Modeling of unconfined compressive strength and Young's modulus of lime and cement stabilized clayey subgrade soil using Evolutionary Polynomial Regression (EPR)

In this study, the evolutionary polynomial regression (EPR) method has been employed to develop simple models with reasonable accuracy to predict the compressive strength and Young's modulus of the lime/cement stabilized clayey subgrade soil. For this purpose, the different specimens with the various cement and lime contents, at three moisture contents (dry side, wet side, and optimum moisture content) were fabricated and were cured for 7, 14, 21, 28 and, 60 days to conduct the unconfined compressive strength (UCS) test. According to the test results, a dataset consisting of 75 records for each additive was prepared. Results of this study show that the R2 value of the developed model for predicting UCS of cement-stabilized clay soil is equal to 0.96 and 0.95 for training and testing sets, respectively. These two values for lime-stabilized soil are 0.91 and 0.87, respectively. Moreover, the R2 for predicting Young's modulus of cement-stabilized clay soil is equal to 0.90 and 0.89 for training and testing set, respectively. These two values for predicting Young's modulus of lime-stabilized soil are 0.88 and 0.94, respectively. The sensitivity analysis showed that for the Portland cement stabilized clayey subgrade, the percentage of the Portland cement and moisture content are the most significant parameters for predicting the UCS and Young's modulus, respectively. In contrast, for the lime-stabilized clayey subgrade soil, the most important parameters are the moisture content and the UCS, respectively

Estrogen and Progesterone Replacement Therapy Prevent Methamphetamine-Induced Synaptic Plasticity Impairment in Ovariectomized Rats

Background: Methamphetamine (METH) is one of the most popular psychostimulants which produce long lasting learning and memory impairment. Previous studies have indicated that estrogen and progesterone replacement therapy attenuate cognitive impairment against a wide array of neurodegenerative diseases. Present study was designed to figure out the effects of estrogen, progesterone alone or in combination, on early long-term potentiation (E-LTP) at the cornu ammonis (CA1) area of the hippocampus in METH-exposed ovariectomized (OVX) rat.Methods: Twenty-one days after ovariectomy, the OVX rats received vehicle, estrogen [1 mg/kg, intraperitoneal (IP)] or progesterone (8 mg/kg, IP) and co-administration of estrogen plus progesterone during 14 consecutive days. On the 28th day, animals were exposed to neurotoxic METH regimens [four injections 6 mg/kg, subcutaneous (SC), 2 h intervals] 30 min after the hormones replacement. Finally, we investigated the effect of those ovarian hormones on synaptic plasticity using in vivo extracellular recording in the CA1 area of the hippocampus 2 days after last treatment.Findings: The findings showed that the induction and maintenance phase of E-LTP was impaired in the METH exposed animals compared to the saline group. Data from this study demonstrated that treatment with estrogen and progesterone showed a significant facilitation for induction and enhancement of the maintenance of LTP in animals that received METH. In addition, co-administration of estrogen plus progesterone did not significantly affect the hippocampal synaptic plasticity in METH-exposed OVX rats in comparison with METH-exposed animals that received vehicle injections.Conclusion: The present findings provide new insight about treatment with ovarian hormones on synaptic plasticity deficits induced by METH

Brain Region Specificity of Mitochondrial Biogenesis and Bioenergetics Response to Nrf2 Knockdown: A Comparison Among Hippocampus, Prefrontal Cortex and Amygdala of Male Rat Brain

ABSTRACT Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) has been identified as the well-known coordinator of intracellular antioxidant defense system. Herein, we aimed to evaluate the effects of Nrf2 silencing on mitochondrial biogenesis markers peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), nuclear respiratory factor-1(NRF-1), mitochondrial transcription factor A (TFAM) and cytochrome c as well activities of two enzymes citrate synthase (CS) and malate dehydrogenase (MDH) in three brain regions hippocampus, amygdala, and prefrontal cortex of male Wistar rats. Small interfering RNA (siRNA) targeting Nrf2 was injected in dorsal third ventricle. Next, western blot analysis and biochemical assays were used to evaluation of protein level of mitochondrial biogenesis factors and CS and MDH enzymes activity, respectively. Based on findings, whilst Nrf2-silencing led to notably reduction in protein level of mitochondrial biogenesis upstream PGC-1α in three brain regions compared to the control rats, the level of NRF-1, TFAM and cytochrome c remained unchanged. Furthermore, although Nrf2 silencing increased CS activity, activity of MDH significantly decreased in hippocampus and prefrontal cortex areas. Interestingly, CS and MDH activities in amygdala did not change after Nrf2 knockdown. In conclusion, the present findings highlighted complexity of interaction of Nrf2 and mitochondrial functions in a brain region-specific manner. However, by outlining the exact interaction between Nrf2 and mitochondria, it would be possible to find a new therapeutic strategies for neurological disorders related to oxidative stress

Short-term co-ingestion of creatine and sodium bicarbonate improves anaerobic performance in trained taekwondo athletes

Background Creatine (CR) and sodium bicarbonate (SB) alone improve anaerobic performance. However, the ergogenic effects of CR and SB co-ingestion on taekwondo anaerobic performance remains unknown. Methods Forty trained taekwondo athletes (21 ± 1 y.; 180.5 ± 7.3 cm; 72.7 ± 8.6 kg) were randomized to: (i) CR and SB (CR + SB; 20 g of CR+ 0.5 g·kg− 1·d− 1 of SB), (ii) CR, (iii) SB, (iv) placebo (PLA), or (v) control (CON) for 5 days. Before and after supplementation, participants completed 3 bouts of a Taekwondo Anaerobic Intermittent Kick Test (TAIKT) to determine changes in peak power (PP), mean power (MP), and fatigue index (FI). Blood lactate (BL) was measured before, immediately following, and 3 min post-TAIKT. Results PP and MP increased over time (P  0.05). BL increased following exercise across all groups; however, CR + SB and SB post-exercise BL was lower compared to CR, PLA, and CON (P < 0.05). Conclusion Short-term CR and SB alone enhance TAIKT performance in trained taekwondo athletes. Co-ingestion of CR and SB augments MP compared to CR and SB alone, with similar PP improvements