RESUMEN
Laser cladding is one of the emerging additive manufacturing technologies and has been adopted in various industrial fields. In this study, the morphological characteristics of a single clad of Inconel 718 manufactured by coaxial laser cladding with high laser power from 4200 W to 5400 W, powder feeding rate from 25 g/min to 50 g/min, and cladding speed from 20 mm/s to 50 mm/s are studied. The cross-section of the melt pool is analyzed and classified by type into three types: shallow dilution, flat dilution, and fluctuating dilution. Nine parameters are designed to describe the morphological characteristics of the clad, and the corresponding linear regression models are developed to establish a quantitative relationship between the combined process parameters and morphological characteristics. The results indicate that the total area of the cross-section A, the clad area above the substrate Ac, the area of the molten substrate Am, the total height of the cross-section H, the height of the clad above the substrate hc, the penetration depth hm, the clad width W, the dilution ratio D, and the wetting angle θ are determined by complex coupling of energy input and mass accumulation, and they are proportional to PF0.4/V, P0.5F/V, P/F0.2/V0.4, P2F0.6/V, PF0.7/V, P2/F/V0.3, P/V0.8, P/FV0.2, and PF7/V0.8, respectively. The large linear regression coefficients and the analysis residuals indicate the high reliability of the statistical linear regression models. This work aims to provide a comprehensive understanding of the influence of the main processing parameters on the morphological characteristics of the clad, which is of great value in providing a reference and laying a basis for the practical application of laser cladding technology at a high deposition rate.
RESUMEN
Background: Polymyxin B (PMB) is a basic cyclic polypeptide antibiotic produced by Bacillus polymyxa, and is one of the last options for treating multi-drug-resistant negative bacterial infections in clinical practice. In recent years, many population pharmacokinetic studies of PMB have been conducted. This paper sought to comprehensively summarize the characteristics of population pharmacokinetic models of PMB and provide a theoretical basis for the individualized use of PMB. Methods: In this review, we systematically searched the PubMed and Embase databases to find articles on population pharmacokinetic models published from database establishment to August 2021. Results: A total of 10 studies were included in this review, including studies on various types of severe infections caused by multi-drug-resistant bacteria, hospital-acquired infections with fibrosis and other male and female populations, and a study of 2 continuous renal replacement therapy (CRRT) patients, aged 16-94 years, who received PMB doses of 10-360 mg/day (0.13-3.45 mg/kg/day), at an administration time of 0.5-6 hours. First-order linear elimination was used in all the studies; a 1-compartment model was used in 5 studies, and a 2-compartment model was used in 5 studies. The most common covariates were creatinine clearance (CrCL) and body weight. Discussion: Although these studies included several covariates and total clearance (CL) was close, but the external validation of some models was poorly correlated between the actual and predicted value. Novel or potential covariates represent important directions for further study.
RESUMEN
Objective: Our study aimed to evaluate the influence of methylenetetrahydrofolate reductase (MTHFR) polymorphism on the clinical features and therapeutic effects in patients with migraine. Methods: The data of 135 patients with migraine were collected from January 2021 to December 2021. The MTHFR C677T polymorphism was analyzed. The pain intensity was evaluated using a numerical rating scale (NRS) during treatment. The levels of folic acid, homocysteine (Hcy), vitamin B12, interleukin-2 (IL-2), IL-4, and ferritin, and changes of NRS were compared between folic acid and conventional treatment groups stratified by different genotypes of MTHFR in migraine patients. Results: The levels of Hcy and ferritin in male patients were higher than that in female patients (P < 0.05); Compared with CC and CT genotype groups, the TT genotype group showed significantly higher Hcy levels (P < 0.05) and lower folic acid levels (P < 0.05); In both folic acid and conventional treatment groups, a significant decrease in NRS score was observed in different genotypes post-treatment (P < 0.05). Patients with TT genotype in the folic acid treatment group showed better therapeutic efficacy than conventional treatment group (P < 0.05). There is no significant difference in the therapeutic efficacy in other genotypes between the two groups (P > 0.05). Conclusion: The MTHFR C677T genotyping may provide a new method to guide and optimize individualized medication for migraine patients.
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An AgCl/Ag3PO4 composite has been successfully fabricated by a simple desorption-precipitation method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV/Vis), and photoluminescence (PL) have been used to study the structural and physicochemical characteristics of the AgCl/Ag3PO4 composite. The photocatalytic activity of the AgCl/Ag3PO4 composite has been tested by the degradation of parabens under visible-light irradiation. 100% of MPB was degraded within 40â¯min in the AgCl/Ag3PO4-visible light system. Moreover, the photocatalytic activity of AgCl/Ag3PO4 remained at 94% of the original level after five runs, which was much higher than that of pure Ag3PO4 (25%). The obtained results confirmed that the AgCl/Ag3PO4 composite exhibited significantly higher photocatalytic performance and improved stability compared with bare Ag3PO4. The enhanced photocatalytic performance of the AgCl/Ag3PO4 composite could be mainly attributed to highly efficient charge separation through a synergistic effect of AgCl, Ag3PO4, and in situ photo-reduced Ag nanoparticles. Trapping experiments confirmed h+ and ·O2- to be the two main active species in the photocatalytic process. Finally, a possible photocatalytic mechanism for the charge-transfer process is proposed to account for the enhanced photocatalytic performance of the AgCl/Ag3PO4 composite.
