1,056 research outputs found
Discrete mode laser diodes with ultra narrow linewidth emission <3kHz
Ex-facet, free-running ultra-low linewidth (<3 kHz), single mode laser emission is demonstrated using low cost, regrowth-free ridge waveguide discrete mode Fabry-Perot laser diode chips
Re-emergence of tularemia in Germany: Presence of <it>Francisella tularensis </it>in different rodent species in endemic areas
<p>Abstract</p> <p>Background</p> <p>Tularemia re-emerged in Germany starting in 2004 (with 39 human cases from 2004 to 2007) after over 40 years of only sporadic human infections. The reasons for this rise in case numbers are unknown as is the possible reservoir of the etiologic agent <it>Francisella (F.) tularensis</it>. No systematic study on the reservoir situation of <it>F. tularensis </it>has been published for Germany so far.</p> <p>Methods</p> <p>We investigated three areas six to ten months after the initial tularemia outbreaks for the presence of <it>F. tularensis </it>among small mammals, ticks/fleas and water. The investigations consisted of animal live-trapping, serologic testing, screening by real-time-PCR and cultivation.</p> <p>Results</p> <p>A total of 386 small mammals were trapped. <it>F. tularensis </it>was detected in five different rodent species with carrier rates of 2.04, 6.94 and 10.87% per trapping area. None of the ticks or fleas (n = 432) tested positive for <it>F. tularensis</it>. We were able to demonstrate <it>F. tularensis-</it>specific DNA in one of 28 water samples taken in one of the outbreak areas.</p> <p>Conclusion</p> <p>The findings of our study stress the need for long-term surveillance of natural foci in order to get a better understanding of the reasons for the temporal and spatial patterns of tularemia in Germany.</p
Could recombinant insulin compounds contribute to adenocarcinoma progression by stimulating local angiogenesis?
Negative effects on the progression of adenocarcinomas by hyperinsulinaemia and the insulin analogue glargine (A21Gly,B31Arg,B32Arg human insulin) have recently been suggested. Most actions of this insulin analogue have hitherto been explained by direct stimulation of growth potential of neoplastic cells and by its IGF-1 related properties. However, insulin-stimulated angiogenesis could be an additional factor involved in tumour progression and clinical outcomes associated with cancer. Five types of human adenocarcinoma (breast, colon, pancreas, lung and kidney) were evaluated for the presence of insulin receptors (IRs) on angiogenic structures. In an in vitro angiogenesis assay, various commercially available insulin compounds were evaluated for their potential to increase capillary-like tube formation of human microvascular endothelial cells (hMVEC). Insulin compounds used were: human insulin, insulin lispro (B28Lys,B29Pro human insulin), insulin glargine and insulin detemir (B29Lys[e-tetradecanoyl],desB30 human insulin). Insulin receptors were found to be strongly expressed on the endothelium of microvessels in all evaluated adenocarcinomas, in addition to variable expression on tumour cells. Low or no detectable expression of IRs was seen on microvessels in extratumoral stroma. Incubation with commercially available insulin compounds increased capillary-like tube formation of hMVEC in vitro. Our results suggest that all tested insulin compounds may stimulate tumour growth by enhancing local angiogenesis. Future studies need to confirm the association between insulin therapy in type 2 diabetes and tumour progressio
The effect of Covid-19 on pediatric surgical case volume.
Introduction
The COVID-19 pandemic has had an unprecedented ef- fect on hospital systems. Policy changes lead to de- creased hospital visits as well as surgical case volume. The literature on pediatric surgical case volume during the pandemic is sparse. Throughout the country, hospitals sought various policies to preserve personal protective equipment and other hospital resources, and to minimize avoidable peri- and postoperative sequelae due to COVID-19 infection. Our hospital first placed a hold on all elective surgeries. Later, all elective cases required a preoperative negative COVID test prior to proceed- ing. We sought to review the sequelae of our hospital’s policy in response to COVID-19. We identified trends in surgical case volume and cancellations due to a positive COVID-19 test. We also reviewed postoperative out- comes of cases with a positive test.
Material and Methods
This study was approved by the institutional IRB. Data was retrospectively collected on all surgical cases at our children’s hospital between March 2019 and March
2021. We marked the start of the COVID-19 pandemic as March 2020, when elective cases were suspended. A required preoperative negative COVID-19 test was im- plemented in May 2020. We identified pre-operative COVID-19 test results,the posted urgency of each case and 30-day outcomes from medical records.
Results
From March 2019 to March 2021, we identified 25,496 completed surgeries and 3,503 cancellations. 12,024 ca- ses proceeded during the first year of the pandemic, which appeared lower, compared to pre-pandemic case numbers. Of those, 2,785 (23%) cases were considered urgent or emergent. The average number of completed monthly cases fell from a pre-pandemic number of 1,123 to a pandemic number of 925. When comparing to a pre- pandemic month, average monthly case volume declined by 19%, with the largest decline noted to be 66%. There was a monthly average of 189 total cancellations between March 2020 and March 2021. 34 (18%) of those were for a positive preoperative COVID test. A total of 139 sur- geries commenced despite concomitant COVID-19 in- fection. 25 (18 %) had identifiable respiratory symptomsdocumented preoperatively. 13 (9 %) were deemed to have a respiratory complication afterward. Of those, three patients (2%) had a prolonged, and one (1%) had an unexpected reintubation. The remaining nine (6%) pa- tients had a prolonged oxygen requirement.
Conclusion
The COVID pandemic left operating rooms struggling to determine how to safely provide care to patients. This study demonstrated how the policies of one hospital af- fected the operating room case volume and how conco- mitant COVID infection affected outcomes in those that proceeded with surgery
A model of AW UMa
The contact binary AW UMa has an extreme mass ratio, with the more massive
component (the current primary) close to the main sequence, while the low mass
star at q ~ 0.1 (the current secondary) has a much larger radius than a main
sequence star of a comparable mass. We propose that the current secondary has
almost exhausted hydrogen in its center and is much more advanced in its
evolution, as suggested by Stepien. Presumably the current secondary lost most
of its mass during its evolution with part of it transferred to the current
primary. After losing a large fraction of its angular momentum, the binary may
evolve into a system of FK Com type.Comment: 5 pages, 6 figures, Accepted to MNRAS, content change
Treponema Infection Associated With Genital Ulceration in Wild Baboons
The authors describe genital alterations and detailed histologic findings in
baboons naturally infected with Treponema pallidum. The disease causes
moderate to severe genital ulcerations in a population of olive baboons (Papio
hamadryas anubis) at Lake Manyara National Park in Tanzania. In a field survey
in 2007, 63 individuals of all age classes, both sexes, and different grades
of infection were chemically immobilized and sampled. Histology and molecular
biological tests were used to detect and identify the organism responsible: a
strain similar to T pallidum ssp pertenue, the cause of yaws in humans.
Although treponemal infections are not a new phenomenon in nonhuman primates,
the infection described here appears to be strictly associated with the
anogenital region and results in tissue alterations matching those found in
human syphilis infections (caused by T pallidum ssp pallidum), despite the
causative pathogen’s greater genetic similarity to human yaws-causing strains
Mitochondrial Priming by CD28
T cell receptor (TCR) signaling without CD28 can elicit primary effector T cells, but memory T cells generated during this process are anergic, failing to respond to secondary antigen exposure. We show that, upon T cell activation, CD28 transiently promotes expression of carnitine palmitoyltransferase 1a (Cpt1a), an enzyme that facilitates mitochondrial fatty acid oxidation (FAO), before the first cell division, coinciding with mitochondrial elongation and enhanced spare respiratory capacity (SRC). microRNA-33 (miR33), a target of thioredoxin-interacting protein (TXNIP), attenuates Cpt1a expression in the absence of CD28, resulting in cells that thereafter are metabolically compromised during reactivation or periods of increased bioenergetic demand. Early CD28-dependent mitochondrial engagement is needed for T cells to remodel cristae, develop SRC, and rapidly produce cytokines upon restimulation—cardinal features of protective memory T cells. Our data show that initial CD28 signals during T cell activation prime mitochondria with latent metabolic capacity that is essential for future T cell responses
Inoculation of Weaned Pigs by Feed, Water, and Airborne Transmission of Salmonella enterica Serotype 4,[5],12:i:-
Salmonella enterica serotype 4,[5],12:i:- (STM) has become an increasing problem for food safety and has been often detected in pork products. For this study, weanling pigs were exposed to STM-contaminated feed, water, or air to determine possible STM transmission routes. An uninoculated control group of pigs was included. The STM was monitored daily in feces and rectal and nasal swabs. The STM colonization was most prevalent in tissues from tonsil, lower intestine, and mesenteric lymph nodes. No differences in lesion severity were observed between inoculated and control pigs. Contaminated feed, water, and aerosolized particles caused infection in weaned pigs; however, no STM colonization was observed in skeletal muscle destined for human consumption. Based on the results from this study, STM contamination in pork products most likely results from cross-contamination of meat by digesta or lymph node tissue during processing
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