Our main objective was to investigate the effect of chronic administration of hydrogen sulphide donor (sodium hydrosulphide) on the expression of intercellular adhesion molecule-1 (ICAM-1) and ...concentration of nuclear factor-kappa B (NF-kB) in a renal ischemia-reperfusion injury (IRI) model of WKY and L-nitro-arginine-methyl-ester (L-NAME)-induced hypertensive rats. Sodium hydrosulphide (NaHS) was administered intraperitoneally (i.p.) for 35 days while cystathionine gamma lyase (CSE) inhibitor dL-propargylglycine (PAG) was administered at a single dose of 50 mg/kg. Animals were anesthetised using sodium pentobarbitone (60 mg/kg) and then prepared to induce renal ischemia by clamping the left renal artery for 30 min followed by 3 h of reperfusion. Pre-treatment with NaHS improved the renal functional parameters in both WKY and L-NAME-induced hypertensive rats along with reduction of blood pressure in hypertensive groups. Oxidative stress markers like malondialdehyde (MDA), total superoxide dismutase (T-SOD) and glutathione (GSH) were also improved by NaHS treatment following renal IRI. Levels of ICAM-1 and NF-kB concentration were reduced by chronic treatment with NaHS and increased by PAG administration after renal IRI in plasma and kidney. Treatment with NaHS improved tubular morphology and glomerulus hypertrophy. Pre-treatment with NaHS reduced the degree of renal IRI by potentiating its antioxidant and anti-inflammatory mechanism, as evidenced by decreased NF-kB concentration and downregulation of ICAM-1 expression.
Advanced research trends in dye-sensitized solar cells Kokkonen, Mikko; Talebi, Parisa; Zhou, Jin ...
Journal of materials chemistry. A, Materials for energy and sustainability,
2021, Letnik:
9, Številka:
17
Journal Article
Recenzirano
Odprti dostop
Dye-sensitized solar cells (DSSCs) are an efficient photovoltaic technology for powering electronic applications such as wireless sensors with indoor light. Their low cost and abundant materials, as ...well as their capability to be manufactured as thin and light-weight flexible solar modules highlight their potential for economic indoor photovoltaics. However, their fabrication methods must be scaled to industrial manufacturing with high photovoltaic efficiency and performance stability under typical indoor conditions. This paper reviews the recent progress in DSSC research towards this goal through the development of new device structures, alternative redox shuttles, solid-state hole conductors, TiO
2
photoelectrodes, catalyst materials, and sealing techniques. We discuss how each functional component of a DSSC has been improved with these new materials and fabrication techniques. In addition, we propose a scalable cell fabrication process that integrates these developments to a new monolithic cell design based on several features including inkjet and screen printing of the dye, a solid state hole conductor, PEDOT contact, compact TiO
2
, mesoporous TiO
2
, carbon nanotubes counter electrode, epoxy encapsulation layers and silver conductors. Finally, we discuss the need to design new stability testing protocols to assess the probable deployment of DSSCs in portable electronics and internet-of-things devices.
Dye-sensitized solar cells (DSSCs) are an efficient photovoltaic technology for powering electronic applications such as wireless sensors with indoor light.
This paper presents mathematical optimization models of residential energy hubs which can be readily incorporated into automated decision making technologies in smart grids, and can be solved ...efficiently in a real-time frame to optimally control all major residential energy loads, storage and production components while properly considering the customer preferences and comfort level. Novel mathematical models for major household demand, i.e., fridge, freezer, dishwasher, washer and dryer, stove, water heater, hot tub, and pool pumps are formulated. Also, mathematical models of other components of a residential energy system including lighting, heating, and air-conditioning are developed, and generic models for solar PV panels and energy storage/generation devices are proposed. The developed mathematical models result in Mixed Integer Linear Programming (MILP) optimization problems with the objective functions of minimizing energy consumption, total cost of electricity and gas, emissions, peak load, and/or any combination of these objectives, while considering end-user preferences. Several realistic case studies are carried out to examine the performance of the mathematical model, and experimental tests are carried out to find practical procedures to determine the parameters of the model. The application of the proposed model to a real household in Ontario, Canada is presented for various objective functions. The simulation results show that savings of up to 20% on energy costs and 50% on peak demand can be achieved, while maintaining the household owner's desired comfort levels.
To determine the age, gender and sites of vestibular schwannoma cases using contrast-enhanced magnetic resonance imaging.
The retrospective descriptive study was conducted at the Department of ...Cyberknife Robotic Radiosurgery, Jinnah Postgraduate Medical Centre, Karachi, and comprised data of patients with vestibular schwannomas from January 2016 to September 2018. Some of them were histologically proven and rest were radiologically proven. Cases were reviewed on contrast-enhanced magnetic resonance imaging of the brain. Statistical Package for the Social Sciences version 20 (SPSS) was applied.
Of the 500 cases of vestibular schwannomas identified with 515 tumours, 300(60%) were males and 200(40%) were female. The overall mean age was 42.7±14.4 years (range: 17-85 years). Out of 515 tumours, the commonest site was the right cerebellopontine angle in 340(66%) cases. There were 15(3%) cases of radiologically-proven neurofibromatosis type 2. Overall, 490(98%) patients had main clinical complaint of progressive unilateral hearing loss, 5(1%) had vertigo and 5(1%) had facial palsy.
Vestibular schwannomas were found to be more common among adults, with male preponderance and right cerebellopontine angle being the common site.
A standard lumbar puncture may be impossible for many anatomic or technical reasons. Previous accounts of caudal epidural anesthesia and other procedures via the sacral hiatus prompted us to test if ...image‐guided percutaneous trans‐sacral hiatus access to the lumbosacral subarachnoid cistern would be anatomically feasible. To study vertebral canal morphometry and curvature, we analyzed midsagittal computed tomography‐myelogram images of 40 normal subjects and digitally measured sacral curvatures between S1 to S5 and S2 to S4 using two methods whereby a lower angle signifies a straighter sacrum. We measured midsagittal vertebral canal area, hiatus width, dural sac termination levels, and distance from sacral hiatus to the dural sac tip (needle distance). Subjects were F:M = 25:15, with a mean age of 44.9 years. The two S1–S5 full sacral curvature mean angles were 57.3° and 60.4°. Almost all sacral hiatuses were at S4, and dural sac terminations were at S1–S2. The mean S2–S4 sacral curvature was 25.1°, and the mean needle distance was 57.7 mm. Using two‐way analysis of variance, there were significant sex differences for needle distances (p = .001), and full and limited sacral curvatures (p = .02, and p = .046, respectively). There were no significant linear regression correlations between age and sacral curvature, needle distance, canal area, or hiatus width. Therefore, despite a frequently prominent full sacral curvature, the combination of S1–S2 dural sac termination plus a relatively straight trajectory of the lower vertebral canal between S2 and S4 support the theoretical feasibility of percutaneous trans‐sacral hiatus and vertebral canal access to the lumbosacral cistern using a standard spinal needle.
The application of natural products and supplements has expanded tremendously over the past few decades.
(
), which is affiliated to the Acanthaceae family, has recently caught the interest of ...researchers from the countries of subtropical Asia due to its medicinal uses in alternative treatment for skin infection conditions due to insect bites, microorganism infections and cancer, as well as for health well-being. A number of bioactive compounds from this plant's extract, namely phenolic compounds, sulphur containing compounds, sulphur containing glycosides compounds, terpens-tripenoids, terpens-phytosterols and chlorophyll-related compounds possess high antioxidant activities. This literature search yielded about one hundred articles which were then further documented, including the valuable data and findings obtained from all accessible electronic searches and library databases. The promising pharmacological activities from
leaves extract, including antioxidant, anti-cancer, anti-viral, anti-bacterial, anti-fungal, anti-venom, analgesic and anti-nociceptive properties were meticulously dissected. Moreover, the authors also discuss a few of the pharmacological aspect of
leaves extracts against anti-hyperlipidemia, vasorelaxation and renoprotective activities, which are seldom available from the previously discussed review papers. From the aspect of toxicological studies, controversial findings have been reported in both in-vitro and in-vivo experiments. Thus, further investigations on their phytochemical compounds and their mode of action showing pharmacological activities are required to fully grasp both traditional usage and their suitability for future drugs development. Data related to therapeutic activity and the constituents of
leaves were searched by using the search engines Google scholar, PubMed, Scopus and Science Direct, and accepting literature reported between 2010 to present. On the whole, this review paper compiles all the available contemporary data from this subtropical herb on its phytochemistry and pharmacological activities with a view towards garnering further interest in exploring its use in cardiovascular and renal diseases.
Carbon footprint reduction, recompense depletion of natural resources, as well as waste recycling are nowadays focused research directions to achieve sustainability without compromising the concrete ...strength parameters. Therefore, the purpose of the present study is to utilize different dosages of marble waste aggregates (MWA) and stone dust (SD) as a replacement for coarse and fine aggregate, respectively. The MWA with 10 to 30% coarse aggregate replacement and SD with 40 to 50% fine aggregate replacement were used to evaluate the physical properties (workability and absorption), durability (acid attack resistance), and strength properties (compressive, flexural, and tensile strength) of concrete. Moreover, statistical modeling was also performed using response surface methodology (RSM) to design the experiment, optimize the MWA and SD dosages, and finally validate the experimental results. Increasing MWA substitutions resulted in higher workability, lower absorption, and lower resistance to acid attack as compared with controlled concrete. However, reduced compressive strength, flexural strength, and tensile strength at 7-day and 28-day cured specimens were observed as compared to the controlled specimen. On the other hand, increasing SD content causes a reduction in workability, higher absorption, and lower resistance to acid attack compared with controlled concrete. Similarly, 7-day and 28-day compressive strength, flexural strength, and tensile strength of SD-substituted concrete showed improvement up to 50% replacement and a slight reduction at 60% replacement. However, the strength of SD substituted concrete is higher than controlled concrete. Quadratic models were suggested based on a higher coefficient of determination (R
) for all responses. Quadratic RSM models yielded R
equaling 0.90 and 0.94 for compressive strength at 7 days and 28 days, respectively. Similarly, 0.94 and 0.96 for 7-day and 28-day flexural strength and 0.89 for tensile strength. The optimization performed through RSM indicates that 15% MWA and 50% SD yielded higher strength compared to all other mixtures. The predicted optimized data was validated experimentally with an error of less than 5%.
Dye-sensitized solar cells (DSSCs) have been intensely researched for more than two decades. Electrolyte formulations are one of the bottlenecks to their successful commercialization, since these ...result in trade-offs between the photovoltaic performance and long-term performance stability. The corrosive nature of the redox shuttles in the electrolytes is an additional limitation for industrial-scale production of DSSCs, especially with low cost metallic electrodes. Numerous electrolyte formulations have been developed and tested in various DSSC configurations to address the aforementioned challenges. Here, we comprehensively review the progress on the development and application of electrolytes for DSSCs. We particularly focus on the improvements that have been made in different types of electrolytes, which result in enhanced photovoltaic performance and long-term device stability of DSSCs. Several recently introduced electrolyte materials are reviewed, and the role of electrolytes in different DSSC device designs is critically assessed. To sum up, we provide an overview of recent trends in research on electrolytes for DSSCs and highlight the advantages and limitations of recently reported novel electrolyte compositions for producing low-cost and industrially scalable solar cell technology.
Agricultural production is greatly influenced by environmental parameters such as temperature, rainfall, humidity, and wind speed. The accurate information about environmental parameters plays a ...vital and useful role when making policies for the agriculture sector as well as for other sectors. Pakistan meteorological department observed these environmental parameters at more than 90 stations. The allocation of these monitoring stations is not made systematically correct. This leads to inaccurate predictions for unobserved locations. The study aims to propose a monitoring network by which these prediction errors of the environmental parameters can be minimized. The well-known prediction techniques named, model-based ordinary kriging and model-based universal kriging (UK) with the known Matheron variogram model are used for prediction purposes. We investigate the monitoring network of Pakistan for rainfall and focus on both the optimal deletion/addition of monitoring stations from/to this network. The two stochastic search algorithms, spatial simulated annealing, and genetic algorithm are used for optimization purposes. Furthermore, the minimization of the Average Kriging Variance (AKV) is taken as the interpolation accuracy measure. The spatial simulated annealing exhibits a lower AKV as compared to the Genetic algorithm when adding/removing the optimal/redundant locations from the monitoring network.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Presently, the rate for the development of ultra-high-performance concrete (UHPC) is increasing due to the requirement of long-span bridges, challenging architectural plans, and high-rise buildings. ...UHPC is still weak in tension and consumes a lot of cement, making it non-eco-friendly. This research is aimed at modifying the cement's matrix by incorporating two sustainable solid waste mineral admixtures, eggshell powder (ESP) and nano-silica (NS), to enhance the bonding between fibers and the binder's matrix and improve the strength characteristics of ultra-high-performance fiber-reinforced concrete (UHPFRC). The improving impacts of the ESP and NS on the double-hooked end (DHE) steel fibers were studied and analyzed by evaluating various strength parameters, i.e., compressive, splitting tensile and flexural strength and the load-deflection performance. To characterize the durability properties of UHPFRC, chloride ion coefficient, ultra-sonic pulse velocity (UPV), and water absorption tests were also carried out. Optimization of added materials was also done using a statistical tool called a design of experiments. Multi-variable statistical analysis was performed using response surface methodology (RSM) and analysis of variance (ANOVA). Both the experimental and statistical test outcomes depicted that introducing 5% ESP and 5% NS significantly improved the effectiveness of DHE steel fibers when the concrete was subjected to splitting tensile and flexural strength. UHPFRC with the 5% ESP and NS depicted 81% and 94% higher flexural strength than the reference mixture. While UHPFRC had almost 35 times higher flexural toughness than its counterparts. The inclusion of 5% and 10% eggshell powder depicted a favorable impact on the resistance of UHPFRC against the infiltration of water and chloride ions. The test outcomes of the present research confirmed the suitability and effectiveness of using ESP and NS as a partial substitute for OPC and significantly improved the engineering properties of UHPFRC, which was verified by the analytical results.
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