Enabling lunar and space missions by laser power transmission

Applications are proposed for laser power transmission on the Moon. A solar-pumped laser in lunar orbit would beam power to the lunar surface for conversion into either electricity or propulsion needs. For example, lunar rovers could be much more flexible and lighter than rovers using other primary power sources. Also, laser power could be absorbed by lunar soil to create a hard glassy surface for dust-free roadways and launch pads. Laser power could also be used to power small lunar rockets or orbital transfer vehicles, and finally, photovoltaic laser converters could power remote excavation vehicles and human habitats. Laser power transmission is shown to be a highly flexible, enabling primary power source for lunar missions

Time Out of General Surgery Specialty training in the UK:A National Database Study

ObjectiveGeneral surgery specialty training in the United Kingdom takes 6 years and allows trainees to take time out of training. Studies from the United States have highlighted an increasing trend for taking time out of surgical training for research. This study aimed to evaluate trends in time out of training and the impact on the duration of UK general surgical specialty training.Design, setting, and participantsA cohort study using routinely collected surgical training data from the Intercollegiate Surgical Curriculum Program database for General surgery trainees registered from August 1, 2007. Trainees were classified as Completed Training or In-Training. Out of training periods were identified and time in training calculated (both unadjusted and adjusted for out of training periods) with a predicted time in training for those In-Training.ResultsOf the trainees still In-Training (n = 994), a greater proportion had taken time out of training compared with those who had completed training (n = 360; 54.5% vs 45.9%, p < 0.01). A greater proportion of the In-Training group had undertaken a formal research period compared with the Completed Training group (35.1% vs 6.1%, p < 0.01). Total unadjusted training time in the Completed Training group was a median 6.0 (interquartile range 6.0-7.0) years compared with a predicted unadjusted training time in the In-Training group, with an out of training period recorded, of a median 8.0 (interquartile range 7.0-9.0) years.ConclusionsTrainees are increasingly taking time out of surgical training, particularly for research, with a subsequent increase in total time of training. This should be considered when redesigning surgical training programs and planning the future surgical workforce

Changing Autonomy in Operative Experience Through UK General Surgery Training:A National Cohort Study

Objectives:To determine the operative experience of UK general surgery trainees and assess the changing procedural supervision and acquisition of competency assessments through the course of training.Background Summary Data: Competency assessment is changing with concepts of trainee autonomy decisions (termed entrustment decisions) being introduced to surgical training.Methods: Data from the Intercollegiate Surgical Curriculum Programme (ISCP) and the eLogbook databases for all UK General Surgery trainees registered from 1st August 2007 who had completed training were used. Total and index procedures (IP) were counted and variation by year of training assessed. Recorded supervision codes and competency assessment outcomes for IPs were assessed by year of training.Results: We identified 311 trainees with complete data. Appendicectomy was the most frequently undertaken IP during first year of training (mean procedures (mp) = 26) and emergency laparotomy during final year of training (mp = 27). The proportion of all IPs recorded as unsupervised increased through training (

Method and apparatus for determining time, direction, and composition of impacting space particles

A space particle collector for recording the time specific particles are captured, and its direction at the time of capture, utilizes an array of targets, each comprised of an MOS capacitor on a chip charged from an external source and discharged upon impact by a particle through a tab on the chip that serves as a fuse. Any impacting particle creates a crater, but only the first will cause a discharge of the capacitor. A substantial part of the metal film around the first crater is burned off by the discharge current. The time of the impulse which burns the tab, and the identification of the target, is recorded together with data from flight instruments. The metal film is partitioned into pie sections to provide a plurality of targets on each of an array of silicon wafers, thus increasing the total number of identified particles that can be collected. It is thus certain which particles were captured at what specific times

A systematic review of population-based studies examining outcomes in primary retroperitoneal sarcoma surgery

Retroperitoneal sarcomas (RPS) are rare mesenchymal tumours. Their rarity challenges our ability to understand expected outcomes. The aim of this systematic review was to examine 30-day morbidity and mortality, overall survival rates and prognostic predictors from population-based studies for patients undergoing curative resection for primary RPS. A systematic literature review of EMBASE, MEDLINE, PUBMED and the Cochrane library was performed using PRISMA for population-based studies reporting from nationally registered databases on primary RPS surgical resections in adults. The main outcomes evaluated were 30-day morbidity and mortality and overall survival rates. The use of additional treatment modalities and predictors of overall survival were also examined. Fourteen studies (n = 12 834 patients) reporting from 3 national databases, (Surveillance, Epidemiology and End Results (SEER), the United States National Cancer Database (US NCDB) and the American College of Surgeons’ National Surgical Quality Improvement Program (ACS NSQIP)) were analysed. The reported overall 30-day morbidity and mortality were 23% (n = 191/846) and 3% (n = 278/10 181) respectively. Reported use of perioperative radiotherapy was 28%. No study reported loco-regional recurrence rates. Overall reported 5-year survival ranged from 52% to 62%. Independent predictors of overall survival were age of the patient, resection margin, tumour grade and size, histological subtype and receipt of radiotherapy. This review of population-based data demonstrated relatively low 30-day morbidity rates in patients undergoing curative surgical resections for primary RPS. Thirty-day mortality rates were similar to other abdominal tumour groups. There remains a paucity of data reporting recurrence rates, however 5-year survival rates ranged from 52 to 62%

The impact of urgency of umbilical hernia repair on adverse outcomes in patients with cirrhosis: a population-based cohort study from England

\ua9 2023, The Author(s). Introduction: Umbilical hernia is common in patients with cirrhosis; however, there is a paucity of dedicated studies on postoperative outcomes in this group of patients. This population-based cohort study aimed to determine the outcomes after emergency and elective umbilical hernia repair in patients with cirrhosis. Methods: Two linked electronic healthcare databases from England were used to identify all patients undergoing umbilical hernia repair between January 2000 and December 2017. Patients were grouped into those with and without cirrhosis and stratified by severity into compensated and decompensated cirrhosis. Length of stay, readmission, 90-day case fatality rate and the odds ratio of 90-day postoperative mortality were defined using logistic regression. Results: In total, 22,163 patients who underwent an umbilical hernia repair were included and 297 (1.34%) had cirrhosis. More patients without cirrhosis had an elective procedure, 86% compared with 51% of those with cirrhosis (P &lt; 0.001). In both the elective and emergency settings, patients with cirrhosis had longer hospital length of stay (elective: 0 vs 1 day, emergency: 2 vs 4 days, P &lt; 0.0001) and higher readmission rates (elective: 4.87% vs 11.33%, emergency:11.39% vs 29.25%, P &lt; 0.0001) than those without cirrhosis. The 90-day case fatality rates were 2% and 0.16% in the elective setting, and 19% and 2.96% in the emergency setting in patients with and without cirrhosis respectively. Conclusion: Emergency umbilical hernia repair in patients with cirrhosis is associated with poorer outcomes in terms of length of stay, readmissions and mortality at 90 days

Migration of Interplanetary Dust

We numerically investigate the migration of dust particles with initial orbits close to those of the numbered asteroids, observed trans-Neptunian objects, and Comet Encke. The fraction of silicate asteroidal particles that collided with the Earth during their lifetime varied from 1.1% for 100 micron particles to 0.008% for 1 micron particles. Almost all asteroidal particles with diameter d>4 microns collided with the Sun. The peaks in the migrating asteroidal dust particles' semi-major axis distribution at the n:(n+1) resonances with Earth and Venus and the gaps associated with the 1:1 resonances with these planets are more pronounced for larger particles. The probability of collisions of cometary particles with the Earth is smaller than for asteroidal particles, and this difference is greater for larger particles.Comment: Annals of the New York Academy of Sciences, 15 pages, 8 Figures, submitte