931 research outputs found

    Surgical correction of pyelonephritis caused by multidrug-resistant Escherichia coli in a dairy cow

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    A four-year-old red Holstein Friesian cow was admitted to the clinic with fever and milk drop. Blood analysis revealed the presence of a chronic infection, and the diagnosis of pyelonephritis of the right kidney was made after repeated ultrasound examinations. The animal was treated with procaine benzylpenicillin, sulfadoxine trimethoprim, oxytetracycline and enrofloxacine but this therapy was not successful. Nephrectomy was performed after the left kidney proved to have a normal function. The removed right kidney was greatly enlarged and filled with pus. Escherichia coli was isolated from the kidney. The strain was multidrug-resistant, including resistance to aminopenicillins, streptomycin, sulfonamides and trimethoprim. The cow was treated with amoxicillin and clavulanic acid after the operation. Postoperatively, an abscess developed and a tube drain was placed during a second surgery to enable daily rinsing with a chlorhexidine solution. After a postoperative care period of two months, the animal was sent back to the farm, where it returned to an acceptable level of milk production. This case demonstrates that with basic surgical skills, a good preparation and knowledge of anatomy, nephrectomy is attainable for a first-opinion veterinarian, with an acceptable economic prognosis for the farmer

    Numerical investigation of crack self-sealing in cement-based composites with superabsorbent polymers

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    Recently the concept of crack self-sealing has been investigated as a method to prevent degradation and/or loss of functionality of cracked concrete elements. To obtain self-sealing effect in the crack, water swelling admixtures such as superabsorbent polymers (SAP) are added into the cementitious mix. In order to design such self-sealing systems in an efficient way, a three-dimensional mesoscale numerical model is proposed to simulate capillary absorption of water in sound and cracked cement-based materials containing SAP. The numerical results yield the moisture content distribution in cracked and sound domain, as well as the absorption and swelling of SAP embedded in the matrix and in the crack. The performance of the model was validated by using experimental data from the literature, as well as experimentally-informed input parameters. The validated model was then used to investigate the role of SAP properties and dosage in cementitious mixtures, on the water penetration into the material from cracks. Furthermore different crack widths were considered in the simulations. The model shows good agreement with experimental results. From the numerical investigation guidelines are suggested for the design of the studied composites

    A dynamic “predict, then optimize” preventive maintenance approach using operational intervention data

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    We investigate whether historical machine failures and maintenance records may be used to derive future machine failure estimates and, in turn, prescribe advancements of scheduled preventive maintenance interventions. We model the problem using a sequential predict, then optimize approach. In our prescriptive optimization model, we use a finite horizon Markov decision process with a variable order Markov chain, in which the chain length varies depending on the time since the last preventive maintenance action was performed. The model therefore captures the dependency of a machine’s failures on both recent failures as well as preventive maintenance actions, via our prediction model. We validate our model using an original equipment manufacturer data set and obtain policies that prescribe when to deviate from the planned periodic maintenance schedule. To improve our predictions for machine failure behavior with limited to no past data, we pool our data set over different machine classes by means of a Poisson generalized linear model. We find that our policies can supplement and improve on those currently applied by 5%, on average

    Comparing OpenBRR, QSOS, and OMM Assessment Models

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    Sonoprinting liposomes on tumor spheroids by microbubbles and ultrasound

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    Ultrasound-triggered drug-loaded microbubbles have great potential for drug delivery due to their ability to locally release drugs and simultaneously enhance their delivery into the target tissue. We have recently shown that upon applying ultrasound, nanoparticle-loaded microbubbles can deposit nanoparticles onto cells grown in 2D monolayers, through a process that we termed "sonoprinting". However, the rigid surfaces on which cell monolayers are typically growing might be a source of acoustic reflections and aspherical microbubble oscillations, which can influence microbubble-cell interactions. In the present study, we aim to reveal whether sonoprinting can also occur in more complex and physiologically relevant tissues, by using free-floating 3D tumor spheroids as a tissue model. We show that both monospheroids (consisting of tumor cells alone) and cospheroids (consisting of tumor cells and fibroblasts, which produce an extracellular matrix) can be sonoprinted. Using doxorubicin-liposome-loaded microbubbles, we show that sonoprinting allows to deposit large amounts of doxorubicin-containing liposomes to the outer cell layers of the spheroids, followed by doxorubicin release into the deeper layers of the spheroids, resulting in a significant reduction in cell viability. Sonoprinting may become an attractive approach to deposit drug patches at the surface of tissues, thereby promoting the delivery of drugs into target tissues

    Tanner-Whitehouse skeletal ages in male youth soccer players : TW2 or TW3?

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    BACKGROUND: The Tanner-Whitehouse radius-ulna-short bone protocol (TW2 RUS) for the assessment of skeletal age (SA) is widely used to estimate the biological (skeletal) maturity status of children and adolescents. The scale for converting TW RUS ratings to an SA has been revised (TW3 RUS) and has implications for studies of youth athletes in age-group sports. OBJECTIVES: The aim of this study was to compare TW2 and TW3 RUS SAs in an international sample of male youth soccer players and to compare distributions of players by maturity status defined by each SA protocol. METHODS: SA assessments with the TW RUS method were collated for 1831 male soccer players aged 11-17 years from eight countries. RUS scores were converted to TW2 and TW3 SAs using the appropriate tables. SAs were related to chronological age (CA) in individual athletes and compared by CA groups. The difference of SA minus CA with TW2 SA and with TW3 SA was used to classify players as late, average, or early maturing with each method. Concordance of maturity classifications was evaluated with Cohen's Kappa coefficients. RESULTS: For the same RUS score, TW3 SAs were systematically and substantially reduced compared with TW2 SAs; mean differences by CA group ranged from - 0.97 to - 1.16 years. Kappa coefficients indicated at best fair concordance of TW2 and TW3 maturity classifications. Across the age range, 42% of players classified as average with TW2 SA were classified as late with TW3 SA, and 64% of players classified as early with TW2 SA were classified as average with TW3 SA. CONCLUSION: TW3 SAs were systematically lower than corresponding TW2 SAs in male youth soccer players. The differences between scales have major implications for the classification of players by maturity status, which is central to some talent development programs

    Glycoprotein Ib activation by thrombin stimulates the energy metabolism in human platelets

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    <div><p>Thrombin-induced platelet activation requires substantial amounts of ATP. However, the specific contribution of each ATP-generating pathway <i>i</i>.<i>e</i>., oxidative phosphorylation (OxPhos) versus glycolysis and the biochemical mechanisms involved in the thrombin-induced activation of energy metabolism remain unclear. Here we report an integral analysis on the role of both energy pathways in human platelets activated by several agonists, and the signal transducing mechanisms associated with such activation. We found that thrombin, Trap-6, arachidonic acid, collagen, A23187, epinephrine and ADP significantly increased glycolytic flux (3–38 times <i>vs</i>. non-activated platelets) whereas ristocetin was ineffective. OxPhos (33 times) and mitochondrial transmembrane potential (88%) were increased only by thrombin. OxPhos was the main source of ATP in thrombin-activated platelets, whereas in platelets activated by any of the other agonists, glycolysis was the principal ATP supplier. In order to establish the biochemical mechanisms involved in the thrombin-induced OxPhos activation in platelets, several signaling pathways associated with mitochondrial activation were analyzed. Wortmannin and LY294002 (PI3K/Akt pathway inhibitors), ristocetin and heparin (GPIb inhibitors) as well as resveratrol, ATP (calcium-release inhibitors) and PP1 (Tyr-phosphorylation inhibitor) prevented the thrombin-induced platelet activation. These results suggest that thrombin activates OxPhos and glycolysis through GPIb-dependent signaling involving PI3K and Akt activation, calcium mobilization and protein phosphorylation.</p></div
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