Digital Planimeter Research Articles

Non-destructively Determining Blueberry (Vaccinium corymbosum L.) Leaf Area Using DPI-Based Software

Blueberries (Vaccinium spp.) are a popular crop all throughout the world. Blueberry (Vaccinium corymbosum L.) leaves were randomly selected from the experimental area of Ondokuz Mayis University, Faculty of Agriculture as a research material. Blueberries are high in polyphenolic chemicals, particularly anthocyanins, which are antioxidants and anti-inflammatory. A total of 1500 leaves were collected, with 100 for each cultivar, to represent the variety of sizes found on 15 plants of each cultivar. Manual leaf area measurement was made with a digital planimeter. The area was measured using a 300dpi resolution image read from the relevant file in such a way that every one of them is defined by 8bits in RGB color space. A weighted sum of the RGB components of the image is used to convert RGB values to grayscale values. This three-dimensional gray image generates a binary image. The Otsu method was used to determine the threshold value required to minimize the in-class variation of the threshold black and white pixels. Simulink was used for easy use of the end-user with the developed software. This software can be used for the area measurement of all plant leaves.

Acoustic pharyngometry vs lateral cephalometry: A comparative evaluation of pharyngeal airway dimensions in patients with skeletal class I and skeletal class II malocclusion

PurposeThe objective of this study was to study the difference in upper airway parameters using two different techniques, i.e. with lateral cephalometry vis-a-vis acoustic pharyngometry in skeletal class I and class II subjects and to find any correlation in airway parameters recorded on cephalogram and acoustic pharyngometer. Materials and methodsSixty orthodontic patients with average growth pattern (FMA=22–28°) were divided in to two groups based on sagittal jaw relationship. Pharyngeal airway dimensions were measured by two different techniques, i.e. on lateral cephalogram and acoustic Pharyngometry. The airway dimensions were compared across both the groups using these techniques. ResultsThe linear airway parameters and total oropharyngeal area measured on lateral cephalogram (P-value 0.008) were significantly higher in skeletal class I patients. Total oropharyngeal area measured using acoustic pharyngometry was significantly higher in skeletal class I patients (P=0.009). The average area on lateral cephalogram and on acoustic pharyngometry did not differ significantly in skeletal class I group (P=0.590). The comparison of average area in skeletal class II malocclusion group on lateral cephalogram and acoustic pharyngometry also did not differ significantly (P=0.603). The average area on lateral cephalogram obtained by digital planimeter and acoustic pharyngometry did not differ significantly in both the classes of malocclusion (P=0.405). ConclusionThe null hypothesis is rejected as there is significant difference in airway dimensions in skeletal class I and class II subjects and there is a positive correlation in airway parameters as recorded on lateral cephalogram and acoustic pharyngometer.

Point-of-care wound visioning technology: Reproducibility and accuracy of a wound measurement app.

BackgroundCurrent wound assessment practices are lacking on several measures. For example, the most common method for measuring wound size is using a ruler, which has been demonstrated to be crude and inaccurate. An increase in periwound temperature is a classic sign of infection but skin temperature is not always measured during wound assessments. To address this, we have developed a smartphone application that enables non-contact wound surface area and temperature measurements. Here we evaluate the inter-rater reliability and accuracy of this novel point-of-care wound assessment tool.Methods and findingsThe wounds of 87 patients were measured using the Swift Wound app and a ruler. The skin surface temperature of 37 patients was also measured using an infrared FLIR™ camera integrated with the Swift Wound app and using the clinically accepted reference thermometer Exergen DermaTemp 1001. Accuracy measurements were determined by assessing differences in surface area measurements of 15 plastic wounds between a digital planimeter of known accuracy and the Swift Wound app. To evaluate the impact of training on the reproducibility of the Swift Wound app measurements, three novice raters with no wound care training, measured the length, width and area of 12 plastic model wounds using the app. High inter-rater reliabilities (ICC = 0.97–1.00) and high accuracies were obtained using the Swift Wound app across raters of different levels of training in wound care. The ruler method also yielded reliable wound measurements (ICC = 0.92–0.97), albeit lower than that of the Swift Wound app. Furthermore, there was no statistical difference between the temperature differences measured using the infrared camera and the clinically tested reference thermometer.ConclusionsThe Swift Wound app provides highly reliable and accurate wound measurements. The FLIR™ infrared camera integrated into the Swift Wound app provides skin temperature readings equivalent to the clinically tested reference thermometer. Thus, the Swift Wound app has the advantage of being a non-contact, easy-to-use wound measurement tool that allows clinicians to image, measure, and track wound size and temperature from one visit to the next. In addition, this tool may also be used by patients and their caregivers for home monitoring.

Normative size of the osseous part of calcaneal bursa and its comparison with other calcaneal articular areas

The retro-calcaneal bursa presents a synovial and a non-synovial osseous part of variable dimensions. Studies objectively measuring the variability of the size of this osseous bursal surface cannot be found in literature. The objective of this study was to investigate (i) the dimension variability of the bony part of the bursa and (ii) the relationship of this surface to other articulating areas of the calcaneus. A digital planimeter was used to measure the bursae (n=86) and other articular surface areas of the calcaneus and statistically compared with ANOVA and correlation estimations. The osseous area measured 1.12 (±0.55) cm2, with only the superior articulating area demonstrating a weak correlation to this osseous surface.The osseous area presents a weak correlation with the axial articulating area of the calcaneus. Information on the size of the bony bursa may help safe excision of retrocalcaneal exostoses and in Achille’s tendon repair around the posterior tuberosity.

Quality Differences in Fresh Domestic, Frozen Domestic, and Frozen Imported Goat Meat

ObjectivesImported goat meat, mostly frozen and from Australia, comprises more than 50% of the goat meat sold in the U.S. The objective of this research was to determine differences in color, water holding capacity (WHC), and yields of leg primal cuts from fresh domestic, frozen domestic, and frozen imported goat leg groups.Materials and MethodsFrozen whole goat carcasses (n = 15) were purchased from a commercial vendor and maintained at 33°C. Kid goats (n = 20) purchased from local domestic sources were slaughtered under state meat inspection and chilled overnight at 4°C. Carcasses were evaluated and selected (n = 15) based on uniformity and split into cold sides. Right sides were wrapped in multiple layers of 0.6 mil polyvinyl chloride film before freezing at -33°C for 5 d. Frozen imported carcasses and domestic sides were thawed at 4°C for 3 d. The left sides of domestic carcasses were used for fresh domestic samples. Rear legs were removed by straight cuts immediately anterior to the femur-pelvic joint and at the stifle joint (USDA AMS Institutional Meat Purchase Specifications for Fresh Goat Series 11) before vacuum packaging and overnight storage at 4°C. After storing overnight at 4°C, legs were removed from packaging and weighed. A 10 to 20-g sample was taken from the surface of the Semimembranosus for WHC (Carver press filter paper technique, 20.7 MPa, 3 min, WHC = exudate area/meat area measured with digital planimeter). Excess fat and connective tissue were trimmed from each leg to make a retail leg cut. After 5 min, color (L*, a*, b*) was measured with a Konica Minolta reflectance colorimeter and hue angle and chroma were calculated. The 15 legs of each group were divided into 3 batch replications of 5 legs each for cooking to 70°C in a smokehouse with 70% humidity. Data was analyzed with SAS 9.4 Proc GLM (SAS Inst. Inc., Cary, NC) for comparison of batch replications and group means using the Tukey function with significance determined at P < 0.05. Paired t tests were conducted for fresh domestic and frozen domestic leg parameters.ResultsBatch within group did not influence (P > 0.35) any parameter. Tukey mean comparison showed no differences (P < 0.08) in cook yield (84.63%), but lower (P < 0.01) drip losses (1.31%) and higher (P < 0.05) WHC (2.13) in frozen imported legs than frozen domestic legs (85.98%, 0.91%, 2.43) or fresh domestic legs (84.98%, 0.37%, 2.44). There were no differences (P > 0.05) in properties between the fresh and frozen domestic legs with Tukey comparisons. The color values (L*, a*, b*, chroma, and hue angle) were lower (P < 0.01) in frozen imported legs (29.92, 12.47, 6.35, 14.00, 0.51) than in frozen domestic legs (34.99, 17.12, 10.14, 20.03, 0.60) and fresh domestic legs (39.24, 19.07, 11.86, 22.47, 0.62). However, when comparing the fresh and frozen domestic legs using paired t tests, the frozen domestic legs had higher (P < 0.01) drip and (P < 0.04) cook losses and lower (P < 0.01) color values than the fresh domestic legs.ConclusionFreezing and thawing of goat legs increased drip and cook losses and decreased color values compared with fresh domestic goat meat. Imported frozen and thawed goat meat had higher drip losses and lower color values than frozen and thawed imported or domestic goat meat.

The effect of 630 nm light emitting diode (LED) irradiation on dermal wound healing

Background: Recently, light emitting diode (LED) array devices are commercially introduced as an alternative for low level laser therapy for wound healing. Purpose: To determined the effects of 630 nm LED array irradiation on full-thickness wound healing. Methods: Twelve male Sprague-Dawley rats (230–250 g) were randomly divided into LED (n= 6) and control group (n= 6). Two 19.63mm2 circular full-thickness dermal wounds including the panniculus carnosus were created on both side of the back. The LED group received a 630 nmLED array irradiationwith 3.6mW/cm2 for 30minutes (6.6 J/cm2) for 7 days, while the control group received sham LED irradiation. Wound surface area was measured using digital planimeter. Epithelial gap and fibroblast number were measured on hematoxylin–eosin staining, collagen density was measured onMasson trichrome staining and proliferating cell nuclear antigen (PCNA) positive cell number was measured on immunohistochemical staining using image analysis system. An independent t-test was conducted to compare the difference between the LED and the control groups. Results: The wound closure rate, epithelial gap, PCNA positive cell number, fibroblast number and collagen density has shown no significant difference between the LED and the control group at day 3 after the treatment. At day 7 after the treatment, the wound closure rate in the LED group was increased when compared with control group (p< 0.05). The epithelial gap in theLEDgroupwas significantly shorten than the control group at day 7 (p< 0.01), The PCNA positive cell number in the LEDgroupwas higher than the control group at day 7 (p< 0.01), The fibroblast number and the collagen density were increased (p< 0.05) when compared with control group at day 7. Conclusion(s): 630 nm LED appeared to enhance dermal wound healing by accelerated keratinocyte proliferation in the epidermis and collagen deposition in the dermis during the proliferative stage of wound healing. Implications: These findings suggest that LED light might be use for wound management as an inexpensive phototherapy modality.

The Effects of Tooth Extraction and Nonextraction on the Soft Tissue Profile in Patients With Class II Division 2 Malocclusion

ABSTRACT Objective: To determine and compare change in the position and area of the upper and lower lips in patients with Class II division 2 malocclusion treated with and without tooth extraction. Materials and Method: This retrospective study included 40 female adolescent patients with Class II division 2 malocclusion who were divided into an extraction treatment group (group E, n=20) and a nonextraction treatment group (group NE, n=20). Pretreatment (T1) and posttreatment (T2) cephalometric variables, and upper-lower lip area (via digital planimeter) were measured on lateral cephalometric radiographs. For soft tissue profile area measurement the upper lip was divided into 2 parts (area 1 and 2), and the lower lip was divided into 3 parts (area 3, 4, and 5). The paired t test was used to determine intragroup differences, and the Student t test was used to determine intergroup differences. Results: Mean age in group E was 15.8 years vs 15.4 years in group NE. A wide range of individual responses to the t...

The Effects of Different Irrigation Programmes in Drip Irrigation on Leaf Properties of Starkrimson Delicious Apple Variety

This study aimed to determine the effects of differ ent irrigation programmes in drip irrigation on leaf properties. The experiment was c arried out at the E girdir Horticultural Research Institute (37°49'17.97N, 30°52'22.44E) in Isparta , Turkey in 2008. Starkrimson Delicious apple variety grafted on the seedling rootstock and drip irrigation method were used in this study. Drip irrigation treatments consisted of eight treatments (two irrigation intervals, 4 and 7 days; four pan coefficients, K cp1 : 0.50; Kcp2 : 0.75; Kcp3 : 1.00; Kcp4 :1.25). The samples were taken from under the leaves and stomata numbers were determined by ocular micrometer to measure stomata densities. The stomata were hypostomatic in apple leaves. Leaf are a values were measured by digital planimeter. The stomata density and leaf area varied from 153 to 21 3 stomata/mm 2 and from 27.83 cm 2 to 36.88 cm 2 , respectively. Leaf area had higher values in 4 days irrigation intervals than 7 days irrigation interv als. The stomata densities of 4 days irrigation interval s were higher than 7 days irrigation intervals exce pt Kcp 4 treatments. It was obtained that the effects of di fferent irrigation programmes in drip irrigation on stomata densities and leaf areas were effected s ignificantly.

The Application of FPGA-Based High Precision Photoeletric Encoder System in Digital Planimeter

The Application of FPGA-Based High Precision Photoeletric Encoder System in Digital Planimeter

Short communication.Validation of a leaf area estimation model for sweet cherry

A leaf area (LA) estimation model developed in a temperate climate for sweet cherry (Prunus avium L.) was tested for validation on 'Regina' trees on two rootstocks of varying vigor, 'Gisela 5' (Gi5) and 'Gisela 6' (Gi6), in a cool temperate climate (the Great Lakes region of North America). To determine the degree of accuracy of the model, actual LA values measured by digital planimeter were plotted against predicted LAs calculated by the model. The relationships (r2 values) were very high and varied little between rootstocks (r2 = 0.9886 for Regina/Gi6 and r2 = 0.9849 for Regina/Gi5). This study demonstrates that the model is valid for use by cherry researchers in different growing regions and for rootstocks that impart different levels of vigor scion, such as 'Regina'.

CT findings of post-pneumonectomy patients

CT findings following pneumonectomy were studied in 28 cases with lung cancer. A total of 53 CT images were evaluated in 13 right pneumonectomy cases and 15 left pneumonectomy patients. The postpneumonectomy pleural space (PS), thoracic space of the operated site (TS) and the thoracic space of the non-operated site (CTS) were measured at 3 slice levels of the brachiocephalic level, subcarinal level and lower pulmonary vein level, using a digital planimeter. There was no significant difference in the TS/CTS ratio, between the right pneumonectomy group and the left pneumonectomy group, but the PS/TS ratio in the left pneumonectomy group was smaller than that in the right pneumonectomy group (p less than 0.01). The PS/TS ratio in both groups and the TS/CTS ratio in the right pneumonectomy group were decreased with time. In the left pneumonectomy group, the TS/CTS ratio was greater in the median sternotomy group that of the posterolateral thoracotomy group (p less than 0.01). Residual pleural effusion was accompanied with a thin circulating lesion along the outer surface. This lesion had been reported as thickening of the parietal pleura, but it could be detected in the case of panpleuropneumonectomized state. Additionally, in some cases, the parietal pleural imaging could be separated from the circulating lesion. So, this structure was thought to be mainly composed of organized effusion. CT images could detect some parts of the episodes in post operated thorax, because of the lack of the information with the sagittal direction. However, the recognition of the common changes and images on CT after the operation might be helpful for the follow-up of the patients.

Storage adaptations among hunter–gatherers: A quantitative approach to the Jomon period

Food storage economies among hunter–gatherers have been fundamentally important in research within anthropological archeology. It is well recognized that food storage was a key element in the evolution of hunter–gatherer societies. This paper examines storage facilities utilizing a digital planimeter to evaluate the volume and morphology of storage pits in the Jomon period (ca. 13,750–500 cal. BC). Quantitative analysis of Jomon storage pits shows temporal and spatial variability in terms of size. This research demonstrates that the quantitative analysis of storage pits is an effective way to improve our understanding of storage and its role in the Jomon economy in particular and subsistence adaptations in general. Thus, this approach has potential applications to other storage economies worldwide.

Leaf area estimation in some species of fruit tree by using models as a non-destructive method

Introduction. Leaf area measurements are used commonly in the study of growth and development of fruit trees. These measurements can be made destructively by using a variety of sen- sitive instruments and/or non-destructively by using models of leaf area estimation. For models of leaf area estimation, some leaf parameters such as the length and width of leaves are usually used in the measurements. Construction of a model of leaf area estimation. Computer programs such as Excel, SAS and SPSS may be used in this process. In brief, after a leaf has been placed on a sheet of paper and photocopied, a digital planimeter or suitable tool may be used to measure the actual leaf area. The leaf width (W) and length (L) of the leaves sampled can be measured by a simple ruler. After this, regression analysis of the data may be performed separately for each genotype, species or cultivar. The analysis can be conducted with various subsets of the independent variables; for ins- tance, leaf length (L), leaf width (W), L 2 , W 2 and (L 2 /W 2 ) to develop the best model for predicting leaf area. Regression analyses should be carried out until the deviation sum of squares is minimized. Models of leaf area estimation for specific crops. In our study, prediction models of leaf area were developed by referring to the relevant current literature that studied such fruits as avocado, banana, blackberry, cacao, cherry, chestnut, grape, guava, kiwifruit, lotus plum, peach, pistachio, rabbiteye blueberry, red currant, red raspberry, sour orange, strawberry, pecan and white mulberry. Advan- tages and disadvantage of the models of leaf area estimation. Some advantages and a disad- vantage of models of leaf area estimation are presented. Conclusion. Our mini-review has shown that the models which have been formulated and which will develop in the future for some fruit spe- cies can be reliably used. Turkey / fruit-growing / models / forecasting / leaf area / methods / measurement / evaluation

Estimation of leaf area in selectedHypericumspecies

The genus Hypericum has attracted scientific interest for recent years, since it is a source of a variety of compounds including hypericin. The present study was conducted out to develop leaf area prediction models for some Hypericum species containing hypericin, namely H. pruinatum, H. perfoliatum, H. aviculariifolium subsp. depilatum var. depilatum (endemic), H. montanum, H. montbretii, H. linarioides, H. triquetrifolium, H. bithynicum and H. perforatum growing wild in Northern Turkey. Lamina width, length and leaf area were measured without destroying to develop the models. The actual leaf areas of the plants were measured by Placom digital planimeter, and multiple regression analysis with Excel 7.0 computer package program was performed for the plants separately. The produced leaf area prediction models in the present study were formulised as LA = (a) + (b 1 × L) + [b 2 × (L × W)] + (b 3 × L 2 ) + (b 4 × W 2 ) + [b 5 × (L × W 2 ] + [b 6 × (L 2 × W)] + [b 7 × (L 2 + W 2 )] where LA is leaf area, Wis le...

Photovoltaic Leaf Area Meter Development and Testing

Photovoltaic (PV) panel was used to develop a simple and practical leaf area meter. Components of the developed PV leaf area meter include a PV panel as sensor, a wooden cabinet as enclosure, a flashlight as light source, and a commercial digital multimeter for voltage measurement. The principle of projected area measurement is the voltage generated by the PV panel varies directly with sample area, when corresponding panel surface is exposed to incident radiation. The PV leaf area meter performance was evaluated using cardboard cutouts of various geometrical shapes of known areas and the voltage generated had good correlation (r = 0.9911) with sample areas. Linear fits adequately modeled the areas from non-dimensional voltages (R2 > 0.98). Leaf samples from mango, sapodilla, guava, custard apple, and cotton covering a wide array of natural shapes were tested and compared among the existing graphical, scanner-based electronic leaf area meter, and digital planimeter methods. Digital planimeter produced better performance (R2 = 0.9996) than scanner-based electronic leaf area meter (R2 = 0.9979), followed by the PV leaf area meter linear regression calibration equations based on direct leaf samples (R2 = 0.9953) and leaf samples with glass cover (R2 = 0.9834). However, on testing with additional leaf samples, the glass cover method gave better predictions than direct leaf method. As leaf was flattened by the glass cover and represented the true projected leaf area, this method was recommended. PV leaf area meter costs only 3.9% of scanner-based electronic leaf area meter and 14.7% of digital planimeter. The developed PV leaf area meter had a mode of operation similar to a commercial electronic leaf area meter, yielded quick and reliable results, and was highly cost effective.

Relation between leaf area and dimensions of selected medicinal plants

In this research, leaf area prediction models were developed for some leaf-used medicinal plants namely Calamintha nepeta, Datura stromonium, Melissa officinalis, Mentha piperita, Nerium oleander, Origanum onites and Urtica dioica growing wild in Black Sea region of Turkey. Lamina width, length and leaf area were measured non-destructively to develop the models. The actual leaf areas of the plants were measured by PLACOM Digital Planimeter, and multiple regression analysis with Excel 7.0 computer package program was performed for the plants separately. The produced leaf area prediction models in the present study were formulized as LA = (a) + (b&lt;sub&gt;1&lt;/sub&gt; &amp;times; L) + [(b&lt;sub&gt;2&lt;/sub&gt; &amp;times; (L &amp;times; W)]&amp;nbsp; + (b&lt;sub&gt;3&lt;/sub&gt; &amp;times; L&lt;sup&gt;2&lt;/sup&gt;) + (b&lt;sub&gt;4&lt;/sub&gt; &amp;times; W&lt;sup&gt;2&lt;/sup&gt;) + [b&lt;sub&gt;5&lt;/sub&gt; &amp;times; (L &amp;times; W&lt;sup&gt;2&lt;/sup&gt;)] + [b&lt;sub&gt;6&lt;/sub&gt; &amp;times; (L&lt;sup&gt;2&lt;/sup&gt; &amp;times; W)] + [b&lt;sub&gt;7&lt;/sub&gt; &amp;times; (L&lt;sup&gt;2&lt;/sup&gt; &amp;times; W&lt;sup&gt;2&lt;/sup&gt;)] where LA&amp;nbsp;is leaf area, W&amp;nbsp;is leaf width, L is leaf length and a, b&lt;sub&gt;1&lt;/sub&gt;, b&lt;sub&gt;2&lt;/sub&gt;, b&lt;sub&gt;3&lt;/sub&gt;, b&lt;sub&gt;4&lt;/sub&gt;, b&lt;sub&gt;5&lt;/sub&gt;, b&lt;sub&gt;6&lt;/sub&gt;, and b&lt;sub&gt;7&lt;/sub&gt; are coefficients. R&lt;sup&gt;2&lt;/sup&gt; values for medicinal plants tested varied with species from 0.82 in Origanum onites to 0.98 in Urtica dioica. All R&amp;sup2; values and standard errors were found to be significant at the P &amp;lt; 0.001 level.

A cephalometric evaluation of lower lip in patients with unilateral cleft lip and palate.

The aim of this study was to evaluate cephalometrically the lower lip position and area of patients with unilateral cleft lip and palate (UCLP) comparatively with Class I skeletodental normal subjects. Lateral cephalometric and hand-wrist radiographs obtained from 24 patients with UCLP (mean age 12.86 years), along with 20 normal individuals (mean age 12.33 years) used as a control group, were examined. In addition to standard cephalometric dentofacial variables, lower lip area (superior, middle, inferior) was also measured using a digital planimeter on the lateral cephalograms. The superior and middle part of the lower lip areas were significantly smaller (p < .05) in the UCLP group, compared to the control group. The inferior and total lower lip areas of patients with UCLP were found to be significantly smaller than controls. The labiomental angle was also smaller (38.79 degrees). The results suggest that the lower lip of patients with UCLP is smaller, retruded, and curved, with a deep labiomental sulcus, compared with normal individuals during puberty. Therefore, practitioners should focus not only on the upper lip of patients with UCLP but also should consider the lower lip as it was found distinct from normal individuals during puberty.

Comparative study of methods for the quantification of biofilm on complete dentures

This study compared the application and reliability of 4 methods for biofilm quantification (computerized, paper-weighing, point-counting, and planimetric) in complete dentures, verifying the correlation between them. The internal surfaces of 62 complete dentures were stained (5% erythrosine) and photographed. The slides were projected on paper, and the areas (total and biofilm-covered) were outlined with a pencil. These areas were measured with an equidistant point grid (point-counting method), a digital planimeter (planimetric method), and for the paper weighing method they were cut and weighed with a precision scale. For the computerized method, ImageTool software was used. In order to perform a validation test of the methods, all of them were applied to slide projections of geometric figures with known dimensions. The correlation tests showed high correlation values (r = 0.82 to 0.99) among the methods. The validation test (ANOVA) showed no statistically significant differences among the values obtained from the measurement of figures using all four quantitative methods and the real dimensions of these geometric figures. Quantitative methods were efficient and reliable for measuring quantity of biofilm in complete dentures, and may be useful in experimental studies on the efficacy of hygiene products. The computerized method was fast and easy to perform.

The glucose area under the profiles obtained with continuous glucose monitoring system relationships with HbA(lc) in pediatric type 1 diabetic patients.

The purpose of this study was to determine whether the continuous glucose monitoring system (CGMS) (MiniMed, Sylmar, CA) 1) is sufficiently representative of the overall metabolic control as assessed by HbA(1c), 2) could be used to identify a particular blood glucose threshold value affecting hemoglobin glycation; and 3) is able to show any relationship between particular glycemic profiles and HbA(1c) levels. Of 44 pediatric patients with type 1 diabetes who wore CGMS devices, 28 subjects were selected for the study. Criteria for inclusion were high levels of HbA(1c) (> or =8%) for more than 1 year or a history of frequent hypoglycemic episodes and a complete CGMS registration for 72 h. Age of the subjects ranged from 5.7 to 24.8 years, the mean duration of disease was 7.63 +/- 4.75 years, and the mean HbA(1c) value was 8.7 +/- 1.3%. CGMS data were downloaded and glucose profiles were analyzed. The area under each glucose profile was calculated by means of a professional digital planimeter. The glucose profiles showed a high frequency of prolonged hyperglycemic periods (80% of subjects) and a low frequency of postmeal glycemic peaks (29% of subjects). Postlunch values were significantly correlated with HbA(1c) levels, but the correlation disappeared when controlling for glucose area values. Glucose area values significantly correlated with HbA(1c) levels both when considered as a whole (40-400 mg/dl; r = 0.53, P = 0.002) and when considered fractioned (40-150, 40-200, 40-250, 40-300 mg/dl), apart from the 40-90 mg/dl partial area. HbA(1c) levels were significantly decreased 3 and 6 months after use of CGMS (P = 0.05 and 0.03, respectively, paired Student's t test). HbA(1c) levels may be decreased by using the information obtained with the CGMS. Three-day glucose profiles are representative of the overall glucose control, because glucose area values correlate with HbA(1c) levels. The only glucose threshold below which there seems to be no correlation with HbA(1c) is 90 mg/dl. Only glucose area, and not postprandial glucose values, are directly and independently correlated with HbA(1c). Therefore, to improve metabolic control, it is necessary to lower the whole mean 24-h glycemia and not just the postprandial glucose values.

Evaluation of porosity in microwave-processed acrylic resin using a photographic method

Statement of Problem. The effect of microwave polymerization on the porosity of denture base resin has not been fully determined. Purpose. This study investigated the effect of microwave energy on the porosity of 2 heat-activated denture base resins. Material and Methods. Two heat-activated denture base resins, one conventional (Paladon 65) and one designed for microwave polymerization (Acron MC), were used to prepare 50 test specimens. Five groups of 10 specimens each were established: Group A (Paladon 65, water bath); Group B1 (Paladon 65, short microwave cycle); Group B2 (Paladon 65, long microwave cycle); Group C1 (Acron MC, short microwave cycle); and Group C2 (Acron MC, long microwave cycle). Half of the specimens in each group were 3 mm thick, the other half 6 mm thick. After being polymerized, specimens were cut so that 3 cross-sectional areas were formed (S1, S2, and S3). These surfaces were polished and photographed under a microscope at ×100 magnification. On the developed photographs, the area of each pore was measured with a digital planimeter, and the total area of pores per surface was calculated in percentage form. The total number of pores on each surface and the topographical distribution of the pores also were recorded. A 3-factor repeated-measures analysis of variance was used to compare porosity data, and a 1-way analysis of variance was performed to determine possible interactions between groups based on material and specimen thickness (P<.05). The effect of surface area on porosity data was analyzed with the use of contrasts. Results. Group A specimens exhibited no pores. In the thicker specimens of Groups B1 and B2, giant pores (area as great as 3.69 mm2) and small, gaseous pores of almost uniform shape and size were found. In Groups C1 and C2, only the smaller pores were found; these were not clinically significant. Of the observed surfaces, 75.3% were free of pores and 24.7% contained at least one pore. In a selected group of pore-bearing surfaces, the majority (81%) had pores located near the center. The thicker specimens in Group B exhibited the greatest amount of porosity (P<.0001); Group C specimens exhibited the least porosity. Repeated-measures analysis of variance showed that polymerization cycle had no effect on porosity (P=.19). The 3 other factors (material, specimen thickness, and surface) and all possible interactions among them were significant (P<.05). Among the surfaces, S1 and S2 exhibited the highest total mean value of porosity (0.71% and 0.74%, respectively) and S3 the lowest (0.025%). S3 showed a different pattern of porosity than S1 and S2. Conclusion. Within the limitations of this in vitro study, minor porosity was identified in thin and more severe porosity in thicker areas of conventional resin specimens that underwent microwave polymerization. The resin designed specifically for microwave polymerization exhibited no clinically significant porosity. (J Prosthet Dent 2002;87:613-9.)