The place of space technology in economic development: Reflections on present and future aspects

The effects of the development of satellite applications on the orientation of the space effort were examined. The gap between available and exploited technology, the impact of the current economic climate and future trends are discussed. Europe's low level of public funding for its space effort, in comparison to other space powers, and the dangers of complacency regarding Europe's competitiveness in the space market are illustrated. A proposal for the general direction which Europe's future strategy must take if European independence in this field is to be preserved is presented

Analysis of surgical complications after 397 hepatic transplantations

The results of 397 consecutive orthotopic hepatic transplantations in 333 recipients were reviewed. One or more surgical complications developed in 172 of 323 patients (55 per cent), excluding ten intraoperative deaths. The six month mortality rate among the patients with surgical complications (55 of 172; 32 per cent) was statistically higher than that among patients without such complications (16 of 151; 11 per cent) (p < 0.001; chi-square, 58.36). Surgical complications including exploratory laparotomy for bleeding or infection in 74 (22 per cent), reconstruction of the bile duct for biliary obstruction or leakage in 55 (17 per cent), external biliary drainage for biliary leakage in four (1 per cent), tracheostomy in 80 (24 per cent), thoracotomy in 12 (4 per cent) and splenectomy in seven (2 per cent). The incidence of biliary obstruction (16 per cent mortality rate) and leakage (48 per cent mortality rate) was 18 per cent (34 of 193) and 2 per cent (four of 193) each after choledochocholedochostomy, which was 3 per cent (five of 187) and 9 per cent (17 of 187) each choledochojejunostomy. Biliary obstruction (16 per cent mortality rate) was more common after choledochocholedochostomy (p < 0.005; chi-square, 23.01), whereas the incidence of more serious biliary leakage (48 per cent mortality rate) was higher after choledochojejunostomy (p < 0.005; chi-square, 8.97). It is concluded that orthotopic hepatic transplantation remains an unforgiving extensive surgical procedure, in which choledochocholedochostomy remains the first-choice reconstruction of the biliary tract because of its lower mortality

Hemodynamic and biochemical changes during normothermic and hypothermic sanguinous perfusion of the porcine hepatic graft

Using an ex vivo liver sanguinous perfusion system, hemodynamic and biochemical changes of the porcine livers were studied, which were preserved cold (4°C) for 24 hr in University of Wisconsin solution and reperfused with normothermic (37°C) (n=8) or hypothermic (32°C) (n=8) blood for 3 hr. Six more livers were reperfused with normothermic blood (37°C) immediately after procurement as controls. The total hepatic blood flow was adjusted to 1 ml/min/g liver weight, in which hepatic artery and portal vein flows were administered at a 1:2 ratio. In livers stored cold for 24 hr in UW solution and perfused normothermically, a statistically higher hepatic artery resistance was exhibited at 30 an 60 min after reperfusion (P<0.05), and there was lower bile output (P<0.05) at 90 and 120 min as compared to the controls. In livers stored cold for 24 hr in UW solution and perfused hypothermically, as compared to ones perfused normothermically, statistically higher hepatic- artery and portal-vein resistances (P<0.05) were observed throughout the perfusion period and 60 min= after reperfusion, respectively. In addition, bile output and oxygen consumption of these livers were statistically lower than those of ones perfused normothermically (P<O.05). In contrast, chemistries of the perfusat of livers perfused hypothermically were comparable to ones perfused normothermically. Histologic examination of the liver perfused hypothermically demonstrated hepatic arterial and/or portal venous congestion and mild-to-moderate hemorrhage in the portal triads. This study suggests that livers preserved for a prolonged period of time demonstrate a high hepatic arterial resistance shortly after revascularization, and that recipient hypothermia after revascularization may be a risk factor for the development of hepatic arterial thrombosis following liver transplantation. © 1990 by Williams & Wilkins

Small bowel stromal tumour revealed by a lower gastrointestinal bleeding

Small bowel stromal tumour must be systematically researched in the presence of obscure and persistent low gastrointestinal bleeding despite a normal endoscopic examination (OGDF and colonoscopy). Video capsule endoscopy is the best diagnosis examination; if it is not available a CT enterography could be useful. Surgical treatment is effective on localized and weak malignancy small bowel stromal tumours

Limiting Carleman weights and anisotropic inverse problems

In this article we consider the anisotropic Calderon problem and related inverse problems. The approach is based on limiting Carleman weights, introduced in Kenig-Sjoestrand-Uhlmann (Ann. of Math. 2007) in the Euclidean case. We characterize those Riemannian manifolds which admit limiting Carleman weights, and give a complex geometrical optics construction for a class of such manifolds. This is used to prove uniqueness results for anisotropic inverse problems, via the attenuated geodesic X-ray transform. Earlier results in dimension $n \geq 3$ were restricted to real-analytic metrics.Comment: 58 page

Improved method of porcine renal allografting for transplantation Research

This study presents a refined, reproducible, and clinically appropriate animal model of renal transplantation. A pair of kidneys are harvested from a donor pig and preserved in Euro-Collins' solution (4°C). After a set period of preservation, the allografts are transplanted to two recipient pigs. The abdomen is entered through a midline incision. The right common iliac artery and vein are dissected and bilateral native nephrectomy is performed. Each allograft is then randomly assigned and transplanted to the recipients. Three minutes before un- clamping, 100 mg offurosemide and 10 g of mannitol are given IV. Immediately after reperfusion, urine output is measured for 1 h. The allograft is biopsied and ureteroneocyslostomy is created. Cystostomy is then placed using a 16F Foley catheter. The bladder neck is ligated to secure complete diversion of urine, and the abdomen is closed in layers. This kidney transplant model allows an absolutely paired study of the kidney allograft function from the same donor and also collection of pure urine at any time postoperatively, obviating the need for metabolic cages or sedation for urinary collection. This model and its unique modifications allow various transplant studies, including organ preservation, immunosuppressive protocol, and the prevention of reperfusion injury from oxygen free radicals © 1991 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted

Hepatic Artery Reconstruction for Hepatic Artery Thrombosis After Orthotopic Liver Transplantation

We evaluated the efficacy of reconstruction of the hepatic artery for intraoperative or postoperative thrombosis in orthotopic liver transplantation. Of 37 grafts with artery thrombosis, 13 (35.1%, 6 intraoperative and 7 postoperative) underwent reconstruction of the hepatic artery. The arterial flow was reestablished and maintained in 5 (38.5%) of the 13. Recurrent thrombosis in the other 8 grafts developed 2 to 24 days (mean, 13.8 days) after transplantation. Reconstruction was successful in 50% (4/8) of the adults, compared with only 20% (1/5) of the children. Satisfactory results were obtained when a definitive cause of thrombosis could be identified. We conclude that early recognition and correction of the cause of hepatic artery thrombosis during or after orthotopic liver transplantation, especially in adults, is often a graft-saving and lifesaving procedure worthy of consideration. © 1990, American Medical Association. All rights reserved

rAAV-Mediated Overexpression of SOX9 and TGF-β via Carbon Dot-Guided Vector Delivery Enhances the Biological Activities in Human Bone Marrow-Derived Mesenchymal Stromal Cells

Scaffold-assisted gene therapy is a highly promising tool to treat articular cartilage lesions upon direct delivery of chondrogenic candidate sequences. The goal of this study was to examine the feasibility and benefits of providing highly chondroreparative agents, the cartilage-specific sex-determining region Y-type high-mobility group 9 (SOX9) transcription factor or the transforming growth factor beta (TGF-β), to human bone marrow-derived mesenchymal stromal cells (hMSCs) via clinically adapted, independent recombinant adeno-associated virus (rAAV) vectors formulated with carbon dots (CDs), a novel class of carbon-dominated nanomaterials. Effective complexation and release of a reporter rAAV-lacZ vector was achieved using four different CDs elaborated from 1-citric acid and pentaethylenehexamine (CD-1); 2-citric acid, poly(ethylene glycol) monomethyl ether (MW 550 Da), and N,N-dimethylethylenediamine (CD-2); 3-citric acid, branched poly(ethylenimine) (MW 600 Da), and poly(ethylene glycol) monomethyl ether (MW 2 kDa) (CD-3); and 4-citric acid and branched poly(ethylenimine) (MW 600 Da) (CD-4), allowing for the genetic modification of hMSCs. Among the nanoparticles, CD-2 showed an optimal ability for rAAV delivery (up to 2.2-fold increase in lacZ expression relative to free vector treatment with 100% cell viability for at least 10 days, the longest time point examined). Administration of therapeutic (SOX9, TGF-β) rAAV vectors in hMSCs via CD-2 led to the effective overexpression of each independent transgene, promoting enhanced cell proliferation (TGF-β) and cartilage matrix deposition (glycosaminoglycans, type-II collagen) for at least 21 days relative to control treatments (CD-2 lacking rAAV or associated to rAAV-lacZ), while advantageously restricting undesirable type-I and -X collagen deposition. These results reveal the potential of CD-guided rAAV gene administration in hMSCs as safe, non-invasive systems for translational strategies to enhance cartilage repair