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Transplantation ; 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33982909


BACKGROUND: Deceased donor and recipient predictors of post transplant steatosis/steatohepatitis and fibrosis are not well known. AIM: Evaluate the prevalence and assess donor and recipient predictors of steatosis, steatohepatitis, and fibrosis in LT recipients. METHODS: Using the ITN A-WISH multicenter study (NCT00135694), donor and recipient demographic and clinical features were collected. Liver biopsies were taken from the donor liver at transplant, and from recipients per protocol and for cause (i.e. abnormal transaminases and/or to rule out rejection) and were interpreted by a central pathologist. RESULTS: 183 paired donor/recipients liver biopsies at the time of transplant and post-transplant follow up (median time 582 days; average time to last biopsies was 704 days (SD ± 402 days) were analyzed. Donor steatosis did not influence recipient steatosis or fibrosis. 10/183 recipients had steatohepatitis on the last biopsy. Recipient BMI at the time of liver biopsy was the most influential factor associated with post-transplant steatosis. Both donor and recipient metabolic syndrome features were not associated with graft steatosis. Untreated HCV infection was the most influential factor associated with the development of allograft fibrosis. CONCLUSIONS: In a large experience evaluating paired donor and recipient characteristics, recipient BMI at the time of liver biopsy was most significantly associated with post-transplant steatosis. Untreated HCV etiology influenced graft fibrosis. Thus relative to untreated HCV, hepatic fibrosis in those with steatosis/steatohepatitis is less common though long term follow up is needed to determine the course of post transplant fibrosis. Emphasis on recipient weight control is essential.

Sensors (Basel) ; 19(17)2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31480410


Electromagnetic Vibration Energy Harvesting (EM-VEH) is an attractive alternative to batteries as a power source for wireless sensor nodes that enable intelligence at the edge of the Internet of Things (IoT). Industrial environments in particular offer an abundance of available kinetic energy, in the form of machinery vibrations that can be converted into electrical power through energy harvesting techniques. These ambient vibrations are generally broadband, and multi-modal harvesting configurations can be exploited to improve the mechanical-to-electrical energy conversion. However, the additional challenge of energy conditioning (AC-to-DC conversion) to make the harvested energy useful brings into question what specific type of performance is to be expected in a real industrial application. This paper reports the operation of two practical IoT sensor nodes, continuously powered by the vibrations of a standard industrial compressor, using a multi-modal EM-VEH device, integrated with customised power management. The results show that the device and the power management circuit provide sufficient energy to receive and transmit data at intervals of less than one minute with an overall efficiency of about 30%. Descriptions of the system, test-bench, and the measured outcomes are presented.

ACS Appl Mater Interfaces ; 7(42): 23575-88, 2015 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26372672


Condensation of water vapor is an essential process in power generation, water collection, and thermal management. Dropwise condensation, where condensed droplets are removed from the surface before coalescing into a film, has been shown to increase the heat transfer efficiency and water collection ability of many surfaces. Numerous efforts have been made to create surfaces which can promote dropwise condensation, including superhydrophobic surfaces on which water droplets are highly mobile. However, the challenge with using such surfaces in condensing environments is that hydrophobic coatings can degrade and/or water droplets on superhydrophobic surfaces transition from the mobile Cassie to the wetted Wenzel state over time and condensation shifts to a less-effective filmwise mechanism. To meet the need for a heat-transfer surface that can maintain stable dropwise condensation, we designed and fabricated a hybrid superhydrophobic-hydrophilic surface. An array of hydrophilic needles, thermally connected to a heat sink, was forced through a robust superhydrophobic polymer film. Condensation occurs preferentially on the needle surface due to differences in wettability and temperature. As the droplet grows, the liquid drop on the needle remains in the Cassie state and does not wet the underlying superhydrophobic surface. The water collection rate on this surface was studied using different surface tilt angles, needle array pitch values, and needle heights. Water condensation rates on the hybrid surface were shown to be 4 times greater than for a planar copper surface and twice as large for silanized silicon or superhydrophobic surfaces without hydrophilic features. A convection-conduction heat transfer model was developed; predicted water condensation rates were in good agreement with experimental observations. This type of hybrid superhydrophobic-hydrophilic surface with a larger array of needles is low-cost, robust, and scalable and so could be used for heat transfer and water collection applications.

Clin Transpl ; : 77-89, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22755404


Since renal transplantation is the definitive therapy for most patients with end stage renal disease, we have the challenge of meeting the needs of this rapidly growing population. Currently greater than 1000 patients are waiting for kidney transplantation at the University of Michigan. To meet this demand we have aggressively expanded the donor pool from both deceased and living donors. The focus of this update has been the evolving living donor program at the University of Michigan. In light of the rising rates of obesity in America, we have developed a specialized evaluation to assess potential obese donors. Individuals with a history of hypertension and no other risk factors for kidney failure are screened according to a protocol seeking to identify patients with a low risk of developing chronic kidney disease. We have developed unique approaches to patients with anatomic anomalies as well as nephrolithiasis. Despite all of these progressive approaches, our living donor outcomes at the University of Michigan have remained excellent and we have continued to provide a high standard of care for our recipients suffering from end stage renal disease.

Falência Renal Crônica/cirurgia , Transplante de Rim , Doadores Vivos/provisão & distribuição , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Seleção do Doador , Feminino , Hospitais Universitários , Humanos , Lactente , Recém-Nascido , Falência Renal Crônica/mortalidade , Transplante de Rim/efeitos adversos , Transplante de Rim/imunologia , Transplante de Rim/mortalidade , Masculino , Michigan , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Medição de Risco , Fatores de Risco , Fatores de Tempo , Obtenção de Tecidos e Órgãos , Resultado do Tratamento , Listas de Espera , Adulto Jovem