Incidents and complications of totally implanted vascular access devices in children: a prospective study.

BACKGROUND: Totally implanted vascular access devices are frequently used in children for repeated blood samples or intravenous treatments. This prospective study aims at identifying the risk factors associated with infections, obstructions and surgical complications of these devices in pediatric patients. METHODS: From January 2006 to January 2008, all children older than one year of age with a diagnosis of solid or blood cell malignancy were included in the study. Insertion was performed by the surgeon according to a standardized protocol after landmark-guided puncture of the subclavian or internal jugular vein by a senior anesthesiologist. Dressing and post-operative care were standardized. Every manipulation was prospectively recorded by specialized dedicated nurses, and all patients were screened for complications one month post-surgery. RESULTS: 45 consecutive patients 1 to 16 years old were enrolled in the study. Mean age at the time of procedure was 8.5 years (range 1.3-15.6; SD +/- 4.88). There were 12 peroperative adverse events in 45 procedures (27%), detailed as follows: 3 pneumothoraces (7%), 3 hematomas (7%), 6 arterial punctures (13%). Among these events, intervention was necessary for two pneumothorax and one arterial puncture. There was no air embolism. At one month, we recorded 5 post-operative complications (11%): 2 thrombotic obstructions, one unsightly scar, and one scapular pain of unknown etiology. One patient needed repositioning of the catheter. There was no catheter-related infection. CONCLUSION: Prospective recording of TIVA insertion in children reveals a significant number of early incidents and complications, mainly associated with the percutaneous puncture technique. We found no infection in this series. Results of a longer follow-up in the same population are pending.

Frequent accesses to totally implanted vascular ports in pediatric oncology patients are associated with higher infection rates.

PURPOSE: Totally implanted vascular (TIVA) ports are used in children for repeated blood samples or intravenous treatments. We have recently published a prospective evaluation of surgical incidents and early complications associated with these devices. This work is the final part of the same study, assessing late complications over a follow-up of 2 yrs. METHODS: From January 2006 to January 2008, children older than 1 yr of age with a diagnosis of solid or blood cell malignancy were included. Insertion technique and care of the device were standardized. Every manipulation was prospectively recorded by specialized nurses. Obstruction was documented clinically. When bacteremia was suspected, routine central and peripheral blood cultures were drawn. RESULTS: Forty-five consecutive patients were enrolled in the study. Mean age at the time of the procedure was 8.5 yrs. There was no catheter-related infection within the first 4 weeks post-surgery. No device had to be removed because of infection or obstruction during follow-up. Frequent accesses to the port (=3 per day over a 10-day period) were associated with an 8-fold risk of infection. CONCLUSION: Insertion and use of TIVA devices were frequently associated with complications. No device had to be removed because of infection or obstruction over the follow-up period, although no prophylactic antibiotic agent was used. Restrictive use of antibiotics may prevent opportunistic infection. Frequent access to the device was significantly associated with line infection (odds ratio=8.43). No risk factor was identified for obstruction which occurred at a rate of 5.3 per 10,000 accesses.

Paperinkeräysyhtiön ympäristölupa sekä energiajakeen vastaanoton, haketuksen ja hyötykäytön suunnittelu ja kannattavuuden arviointi

Papinniemi Oy harjoittaa paperiteollisuuskuidun jatkojalostus- ja paperinkeräystoimintaa. Yhteensä raaka-ainetta tulee käsiteltäväksi noin 10 000 t/a. Työn tavoitteena oli uudistaa yhtiön jätelain (1072/1993) 42 §:n mukainen jätelupa hakemalla toiminnalle uusi ympäristönsuojelulain (86/2000)mukainen ympäristölupa. Lupahakemus toimitettiin Kaakkois-Suomen ympäristökeskuksen Lap-peenrannan toimipisteeseen 22.6.2006. Hakemuksen kuulutusajan ja lausuntokierroksen jälkeen ympäristökeskus teki asiasta myönteisen ympäristölupapäätöksen 1.11.2006. Lupapäätöksen kuulu-tusaika on 30 päivää, jonka jälkeen päätös saa lainvoiman, ellei siitä valiteta. Papinniemi Oy:n tulee tehdä hakemus lupamääräysten tarkistamiseksi 30.6.2017 mennessä. Papinniemi Oy aikoo tulevaisuudessa laajentaa toimintaansa energiajakeen vastaanotto- ja kierrä-tyspolttoaineen valmistustoimintaan. Työn toisena tavoitteena oli laatia suunnitelma ja kannatta-vuuslaskelma ko. toiminnan aloittamiseksi. Saatujen tulosten perusteella kierrätyspolttoaineen val-mistus on kannattavaa, mikäli energiajakeen saatavuus Imatran seudulla on vähintään 1700 t/a. Täl-löin yhden kierrätyspolttoainetonnin valmistuskustannus on 90 ¤. Kustannus vastaa edullisimman Imatralla kilpailevaa toimintaa harjoittavan yrityksen energiajakeen vastaanottohintaa. Polttokel-poista jätettä tuottaville yrityksille tehdyn kyselyn perusteella energiajakeen saatavuus Imatran seu-dulla on noin 3000 t/a, jolloin yhden kierrätyspolttoainetonnin valmistuskustannus on 51,49 ¤. Vaikka kierrätyspolttoaineen hinta romahti EU:n jätteenpolttodirektiivin (2000/76/EY) vaatimusten voimaantulon myötä vuoden 2006 alussa, tullee kierrätyspolttoaineen hinta nousemaan lähivuosina takaisin direktiiviä edeltäneelle tasolle (24 ¤/t). Tällöin energiajakeen vastaanottohinta toiminnan kannattavuusrajalla on 27,49 ¤/t. Kierrätyspolttoaineiden käyttöä tulevaisuudessa lisännee muiden polttoaineiden hinnan nousu, meneillään olevakierrätyspolttoaineiden standardisoimistyö, jätteiden hyödyntämisasteen parantamistavoitteet, jätteiden kaatopaikkasijoituskustannusten nousu ja päästö-kaupan vaikutus.

Tecnologia de células a combustível

The fuel cell principle was discovered by Sir Grove 150 years ago. However material problems prohibited its commercialization for a long time. A change has been occurring during the last 30 years, so two types of fuel cell technologies can be distinguished: low and high temperature operation cells. Nowadays, only phosphoric acid cells are commercially offered as 200 kWel power plants. Membrane cells are more suitable for automobile electrotraction with a very low (or no) environmental impact. The fuel continues, however, to play a very particular role, since hydrogen is not easy to store and to transport. The more promising target is the utilization of liquid methanol. The Brazilian scenario concerning this kind of technology is discussed.

Pienen mittakaavan CHP-laitokset osana hiilineutraalia maaseutuyhteiskuntaa

Maapallon ilmasto lämpenee koko ajan kasvihuonekaasujen määrän lisääntyessä ilmakehässä. Merkittävin ihmisten aiheuttama päästöjen lähde on fossiilisten polttoaineiden käyttö energiantuotannossa ja liikenteessä, jonka vuoksi on tärkeää lisätä uusiutuvien energialähteiden käyttöä. Tämän diplomityön tavoitteena oli selvittää esimerkkialueena olevan maaseutuyhteiskunnan mahdollisuutta olla energiaomavarainen ja materiaalikierroiltaan suljettu, jos alueen tarvitsema sähkö ja lämpö tuotettaisiin paikallisilla biomassavaroilla kahdella rinnakkaisella pienen mittakaavan CHP-laitoksella. Tarkastellut laitokset olivat anaerobisen mädätyksen ja polttokennojen yhdistelmä sekä termisen käsittelyn ja ORC-prosessin yhdistelmä. Työssä tehdyt laskelmat osoittivat, että esimerkkialue saisi tuotettua omilla biomassavaroillaan tarvitsemastaan sähköstä 75 % ja lämmöstä 90 % esimerkkilaitosten avulla. Laskelmissa ei kuitenkaan huomioitu kesä- ja talvikuukausien välistä eroa lämmön kulutuksessa, jonka vuoksi molemmat laitokset eivät voisi toimia koko ajan täydellä teholla. Lisäksi tuotetun lämmön hyötykäyttöä rajoittaa riittävän laajan kaukolämpöverkon puuttuminen esimerkkialueelta. Nykyisen kaukolämpöverkon avulla saataisiin hyödynnettyä vain kolmasosa ORC-prosessilla tuotetusta lämpöenergiasta. Laskelmat osoittivat myös, että alueen kasvihuonekaasupäästöt pienenisivät 21 % eli noin 6 000 hiilidioksidiekvivalenttitonnia vuodessa, jos suurin osa energiasta tuotettaisiin omista biomassavaroista CHP-laitosten avulla ja mädätyksen seurauksena syntyvä reaktorijäännös korvaisi kemiallisten lannoitteiden käytön.

Células a combustível de baixa potência para aplicações estacionárias

A paradigmatic shift in developing fuel cell for stationary applications has been occurring in the last ten years. Previously, 100 kW class to a few MW class power plants were preferred but recently, the development has drifted towards units of only a few kW. The motivation is the present market situation, which favors disperse residential electric power generation from natural or liquefied gas. Membrane-type fuel cells are very promising for this application, due to their present state of development in the automobile industry. More recently, small ceramic fuel cells (SOFC) has also been found to be adequate for this application. Considering a family of 4 members, 1 kW (electric) units seem to be optimal for individual residences. This presentation discusses briefly the Brazilian scenario with respect to these units.

Akku ja vetypolttokenno sähköauton voimanlähteenä

Tässä kandidaatintyössä on käsitelty akkuja ja vetypolttokennoja sähköauton voimanlähteenä. Työssä on esitelty sähköautojen ja niiden voimanlähteiden teknologioiden periaatteita, energiankantajia, hyötysuhteita ja päästöjä. Lisäksi on tarkasteltu polttomoottorikäyttöisiä autotekniikoita vertailukohdan saamiseksi. Työn lopuksi on analysoitu sähköautojen markkinoita ja niiden yleistymiseen vaikuttavia tekijöitä. Sähköautot mahdollistavat vaihtoehtoisten energialähteiden käytön, joka antaa tilaisuuden saasteiden ja päästöjen keskitettyyn vähentämiseen ja talteenottoon. Niiden avulla päästään myös pois öljyriippuvuudesta ja paikallisesti aiheutuneista päästöistä. Nykyisten polttoaineiden helpon käsiteltävyyden, kohtuullisien energiatiheyksien ja laajojen infrastruktuurien vuoksi käytössä olevien tekniikoiden syrjäyttäminen on vaikeaa. Uusien tekniikoiden etuja ja haittoja voidaan tarkastella yksinkertaisilla metodeilla, kuten kustannusten, hyötysuhteiden, päästöjen ja polttoaineiden elinkaarien vertailulla. Vertailua vaikeuttaa tosin hintatasojen ja verotuksen eroavaisuudet eri maissa, ja se on siksi suoritettava osin maakohtaisesti. Suurimpia esteitä uusille tekniikoille ovat tällä hetkellä niiden tuomat lisäkustannukset, infrastruktuurien puuttuminen ja nykyisten polttoaineiden korvaaminen toisella.

Eletrocatálise das reações de oxidação de hidrogênio e de redução de oxigênio

This work discusses the electrocatalytic processes taking place in the polymer electrolyte fuel cell electrodes, specifically the hydrogen oxidation reaction (HOR) and the oxygen reduction reaction (ORR), because these are clear examples of electrochemical reactions favored by the use of electrocatalysts. Since the gaseous reactants are very little soluble in the electrolyte, the use of special electrodes, named gas diffusion electrodes, is required to promote easy and continuous access of reactant gases to the electrocatalytic sites. Besides this, other important aspects such as the use of spectroscopic techniques and of theoretical models to improve the knowledge of the electrocatalytic systems are shortly discussed.

Estudo do efeito de tratamentos térmicos em catalisadores de PtRu/C frente à reação de oxidação de hidrogênio na presença de CO

In this work the effects of time and temperature of thermal treatments under reducing atmosphere (H2) on PtRu/C catalysts for the hydrogen oxidation reaction (HOR) in the presence of CO on a proton exchange membrane fuel cell (PEMFC) single cells have been studied. It can be seen that the increase of the treatment temperature leads to an increasing sintering of the catalyst particles with reduction of the active area, although the catalyst treated at 550 ºC presents more CO tolerance for the HOR.

Avaliação da eficiência de uma célula a combustível estacionária de ácido fosfórico

Operation and performance of a commercial PAFC power plant were analyzed. Processes influencing energy conversion efficiency were studied in each module of the fuel cell power plant. The main processes were simulated using mass and energy balance equations, and the results were validated by means of experimental data. It was concluded that the electrical efficiency is higher in comparison with microturbines. The main result achieved is a better understanding of balance of plant processes, knowledge necessary for fuel cell power plant development.

Cério: propriedades catalíticas, aplicações tecnológicas e ambientais

Cerium based-compounds have great importance in a wide range of technological applications, such as: fuel cell devices development; metallurgic processes, petroleum refining; glass and ceramic production. Recently, its catalytic properties have been also explored for environmental applications, especially those to prevent or to control atmospheric and water pollution. Subjects covered in this work include a brief description of the fundaments of cerium catalytic properties and some relevant technological applications. Special attention is given to its photocatalytic activity and its ability to degrade pollutants. Recent results and future prospect about these applications are also evaluated.

Montagem e caracterização elétrica de pilhas a combustível de óxido sólido (PaCOS)

This paper is focused on a review of the design features and the electrochemistry characterization of anode-supported planar SOFC. Studies and results of metallic alloy interconnectors and recovery for protection against corrosion and for contact layer are showed. Moreover a discussion of examples of measurements of impedance spectrometry, according to the literature and our experimental results are made. For the anode supported fuel cells the power density varies from 0.1 to 0.5 Wcm², according to results in the literature (showed in this paper). For electrolyte supported fuel cell the power density can be 10 Wcm-2 for high temperatures. An English-Portuguese glossary of most used terms in SOFC stack is given for greater clarity and to introduce new terms to the reader.

Desenvolvimento de conjunto membrana-eletrodos para célula a combustível de metanol direto passiva

Direct methanol fuel cells (DMFCs) without external pumps or other ancillary devices for fuel and oxidant supply are known as passive DMFCs and are potential candidates to replace lithium-ion batteries in powering portable electronic devices. This paper presents the results obtained from a membrane electrode assembly (MEA) specifically designed for passive DMFCs. Appropriated electrocatalysts were prepared and the effect of their loadings was investigated. Two types of gas diffusion layers (GDL) were also tested. The influence of the methanol concentration was analyzed in each case. The best MEA performance presented a maximum power density of 11.94 mW cm-2.

Pilhas de combustíveis microbianas utilizadas na produção de eletricidade a partir de rejeitos orgânicos: uma perspectiva de futuro

In this review is presented an innovative technology for use of animal and vegetable waste with high pollution levels in microbial fuel cell (MFC) as an alternative to waste remediation and simultaneously producing electricity and fertilizer for agriculture. A brief history of MFC, the studies about the electron transfer mechanisms, discussion of the biological nanowires in bacteria and the use of chemical mediators or carriers of electrons are explained. The factors influencing the performance of MFCs, the application in waste and sewage treatment and power generation are also discussed.

Desenvolvimento de tecnologia para confecção de eletrodos e conjuntos eletrodo-membrana-eletrodo (MEA) por impressão à tela para aplicação em módulos de potência de células PEMFC

Significant functions in the Proton Exchange Membrane Fuel Cells (PEMFCs) rely on Gas Diffusion Layers (GDLs), such as control the water balance in the membrane electrode assembly (MEA), allow suitable gas permeability and porosity, etc. Aware of the GDL importance in the cell performance and its great demand in scale-up projects, the fuel cell research group at Instituto de Pesquisas Energéticas e Nucleares (IPEN) has developed a Sieve Printing method (innovative in Brazil) as a strategic solution for producing GDL and electrodes used in high power PEMFC stacks. The method has shown to be adequate to fabricate low cost electrodes, GDLs of different dimensions and to produce any amount of MEAs for power stacks.