A Concern for Intraoperative Distractions and Interference: An Observational Study Identifying, Measuring, and Quantifying Both within the Operating Theatre

Background. Modern surgical research has broadened to include an interest into the investigation of surgical workflow. Rigorous analysis of the surgical process has a particular focus on distractions. Operating theatres are inherently full of distractions, many not pertinent to the surgical process. Distractions have the potential to increase surgeon stress, operative time, and complications. Our study aims to objectively identify, classify, and quantify distractions during the surgical process. Methods. 46 general surgical procedures were observed within a tertiary Irish hospital between June 2019 and October 2019. An established observational tool was used to apply a structured observation to all operations. Additionally, a nine-point ordinal behaviourally anchor scoring scale was used to assign an interference level to each distraction. Results. The total operative observation time was 4605 minutes (mean = 100.11 minutes, std. deviation: 45.6 minutes). Overall, 855 intraoperative distractions were coded. On average, 18.58 distractions were coded per operation (std. deviation: 6.649; range: 5–34), with 11.14 distractions occurring per hour. Entering/exiting (n = 380, 42.88%) and case irrelevant communication (n = 251, 28.32%) occurred most frequently. Disruption rate was highest within the first (n = 275, 32%) and fourth operative quartiles (n = 342, 41%). Highest interference rates were observed from equipment issue and procedural interruptions. Anaesthetists initiated CIC more frequently (2.72 per operation), compared to nurses (1.57) and surgeons (1.17). Conclusion. Our results confirm that distractions are prevalent within the operating theatre. Distractions contribute to significant interferences of surgical workflow. Steps can be taken to reduce overall prevalence and interference level by drawing upon a systems-based perspective. However, due to the ubiquitous nature of distractions, surgeons may need to develop skills to help them resume interrupted primary tasks so as to negate the effects distraction has on surgical outcomes. Data for the above have been presented as conference abstract in 28th International Congress of the European Association for Endoscopic Surgery (EAES) Virtual Congress, 23–26 June 2020.

Morphological Change and Cell Disruption of Haematococcus pluvialis Cyst during High-Pressure Homogenization for Astaxanthin Recovery

Haematococcus pluvialis accumulates astaxanthin, which is a high-value antioxidant, during the red cyst stage of its lifecycle. The development of a rigid cell wall in the cysts hinders the recovery of astaxanthin. We investigated morphological changes and cell disruption of mature H. pluvialis cyst cells while using high-pressure homogenization for astaxanthin extraction. When treated with French-press-cell (pressure, 10,000–30,000 psi; passage, 1–3), the intact cyst cells were significantly broken or fully ruptured, releasing cytoplasmic components, thereby facilitating the separation of astaxanthin by ethyl acetate. Fluorescence microscopy observations using three different fluorescent dyes revealed that a greater degree of cell breakage caused greater external dispersion of astaxanthin, chlorophyll, lipids, proteins, and carbohydrates. The mechanical treatment resulted in a high cell disruption rate of up to 91% based on microscopic cell typing and Coulter methods. After the ethyl acetate extraction, the astaxanthin concentration significantly increased by 15.2 mg/L in proportion to the increase in cell disruption rate, which indicates that cell disruption is a critical factor for solvent-based astaxanthin recovery. Furthermore, this study recommends a synergistic combination of the fast instrumental particle-volume-distribution analysis and microscope-based morphologic phenotyping for the development of practical H. pluvialis biorefinery processes that co-produce various biological products, including lipids, proteins, carbohydrates, chlorophyll, and astaxanthin.

Star accretion onto supermassive black holes in axisymmetric galactic nuclei

Tidal Disruption (TD) of stars by supermassive central black holes from dense rotating star clusters is modeled by high-accuracy direct N-body simulation. We study the time evolution of the stellar tidal disruption rate and the origin of tidally disrupted stars. Compared with that in spherical systems, we found a higher TD rate in axisymmetric systems. The enhancement can be explained by an enlarged loss-cone in phase space which is raised from the fact that total angular momentum J is not conserved. As in the case of spherical systems, the distribution of the last apocenter distance of tidally accreted stars peaks at the classical critical radius. However, the angular distribution of the origin of the accreted stars reveals bimodal features. We show that the bimodal structure can be explained by the presence of two families of regular orbits, namely short axis tube and saucer orbits.

The Study on the Sludge Anaerobic Digestion after the Ultrasonic Treatment

This paper studied on the energy efficiency of the sludge anaerobic digestion after the pretreatment of ultrasonic wave. Adding ratio of the sludge after the ultrasonic pretreatment was 30 %，50 %，70 % respectively, the retention time of the digested sludge was 27 d，20 d，16 d. The experiment results show that to treat the sludge by ultrasonic wave in 50-90s is considered to be suitable and the Energy Consumption is relatively less. The ultrasonic disruption rate is 3 %-4.2 % which met the requirement of the sludge anaerobic digestion technique. When the adding ratio of the sludge by the ultrasonic pretreatment was 70 % and the retention time of the digested sludge was 20 d, the gas production of the unit sludge is the highest. When the adding ratio of the sludge by the ultrasonic pretreatment was 30 % and the retention time of the digested sludge was 20 d, the effect is better than others.