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Abstract The risk of virus transmission via the touching of contaminated masks has long been assumed by infection control teams. Yet, robust evidence to support this belief has been lacking. This risk was investigated in a laboratory setting by measuring the amount of viable influenza virus successfully transferred from artificially contaminated medical (surgical) mask surfaces to a human finger used to swipe their outer surface under various experimental conditions. Despite being exposed to high levels of virus contamination on the masks, very little or no viable virus was successfully transferred from the mask to the finger in these experiments.

Abstract Background Pancreas divisum (PD), the most common pancreatic anomaly, is caused by the failure of pancreatic bud fusion in the embryo. Although most cases are asymptomatic, it can cause pancreatitis or epigastric pain. We report an unusual case of PD in an infant. Case presentation The patient was a 9-month-old girl with no pertinent medical history. She had suffered vomiting and diarrhea for 1 week before transfer to our hospital. Her general condition was poor, and abdominal distention was noted. Blood tests revealed microcytic anemia with normal chemical markers. The parents reported no episode of pancreatitis. Ultrasonography revealed massive ascites, which was later found to be bloody. Enhanced computed tomography and magnetic resonance imaging depicted a cystic lesion, approximately 2 cm in size, anterior to the second portion of the duodenum. During exploratory laparotomy, a pinhole was identified on the cyst wall, which was mistakenly identified as a duodenal perforation, and direct closure was performed. Postoperative levels of serum amylase and inflammation markers were elevated, and the amount of ascites increased, impairing oral feeding. The level of pancreatic enzymes in the ascites was high. Imaging studies were repeated, but the cause of pancreatic fistula was not identified. Conservative therapy, including administration of total parenteral nutrition, antibiotics, and octreotide, was initiated, but the situation did not improve. Three months after admission, endoscopic retrograde cholangiopancreatography showed a thick dorsal pancreatic duct communicating with a hypoplastic ventral duct, which was indicative of PD. Contrast medium leaking from the dorsal duct near the minor ampulla revealed the presence of a pseudocyst. Stenting via the minor papilla was impossible because the minor papilla was obstructed. Instead, a stent was inserted into the ventral pancreatic duct. Endoscopic transgastric drainage of the cyst was effective, and the patient was discharged, 7 months after admission. The patient is healthy, but the gastric stent needs to be replaced regularly. Conclusion In children, PD can manifest with pancreatic pseudocyst that causes pancreatic ascites, even in the absence of pancreatitis. This may be a previously unrecognized manifestation of PD in children, and clinicians need to be aware of it.

Abstract Although the surface of the human hands contains high antimicrobial activity, studies investigating the precise components involved and the relationship between natural antimicrobial activity and morbidity in infectious diseases are limited. In this study, we developed a method to quantitatively measure the antimicrobial activity of hand surface components. Using a clinical survey, we validated the feasibility of our method and identified antimicrobial factors on the surface of the human hand. In a retrospective observational study, we compared the medical histories of the participants to assess infectious diseases. We found that the antimicrobial activity on the surface of the hands was significantly lower in the high morbidity group (N = 55) than in the low morbidity group (N = 54), indicating a positive association with the history of infection in individuals. A comprehensive analysis of the hand surface components indicated that organic acids, especially lactic acid and antimicrobial peptides, are highly correlated with antimicrobial activity. Moreover, the application of lactic acid using the amount present on the surface of the hand significantly improved the antimicrobial activity. These findings suggest that hand hygiene must be improved to enhance natural antimicrobial activity on the surface of the hands.

Abstract The existence of new vector-like quarks is often predicted by models of new physics beyond the Standard Model, and the development of discovery strategies at colliders is the object of an intense effort from the high-energy community. Our analysis aims at identifying the constraints on and peculiar signatures of simplified scenarios containing two vector-like quark doublets mixing with any of the SM quark generations. This scenario is a necessary ingredient of a broad class of theoretically motivated constructions. We focus on the two charge 2/3 states t 1,2 ′ that, due to their peculiar mixing patterns, feature new production and decay modes that are not searched for at the LHC: single production of the heavier state can dominate over the light one, while pair production via electroweak interactions overcomes the QCD one for masses at the TeV scale.

It is well known that the surface roughness of metal substrates considerably influences the tribological properties of solid lubricants. In this study, the surfaces of metal substrates were modified by wet-blasting and polishing, and the lubrication performance of synthetic mica-organic intercalation compounds on these substrates was evaluated using an upsetting-ironing type tribometer. Wet-blasted substrates lubricated with synthetic mica exhibited the best anti-seizure ability, whereas a lubricated polished metal surface produced the worst results. Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS) revealed that concavities prepared by wet-blasting still remained on the ironed substrate surface, and the intercalated synthetic mica trapped in concavities was supplied to the flat areas as ironing advanced across the substrate surface. Furthermore, EDS and Fourier-transform infrared spectroscopy (FTIR) analysis showed that intercalated synthetic mica extended on the ironed surface while releasing organic compounds from its interlayer spaces. As the ironing process continued to progress, the initial concavities gradually became shallow, but they did not completely flatten. Therefore, a roughened surface is more advantageous for achieving improved lubricity due to the continuous supply of solid lubricant from concavities to the flattened areas where seizure is likely to take place.

This work provides an overview on the current status of phenomenology and searches for heavy vector-like quarks, which are predicted in many models of new physics beyond the Standard Model. Searches at Tevatron and at the LHC, here listed and shortly described, have not found any evidence for new heavy fermionic states (either chiral or vector-like) and have therefore posed strong bounds on their masses: depending on specific assumptions on the interactions and on the observed final state, vector-like quarks with masses up to roughly 400–600 GeV have been excluded by all experiments. In order to be as simple and model independent as possible, the chosen framework for the phenomenological analysis is an effective model with the addition of a vector-like quark representation (singlet, doublet, or triplet under SU(2)L) which couples through Yukawa interactions with all SM families. The relevance of different observables for the determination of bounds on mixing parameters is then discussed and a complete overview of possible two body final states for every vector-like quark is provided, including their subsequent decay into SM particles. A list and short description of phenomenological analyses present in the literature are also provided for reference purposes.

This is the first report of a primary mucinous cystadenoma (MCA) arising from behind the posterior peritoneum of the descending colon in a paediatric patient. A large intra-abdominal cystic lesion was found incidentally during renal ultrasonography in a 14-year-old girl. Imaging studies showed a 13 × 9 × 15 cm homogeneous cystic lesion with mild contrast enhancement of the wall. The cyst appeared to originate from the retroperitoneum, but was separated from the left kidney, ovary, and pancreas. At laparotomy, there was a cyst behind the posterior peritoneum of the descending colon. The cyst was successfully excised, and histopathology showed MCA. Although primary MCA in the retroperitoneum is extremely rare in children, it should be considered in the differential diagnosis of an intra-abdominal cyst, since it needs to be excised to eliminate the risk of infection, recurrence, and malignancy.