Tubular roof bit design, and evaluation of roof drag-bits

The method of supporting excavated roof in coal mines by conventional roof bolting systems is challenged due to its shortcomings of the timeconsuming installation and the increased number of accidents attributable to the work under unsupported roofs. Though a few alternatives have been considered, the ultimate and most efficient bolting method has often been conceived as the one called a self-drilling roof bolt, or a Rapid Face Bolting System. The on-going Rapid Face Bolting project undertaken by the University of Wollongong includes a special drilling bit design, and the principal design considerations for this tubular roof bit are high efficiency and low cost. Through review of the physical properties of different cutting materials, considering the special needs of the project and establishing a series of special criteria for a tubular roof bit design, two kinds of tubular roof bolts are proposed to suit hard and soft rock formations, respectively

Whirlpool No More: A Case of Misdiagnosed Malrotation with Midgut Volvulus

Introduction: Adult intestinal malrotation with midgut volvulus is rare and most often diagnosed on abdominal imaging. Once the diagnosis is made, prompt surgical intervention is necessary. A finding suggestive of malrotation with midgut volvulus on abdominal imaging is the “whirlpool” sign where the superior mesenteric vein and superior mesenteric artery twist at the root of the abdominal mesentery. This sign was once thought to be pathognomonic, but recent studies have shown that it can be seen in asymptomatic patients.Case Report: A 20-year-old female presented to our emergency department with diffuse abdominal pain. Computed tomography demonstrated the “whirlpool” sign with a concern for malrotation with midgut volvulus. Surgical consultation was obtained and the patient was rushed to the operating room for an exploratory laparotomy. Normal mesenteric attachments were seen and no significant pathology was identified during the laparotomy. The patient was eventually diagnosed with gastritis and discharged in stable condition.Conclusion: Emergency physicians and surgeons alike should be cautious in confirming malrotation with midgut volvulus solely due to the “whirlpool” sign on abdominal imaging. Premature diagnostic closure can lead to unnecessary procedures and interventions for patients as in the case we report here

Role of POCUS in Assessing an Acute Aortic Thrombus

A 67-year-old female patient presented with abdominal pain with a recent diagnosis of paroxysmal atrial fibrillation. Computed tomography (CT) of the abdomen demonstrated a filling defect concerning for an aortic thrombus. Point of care ultrasound (POCUS) confirmed a mobile thrombus in the proximal abdominal aorta in close proximity to several major arterial branches, leading to urgent surgical consultation due to a concern for mesenteric and end-organ ischemia. POCUS played a role in determining patient management in this novel case, and the patient was anticoagulated and ultimately discharged from the hospital

Epinephrine in Cardiac Arrest: Identifying a Potential Limit for Resuscitation

Introduction: Epinephrine continues to be a fundamental part of the Advanced Cardiac Life Support algorithm despite a lack of evidence that it improves neurologically intact survival. Our aim was both to identify a potential upper limit of epinephrine use in resuscitations and to demonstrate real-world epinephrine use in different patient subgroups.Methods: This was a single-center, retrospective cohort study, conducted between August 1, 2016–July 1, 2021, of patients with medical cardiac arrest who were administered a known number of epinephrine doses. The primary outcome was neurologically intact discharge defined by a modified Rankin scale ≤3, with secondary outcomes of comparing epinephrine doses by age, rhythm, and emergency medical services vs emergency department administration of epinephrine.Results: The study included 1,330 patients, with 184 patients (13.8%) surviving to neurologically intact discharge. The primary outcome of neurologically intact discharge was found in 89 (65.4%) patients in the zero epinephrine dose group, 75 (20.0%) in the 1-3 dose group, 15 (4.3%) in the 4-6 dose group, and one (0.002%) in the ≥7 dose group (P < 0.001). Patients received similar amounts of epinephrine when stratified by age, while patients with shockable rhythms received more epinephrine than patients with non-shockable rhythms.Conclusion: There was a significant decrease in neurologically intact discharge with increasing number of epinephrine doses, and our data suggests that seven or more doses of epinephrine is almost always futile. While further prospective studies are needed, clinicians should consider epinephrine doses when weighing the futility or benefit of continued resuscitation efforts

Prevalence of Phantom Scanning in Cardiac Arrest and Trauma Resuscitations: The Scary Truth

Background: The prevalence of phantom scanning, or point of care ultrasound (POCUS) performed without saving images, has not been well studied. Phantom scanning can negatively affect patient care, reduce billed revenue, and can increase medicolegal liability. We sought to quantify and compare the prevalence of phantom scanning among emergency department (ED) cardiac arrests and trauma resuscitations. Methods: This was a single center, retrospective cohort study from July 1, 2019, to July 1, 2021, of all occurrences of POCUS examination documented on the resuscitation run sheet during cardiac arrest and trauma resuscitations. Two investigators reviewed the run sheets to screen for POCUS documentation. Instances where documentation was present were matched with saved images in the picture archiving and communication system. Instances where documentation was present but no images could be located were considered phantom scans. A two-tailed student’s t test was utilized to compare the phantom scanning rate between cardiac arrest and trauma resuscitations. Results: A total of 1,862 patients were included in the study period, with 329 cardiac arrests and 401 trauma resuscitations having run sheet documentation of POCUS performance. The phantom scanning rate in cardiac arrests and trauma resuscitations was 70.5% (232/329) and 86.5% (347/401), respectively (p < 0.001). Conclusion: Phantom scanning is common in both cardiac arrests and trauma resuscitations in the ED at our institution, but is significantly higher in trauma resuscitations. Further research is needed to assess causes and develop potential solutions to reduce the high prevalence of phantom scanning

The complete genome of the crenarchaeon Sulfolobus solfataricus P2

The genome of the crenarchaeon Sulfolobus solfataricus P2 contains 2,992,245 bp on a single chromosome and encodes 2,977 proteins and many RNAs. One-third of the encoded proteins have no detectable homologs in other sequenced genomes. Moreover, 40% appear to be archaeal-specific, and only 12% and 2.3% are shared exclusively with bacteria and eukarya, respectively. The genome shows a high level of plasticity with 200 diverse insertion sequence elements, many putative nonautonomous mobile elements, and evidence of integrase-mediated insertion events. There are also long clusters of regularly spaced tandem repeats. Different transfer systems are used for the uptake of inorganic and organic solutes, and a wealth of intracellular and extracellular proteases, sugar, and sulfur metabolizing enzymes are encoded, as well as enzymes of the central metabolic pathways and motility proteins. The major metabolic electron carrier is not NADH as in bacteria and eukarya but probably ferredoxin. The essential components required for DNA replication, DNA repair and recombination, the cell cycle, transcriptional initiation and translation, but not DNA folding, show a strong eukaryal character with many archaeal-specific features. The results illustrate major differences between crenarchaea and euryarchaea, especially for their DNA replication mechanism and cell cycle processes and their translational apparatus