ABSTRACT
The need to replace conventional fuels with renewable sources is a great challenge for the science community. H2 is a promising alternative due to its high energy density and availability. H2 generation from formic acid (FA) decomposition occurred in a batch and a packed-bed flow reactor, in mild conditions, using a 2% Pd6Zn4/HHT (high heated treated) catalyst synthesised via the sol-immobilisation method. Experimental and theoretical studies took place, and the results showed that in the batch system, the conversion was enhanced with increasing reaction temperature, while in the continuous flow system, the conversion was found to decrease due to the deactivation of the catalyst resulting from the generation of the poisoning CO. Computational fluid dynamics (CFD) studies were developed to predict the conversion profiles, which demonstrated great validation with the experimental results. The model can accurately predict the decomposition of FA as well as the deactivation that occurs in the continuous flow system. Of significance was the performance of the packed-bed flow reactor, which showed improved FA conversion in comparison to the batch reactor, potentially leading to the utilisation of continuous flow systems for future fuel cell applications for on-site H2 production.
ABSTRACT
BACKGROUND: Laparoscopic splenectomy is an alternative for the treatment of patients undergoing elective splenectomy. One of its main indications is in hematologic diseases non-responsive to pharmacological treatment. Videolaparoscopy presents advantages to patients when compared to laparotomy: less post-operative pain, recovery of the functions of the gastrointestinal tract, better cosmetic results and shorter hospitalization. AIM: To present a case series of laparoscopic splenectomy in a university hospital. METHODS: Were analyzed all the laparoscopic splenectomies between June 2005 and October 2012. The analysis was conducted prospectively divided into pre-, trans-, and post-operative data on: gender, age, indication for surgery, rate of conversion to open surgery, duration of surgery, spleen size, presence of an accessory spleen, time hospitalization and short-term response in eight weeks after the procedure, by analyzing hemoglobin and platelets pre- and post-operative, broken down by gender. RESULTS: Were analyzed 44 laparoscopic splenectomies performed in the period. Patients diagnosed with idiopathic thrombocytopenic purpura accounted for 56.8%, non-responsive to pharmacological treatment; autoimmune hemolytic anemia was 13.6%; spherocytosis, 11.3% and 18.3% by other non-hemolytic causes. Six patients had to be converted to open surgery (13.63%), four due to excessive bleeding. The mean operative time was 166.7 (60-319) minutes and the length of hospitalization was 12 days. Only four patients (9.1%) had post-operative complications, and none had bleeding after surgery and the positive response in the short term, after eight weeks of treatment, was achieved by 88% of patients. CONCLUSIONS: Laparoscopic splenectomy is a safe alternative for all major indications of splenectomy and can be routinely used.
Subject(s)
Laparoscopy , Splenectomy/methods , Video-Assisted Surgery , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Prospective Studies , Young AdultABSTRACT
RACIONAL: A esplenectomia laparoscópica é alternativa para o tratamento de pacientes submetidos à esplenectomia eletiva. Uma de suas principais indicações está nas doenças hematológicas que não respondem ao tratamento clínico. A videolaparoscopia apresenta vantagens para os pacientes, quando comparados à laparotomia: menos dor no pós-operatório, recuperação mais célere das funções do trato gastrointestinal, melhores resultados estéticos e menor tempo de hospitalização. OBJETIVO: Apresentar série de casos de esplenectomia videolaparoscópica de um hospital universitário. MÉTODOS: Forram avaliadas as esplenectomias realizadas entre junho de 2005 e outubro de 2012. A análise foi prospectiva dividida em pré, trans e pós-operatórios dos seguintes dados: gênero, idade, indicação da operação, taxa de conversão para laparotomia, duração do procedimento, tamanho do baço, presença de baço acessório, tempo de internação e resposta em oito semanas do pós-operatório. RESULTADOS: Foram analisadas 44 esplenectomias laparoscópicas realizadas no período. Os pacientes foram com púrpura trombocitopênica idiopática sem resposta ao tratamento farmacológico representaram 56,8%; anemia hemolítica auto-imune foi de 13,6%; esferocitose de 11,3% e 18,3% por outras causas não-hemolíticas. O tempo cirúrgico médio foi de 166,7 (60-319) minutos. Apenas quatro pacientes (9,1%) tiveram complicações pós-operatórias, e nenhum deles teve sangramento pós-operatório. A resposta positiva, em curto prazo, após oito semanas do tratamento foi conseguida por 88% dos pacientes. CONCLUSÕES: A esplenectomia laparoscópica é alternativa segura para todas as principais indicações de esplenectomia e pode ser utilizada de forma rotineira.
BACKGROUND: Laparoscopic splenectomy is an alternative for the treatment of patients undergoing elective splenectomy. One of its main indications is in hematologic diseases non-responsive to pharmacological treatment. Videolaparoscopy presents advantages to patients when compared to laparotomy: less post-operative pain, recovery of the functions of the gastrointestinal tract, better cosmetic results and shorter hospitalization. AIM: To present a case series of laparoscopic splenectomy in a university hospital. METHODS: Were analyzed all the laparoscopic splenectomies between June 2005 and October 2012. The analysis was conducted prospectively divided into pre-, trans-, and post-operative data on: gender, age, indication for surgery, rate of conversion to open surgery, duration of surgery, spleen size, presence of an accessory spleen, time hospitalization and short-term response in eight weeks after the procedure, by analyzing hemoglobin and platelets pre- and post-operative, broken down by gender. RESULTS: Were analyzed 44 laparoscopic splenectomies performed in the period. Patients diagnosed with idiopathic thrombocytopenic purpura accounted for 56.8%, non-responsive to pharmacological treatment; autoimmune hemolytic anemia was 13.6%; spherocytosis, 11.3% and 18.3% by other non-hemolytic causes. Six patients had to be converted to open surgery (13.63%), four due to excessive bleeding. The mean operative time was 166.7 (60-319) minutes and the length of hospitalization was 12 days. Only four patients (9.1%) had post-operative complications, and none had bleeding after surgery and the positive response in the short term, after eight weeks of treatment, was achieved by 88% of patients. CONCLUSIONS: Laparoscopic splenectomy is a safe alternative for all major indications of splenectomy and can be routinely used.
