated fiber length and the real length, calculated with the help of a micrometer caliper. From the comparison, it is confirmed that the fiber length is calculated with high accuracy, if the occlusion problem does not occur.

Morphologic Study of Nipple-Areola Complex in 600 Breasts

To investigate the morphologic characteristics of the nipple-areola complex, the diameter of the nipple-areola complex and the height of the nipple in 300 adult women (600 breasts) were measured using micrometer calipers. Furthermore, the morphologic characteristics were classified into four types by visual observation. Mean diameter of the areola was 4.0 cm, mean diameter of the nipple was 1.3 cm, and mean height of the nipple was 0.9 cm. From the morphologic point of view, the elevated plateau type without constriction (IIs) was most commonly found, being present in 60.2% of breasts. Inverted nipples (III) were found in 3.5% and unclassified type (IV) such as multiple or divided nipples was found in 0.3%. Because women have become sensitive about the appearance of their breasts and there is increasing cosmetic interest following surgery for breast carcinoma, operations on the nipple-areola complex are now common. When a surgeon counsels a patient and designs a reconstruction method prior to operation, these data may be helpful.

Ultraviolet B Suppresses Immunity by Inhibiting Effector and Memory T Cells

Contact hypersensitivity is a T-cell-mediated response to a hapten. Exposing C57BL/6 mice to UV B radiation systemically suppresses both primary and secondary contact hypersensitivity responses. The effects of UVB on in vivo T-cell responses during UVB-induced immunosuppression are unknown. We show here that UVB exposure, before contact sensitization, inhibits the expansion of effector CD4+ and CD8+ T cells in skin-draining lymph nodes and reduces the number of CD4+ and IFN-gamma+ CD8+ T cells infiltrating challenged ear skin. In the absence of UVB, at 10 weeks after initial hapten exposure, the ear skin of sensitized mice was infiltrated by dermal effector memory CD8+ T cells at the site of challenge. However, if mice were previously exposed to UVB, this cell population was absent, suggesting an impaired development of peripheral memory T cells. This finding occurred in the absence of UVB-induced regulatory CD4+ T cells and did not involve prostaglandin E2, suggesting that the importance of these two factors in mediating or initiating UVB-induced immunosuppression is dependent on UVB dose. Together these data indicate that in vivo T-cell responses are prone to immunoregulation by UVB, including a novel effect on both the activated T-cell pool size and the development of memory T cells in peripheral compartments.

Comparison of the Physical Properties of Dental Restorative Materials Used in Endodontics

There is little information concerning the physical properties of various commercialized water-based temporary filling materials. In this study, the setting characteristics of 5 water-based temporary filling cements, i.e., Caviton, HY-seal, Lumicon, Cavit-G, and Cavit-W, were examined. Reinforced plastic pipes were filled with the test materials, and the specimens were then immersed in distilled water at 37°C. Setting time of each specimen was determined by a penetration test using a Vicat penetrometer; and setting layer depth was measured with micrometer calipers. Cavit-W exhibited the fastest setting time, whereas Caviton and HY-seal demonstrated the slowest setting time. These results indicate that the setting properties of these materials used in this study were significantly different for each material, which showed some changes on the surface and the internal part after the start of water absorption.

Enhanced micrometer caliper for analysis of plaster dental models

Enhanced micrometer caliper for analysis of plaster dental models