on the protonation of glycocholate and glycodeoxycholate ions

AbstractThe protonation of glycocholate (GC−) and glycodeoxycholate (GDC−) ions was studied at 25°C and in N(CH3)4Cl as an ionic medium at concentrations 0.100, 0.500 and 0.800 mol L−1 by measuring the electromotive force of a galvanic cell containing a glass electrode, as a function of acidity of solution. Also the solubility of glycocholic and glycodeoxycholic acids was determined in the same experimental conditions. The protonation constants of GC− and GDC− were determined and it was found that a further protonation of HGC occurs by increasing acidity. Its protonation constant was also determined

Macroscopic transport by synthetic molecular machines

Nature uses molecular motors and machines in virtually every significant biological process, but demonstrating that simpler artificial structures operating through the same gross mechanisms can be interfaced with—and perform physical tasks in—the macroscopic world represents a significant hurdle for molecular nanotechnology. Here we describe a wholly synthetic molecular system that converts an external energy source (light) into biased brownian motion to transport a macroscopic cargo and do measurable work. The millimetre-scale directional transport of a liquid on a surface is achieved by using the biased brownian motion of stimuli-responsive rotaxanes (‘molecular shuttles’) to expose or conceal fluoroalkane residues and thereby modify surface tension. The collective operation of a monolayer of the molecular shuttles is sufficient to power the movement of a microlitre droplet of diiodomethane up a twelve-degree incline.

Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

HISTIDINE AND ORNITHINE AS LIGANDS TOWARDS ZINC(II)

The equilibria occurring in the systems zinc(II)-histidine and zinc(II)-ormthine have been studied at 25°C in 1.00 M NaCl as constant ionic medium by measuring the electromotive force of galvanic cells containing zinc amalgam and glass electrodes. The experimental data for both systems were accounted for by assuming the existence of the species ZnL+, ZnL2, ZnHL2 +, ZnHL2 +, ZnH2L2 2+ and ZnH2L3+, where L indicates the uninegative ligand anion (histidine or ornithine). For all the proposed species the stability constants have been determined. The protonation constants of histidine and ornithine were determined under the same experimental conditions, by using a H2 electrode. The validity of the results is supported by the good agreement between experimental data and calculated values

pH variations for milk.

Summary The pH variaton of raw and pasteurized milk with time was determined . It is recommended to employ pH measurements for grading milk samples regarding acidity

On the protonation of glycocholate and glycodeoxycholate ions

The protonation of glycocholate (GC−) and glycodeoxycholate (GDC−) ions was studied at 25°C and in N(CH3)4Cl as an ionic medium at concentrations 0.100, 0.500 and 0.800 mol L−1 by measuring the electromotive force of a galvanic cell containing a glass electrode, as a function of acidity of solution. Also the solubility of glycocholic and glycodeoxycholic acids was determined in the same experimental conditions. The protonation constants of GC− and GDC− were determined and it was found that a further protonation of HGC occurs by increasing acidity. Its protonation constant was also determined