56 research outputs found

    Intrahepatic cholestasis of pregnancy

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    Intrahepatic cholestasis of pregnancy (ICP) is a cholestatic disorder characterized by (i) pruritus with onset in the second or third trimester of pregnancy, (ii) elevated serum aminotransferases and bile acid levels, and (iii) spontaneous relief of signs and symptoms within two to three weeks after delivery. ICP is observed in 0.4–1% of pregnancies in most areas of Central and Western Europe and North America, while in Chile and Bolivia as well as Scandinavia and the Baltic states roughly 5–15% and 1–2%, respectively, of pregnancies are associated with ICP. Genetic and hormonal factors, but also environmental factors may contribute to the pathogenesis of ICP. Intrahepatic cholestasis of pregnancy increases the risk of preterm delivery (19–60%), meconium staining of amniotic fluid (27%), fetal bradycardia (14%), fetal distress (22–41%), and fetal loss (0.4–4.1%), particularly when associated with fasting serum bile acid levels > 40 μmol/L. The hydrophilic bile acid ursodeoxycholic acid (10–20 mg/kg/d) is today regarded as the first line treatment for intrahepatic cholestasis of pregnancy. Delivery has been recommended in the 38th week when lung maturity has been established

    Surface pretreatments for medical application of adhesion

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    Medical implants and prostheses (artificial hips, tendono- and ligament plasties) usually are multi-component systems that may be machined from one of three material classes: metals, plastics and ceramics. Typically, the body-sided bonding element is bone. The purpose of this contribution is to describe developments carried out to optimize the techniques , connecting prosthesis to bone, to be joined by an adhesive bone cement at their interface. Although bonding of organic polymers to inorganic or organic surfaces and to bone has a long history, there remains a serious obstacle in realizing long-term high-bonding strengths in the in vivo body environment of ever present high humidity. Therefore, different pretreatments, individually adapted to the actual combination of materials, are needed to assure long term adhesive strength and stability against hydrolysis. This pretreatment for metal alloys may be silica layering; for PE-plastics, a specific plasma activation; and for bone, amphiphilic layering systems such that the hydrophilic properties of bone become better adapted to the hydrophobic properties of the bone cement. Amphiphilic layering systems are related to those developed in dentistry for dentine bonding. Specific pretreatment can significantly increase bond strengths, particularly after long term immersion in water under conditions similar to those in the human body. The bond strength between bone and plastic for example can be increased by a factor approaching 50 (pealing work increasing from 30 N/m to 1500 N/m). This review article summarizes the multi-disciplined subject of adhesion and adhesives, considering the technology involved in the formation and mechanical performance of adhesives joints inside the human body

    Response matrix minimization used in groundwater management with mathematical programming: A case study in a transboundary aquifer in Northern Greece

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    Groundwater has always been considered to be a readily available source of water for domestic, agricultural and industrial use. The last decades, the lack of policymaking for the utilization of groundwater, has led to overexploitation in many areas. The cooperation of a wide range of scientists such as mathematicians, engineers, computer scientists, environmentalists and economists - operation researchers, have led to the design and construction of commercial computer programs concerned on water management and specifically on the optimal distribution of limited water resources using groundwater management models. These combined models, via simulation and optimization algorithms, result in one optimal solution through operations research and mathematical programming methods. The groundwater management models are based on the method of space superposition or the combination of space and time superposition for steady and unsteady state problems, respectively. In the present study, an algorithm is presented, which minimizes the dimension of the response matrix, concerning on two assumptions: the first is the added fixed cost which represents the water supply pumping well and the second is the removal of time superposition. The study area is a transboundary phreatic aquifer in Northern Greece, in the area of Eidomeni, a small Hellenic village just on the borderline with FYROM. The aquifer has a total area of 10,84 km(2), 26 operating - pumping wells, which the 9 of them consist control points of the hydraulic head. The number of the management periods is 12 months
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