RESUMEN
In this work, we studied the corrosion of Cu metal in 0.5 mol L-1 HCl and the inhibition effect of the expired Cefazolin drug. The inhibition efficiency (IE) of Cefazolin varied according to its concentration in solution. As the Cefazolin concentration increased to 300 ppm, the IE increased to 87% at 298 K and decreased to 78% as the temperature increased to 318 K. The expired drug functioned as a mixed-type inhibitor. The adsorption of the drug on the copper surface followed Temkin's adsorption model. The magnitudes of the standard free energy change (ΔGoads) and adsorption equilibrium constant (Kads) indicated the spontaneous nature and exothermicity of the adsorption process. Energy dispersive X-ray (EDX) and scanning electron microscopy (SEM) techniques showed that the drug molecules were strongly attached to the Cu surface. The electrochemical frequency modulation (EFM), potentiodynamic polarization (PP), and electrochemical impedance spectroscopy (EIS) results were in good agreement with the results of the weight loss (WL) method. The density functional tight-binding (DFTB) and Monte Carlo (MC) simulation results indicated that the expired drug bound to the copper surface through the lone pair of electrons of the heteroatoms as well as the π-electrons of the tetrazole ring. The adsorption energy between the drug and copper metal was -459.38 kJ mol-1.
RESUMEN
This work illustrated the synthesis of a new simple resorcinol derivative, 4,6-dimethoxyisophthalohydrazide (DMIH) and confirmed its structure using 1H-NMR spectroscopy. The inhibiting performance of the DMIH compound in resisting the pitting action of a 0.5 mol L-1 HCl solution on low-carbon steel (LCS) was assessed. The newly synthesized compound had a simple structure and was dissolved in acidic media. The efficiency of the inhibitor was examined using chemical and electrochemical methods. The DMIH compound significantly decreased the rate of dissolution of LCS in HCl solution by adsorption. The adsorption was based on the Langmuir model. The DMIH compound is adsorbed on LCS via both chemisorption and physisorption. The DMIH compound is a mixed-type inhibitor. An inhibition efficiency (IE) of 83.8% was obtained using 300 ppm of the DMIH compound at 298 K. The IE decreased to 72% as the temperature increased to 328 K. When the concentration of DMIH increased from 50 to 300 ppm, the charge transfer resistance (R ct) increased from 134.7 to 404.8 ohm cm2, and the capacitance of the adsorbed layer decreased from 38 × 10-6 to 11 × 10-6 F cm-2. The high IE of the synthesized inhibitor was validated by the quantum characteristics. Monte Carlo (MC) simulations revealed that the DMIH compound adsorbed to the LCS quite well. The presence of a protective film on the LCS specimen was verified by the scanning electron microscopy (SEM) and atomic force microscopy (AFM) results. DMIH has significant potential to function as a corrosion inhibitor, as indicated by the comparative study between its performance and that of previously reported compounds. Although the structure of the DMIH compound is simpler than that of other inhibitors, it has been proven to be more effective.
RESUMEN
An ecofriendly resorcinol derivative, dimethyl-4,6-dihydroxyisophthalate (DDIP) is examined as an anticorrosion agent for low carbon steel (CS) in a 0.5 mol L-1 HCl solution. Electrochemical and chemical methods are used to determine the effectiveness of the inhibitor. The DDIP compound decreased the rate of CS corrosion. The mitigation efficiency rose from 61.8 to 79.9% as the DDIP dose increased from 50 to 300 ppm in the corrosive medium. At 300 ppm, however, the efficiency decreased from 79.9 to 70.05% as the temperature increased from 25 to 55 °C. Physical quantities and thermodynamic parameters are discussed. The compound's adsorption follows Langmuir's concept. Adsorption of the DDIP compound is a mix of physisorption and chemisorption. The difference in E corr values is less than 85 mV, indicating that the examined compound is a mixed-type inhibitor. Scanning electron microscopy and atomic force microscopy revealed the development of a coherent film at CS in the presence of the DDIP inhibitor. The results obtained using various techniques were closely related, indicating validity and accuracy. The interaction between the DDIP molecules and the CS was explained by the density functional theory and Monte Carlo simulation. The quantum characteristics confirmed that the DDIP compound is a promising inhibitor.
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OBJECTIVE: To evaluate the value of intrauterine platelet-rich concentrates among patients with intrauterine adhesions (IUAs) after hysteroscopic adhesiolysis. METHODS: Four different databases (PubMed, Cochrane Library, Scopus, and ISI web of science) were searched for the available studies from inception to November 2021. We selected randomized clinical trials (RCTs) that compared platelet-rich concentrates in the intervention group versus no injection of platelet-rich concentrates in the control group among women with intrauterine adhesions after operative hysteroscopy. Revman software was utilized for performing our meta-analysis. Our primary outcomes were the adhesion score and incidence of recurrence of severe intrauterine adhesions postoperatively. Our secondary outcomes were the clinical pregnancy rate, menstrual flow duration in days, and menstrual flow amount (number of pads). RESULTS: Five RCTs met our inclusion criteria with a total number of 329 patients. We found that platelet-rich concentrates were linked to a significant reduction in the postoperative adhesion score (MD = -1.00, 95% CI [-1.68, -0.32], p = 0.004). Moreover, there was a significant reduction in the incidence of severe IUAs recurrence among the platelet-rich concentrates group (7.6%) compared to the control group (23.4%) after hysteroscopy (p = 0.001). The clinical pregnancy rate was significantly increased among the platelet-rich concentrates group (37.1%) in comparison with the control group (20.7%) after hysteroscopic adhesiolysis (p = 0.008). There were significant improvements in the menstrual flow duration and amount among the platelet-rich concentrates group (p < 0.001). CONCLUSIONS: Intrauterine placement of platelet-rich concentrates is an effective method for the treatment of intrauterine adhesions after hysteroscopy.
Asunto(s)
Histeroscopía , Enfermedades Uterinas , Femenino , Humanos , Histeroscopía/efectos adversos , Histeroscopía/métodos , Embarazo , Índice de Embarazo , Ensayos Clínicos Controlados Aleatorios como Asunto , Adherencias Tisulares/etiología , Adherencias Tisulares/cirugía , Enfermedades Uterinas/epidemiologíaRESUMEN
OBJECTIVE: To evaluate the impact of virtual reality on pain management during normal labor. METHODS: A systematic search was performed in September 2021 through PubMed, Cochrane Library, Scopus, and ISI web of science. We selected randomized clinical trials (RCTs) that compared virtual reality in the intervention group versus placebo or no intervention in the control group among laboring women during their normal delivery. Revman software was used for performing our meta-analysis. Our primary outcome was the pain score evaluated during the labor process by the Visual Analog Scale (VAS). Our secondary outcomes were anxiety and satisfaction scores during childbirth in addition to the duration of the first and second stages of labor. RESULTS: Eight RCTs met our inclusion criteria with a total number of 466 patients. We found virtual reality was linked to a significant reduction in the VAS pain score during labor compared to the control group (MD = -1.40, 95% CI [-1.83, -0.96], p < 0.001). The anxiety score during labor was significantly reduced among the virtual reality group (SMD = -1.15, 95% CI [-2.18, -0.12], p = 0.03). Moreover, virtual reality significantly improved the satisfaction score during labor (MD = 15.58, 95% CI [4.93, 26.22], p = 0.004). However, there were no significant differences between virtual reality and control groups regarding the duration of the first and second stages of labor. CONCLUSIONS: Virtual reality is an effective technique for reducing anxiety, increasing satisfaction, and improving pain management during normal labor.