Introduction: Determining working length is regarded as an important step in root canal treatment, for which electronic apex locator can be applied. New apex locators are preferred, since they work via applying alternating current. Furthermore, the two factors of dentin specific resistance and capacitance seem to be effective principles in their operating. Therefore, this study aimed to determine and compare the dentin capacitance in young and old teeth.Methods: In order to glean the study data, 60 human permanent teeth were collected consisting of 30 permanent teeth under twenty-five years and 30 permanent teeth over sixty year. The sixty samples of same dimensions were prepared from mid levels of the teeth roots. The capacitance circuit rates created in three frequencies of 100 HZ, 1KHZ and 10KHZ were measured. Moreover, in order to analyze the study data, ANOVA and Mann-Whitney tests were utilized.Results: The mean value of capacitance circuit teeth under twenty five years and over sixty years respectively involved 60 and 137 in 100HZ, 2.5 and 9.5 in 1KHZ and 0.05 and 0.3 in 10KHZ, which this difference was proved to be statistically significant (P Value =0.000) Conclusion: The study findings revealed a different capacitance between young and old teeth. Regarding the influence of this factor in the operating principle of apex locators, calibrate the device may be necessitated while applying it in young and old teeth.

Introduction: The first permanent molar, with its large occlusal surface and early eruption, plays a pivotal role in oral health. This study assessed the association between caries in the first permanent molar and caries in the second molar, second premolar, and overall dentition. Materials and Methods: In this cross-sectional study, 632 volunteers aged 18–20 years from Qazvin (2023) were examined using clinical and radiographic assessments based on a standardized checklist. Pearson’s correlation test was applied, with significance set at P = 0.05. Results: A significant association was observed between the condition of the first permanent molar and both the second premolar and second permanent molar. Individuals with caries in the first permanent molar were more likely to have decay in the second permanent molar (r = 0.024) and second premolar (r = 0.021). A positive correlation was also found between the DMF index (Decayed, Missing, and Filled teeth) and the DMF6 index (specific to first permanent molars), showing that higher DMF6 values were associated with higher overall DMF scores (P = 0.001). Conclusion: The status of the first permanent molar reflects overall oral health and total DMFT score and may serve as a predictive indicator for other teeth. Early monitoring of first molar status can guide preventive interventions, a finding of considerable interest to dental researchers and clinicians.

In this study, the researcher attempted to addresses the relationships within the family from the perspective of relationships between two generations: old women, and young women. What discourses are subject to these relationships and are these discourses close together or considered as obvious sign of the gap between the two generations? The method used by researcher was taking advantage of the qualitative approach, based on an analysis of the position as one of the way of Grounded Theory method and used narrative interviews. Purposefully sample was chosen to the number 20 cases of Tehran citizens. Findings of research showed that the relations among two generations of women in Iranian families is convergent. While there is difference between the traditionalism discourse of elders and forerunner young people. But all two come together in the discourse, which is modernism discourse. And while family has differences, is not in the way of generational threat and still family is an important issue and priority of generations.

Background: Obstetricians regard maternal age of 20 to 35 years as the optimal age for pregnancy. Adolescent pregnancy and pregnancy at the ages of 35 years and above are associated with higher risks. Pregnancy is pro-arrhythmic and rarely precipitates ventricular arrhythmias.Objectives: QT dispersion is an index of heterogeneity of ventricular repolarization and a predictor of propensity of ventricular arrhythmias. In this study, this index was used to find any relationship between maternal age and ventricular arrhythmia risk.Methods: This study was performed among a group of healthy pregnant ladies between 36 and 40 weeks of gestation. An ECG was taken from each patient. QT dispersions were calculated on a computer screen with high magnitude. The results were then divided into three groups based on the age of the participants. The first, second, and third groups included the women below 20, between 20 and 35, and over 35 years, respectively. The three groups were compared using Kruskal-Wallis test.Results: The mean QTd was 61.77 ms (±16.61) in the first group, 64.15 ms (±18.65) in the second group, and 55.95 ms (±23.04) in the third group. Although QTd was prolonged in all, no significant difference was observed among the three groups regarding QTd.Conclusions: Our results showed QT prolongation in pregnancy, but showed that maternal age did not affect the heterogeneity of ventricular repolarization and propensity of ventricular arrhythmias in pregnancy.

Introduction: The aim of this study was to compare ultra structure of embryos obtained from young and old mouse oocytes.Materials and Methods: Metaphase II oocytes were retrieved from old NMRI mouse (7-9 months old) and young NMRI (10-12 weeks old) after ovarian stimulation. NMRI mouse sperms (10-12 weeks old) were added to T6 medium containing retrieved oocytes.After PN formation, embryos were transferred to culture medium (comtaining 15mg/ml BSA).Developmenting of embryos was recorded every 24 hours. 2 cell embryos after were fined in 2.5% glutardehid phosphate the samples dehydrated and embedded. Blokcs were sliced after timming. Seim thin (500 nm) and ultra thin (70 nm) sections had been (collected on copper grids) stained. Samples were studied by election microscopy.Results: At the (LM) level, embryos driven from young and old oocytes were surrounded by zona pellocida polar bodies and cellular fragmentation were seen in perivitelline space which was morefrequent in older embryos.In embryos driven from old oocytes, perivittelline space was more enpanded and microvillies were arragned reqularly. Nuclei of blastocytes were enchromatin in both embroyos. In old embryos, intramuscular anulatellae lamllae was ween which was secndary to folding of nucleous inhere membra.Mithochondies and intermediate filaments were seen in both embryos in cytoplasm. Which were similar in morphology and ultra structure. But their arrangement and distribution were different.In embryos dreven from oocytes. Most of mitochonderies were central and around the nucleuses.While in young embryos, they were distributed in cytoplasm.SER collection was higher in young embryos while residual bodies and lipid were more frequent in old embryos.Conclusion: This study revels that embryos driven from old oocytes had several ultra structure changes in comparison to young embryos. This may be one of the reason follow implantation and birth rate in old subjects.

Background: An appropriate personalized molecular testing ensures the most efficacious treatment in lung cancer. It is still controversial whether younger lung adenocarcinoma (LUAD) patients have different molecular features compared with their older counterparts. MicroRNAs have been involved in lung cancer and their altered expression has been suggested as a potential biomarker in the pathogenesis, diagnosis, prognosis, and therapy of LUAD. Materials and Methods: To analyze putative differences in miR‑ 25 expression between young (with age ≤ 50 years) and old adenocarcinoma patients, we quantified miR‑ 25 levels with NanoString technology in 88 LUAD specimens. We further investigated a cohort of 309 LUAD patients from the cancer genome atlas (TCGA) database to test our hypothesis. Results: miR‑ 25 expression was upregulated in young LUAD patients in comparison to the older ones (P = 0. 03) in our series. The analysis of public database TCGA confirmed our results, which miR‑ 25 differentially expressed in the two aged groups (P = 0. 0009). Moreover, a consequential pairing of miR‑ 25 with a target region in phosphatase and tensin homolog (PTEN) 3’ untranslated region (UTR) and actually low PTEN expression seemed to be associated with high miR‑ 25 (P = 0. 001) in young patients. Conclusions: The interaction of miR‑ 25 and PTEN in young LUAD may define a subgroup of patients, highlighting the concept of molecular testing in different age subtypes.