Corneal biomechanical properties distribution in myopic population

AIM: To evaluate distribution of corneal biomechanical measurements in normal myopia and myopic-astigmatism population.<p>METHODS:One hundred and eighty eyes with myopia and myopic-astigmatism candidated for laser refractive surgery were included in this study. Complete examination of anterior and posterior segments, manifest refraction spherical equivalent(MRSE), Orbscan and Zywave were performed preoperatively. Ocular response analyzer(ORA)was used to measure corneal hysteresis(CH), corneal resistance factor(CRF), Goldmann-correlated intraocular pressure(IOPg)and corneal compensated IOP(IOPcc). Distribution of all corneal biomechanical properties and correlation between these parameters and MRSE, age and sex were determined. Statistical analysis was performed using SPSS 17 software and a <i>P</i>-Value less than 0.05 was considered significant. <p>RESULTS: Mean age was 28.20±6.78 years. Mean MRSE was -4.21±1.19D. Mean CH, CRF, IOPg and IOPcc was 10.00±1.28mmHg, 10.17±1.45mmHg, 15.71±2.67mmHg and 16.68±2.41mmHg respectively. 28.4% of all myopic population had CH about 10mmHg, and 71% had CH, 9mmHg up to 11mmHg. CRF in 25.9% of myopic population was 10mmHg, and in 48.7% was 9mmHg up to 11mmHg. There was very poor positive correlation between MRSE& CH(Rs=0.001, <i>P</i>=0.71)and MRSE& CRF(Rs=0.01, <i>P</i>=0.18).<p>CONCLUSION: Our study demonstrated the distribution of corneal biomechanical properties(CH, CRF, IOPg, IOPcc)in normal myopia and myopic-astigmatism population in Iran, and confirmed that, there was no statistically significant correlation between CH, CRF and MRSE, age and sex but there was significant correlation between IOPg, IOPcc and formerly mentioned parameters

Corneal collagen cross-linking effects on pseudophakic bullous keratopathy

AIM: To evaluate the efficacy of riboflavin administration and ultraviolet A(UVA)cross-linking on advanced symptomatic bullous keratopathy. <p>METHODS: Fifteen patients with symptomatic pseudophakic bullous keratopathy(PBK)were included. Slit-lamp examination, visual acuity, foreign body sensation(FBS)questionnaire, corneal clarity grading, ocular pain intensity scale and corneal thickness measures with Pentacam and ultrasound pachymetry(UP), were performed before corneal cross-linking and 1 and 6mo thereafter. After using sodium chloride solution, for one week, the central 8mm(diameter)of the corneal epithelium was removed, and cross-linking, with riboflavin instillation every 3min for 30min, and UVA irradiation for 30min was performed. <p>RESULTS: Five males and 10 females with mean age of 66±13y were included. Mean follow up time was 6.2mo. Corneal transparency in all eyes was statistically significantly better 1 month after treatment than preoperatively(<i>P</i><0.05). At 6mo, however, corneal transparency was better in 8 eyes, the same in 5 eyes, and worse in 2 eyes compared with preoperative levels(<i>P</i>= 0.218). Foreign body sensation subsided in 70% of patients. The average CCT decreased within 1mo after the procedure(<i>P</i><0.05). At 6mo, all but 3 eyes had progressive swelling, and the CCT increased; however, the CCT was still statistically significantly thinner than preoperatively(<i>P</i>=0.006). The improvement in mean CDVA from preoperatively to 1mo postoperatively was statistically significant(<i>P</i>=0.010). At 6mo, no significant differences were observed(<i>P</i>=0.130). The pain scores at 1mo were statistically significantly better than preoperatively(<i>P</i>=0.007). At 6mo, however the mean pain score was higher than at 1mo and not statistically significantly different from the preoperative score(<i>P</i>=0.070). <p>CONCLUSION: Corneal CXL significantly improved corneal transparency, corneal thickness, and ocular pain 1 month postoperatively. However, it did not seem to have a long-lasting effect in decreasing pain and maintaining corneal transparency in patients with PBK. This procedure extends the time interval for corneal transplantation and increases visualization at DSAEK procedure

A Novel Hybrid Framework for Co-Optimization of Power and Natural Gas Networks Integrated With Emerging Technologies

In a power system with high penetration of renewable power sources, gas-fired units can be considered as a back-up option to improve the balance between generation and consumption in short-term scheduling. Therefore, closer coordination between power and natural gas systems is anticipated. This article presents a novel hybrid information gap decision theory (IGDT)-stochastic cooptimization problem for integrating electricity and natural gas networks to minimize total operation cost with the penetration of wind energy. The proposed model considers not only the uncertainties regarding electrical load demand and wind power output, but also the uncertainties of gas load demands for the residential consumers. The uncertainties of electric load and wind power are handled through a scenario-based approach, and residential gas load uncertainty is handled via IGDT approach with no need for the probability density function. The introduced hybrid model enables the system operator to consider the advantages of both approaches simultaneously. The impact of gas load uncertainty associated with the residential consumers is more significant on the power dispatch of gas-fired plants and power system operation cost since residential gas load demands are prior than gas load demands of gas-fired units. The proposed framework is a bilevel problem that can be reduced to a one-level problem. Also, it can be solved by the implementation of a simple concept without the need for Karush–Kuhn–Tucker conditions. Moreover, emerging flexible energy sources such as the power to gas technology and demand response program are considered in the proposed model for increasing the wind power dispatch, decreasing the total operation cost of the integrated network as well as reducing the effect of system uncertainties on the total operating cost. Numerical results indicate the applicability and effectiveness of the proposed model under different working conditions

Day-Ahead Network-Constrained Scheduling of CHP and Wind Based Energy Systems Integrated with Hydrogen Storage Technology

The integration of renewable energy sources is vastly increased in recent decades considering environmental concerns and lack of fossil fuels. Such integration has appeared novel challenges in electrical energy systems according to their uncertain nature. The hydrogen energy storage (HES) system plays a significant role is power systems by converting extra wind power to the hydrogen using power to hydrogen (P2H) technology. In addition, the emerging technologies such as combined heat and power (CHP) units are effective in increasing the efficiency of power systems. This work presents a day-ahead scheduling scheme for CHP-HES based electrical energy networks with high integration of wind power sources. The effectiveness of the presented model is investigated by implementation on the IEEE 6-bus system. The impact of heat load increment has been studied on scheduling of generation plants, wind power dispatch and operation cost of the system. The simulation results prove that operation cost of the system and wind power curtailment have been decreased using the HES technology

Effects of Iron Oxide Nanoparticles on Mouse Sperm Parameters and Testicular Tissue

Background: Iron oxide nanoparticles are commonly used for various purposes, such as biomedical, medical, and cosmetic services and research. However, there is a little information about the effects of the nanoparticles on human health. The current investigation was conducted to evaluate the adverse effects of iron oxide nanoparticles (FeNP) on the reproductive organs of mice, such as the testicular tissue and sperm cells. Methods: Twenty-eight male NMRI mice were randomly divided in four groups (N=7). The control group received only a regular diet. The experimental groups were administered FeNP in doses of 50, 150 and 300 mg/Kg intraperitoneally (IP), over four days. Epididymal sperm parameters, such as sperm number and motility were assessed by computer-assisted sperm analysis (CASA). Stereological analysis was also conducted on the histological sections. Results: The results demonstrated that FeNP (300 mg/Kg/day) caused a significant decrease in the sperm parameters, such as motility, spermatogonia, primary spermatocytes, spermatid, Sertoli, Leydig cells, total length of seminiferous tubules, and testicular interstitial tissue volumes. Conclusion: In summary, FeNP affected several reproductive tissue and cellular parameters at the administered dosage. Further research is required to examine the mechanism of action of FeNP the mice reproductive system

Two-stage Robust-Stochastic Electricity Market Clearing Considering Mobile Energy Storage in Rail transportation

This paper proposes a two-stage robust-stochastic framework to evaluate the effect of the battery-based energy storage transport (BEST) system in a day-ahead market-clearing model. The model integrates the energy market-clearing process with a train routing problem, where a time-space network is used to describe the limitations of the rail transport network (RTN). Likewise, a price-sensitive shiftable (PSS) demand bidding approach is applied to increase the flexibility of the power grid operation and reduce carbon emissions in the system. The main objective of the proposed model is to determine the optimal hourly location, charge/discharge scheduling of the BEST system, power dispatch of thermal units, flexible loads scheduling as well as finding the locational marginal price (LMP) considering the daily carbon emission limit of thermal units. The proposed two-stage framework allows the market operator to differentiate between the risk level of all existing uncertainties and achieve a more flexible decision-making model. The operator can modify the conservatism degree of the market-clearing using a non-probabilistic method based on info-gap decision theory (IGDT), to reduce the effect of wind power fluctuations in real-time. In contrast, a risk-neutral-based stochastic technique is used to meet power demand uncertainty. The results of the proposed mixed-integer linear programming (MILP) problem, confirm the potential of BEST and PSS demand in decreasing the LMP, line congestion, carbon emission, and daily operation cost

Executive Function Assessment in Patients With Idiopathic Generalized Epilepsy: Applyingthe Frontal Assessment Battery

&nbsp; &nbsp;Background: Executive dysfunction is seen in idiopathic generalized epilepsy (IGE). The Frontal Assessment Battery (FAB) is a short neuropsychological instrument designed in clinical settings to evaluate frontal lobe activity. We aimed to assess the clinical use of FAB in patients with IGE for to detect executive impairment. Method: In this study, 30 patients with IGE and 30 age- and sex-matched healthy controls were included. The presence and severity of executive dysfunction was investigated with FAB. Cognitive flexibility, decision making, working memory, and general intelligence level were examined using Wisconsin Card Sorting Task (WCST), Iowa Gambling Task (IGT), N-back, and Wechsler Adult Intelligence Scale, respectively. In patients with IGE, FAB results were related to their neuropsychological task performance. Results: The FAB score in patients with IGE was significantly lower compared to healthy participants. In motor programming tasks, patients with IGE performed substantially worse. However, no correlation was found between FAB and neuropsychological task and clinical characteristics. Conclusion: Executive dysfunction was present in patients with IGE and FAB may be used in these patients as an effective tool for evaluating frontal lobe function

Investigating the effect of exercise training in different periods of growth on protein synthesis (4E-BP1) and proliferation of cardiac cells (S6K1) in male rats

We investigate the effect of exercise training in different stages of growth on protein synthesis (4E-BP1) and proliferation of heart cells (S6K1) in male rats. 30 male Wistar rats were prepared in three age groups of 2 weeks, 8 weeks, and 90 weeks (10 in each group), and each age group was divided into two control and training groups (5 in each group). In the exercise training group, the animals performed the resistance and aerobic training program every day (interval). The amount of overload for the resistance-training program was determined based on the body weight of the animals. For the aerobic training group, the training intensity increased from 50% of maximum speed in the first week to 80% in the last week. The results showed that there is no significant difference between the control and training groups in each age, as well as between the training groups in the three age (p>0.05). In contrast, the 2-week exercise groups (p=0.022) showed a significant increase and the 90 weeks control group (p=0.002) showed a significant decrease in S6K1 protein in cardiac tissue compared to the 2-week control groups. In the analysis of gene expression, it was also found that the 2-week training group showed a significant increase in S6K1 gene expression compared to the 2-week control group (p=0.018). It seems that doing combined exercise at different ages, especially childhood, has a greater effect on the proliferation index of heart cells (S6K1). However, studies with longer training durations should also be considered