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CO 2 -based hydroesterification is an attractive route to produce value added ester compounds, which could replace widely used CO-based hydroesterification processes if sufficient catalytic technologies are developed. One path to CO 2 -based hydroesterification could proceed through an organoformate intermediate, which is then used in olefin hydroesterification to generate the desirable esters. This route opens the possibility of creating a net CO 2 -based hydroesterification process using tandem catalytic systems for CO 2 hydrogenation to organoformate paired with formate-olefin hydroesterification. The tandem use of tripodal phosphine ruthenium(II) and 1,2-bis(di-tert-butylphosphinomethyl)benzene palladium catalysts were found to successfully produce methyl nonanoate from CO 2 , H 2 , methanol and 1-octene in a single-stage batch process. The CO 2 -based hydroesterification catalysis efficiency was found to be largely limited by the productivity of organoformate generation and competitive 1-octene reduction. Catalytic yields of methyl nonanoate can be enhanced by adjustments in reaction procedures, including the use of a two-stage batch reaction process or delayed introduction of 1-octene, achieving a yield of up to 32 %. Under select conditions, control experiments indicate yields of methyl nonanoate can be improved to ca 75 %. Preliminary studies indicate significant interplay between the two ligands employed in the molecular tandem catalytic systems and establish the first catalytic protocol for the selective CO 2 -based hydroesterification of olefins via organoformates., (© 2025 Wiley-VCH GmbH.)

Background: Tridimensional medical knowledge of human anatomy is a key step in the undergraduate and postgraduate medical education, especially in surgical fields. Training simulation before real surgical procedures is necessary to develop clinical competences and to minimize surgical complications., Methods: Latex injection of vascular system in brain and in head-neck segment is made after washing out of the vascular system and fixation of the specimen before and after latex injection., Results: Using this latex injection technique, the vascular system of 90% of brains and 80% of head-neck segments are well-perfused. Latex-injected vessels maintain real appearance compared to silicone, and more flexible vessels compared to resins. Besides, latex makes possible a better perfusion of small vessels., Conclusions: Latex vascular injection technique of the brain and head-neck segment is a simulation model for neurosurgical training based on real experiencing to improve surgical skills and surgical results., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (© 2024 Pérez-Cruz, Macías-Duvignau, Reyes-Soto, Gasca-González, Baldoncini, Miranda-Solís, Delgado-Reyes, Ovalles, Catillo-Rangel, Goncharov, Nurmukhametov, Lawton, Montemurro and Encarnacion Ramirez.)

Introduction The spine is the third most frequent site of metastasis, after the lungs and liver, in breast cancer patients. The current treatment modality is based on the prognosis calculated according to multiple clinical features; therefore, multiple scores have been developed to make the therapeutic decision; however, there are no specific scores to take an adequate therapeutic approach in the treatment of vertebral metastases due to breast cancer. The aim of the study is to identify the prognostic factors associated with survival in breast cancer patients with spinal metastatic disease. Methods A retrospective cohort study was carried out at the National Cancerology Institute (INCAN) in Mexico City from January 2011 to December 2017. To this extent, 56 consecutive cases of patients with breast cancer were included. Multiple demographic, laboratory, and clinical variables were taken into account for the survival calculation. Kaplan-Meier graphs and log-rank tests were performed to observe significant differences by subgroups in survival, and Cox regression was used for multivariate analysis. Results Concerning the survival analysis, the patients who presented extra-spinal metastases, an unstable spine, and Frankel grade C had a statistically significantly worse prognosis. In the multivariate analysis, the variables included extra-spinal metastases, age >50 years, spinal instability, serum alkaline phosphatase, and CA 15.3 serum levels, finding statistical significance with a p=0.015. Conclusion Prognostic factors associated with shorter overall survival in breast cancer patients with metastatic spinal disease were the presence of extra-spinal metastases and spinal instability. Additionally, the use of the Tomita and Tokuhashi scores for patients with breast cancer and spinal metastases is not justified at present. The study should be continued with a larger population to decrease biases and obtain a more homogeneous sample, as well as to obtain a personalized score to determine a more efficient treatment for these patients., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Reyes Soto et al.)

Laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma optical emission spectrometry (LA-ICP-OES) were used simultaneously for the elemental analysis of asphaltene samples using minimum sample pretreatment in combination with low laser energy to reduce the amount of removed particles and avoid carbon deposits in the ablation cell. Quantitative analyses of S, Ni, and V were accomplished with LA-ICP-OES using external calibration with the C line as internal standard. The aromatic/paraffinic nature of the asphaltenes was also obtained throughout the H/C ratio using LIBS and partial least square regression model. The results showed very good agreement (±10%) between the concentration obtained by LA-ICP-OES and microwave-assisted acid digestion values.

The synthesis and characterization of molybdenum colloidal particles were evaluated using thermal and sonochemical methods and starting from different metal precursors, Mo(CO)6 and (NH4)2MoS4. The products were characterized by elemental analysis, spectroscopic (UV, FTIR), and surface analysis (XPS) techniques, as well as by transmission electron microscopy (TEM) for determining the particle sizes. Using Mo(CO)6 as metal source, particle sizes with an average diameter of 1.5 nm can be obtained using tert-amyl alcohol as solvent and tetrahydrothiophene as sulfurating ligand. The characterization of these particles showed that they are composed of molybdenum oxide MoO3. Using (NH4)2MoS4 as metal precursor, particles with average diameters of 4.7 and 2.5 nm were synthesized using thermal and sonochemical methods, respectively. The characterization of these particles showed them to be composed of molybdenum sulfide, MoS2. The sonochemical method proved to be the fastest and most convenient synthetic pathway of obtaining small colloidal particles at low temperatures and with control of the average size. Copyright 1998 Academic Press.