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BACKGROUND: Veterinary antibiotics are chemical compounds used to kill or inhibit the growth of pathogenic bacteria associated with animal diseases. These molecules can be defined by their retention times (tR) in liquid chromatography–mass spectrometry (LC–MS). One strategy to predict the tR of new veterinary antibiotics is the development of predictive quantitative structure–property relationships (QSPRs), which were used in this study. RESULTS: A database of 122 antibiotics was selected in which the tR was measured using a Hypersil GOLD column. An optimal three‐feature model was developed by integrating the unsupervised variable reduction, replacement method variable subset selection, and multiple linear regression. The negligible differences among the coefficient of determination and the root‐mean‐square error for the training set (R2 = 0.902 and RMSEC = 0.871) and test set (Q2 = 0.854 and RMSEP = 1.064) indicate a stable and predictive model. In a further step, a more in‐depth explanation of the mechanism of action of each descriptor in predicting the tR is provided, with the construction of the theoretical chemical space for accurate predictions of new antibiotics. CONCLUSION: The in silico model developed in this work identified three molecular descriptors associated with aqueous solubility, octanol–water partition coefficient, and the presence of negative and lipophilic atom pairs. The QSPR developed here could be implemented by agricultural and food chemists to identify and monitor existing and new antibiotics within the framework of LC–MS. The computational model was developed in accordance with five principles outlined by the Organization for Economic Co‐operation and Development. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The influence of additives on the structural behaviour of cement-stabilised rammed earth was investigated through an experimental programme based on 13 different mixes with varying cement contents (6, 8 and 10% by earth weight) and three different types of additives (superplasticiser, air-entraining agent (AEA) and hardening accelerator). In total, 156 specimens were fabricated and tested at 7 and 28 days in order to compare their compressive strength and other properties such as stress–strain relationships, shrinkage and workability. The results highlighted the essential role of cement in increasing the compressive strength of the material. Specifically, cement contents of 6%, 8% and 10% corresponded, respectively, to strength increases of 41%, 80% and 92% compared with the reference mix with a mean compressive strength of 1.15 MPa. The AEA was found to be the most effective additive for increasing the compressive strength, with obtained strengths of up to 2.93 MPa (an increase of 155% compared with the reference mix). The efficiency of each mix was evaluated through a strength/cost ratio. In addition, an overall comparison of compressive strength, shrinkage, deformation, cost and workability was performed using an analytic hierarchy process. Finally, the experimental results were compared with the mechanical requirements of various codes. [ABSTRACT FROM AUTHOR]

Objectives: to evaluate the effect of sublingual dexmedetomidine versus nasal dexmedetomidine plus remifentanil-propofol infusion pump in gynecological procedures. Methods: Uncontrolled, double-blind, prospective clinical trial. 68 patients with inclusion criteria were divided into 3 groups, group A [sublingual dexmedetomidine at 0.75 ug/kg], group B [nasal dexmedetomidine at 0.9 ug/kg] and group C [control] plus the addition of remifentanil and propofol by infusion pumps. Statistical analysis of qualitative variables with chisquare, quantitative variables with free distribution used Kruskal-Wallis and normal distribution Anova. Confidence level of 95% and margin of error of 9%. Results: age with a range of 30 to 32 years, the starting and maintenance dose of both remifentanil and propofol was halved compared to the control group, mainly in group A. With little variability in hemodynamic parameters without clinical repercussion. The most frequent adverse effects were respiratory depression in the control group, no analgesia was observed with the use of dexmedetomidine. And with a shorter stay in recovery rooms in patients who received nasal dexmedetomidine. Conclusions: sublingual administration is superior to nasal due to the lower requirement of propofol, less changes in mean blood pressure, with no adverse effects that can be managed, and with greater ease of administration. Although nasal administration produces a faster awakening and better control of heart rate. [ABSTRACT FROM AUTHOR]