Accuracy of linear measurement using cone-beam computed tomography at different reconstruction angles

Purpose: This study was performed to evaluate the effect of changing the orientation of a reconstructed image on the accuracy of linear measurements using cone-beam computed tomography (CBCT). Materials and Methods: Forty-two titanium pins were inserted in seven dry sheep mandibles. The length of these pins was measured using a digital caliper with readability of 0.01 mm. Mandibles were radiographed using a CBCT device. When the CBCT images were reconstructed, the orientation of slices was adjusted to parallel (i.e., 0°), +10°, +12°, -12°, and -10° with respect to the occlusal plane. The length of the pins was measured by three radiologists, and the accuracy of these measurements was reported using descriptive statistics and one-way analysis of variance (ANOVA); p<0.05 was considered statistically significant. Results: The differences in radiographic measurements ranged from -0.64 to +0.06 at the orientation of -12°, -0.66 to -0.11 at -10°, -0.51 to +0.19 at 0°, -0.64 to +0.08 at +10°, and -0.64 to +0.1 at +12°. The mean absolute values of the errors were greater at negative orientations than at the parallel position or at positive orientations. The observers underestimated most of the variables by 0.5-0.1 mm (83.6%). In the second set of observations, the reproducibility at all orientations was greater than 0.9. Conclusion: Changing the slice orientation in the range of -12°to +12°reduced the accuracy of linear measurements obtained using CBCT. However, the error value was smaller than 0.5 mm and was, therefore, clinically acceptable. © 2014 by Korean Academy of Oral and Maxillofacial Radiology

Comparison of the Effect of Peer-led Education and Education by the Healthcare Personnel on Awareness, Attitude and Performance of Lettered People toward Organ Donation

BACKGROUND AND OBJECTIVE: Lack of donation is one of the major limitations of organ transplantation. Promoting organ donation requires increased awareness and creation of a positive attitude through training in specific ways. The purpose of this study was to compare the effect of peer-led education and education by healthcare personnel on awareness, attitude and performance of lettered people in regard with organ donation. METHODS: This case-control clinical trial was performed on 120 lettered people who were randomly assigned to three groups of 40, including peer-led, healthcare personnel and control groups. The two intervention groups underwent training sessions. Before and after the intervention, the data were collected and compared using questionnaires in three groups in three areas of awareness, attitude and performance. FINDINGS: Most of the lettered people (58.33%) were female. 61.66% had a bachelor's degree and 60.83% were teachers at elementary school. There was a significant difference in the mean scores of awareness, attitude and performance toward organ donation in the two intervention groups before the intervention (in peer-led group were 11.52 ± 2.12, 92.05 ± 10.24, and 1.87 ± 1.42 and in healthcare group were 11.30 ± 3.00, 90.73 ± 10.92, and 1.38 ± 1.29, respectively) and after the intervention (in peer-led group were 15.47 ± 1.13, 98.78 ± 5.70, and 3.53 ± 0.50 and in healthcare group were 15.13 ± 1.49, 96.95 ± 5.52, and 3.05 ± 0.81, respectively) ( P < 0.05). The mean score of attitude and performance of the lettered people in the peer-led group was significantly higher than the other groups (P < 0.05). CONCLUSION: The results of the study showed that peer-led education is a more effective method than education by healthcare personnel to promote and institutionalize organ donation

Effect of tapered roller bearing supports on the dynamic behaviour of hypoid gear pair differentials

Noise and vibration refinement and energy efficiency are the key drivers in powertrain development. The final drive (the differential) is a source of vibration concern and also contributes to the powertrain inefficiency. To optimise differential characteristics for the key objectives of refinement and efficiency, detailed models of the gear interactions as well as the support bearing dynamics are required. This study reports the integrated lubricated bearing and gear contacts with an eight-degree-of-freedom dynamic analysis (a tribo-dynamic model). Non-Newtonian shear behaviour of thin lubricant-film conjunctions is taken into account in the integrated tribo-dynamic analysis, which has not hitherto been reported in the literature. The results show that the transmitted vibration spectra from the system onto the differential casing are dominated by the bearing frequencies rather than by those due to the meshing of gears. It is also shown that a sufficiently high bearing preload improves the vibration refinement but can lead to a marginally reduced transmission efficiency

Impact of melatonin supplementation in the rat spermatogenesis subjected to forced swimming exercise

Oxygen consumption increases many times during exercise, which can increase reactive oxygen species. It negatively affects fertility in male athletes. Melatonin is exerting a regulatory role at different levels of the hypothalamic-pituitary-gonadal axis. However, there is no evidence that the protective effects of melatonin persist after long duration exercise on the spermatogenesis. Therefore, this study was conducted to examine the impacts of melatonin on the testis following the administration of swimming exercise. Rats were separated into five different groups, including Control, sham M: received the solvent of melatonin, M: received melatonin, S: the exercise protocol, MS: received melatonin and the exercise protocol. After 8weeks, animals were scarified and antioxidant enzymes levels of testes, spermatogenic cells apoptosis and sperm quality were measured. Swimming decreased all parameters of spermatozoa. Nevertheless, melatonin could significantly improve the progressive motility of spermatozoa in MS rats. Swimming caused an increased apoptosis of S group and decreased all antioxidant enzymes. Melatonin could drastically reduce apoptosis and increased these enzymes. Therefore, melatonin seems to induce the production of antioxidant enzymes of testicular tissues and diminish the extent of apoptotic changes caused by forced exercise on the testis, which can, in turn, ameliorate the sperm parameters

Effects of energy drinks on blood pressure, heart rate, and electrocardiographic parameters: An experimental study on healthy young adults

Objective: To evaluate the effects of the consumption of energy drinks on cardiovascular parameters in a group of healthy young individuals. Methods: In a quasi-experimental study, 44 healthy adult participants aged between 15 and 30 years were evaluated. The blood pressure (BP) as well as electrocardiographic indices, including heart rate (HR), PR interval, QRS duration, corrected QT (QTc) interval, and ST-T changes were recorded before consumption of a caffeine-containing energy drink and at the specific time points over a 4-h test duration. Results: We found statistically significant HR decline (p=0.004) and more frequent ST-T changes (p=0.004) after the participants consumed the energy drink. However, readings for systolic BP (p=0.44), diastolic BP (p=0.26), PR interval (p=0.449), QRS duration (p=0.235), and QTc interval (p=0.953) showed no significant change post-consumption. Conclusion: In conclusion, we demonstrated that the consumption of energy drinks could contribute to HR decline and ST-T change in healthy young adults. © 2016 by Turkish Society of Cardiology

Teratogenic effects of carbamazepine on embryonic eye development in pregnant mice

Background: Carbamazepine is an antiepileptic drug used widely for the treatment of epileptic seizures and neuropathic pain. Several malformations in humans, mainly neural tube defects, have been reported as a consequence of its use during pregnancy. The association between maternal use of carbamazepine and congenital eye malformations is not very well understood. Objective: The purpose of this study was to examine this association after intraperitoneal injection of carbamazepine during the period of organogenesis in mice. Methods: Balb/c timed-pregnant mice were divided into 4 experimental and control groups. Two experimental groups received daily intraperitoneal injections of 15mg/kg (group I) or 30mg/kg (group II) of carbamazepine on gestational days 6 to 15. Two control groups received normal saline or Tween 20 (polysorbate 20). Dams underwent Cesarean section on gestational day 18 and embryos were harvested. External examination for eye malformations, routine histological processing of malformed fetuses to study eye morphology, and skeletal staining were performed. Results: The mean weight and crown-rump of the fetuses in both experimental groups were significantly reduced compared with those of the control groups. Various malformations were detected such as brachygnathia, calvarial deformity, vertebral deformity, short tail, and brachydactyly. Premature opening of one or both eyes with mild to severe exophthalmos occurred in the 2 experimental groups. Deformed lens, retinal folds with undeveloped layers, and corneal folds with absence of surface epithelium were detected in both experimental groups. Conclusions: This study, to the best of our knowledge, showed for the first time that intraperitoneal administration of carbamazepine at clinically comparable doses during organogenesis can induce several eye malformations in mice. The implication of these results needs to be considered when carbamazepine is administered during human pregnancy. © 2010 Informa UK Ltd

Seroprevalence of Toxoplasma gondii

Toxoplasma gondii is an obligate intracellular protozoan parasite causing toxoplasmosis in animals and humans. Primary maternal infection with toxoplasmosis during pregnancy is frequently associated with transplacental transmission to the fetus. However it is not certain whether Toxoplasma infection can cause recurrent abortion. The aim of this study was to determine the relationship between Toxoplasma infection and abortion via detection of anti-Toxoplasma gondii antibodies in sera of women with obstetrical problems and compare the results with control group consisting of women with history of normal delivery. Sera from 130 women with abortion and sera of 130 women with normal delivery were tested for IgG and IgM anti-Toxoplasma gondii antibodies by ELISA method. The present study revealed 24.6% of the samples with abortion and 21.5% of the samples with normal delivery were positive for IgG antibodies. However, statistical analysis indicated no significant differences (P>0.05). In addition, IgM antibody was detected in one woman who had aborted but not in women with normal childbirth. This study showed no significant difference between the case and control groups in IgG anti-Toxoplasma antibody but detected one sample with IgM antibodies in woman with abortion during the first trimester of pregnancy. In order to determine the relationship between Toxoplasma infection and abortion, anti-Toxoplasma IgG avidity and PCR to discriminate between recent and prior infections are recommended

Enhanced Performance of Dye-Sensitized Solar Cells based on TiO2 Nanotube Membranes using Optimized Annealing Profile

We use free-standing TiO2 nanotube membranes that are transferred onto FTO slides in front-side illuminated dye-sensitized solar cells (DSSCs). We investigate the key parameters for solar cell arrangement of self-ordered anodic TiO2 nanotube layers on the FTO substrate and namely the influence of the annealing procedure on the DSSC light conversion efficiency. The results show that using an optimal temperature annealing profile can significantly enhance the DSSC efficiency (in our case 9.8 %), as it leads to a markedly lower density of trapping states in the tube oxide, and thus to strongly improved electron transport properties