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The levels of soils pollutants such as lead (Pb) and cadmium (Cd) have significantly increased recently resulting in ecological disturbances and threatening crop production. Various amendments have been employed to enhance the tolerance of crops to withstand Cd and Pb stresses. However, the role of combined application of potassium (K) and of salicylic acid (SA) for Cd and Pb stress mitigation and phytoremediation by quinoa (Chenopodium quinoa Willd) has not been comprehended well. In the present study, the effect of 10 mM K and 0.1 mM SA was tested on the quinoa plants subjected to 250 µM Pb and/or 100 µM Cd. The Pb and Cd treatments were applied separately or together. Phytotoxicity induced by Pb and Cd resulted in drastic decrease (>60%) in chlorophyll contents, stomatal conductance, and plant biomass. The collective treatment of Pb and Cd induced an increase in the concentration of hydrogen peroxide (13-fold) and lipid peroxidation (16-fold) that resulted in a 61% reduction in membrane stability. The application of 10 mM K and/or 0.1 mM SA was remarkable in mitigating the adverse effect of Pb and Cd. The reduction in plant biomass was 17% when 10 mM K and 0.1 mM SA were applied together under the combined treatment of both the metals. The simultaneous application of K and SA effectively mitigated oxidative stress by enhancing the activities of superoxide dismutase, peroxidase, ascorbate peroxidase, and catalase by 12, 10, 7 and 10-folds respectively. The positive effect of K and SA on these attributes resulted in a remarkable reduction in metal accumulation and translocation and lipid peroxidation. The stressed plants supplemented with K and SA exhibited a significant improvement in the membrane stability index, chlorophyll content, and stomatal conductance. This study concluded that the combined application of K and SA could be a good approach for reducing Pb and Cd phytotoxicity in quinoa and enhancing their phytostabilization potential in the contaminated soils.
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Background and Objectives: Postpartum depression (PPD) is prevalent among women after childbirth, but accessing mental healthcare for PPD is challenging. This study aimed to assess the treatment gap and barriers to mental healthcare access for women with PPD symptoms living in Punjab, Pakistan. Methods: A multicenter cross-sectional study was conducted in five populous cities of Punjab from January to June 2023 by administering the questionnaire to the women using stratified random sampling. A total of 3,220 women in first 6 months postpartum were screened using the Edinburgh Postnatal Depression Scale. Of them, 1,503 women scored thirteen or above, indicating potential depressive disorder. Interviews were conducted to explore help-seeking behavior and barriers to accessing mental healthcare. Descriptive statistics along with nonparametric tests (e.g., Kruskal-Wallis, Mann-Whitney U) were used and group differences were examined. Scatter plot matrices with fitted lines were used to explore associations between variables. Classification and regression tree methods were used to classify the importance and contribution of different variables for the intensity of PPD. Results: Only 2% of women (n = 33) with high PPD symptoms sought mental healthcare, and merely 5% of women (n = 75) had been in contact with a health service since the onset of their symptoms. 92.80% of women with PPD symptoms did not seek any medical attention. The majority of women, 1,215 (81%), perceived the need for mental health treatment; however, 91.23% of them did not seek treatment from healthcare services. Women who recently gave birth to a female child had higher mean depression scores compared to those who gave birth to a male child. Age, education, and birth location of newborn were significantly associated (p < 0.005) with mean barrier scores, mean social support scores, mean depression scores and treatment gap. The results of classification and regression decision tree model showed that instrumental barrier scores are the most important in predicting mean PPD scores. Conclusion: Women with PPD symptoms encountered considerable treatment gap and barriers to access mental health care. Integration of mental health services into obstetric care as well as PPD screening in public and private hospitals of Punjab, Pakistan is critically needed to overcome the treatment gap and barriers.
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Depresión Posparto , Accesibilidad a los Servicios de Salud , Servicios de Salud Mental , Humanos , Depresión Posparto/terapia , Depresión Posparto/epidemiología , Depresión Posparto/diagnóstico , Femenino , Pakistán/epidemiología , Adulto , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Estudios Transversales , Servicios de Salud Mental/estadística & datos numéricos , Encuestas y Cuestionarios , Aceptación de la Atención de Salud/estadística & datos numéricos , Aceptación de la Atención de Salud/psicología , Adulto Joven , Conducta de Búsqueda de Ayuda , Escalas de Valoración PsiquiátricaRESUMEN
Advanced glycation end products (AGEs) play an important role in the pathogenesis of age-linked disorders and diabetes mellitus. The aim of this study was to assess the repurposing potential of Phloroglucinol (PHL the antispasmodic drug), as an anti-glycation agent using Fructose-BSA model. The ability of PHL to inhibit AGE formation was evaluated using AGEs formation (Intrinsic fluorescence), fructosamine adduct (NBT) and free lysine availability (TNBSA) assays. The BSA protein conformation was assessed through Thioflavin-T, Congo-Red and Circular Dichroism assays. The lysine blockade and carbonyl entrapment were explored as possible mode of action. Our data showed that PHL significantly decreased the formation of AGEs with an IC50 value of 0.3mM. The fructosamine adducts and free lysine load was found to be reduced. Additionally, the BSA conformation was preserved by PHL. Mechanistic assays did not reveal involvement of lysine blockade as underlying reason for reduction in AGEs load. This was also supported by computational data whereby PHL failed to engage any catalytic residue involved in early fructose-BSA interaction. However, it was found to entrap the carbonyl moieties. In conclusion, the PHL demonstrated anti-glycation potential, which can be attributed to its ability to entrap carbonyl intermediates. Hence, the clinically available antispasmodic drug, presents itself as a promising candidate to be repurposed as anti-glycation agent.
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Productos Finales de Glicación Avanzada , Floroglucinol , Albúmina Sérica Bovina , Productos Finales de Glicación Avanzada/metabolismo , Albúmina Sérica Bovina/química , Albúmina Sérica Bovina/metabolismo , Floroglucinol/farmacología , Floroglucinol/química , Glicosilación/efectos de los fármacos , Lisina/metabolismo , Lisina/química , Fructosa/química , Fructosa/metabolismo , Animales , Fructosamina/metabolismo , Simulación del Acoplamiento Molecular , BovinosRESUMEN
Direct AC-AC converters are strong candidates in the power converting system to regulate grid voltage against the perturbation in the line voltage and to acquire frequency regulation at discrete step levels in variable speed drivers for industrial systems. All such applications require the inverted and non-inverted form of the input voltage across the output with voltage-regulating capabilities. The required value of the output frequency is gained with the proper arrangement of the number of positive and negative pulses of the input voltage across the output terminals. The period of each such pulse for low-frequency operation is almost the same as the half period of the input grid or utility voltage. These output pulses are generated by converting the positive and negative input half cycles in noninverting and inverting forms as per requirement. There is no control complication to generate control signals used to adjust the load frequency as the operating period of the switching devices is normally greater than the period of the source voltage. However, high-frequency pulse width modulated (PWM) control signals are used to regulate the output voltage. The size of the inductor and capacitor is inversely related to the value of the switching frequency. Similarly, the ripple contents of voltage and currents in these filtering components are also inversely linked with PWM frequency. These constraints motivate the circuit designer to select high PWM frequency. However, the alignment of the high-frequency control input with the variation in the input source voltage is a big challenge for a design engineer as the switching period of a high-frequency signal normally lies in the microsecond. It is also required to operate some high-frequency devices for various half cycles of the source voltage, creating control complications as the polarities of the half cycles are continuously changing. This requires at least the generation of two high-frequency signals for different intervals. The interruption of the filtering inductor current is a big source of high voltage surges in circuits where the high-frequency transistors operate in a complementary way. This may be due to internal defects in the switching transistors or some unnecessary inherent delay in their control signals. In this research work, a simplified AC-AC converter is developed that does not need alignment of high-frequency control with the polarity of the source voltage. With this approach, high-frequency signals can be generated with the help of any analog or digital control system. By applying this technique, only one high-frequency control signal is generated and applied in AC circuits, as in a DC converter, without applying a highly sensitive polarity sensing circuit. So, controlling complications is drastically simplified. The circuit and configuration always avoid the current interruption problem of filtering the inductor. The proposed control and circuit topology are tested both in computer-based simulation and practically developed circuits. The results obtained from these platforms endorse the effectiveness and validation of the proposed work.
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Glycation is among the underlying mechanisms attributed to ageing and associated morbidities. There is no drug available to combat this deleterious phenomenon. The present study aimed to explore phloroglucinol (PHL) for its anti-glycation potential at preclinical level. The rats were treated with methylglyoxal (MGO, 17.25 mg/kg, i.p. for 14 days) to induce glvcative stress. The treatment groups received additional administration of test drug (PHL; 0.25mg/kg, 0.5mg/kg, and 1mg/kg) or standard aminoguanidine (AG, 50 mg/kg) or saline (control, 5ml/kg). During 14 days, the weight and food intake was noted. Afterwards, the cognitive function was evaluated using Morris Water Maze (MWM) while hepatic and renal functions were assessed through liver function test (bilirubin, alkaline phosphatase, SGPT, and SGOT) and creatinine respectively, using chemical analyzer. The carboxymethyllysine (CML) levels were quantified in the blood using ELISA technique. Histopathological study was performed on the brain, liver, and kidney using H&E staining. Additionally, the qPCR was used to quantify the expression of TNF-α, RAGE and BACE-1 (brain), RAGE, TNF-α, and glyoxalase-I (liver) and RAGE, TNF-α, and VEGF (kidney), while glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as a reference housekeeping gene. The data regarding weight and food intake did not reveal significant alterations. In MWM, the MGO treatment caused significant increase in the time to reach target quadrant, while decrease in the time spent in target quadrant and number of crossings through platform position. All these effects were inhibited by both AG and PHL. The navigation maps also exhibit that the retention of spatial memory. Additionally, the MGO-induced alteration in hepatic and renal function indicators was ameliorated by both AG and PHL treatments. The plasma CML levels were found to be elevated following MGO treatment, while the concomitant administration of AG and PHL has resisted this raise. Histopathological assessment revealed no specific pathology in liver kidney and brain tissues. The qPCR data revealed enhanced expression of all genes, especially TNF-α and BACE, which were found to be reduced following both AG and PHL treatments. PHL prevented the brain, hepatic, and renal impairments caused by MGO induced glycative stress. Hence, the PHL, a clinically used anti-spasmodic drug, presents itself as a potential candidate to be repurposed as anti-glycation drug.
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A random initialization of the search particles is a strong argument in favor of the deployment of nature-inspired metaheuristic algorithms when the knowledge of a good initial guess is lacked. This article analyses the impact of the type of randomization on the working of algorithms and the acquired solutions. In this study, five different types of randomizations are applied to the Accelerated Particle Swarm Optimization (APSO) and Squirrel Search Algorithm (SSA) during the initializations and proceedings of the search particles for selective harmonics elimination (SHE). The types of randomizations include exponential, normal, Rayleigh, uniform, and Weibull characteristics. The statistical analysis shows that the type of randomization does impact the working of optimization algorithms and the fittest value of the objective function.
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The current study goal was to improve mucoadhesive potential and ocular pharmacokinetics of nanoparticles of thiolated xyloglucan (TXGN) containing moxifloxacin (MXF). Thiolation of xyloglucan (XGN) was achieved with esterification with 3-mercaptopropionic acid. TXGN was characterized by NMR and FTIR analysis. The nanoparticles of TXGN were prepared using ionic-gelation method and evaluate the antibacterial properties. TXGN and nanoparticles were determined to possess 0.06 and 0.08 mmol of thiol groups/mg of polymer by Ellman's method. The ex-vivo bioadhesion time of TXGN and nanoparticles was higher than XGN in a comparative assessment of their mucoadhesive properties. The creation of a disulfide link between mucus and TXGN is responsible for the enhanced mucoadhesive properties of TXGN (1-fold) and nanoparticles (2-fold) over XGN. Improved MXF penetration in nanoparticulate formulation (80 %) based on TXGN was demonstrated in an ex-vivo permeation research utilizing rabbit cornea. Dissolution study showed 95 % release of MXF from nanoparticles. SEM images of nanoparticles showed spherical shape and cell viability assay showed nontoxic behavior when tested on RPE cell line. Antibacterial analysis revealed a zone of inhibition of 31.5 ± 0.5 mm for MXF, while NXM3 exhibited an expanded zone of 35.5 ± 0.4 mm (p < 0.001). In conclusion, thiolation of XGN improves its bioadhesion, permeation, ocular-retention and pharmacokinetics of MXF.
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Glucanos , Moxifloxacino , Nanopartículas , Xilanos , Xilanos/química , Glucanos/química , Moxifloxacino/química , Moxifloxacino/farmacocinética , Moxifloxacino/farmacología , Animales , Conejos , Nanopartículas/química , Portadores de Fármacos/química , Antibacterianos/farmacocinética , Antibacterianos/química , Antibacterianos/farmacología , Antibacterianos/administración & dosificación , Compuestos de Sulfhidrilo/química , Córnea/metabolismo , Córnea/efectos de los fármacos , Humanos , Sistemas de Liberación de Medicamentos , Permeabilidad , Línea Celular , Administración Oftálmica , Adhesividad , Adhesivos/químicaRESUMEN
A substantial level of significance has been placed on renewable energy systems, especially photovoltaic (PV) systems, given the urgent global apprehensions regarding climate change and the need to cut carbon emissions. One of the main concerns in the field of PV is the ability to track power effectively over a range of factors. In the context of solar power extraction, this research paper performs a thorough comparative examination of ten controllers, including both conventional maximum power point tracking (MPPT) controllers and artificial intelligence (AI) controllers. Various factors, such as voltage, current, power, weather dependence, cost, complexity, response time, periodic tuning, stability, partial shading, and accuracy, are all intended to be evaluated by the study. It is aimed to provide insight into how well each controller performs in various circumstances by carefully examining these broad parameters. The main goal is to identify and recommend the best controller based on their performance. It is notified that, conventional techniques like INC, P&O, INC-PSO, P&O-PSO, achieved accuracies of 94.3, 97.6, 98.4, 99.6 respectively while AI based techniques Fuzzy-PSO, ANN, ANFIS, ANN-PSO, PSO, and FLC achieved accuracies of 98.6, 98, 98.6, 98.8, 98.2, 98 respectively. The results of this study add significantly to our knowledge of the applicability and effectiveness of both AI and traditional MPPT controllers, which will help the solar industry make well-informed choices when implementing solar energy systems.
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The water quality in Karachi (Pakistan) is uncertain due to the occurrence of fungi and other microorganisms. A total of twenty-five water samples were collected from public places, educational institutes, hospitals, water supply systems and surface water of the canal of Karachi (Pakistan). The different fungal species including Acremonium sp., Alternaria alternata, Aspergillus flavus, A. fumigatus, A. sulphureus, Cladosporium sp., Fusarium sp., Clonostachys (Gliocladium) sp., Macrophomina phaseolina, Mucor racemosus, Paecilomyces sp. Penicillium chrysogenum, P. citrinum, P. commune, P. expansum, Rhizoctonia sp. and Stachybotrys sp. were isolated from these drinking water samples. However, the bacteria, microalgae and some other microorganisms were present in low concentrations. The reason for fungi infection and production of mycotoxicity depends upon various factors and the availability of their nutrients in filtration plants. The major threats to human health are fungal mycotoxicity which is responsible for carcinogenic and other lethal diseases. Mostly, the genus Aspergillus was dominated and isolated with a maximum of 88-98% of occurrence in the different samples of drinking water by the direct plate-spread method. For the control of fungi, various Physico-chemical coagulation treatments were used, but Potassium alum, clay pot, and hot water treatment disinfected effectively 69-70% removal of the fungi and its spore or mycelia from the water. In addition, it is concluded that drinking water purifications such as chlorination, filtration and lime did not eliminate thermophilic fungal spores or mycelia including Penicillium, Paecilomyces and Mucor from the water.
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The widespread application of herbicides raises concerns about their impact on non-target aquatic organisms. This study aimed to evaluate the toxicity of a commercially available herbicide formulation containing Bromoxynil+MCPA (2-Methyl-4-chlorophenoxyacetic acid) on Cirrhinus mrigala (economically significant fish). A total of 210 juvenile fish were subjected to a triplicate experimental setup, with 70 fish allocated to each replicate, exposed to seven different concentrations of herbicide: 0 mg/L, 0.133 mg/L, 0.266 mg/L, 0.4 mg/L, 0.5 mg/L, 0.66 mg/L, and 0.8 mg/L, respectively, for a duration of 96 h. The median lethal concentration (LC50) was determined to be 0.4 mg/L. Significant hematological alterations were observed, including decreases in RBC counts, hemoglobin, hematocrit, and lymphocyte counts, along with an increase in erythrocyte indices. Biochemical analysis revealed elevated levels of neutrophils, WBCs, bilirubin, urea, creatinine, ALT, AST, ALP, and glucose in treated groups. Morphological abnormalities in erythrocytes and histopathological changes in gills, liver, and kidneys were noted. Pathological alterations in gills, liver and kidneys including epithelial cell uplifting, lamellar fusion, hepatolysis, and renal tubule degeneration were observed. Oxidative stress biomarkers such as TBARS (Thiobarbituric Acid Reactive Substance), ROS (Reactive Oxygen Species), and POD (Peroxides) activity increased, while antioxidant enzymatic activities decreased as toxicant doses increased from low to high concentrations. The study reveals that Bromoxynil+MCPA significantly disrupts physiological and hematobiochemical parameters in Cirrhinus mrigala, which highlights the substantial aquatic risks. In conclusion, the herbicide formulation induced significant alterations in various fish biomarkers, emphasizing their pivotal role in assessing the environmental impact of toxicity. This multi-biomarker approach offers valuable insights regarding the toxicological effects, thereby contributing substantially to the comprehensive evaluation of environmental hazards.
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Ácido 2-Metil-4-clorofenoxiacético , Cyprinidae , Herbicidas , Contaminantes Químicos del Agua , Animales , Herbicidas/toxicidad , Ácido 2-Metil-4-clorofenoxiacético/toxicidad , Nitrilos , Biomarcadores , Hígado , Branquias/patología , Contaminantes Químicos del Agua/toxicidadRESUMEN
Oral delivery, the most common method of therapeutic administration, has two significant obstacles: drug solubility and permeability. The challenges of current oral medicine delivery are being tackled through an emerging method that uses structures called polymeric micelles. In the present study, polymeric micelles were developed using conjugates of linoleic acid-carboxymethyl chitosan (LA-CMCS) for the oral delivery of paclitaxel (PCL). The developed micelles were evaluated by particle size, zeta potential, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). When PCL was contained within micelles, its solubility increased by almost 13.65 times (around 60 µg/mL). The micelles' zeta potentials were -29 mV, their polydispersity indices were 0.023, and their particle diameters were 93 nm. Micelles showed PCL loading and entrapment efficiencies of 67% and 61%, respectively. The sustained release qualities of the PCL release data from micelles were good. In comparison to the pure PCL suspension, the permeability of the PCL from micelles was 2.2 times higher. The pharmacokinetic data revealed that PCL with LA-CMCS micelles had a relative bioavailability of 239.17%, which was much greater than the PCL in the suspension. The oral bioavailability of PCL was effectively increased by LA-CMCS micelles according to an in vivo study on animals. The polymer choice, maybe through improved permeability, plays an essential role when assessing oral bioavailability enhancement and solubility improvement (13.65 times). The outcomes demonstrated that PCL's solubility and pharmacokinetics were improved in the micelles of the LA-CMCS conjugate.
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The potential of solid waste as an energy source is clear, owing to its wide availability and renewable properties, which provide a critical answer for energy security. This can be especially effective in reducing the environmental impact of fossil fuels. Countries that rely heavily on coal should examine alternatives such as electricity from solid waste to provide a constant energy supply while also contributing to atmospheric restoration. In this regards, Low Emissions Analysis Platform (LEAP) is used for simulation the entire energy system in Pakistan and forecasted its capital cost and future CO2 emissions in relation to the use of renewable and fossil fuel resources under the different growth rates of solid waste projects like 20%, 30% and 40% for the study period 2023-2053. The results revealed that, 1402.97 TWh units of energy are generated to meet the total energy demand of 1193.93 TWh until 2053. The share of solid waste based electricity in total energy mix is increasing from a mere 0.81% in 2023 to around 9.44% by 2053 under the 20% growth rate, which then increase to 39.67% by 2053 under the 30% growth rate and further increases to 78.33% by 2053 under the 40% growth rate. It is suggested that 40% growth rate for solid waste based electricity projects is suitable for Pakistan until 2053 because under this condition, renewable sources contributes 95.2% and fossil fuels contributed 4.47% in the total energy mix of Pakistan. Hence, CO2 emissions are reduced from 148.26 million metric tons to 35.46 million metric tons until 2053 but capital cost is increased from 13.23 b$ in 2023 to 363.11 b$ by 2053.
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Cellulose is the basic component of lignocellulosic biomass (LCB) making it a suitable substrate for bioethanol fermentation. Cellulolytic and ethanologenic bacteria possess cellulases that convert cellulose to glucose, which in turn yields ethanol subsequently. Heterotermes indicola is a subterranean termite that causes destructive damage by consuming wooden structures of infrastructure, LCB products, etc. Prospectively, the study envisioned the screening of cellulolytic and ethanologenic bacteria from the termite gut. Twenty six bacterial strains (H1-H26) based on varied colonial morphologies were isolated. Bacterial cellulolytic activity was tested biochemically. Marked gas production in the form of bubbles (0.1-4 cm) in Durham tubes was observed in H3, H7, H13, H15, H17, H21, and H22. Sugar degradation of all isolates was indicated by pink to maroon color development with the tetrazolium salt. Hallow zones (0.42-11 mm) by Congo red staining was exhibited by all strains except H2, H7, H8, and H19. Among the 26 bacterial isolates, 12 strains were identified as efficient cellulolytic bacteria. CMCase activity and ethanol titer of all isolates varied from 1.30 ± 0.03 (H13) to 1.83 ± 0.01 (H21) umol/mL/min and 2.36 ± 0.01 (H25) to 7.00 ± 0.01 (H21) g/L, respectively. Likewise, isolate H21 exhibited an ethanol yield of 0.40 ± 0.10 g/g with 78.38 ± 2.05% fermentation efficiency. Molecular characterization of four strains, Staphylococcus sp. H13, Acinetobacter baumanni H17, Acinetobacter sp. H21, and Acinetobacter nosocomialis H22, were based on the maximum cellulolytic index and the ethanol yield. H. indicola harbor promising and novel bacteria with a natural cellulolytic tendency for efficient bioconversion of LCB to value-added products. Hence, the selected cellulolytic bacteria can become an excellent addition for use in enzyme purification, composting, and production of biofuel at large.
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Optimal power flow is a complex and highly non-linear problem in which steady-state parameters are needed to find a network's efficient and economical operation. In addition, the difficulty of the Optimal power flow problem becomes enlarged when new constraints are added, and it is also a challenging task for the power system operator to solve the constrained Optimal power flow problems efficiently. Therefore, this paper presents a constrained composite differential evolution optimization algorithm to search for the optimum solution to Optimal power flow problems. In the last few decades, numerous evolutionary algorithm implementations have emerged due to their superiority in solving Optimal power flow problems while considering various objectives such as cost, emission, power loss, etc. evolutionary algorithms effectively explore the solution space unconstrainedly, often employing the static penalty function approach to address the constraints and find solutions for constrained Optimal power flow problems. It is a drawback that combining evolutionary algorithms and the penalty function approach requires several penalty parameters to search the feasible space and discard the infeasible solutions. The proposed a constrained composite differential evolution algorithm combines two effective constraint handling techniques, such as feasibility rule and É constraint methods, to search in the feasible space. The proposed approaches are recognized on IEEE 30, 57, and 118-bus standard test systems considering 16 study events of single and multi-objective optimization functions. Ultimately, simulation results are examined and compared with the many recently published techniques of Optimal power flow solutions owing to show the usefulness and performance of the proposed a constrained composite differential evolution algorithm.
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The adsorption of organic molecules to surfaces is a central issue to achieve fully-functional molecular devices, for which porphyrins are well-studied due to their chemical stability and functional diversity. Herein, we investigate both the physical and the chemical adsorption of the free-base tetraphenylporphyrin 2H-TPP on the Cu(111) surface within the framework of density functional theory and find that the most stable physisorbed configuration is more weakly bound by -0.31 eV than the chemisorbed configuration. We use the electron localization function to investigate the difference in binding mechanisms between strong physisorption and weak chemisorption. We have computed a reaction barrier of 0.12 eV in going from physical binding to chemical bonding to the surface, and a barrier of 50 meV in going between neighboring physical binding sites. Our results support the possibility of realizing free-base porphyrins either physisorbed or chemisorbed on Cu(111) depending on the deposition procedure and experimental conditions.
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The applications of cellulose ethers in the petroleum industry represent various limitations in maintaining their rheological properties with an increase in both concentration and temperature. This paper proposed a new method to improve the rheological properties of hydroxyethyl methyl cellulose (HEMC) by incorporating diethyl carbonate (DEC) as a transesterification agent and alkali base solutions. Fourier transform infrared (FTIR) analysis confirmed the grafting of both composites onto the HEMC surface. The addition of sodium hydroxide (NaOH) improved the stability of the polymeric solution as observed from ζ-potential measurement. Shear viscosity and frequency sweep experiments were conducted at concentrations of 0.25-1 wt % at ambient and elevated temperatures ranging from 80-110 °C using a rheometer. In the results, the increase in viscosity at specific times and temperatures indicated the activation of DEC through the saponification reactions with alkali solutions. All polymeric solutions exhibited shear-thinning behavior and were fitted well by the Cross model. NaOH-based modified solution exhibited low shear viscosity compared to the DEC-HEMC solution at ambient temperature. However, at 110 °C, its viscosity exceeded that of the DEC-HEMC solution due to the activation of DEC. In frequency sweep analysis, the loss modulus (Gâ³) was greater than the storage modulus (G') at lower frequencies and vice versa at higher frequencies. This signifies the viscoelastic behavior of modified solutions at 0.50 wt % and higher concentrations. The flow point (G' = Gâ³) shifted to a low frequency, indicating the increasing dominance of elastic behavior with the rising temperature. At 110 °C, the NaOH-based modified solution exhibited both viscous and elastic behavior, confirming the solution's thermal stability and flowability. In conclusion, modified HEMC solution was found to be effective in controlling viscosity under ambient conditions, enhancing solubility, and improving thermal stability. This modified composite could play a significant role in optimizing viscoelastic properties and fluid performance under challenging wellbore conditions.
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[This corrects the article DOI: 10.3389/frai.2023.1339988.].
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Objective: To evaluate thyroid function tests (TFTs) during pregnancy in women with previous history of miscarriage or stillbirth. Methods: A cross-sectional study was carried out at the department of Obstetrics & Gynaecology and Endocrinology, Lady Reading Hospital, Peshawar from February 2021 to March 2022. All multigravida women attending the antenatal clinics were included using consecutive sampling. These women were placed into two groups, Group-A comprised of women with no prior history of miscarriages or stillbirths, and those with a history of foetal death during previous pregnancies were assigned Group-B. Free T4, thyroid stimulating hormone (TSH) and anti-thyroid peroxidase (TPO) antibodies were measured and the former two were used to label patients with thyroid dysfunction. Results: A total of 139 multigravida women were included in the study. About 43% of the women had a history of miscarriages or stillbirths. Thyroid dysfunction was observed overall in 36.69 % women, of whom 25.18% had sub-clinical hypothyroidism, 6.47% had hypothyroidism and 5.04 % were sub-clinical hyperthyroid. Women in Group-B had more thyroid functions abnormalities compared to Group-A (p<0.05). Moreover, there was significant difference in median TSH and freeT4 between the groups (p<0.001). Overall, thyroid dysfunction was found in 66.67% of patients who had a history of foetal death. Conclusions: In pregnant women with a history of miscarriage or abortion, thyroid functions abnormalities are common therefore routine thyroid testing is advised in pregnant women to prevent adverse perinatal outcomes.
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Variations in water chemistry may lead to the release of harmful heavy metals in drinking water distribution systems (DWDSs). In this study, the effects of chloride on the release of heavy metals such as Fe, Mn, As, Cr, Mo, V, Sr, and Co were examined using steel and cast iron pipe loops. After chloride was added, the relative contents of goethite (α-FeOOH), lepidocrocite (γ-FeOOH), and siderite (FeCO3) in pipe scales increased, but the contents of magnetite (Fe3O4) decreased. The most prevalent compounds were α-FeOOH and γ-FeOOH. When the chloride levels were increased, the effluent concentrations of Fe, Mn, As, Cr, Mo, V, Sr, and Co significantly increased. These heavy metals were released presumably because of the destabilization and dissolution of corrosion scales induced by chloride and adsorption site competition. Strong positive correlations were also observed between Fe&Mn, Fe/Mn&As, Fe/Mn&Cr, Fe/Mn&Mo, Fe/Mn&V, Fe/Mn&Sr, and Fe/Mn&Co, indicating the co-release of Fe, Mn, and other metals. This study may be helpful for the potential strategies on avoidance of heavy metal release and improvement of water supply security.