Regional differences in statistical geometry of endothelial dense granules in human extremity veins

2014 ◽  
Vol 30 (7) ◽  
pp. 481-485 ◽  
Author(s):  
G Gősi ◽  
GL Nádasy ◽  
G Raffai ◽  
E Fehér ◽  
Z Szeberin ◽  
...  

Objectives Leg and arm human veins are exposed to different gravitational stresses. We investigated if there is difference in the amount and geometry of secretory vesicles in their endothelium. Methods Superficial small vein segments were removed during vascular operations for electromicroscopic analysis. Vesicular area/total endothelial cross-sectional area was determined by computer-based morphometry. Long and short axes of granule cross sections were measured by image analyzing software. Results Vesicular density in all samples was 2.26 ± 0.34%. There was no significant difference between the vesicular densities of upper extremity and leg. The shape of the vesicles was more frequently elongated in leg than in arm sections ( p < 0.01). Conclusions The density of the vesicles does not depend on vascular region or orthostatic load. Ellipticity of these granules is significantly different in areas exposed to different gravitational stresses. This might contribute to the differences of thrombotic and hemodynamic properties of leg and upper body veins.

2021 ◽  
Vol 2 (7(71)) ◽  
pp. 33-39
Author(s):  
A. Bidakov ◽  
O. Pustovoitova ◽  
I. Raspopov ◽  
B. Strashko

The γ-method and the Timoshenko method are most often used for calculation the bending strength of CLT panels, the latter of which takes into account the transverse shear deformations of the transverse layers of boards, which are due to the significant difference between the modulus of elasticity and the shear modulus apply the method of Timoshenko's beams. The γ-method treats the CLT panel as a beam on flexible joints, similar to the Derevyagin system beam on plate dowels or Kubler cubes, where the transverse layers of the boards are considered as flexible joints and are not taken into account when calculating the geometric characteristics of cross sections of CLT panels. Taking into account the amount of shear for each type of panels, depending on the configuration of the cross-sectional components, is performed by introducing shear correction factors, which in turn depend on the thickness of the CLT panel layers and their distance from the center of gravity of the panel. The γ-method, like Timoshenko's method, is used in engineering practice more often than the shear analogy method. Each technique has its advantages and disadvantages, as it has a number of specific assumptions to simplify the calculations. This paper highlights the advantages and disadvantages of the γ-method and the Timoshenko method, which are the most common and are contained in many technical opinions of various manufacturers of CLT panels.


2013 ◽  
Vol 14 (3) ◽  
pp. 451-455
Author(s):  
Anil Dhingra ◽  
Surbhi Kakar

ABSTRACT Aim To assess and compare the shaping potential of manual NiTi K-files and Rotary ProTaper instruments in narrow canals using CT. Objective To assess the shaping potential of manual NiTi K-files and Rotary ProTaper and analyzing the final outcome of shaped canals using CT and determining different variables, like • Working time • Change in volume • Change in cross-sectional area. Materials and methods From a pool of fifty freshly extracted permanent maxillary molars (1st and 2nd), 30 were selected with curvatures (20 to 40°) (Schneider 1971). Tissue fragments and calcified debries were removed from the teeth by scaling. The teeth were then stored in normal saline until used. All the mesiobuccal canals were scanned by CT to obtain preinstrumented images. Teeth were scaled and stored in normal saline. This study was divided in two groups with 15 samples each. Group I (ProTaper Rotary) Canals were instrumented with Protaper Rotary instruments using crown down technique according to manufacturer's instructions. Group II (NiTi K-file) Were instrumented by NiTi K-files using step back technique with a quarter turn/pull motion. Evaluations of working time Comparative evaluations of working time was done for both the experimental groups. CT analysis and measurements The samples were analyzed and evaluated for: • Postinstrumentation change in volume. • Postinstrumentation change in cross-sections area. Result From the observations and statistical analysis carried out in this study, it was found that: There was a statistically significant difference between all the parameters judged for the present study that is: 1. Instrumentation with ProTaper Rotary system took significantly less time than instrumentation with manual NiTi K-file. 2. Change in the canal volume following instrumentation with ProTaper Rotary was significantly greater than that produced by manual NITi K-file. 3. a. Change in cross-section area at 2 and 3 mm from the apex was significantly greater with manual NiTi K-file as compared to ProTaper Rotary. b. Change in cross sections at 4.5, 6 and 7.5 mm from the apex with ProTaper Rotary was significantly greater than that produced by manual NITi K-file. Conclusion This clearly establishes that there is a drastic difference in the shaping ability of manual and Rotary NiTi instruments used with step back and crown down technique respectively with the rotary instrumentation being faster and producing greater changes in the canal anatomy. How to cite this article Kakar S, Dhingra A, Sharma H. Shaping Potential of Manual NiTi K-File and Rotary ProTaper and Analyzing the Final Outcome of Shaped Canals using CT. J Contemp Dent Pract 2013;14(3):451-455.


Author(s):  
Roshanak Ali-Akbar Navahi ◽  
Samira Chaibakhsh ◽  
Sayyed Amirpooya Alemzadeh ◽  
Kaveh Abri Aghdam

Purpose: To determine the appropriate number of histopathological cross-sections that are required for a conclusive diagnosis of giant cell arteritis (GCA). Methods: In this cross-sectional study, the number of sections per slide for paraffin-embedded blocks for 100 randomly selected cases where GCA was suspected and those for negative temporal artery biopsies (TABs) were compared with the number of cross-sections per specimen for eight positive-TABs. All aforementioned examinations were conducted at our center from 2012 to 2016. Then, negative-TABs were retrieved and re-evaluated using light microscopy considering the histopathological findings of GCA. Results: Ninety-five paraffin blocks were retrieved. The original mean biopsy length was 15.39 ± 7.56 mm. Comparison of the mean number of cross-sections per specimen for both the positiveand negative-TABs (9.25 ± 3.37 and 9.53 ± 2.46) showed that 9.87 ± 2.77 [95% confidence intervals (CI)] cross-sections per specimen were sufficient for a precise GCA diagnosis. There was no statistically significant difference in the mean biopsy length (P = 0.142) among the eight positive-TABs. Similarly, no significant difference was observed in the number of cross-sections per specimen (P = 0.990) for positive-TABs compared to those for the negative-TABs. After the retrieval of negative-TABs, the mean number of total pre- and post-retrieval cross-sections per specimen was 17.66 ± 4.43. Among all retrieved specimens, only one case (0.01%) showed the histopathological features of healed arteritis. Conclusion: Positive-TABs did not reveal more histological cross-sections than the negative ones and increasing the number of cross-sections did not enhance the accuracy of TAB.


2015 ◽  
Vol 40 (4) ◽  
pp. 440-448 ◽  
Author(s):  
C Rengo ◽  
C Goracci ◽  
G Ametrano ◽  
N Chieffi ◽  
G Spagnuolo ◽  
...  

SUMMARY Objective The aim of the study was to compare in Class V composite restorations marginal leakage measurements obtained with microcomputed tomography (micro-CT) and scanning electron microscopy (SEM) observations. Methods Class V cavities were prepared on 10 human molars and restored using Optibond FL (Kerr, Orange, CA, USA) and Premise Flowable (Kerr). Sealing ability was evaluated by assessing silver-nitrate penetration depth along enamel and dentin margins. Leakage was quantified using a scoring system. Micro-CT analysis provided 502 cross-sectional images for each tooth. Microleakage evaluation was performed first on three cross-sections corresponding to the sections examined by SEM, then on all 502 of the obtained micro-CT images. SEM observations were performed first at 20× magnification, then, if showing a zero score, at 80× magnification. Enamel and dentin microleakage scores assigned to corresponding sections through micro-CT and SEM (20×) were compared (Wilcoxon signed-rank test, α=0.05). Results No statistically significant difference in leakage scores emerged between micro-CT and 20×-magnification SEM. Eight tooth sections that were given a zero score under SEM at 20× magnification showed to be infiltrated at the higher magnification (80×). For five teeth a higher score was assigned following scanning of 502 cross-sections than based on the observation of three sections. Conclusions Micro-CT presents as a valid, nondestructive in vitro method to quantitatively evaluate marginal leakage of adhesive restorations.


Author(s):  
T.B. Ball ◽  
W.M. Hess

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.


2020 ◽  
Vol 63 (6) ◽  
pp. 2016-2026
Author(s):  
Tamara R. Almeida ◽  
Clayton H. Rocha ◽  
Camila M. Rabelo ◽  
Raquel F. Gomes ◽  
Ivone F. Neves-Lobo ◽  
...  

Purpose The aims of this study were to characterize hearing symptoms, habits, and sound pressure levels (SPLs) of personal audio system (PAS) used by young adults; estimate the risk of developing hearing loss and assess whether instructions given to users led to behavioral changes; and propose recommendations for PAS users. Method A cross-sectional study was performed in 50 subjects with normal hearing. Procedures included questionnaire and measurement of PAS SPLs (real ear and manikin) through the users' own headphones and devices while they listened to four songs. After 1 year, 30 subjects answered questions about their usage habits. For the statistical analysis, one-way analysis of variance, Tukey's post hoc test, Lin and Spearman coefficients, the chi-square test, and logistic regression were used. Results Most subjects listened to music every day, usually in noisy environments. Sixty percent of the subjects reported hearing symptoms after using a PAS. Substantial variability in the equivalent music listening level (Leq) was noted ( M = 84.7 dBA; min = 65.1 dBA, max = 97.5 dBA). A significant difference was found only in the 4-kHz band when comparing the real-ear and manikin techniques. Based on the Leq, 38% of the individuals exceeded the maximum daily time allowance. Comparison of the subjects according to the maximum allowed daily exposure time revealed a higher number of hearing complaints from people with greater exposure. After 1 year, 43% of the subjects reduced their usage time, and 70% reduced the volume. A volume not exceeding 80% was recommended, and at this volume, the maximum usage time should be 160 min. Conclusions The habit of listening to music at high intensities on a daily basis seems to cause hearing symptoms, even in individuals with normal hearing. The real-ear and manikin techniques produced similar results. Providing instructions on this topic combined with measuring PAS SPLs may be an appropriate strategy for raising the awareness of people who are at risk. Supplemental Material https://doi.org/10.23641/asha.12431435


Author(s):  
M. Trajchevska ◽  
A. Lleshi ◽  
S. Gjoshev ◽  
A. Trajchevski

Background: The respect of the needs and wishes of the patients is in the focus of the human health system. The experience of the parents in terms of child’s health care may be used as an indicator of quality of the health care. Material and methods: The research is a quantitative analytical cross-sectional study. In accordance with the inclusion and exclusion criteria, simple random sample of 207 parents / guardians is covered, whose children in the period of three months, had been hospitalized in the hospital department JZUU Pediatric Surgery Clinic in Skopje.It was used a two parted questionnaire. The first part is a standardized questionnaire (Parent Experience of Pediatric Care - PECP), and the second part concerns the general socio-demographic data of the parent/guardian. Statistical evaluation was performed using appropriate statistical programs (Statistics for Windows 7,0 and SPSS 17.0). Results: In accordance with the age of the parents, the survey respondents were divided into two groups: a) age ≤ 33 years - 107 (51.69%) and b) age> 33 years - 100 (48.31%).Significant independent predictor of parental satisfaction from the receipt of their child to the clinic research confirms the age of the parent under / over 33 years due to 4.1% of the change in satisfaction (R2 = 0,041). Parents generally believe that their children's room of the clinic is "good", without significant difference between parental satisfaction from both age groups (Mann-Whitney U Test Z = -0,9613 p = 0,3364). Significant independent predictor of parental satisfaction from the room of their child improves the health status after treatment due to 6% of the change in satisfaction (R2 = 0,060). Parents generally believe that testing and treatment of their children in the clinic was "very good" and an independent significant predictor is to improve the health status after the treatment - 7,8% (R2 = 0,078). Conclusions: Regardless of the generally good parental satisfaction about health care for their children, it is necessary to continuously monitor the status of the clinic in order to consider the possible deficiencies and needs of intervention.


2018 ◽  
Vol 8 (2) ◽  
pp. 80-83
Author(s):  
Nadia Tariq ◽  
Tamkeen Jaffry ◽  
Rahma Fiaz ◽  
Abdul Majid Rajput ◽  
Sadaf Khalid

Background: Indoor air pollutants are increasingly being associated with respiratory illnesses leading to high degree of morbidity and mortality. There are not sufficient epidemiological studies from Pakistan which assess level of awareness of indoor air pollution resulting in respiratory diseases in population. Methods: This cross sectional survey was carried out on general population of Rawalpindi/Islamabad. Sample size was 223 study subjects selected by non-probability convenient sampling. Knowledge of the study subjects was determined with regard to indoor air pollution, its effects on health and different sources of indoor air pollution with the help of a questionnaire. The influence of age, gender, educational status and socio economic status on the level of awareness was also analyzed. Results: Out of total 223 participants, 115 were males and108 females. Participants aware of indoor air pollution were 91.5% and adequate awareness about its sources was 80.7%. Those who knew indoor air pollution is detrimental to health were 95.1%. Awareness about building construction dust as source of indoor air pollution was maximum (84.8%). There was significant difference in awareness among participants with different monthly incomes and educational status and also between males and females. Conclusion: This study concludes that general population of Rawalpindi/Islamabad has fairly good awareness about sources of indoor air pollution. Use of harmful material causing indoor air pollution should be limited or substituted with better ones where possible.


Author(s):  
Bhagavathami Meenaksh ◽  
Chitraa R. Chandran ◽  
Aravindhan Thathchari Ranganathan ◽  
Kavindapadi Venkateswaran Rama ◽  
Valarmathy Srinivasan

Background: This study aims to determine and compare the levels of trace elements copper, zinc, selenium and chromium in GCF and serum of patients with periodontitis and healthy individuals. Methods: This cross sectional study includes 24 study subjects recruited from the patients reporting to the Department of Periodontics , Tagore Dental College Chennai. All the selected patients were subjected to a clinical examination done by a single examiner. The estimation of trace elements Copper, Zinc, Selenium and Chromium in GCF and serum is performed using Perkin Elmer optima 5300 Inductively Coupled Plasma Emission Spectrometer (ICPOES). Results: GCF and serum copper levels showed no significant difference in both periodontitis and healthy groups . Selenium levels tend to be the same in both groups. Serum zinc levels are more in periodontitis patients than healthy subjects (p less than 0.01). GCF chromium levels are found to be more in patients with periodontitis than healthy. Conclusions : More research is therefore needed to monitor the role of these trace elements C with an increased sample size to ascertain whether they are associated with a reduced risk of periodontitis.


Author(s):  
Zeina A Munim Al-Thanoon ◽  
Zeina A Munim Al-Thanoon ◽  
Mustafa Basil ◽  
Nasih A Al-Kazzaz

Iron chelation therapy with deferoxamine (DFO),the current standard for the treatment of iron overload in patients with betathalassemia,requires regular subcutaneous or intravenous infusions. This can lead to reduced quality of life and poor adherence,resulting in increased morbidity and mortality in iron-overloaded patients with beta-thalassemia. Deferasirox (DFX) is an orally administered iron chelator that has been approved for use in many countries. The requirement of an effective,well tolerated iron chelator with a less demanding mode of administration has led to the development of deferasirox. The present study was aimed to compare the satisfaction and compliance with deferoxamine versus deferasirox (Exjade®),a novel oral iron chelator in patients with transfusion - dependent beta- thalassemia. A cross-sectional,single-center investigation study was carried out in the Thalassemia Center of Ibn-Atheer Teaching Hospital in Nineveh province,Iraq. One hundred and eight thalassemic patients aged between 2- 20 years old having received multiple blood transfusions and a serum ferritin greater than 1500 ng/ml. Patients were randomised into two groups. Group 1 received deferoxamine at a dose of 20-50mg/kg/day and group 2 received deferasirox at the dose of 10-30 mg/kg/day. Another 56 apparently healthy volunteers were used as a control group. The assessment of chelation was done during the period between November 2013 and February 2014 by measurement of serum ferritin. Satisfaction and compliance was assessed by using a special questionnaire prepared by the researcher. Out of the 108 thalassemic patients enrolled there was no discontinuation in treatment with the two drugs under study. The serum ferritin did not change significantly in any of the chelation groups. In comparison with the patients who were treated with DFO,those receiving DFX reported a significantly higher rate of compliance and satisfaction (P < 0.05). However,no significant difference was observed between the two groups regarding their satisfaction (P > 0.05).Compliance with deferasirox (50 %) was more than that with deferoxamine (20 %). Satisfaction with deferoxamine was significantly lower than deferasirox (p= 0.00).


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