Early detection of injuries in leaves of Clusia hilariana Schltdl. (Clusiaceae) caused by particulate deposition of iron

This study aims to evaluate the prognostic value of microscopic parameters of asymptomatic leaves of Clusia hilariana Schltdl. subjected to particulate deposition of iron (2.14 mg cm-2 day-1) for 45 consecutive days. Samples of young and expanded leaves without symptoms were collected and subjected to light and scanning electron microscopy techniques. The height of the epidermal cells on both surfaces of the leaf and the thickness of the hypodermis, the chlorophyll parenchyma, and the leaf blade were measured. Micromorphological injury occurred in the abaxial surface of young leaves and on both surfaces of expanded leaves. Erosion of the epicuticular wax and cuticle rupture were frequent on the adaxial surface, while on the abaxial surface of both leaves there was a loss of sinuosity on the anticlinal wall of the epidermal cells, stomatal deformity and obstruction. Micromorphometric alterations were seen in all leaf tissues except in the height of epidermic cells, probably due to the thick cuticle and prominent cuticular flanges. The highest difference in thickness of the leaf blade was seen in young leaves of plants subjected to SPMFe, indicating greater sensibility to particulate iron in comparison to the expanded leaves. The micromorphological and micromorphometric alterations in the leaf blade of Clusia hilariana Schltdl. showed the prognostic potential of these tools on the evaluation of impacts caused by the deposition of particulate matter, especially in the 'Restinga' natural vegetation, where the exposure is increasing due to the presence of iron ore industry in their surroundings.

Modelo dinâmico de simulação e otimização da força normal de reação do solo para um mecanismo de corte basal

O modelo físico foi baseado no método de Newton-Euler, sendo o mesmo desenvolvido utilizando o programa computacional científico Mathematica®. Realizaram-se várias simulações, nas quais se procurou obter a força normal de reação do solo variando velocidades de avanço (0,69; 1,12; 1,48; 1,82 e 2,12 m s-1); perfis de solo (senoidal, rampa ascendente e descendente) e altura do camalhão (0,025 e 0,05 m). Após as simulações iniciais, o mecanismo foi otimizado utilizando o programa computacional científico Matlab®, tendo como critério (função-objetivo) a minimização da força normal de reação do perfil (F N) e como variáveis de projeto os comprimentos das barras (L1y, L2, l3 e L4), altura da operação (L7), o comprimento inicial da mola (Lmo) e a constante elástica da mola (k t). A falta de robustez do mecanismo em relação à variável altura de operação foi contornada por meio do uso de mola com baixa rigidez e grande comprimento. Os resultados demonstraram que o mecanismo otimizado obteve desempenho de flutuação muito bom, em relação ao mecanismo inicial.

Projeto de um cortador de base para colhedora de cana-de-açúcar utilizando otimização matemática

Um cortador de base representado por um mecanismo de quatro barras foi desenvolvido utilizando-se do programa Autocad. Suas partes constituintes foram pré-dimensionadas em função das características operacionais de uma colhedora de cana-de-açúcar em sistema de cana crua e inteira, colhendo uma linha de cana por passada. A força normal de reação do perfil no ponto de contato foi determinada por meio da análise dinâmica, sendo as equações de equilíbrio dinâmico baseadas nas leis de Newton-Euler. O processo de otimização teve como objetivo minimizar a força normal de reação do solo, submetida a restrições de posição, trajetória, comprimento das barras, constante da mola e da força normal. Implementou-se o Algoritmo de Programação Quadrática Seqüencial - SQP do módulo de otimização do programa computacional Matlab. Os resultados mostraram melhora significativa no desempenho de flutuação do mecanismo, representada pela força normal de reação do perfil, a qual foi reduzida de 4.250,33 para 237,13 N. Posteriormente, outras variáveis foram incorporadas ao mecanismo otimizado e um segundo processo de otimização foi implementado.

Modelagem computacional do fluxo unidimensional de água em meio não saturado do solo

O estudo do fluxo de água em zonas não saturadas do solo é de grande importância para pesquisas relacionadas à disponibilidade hídrica para o desenvolvimento das plantas. Devido ao alto custo, ao tempo demandado e ao esforço humano nas investigações de campo, os modelos matemáticos, aliados às técnicas numéricas e avanços computacionais, constituem-se em uma ferramenta importante na previsão desses estudos. No presente trabalho, objetivou-se solucionar a equação diferencial parcial não linear de Richards mediante a aplicação do Método de Elementos Finitos. Na aproximação espacial, foi empregada a adaptatividade com refinamento "h" na malha de elementos finitos e, na derivada temporal, foi aplicado o esquema de Euler Explícito. A função interpolação polinomial utilizada foi de grau 2, e a que garantiu a conservação de massa da estratégia de adaptação. Para a validação do modelo, foram utilizados dados disponíveis em literatura. A utilização da função interpolação polinomial de grau 2 e o refinamento "h", com considerável redução do tempo de execução da rotina computacional, permitiram uma boa concordância do modelo em comparação a soluções disponíveis na literatura.

Síndrome da alça aferente com necrose simulando pseudocisto de pâncreas

Afferent loop obstruction after gastrectomy and Billroth II reconstruction is an uncommon problem. Complete acute obstruction requires emergent laparotomy. We describe a patient who developed acute abdominal pain, hyperamylasemia, and palpable abdominal mass, five years after Billroth II gastrectomy. At laparotomy the patient was found to have a complete stricture of the afferent limb with evidence of strangulation and necrosis. There was no evidence of pancreatitis or pancreatic pseudocyst. The patient underwent pancreaticoduodenectomy plus degastrectomy and died 18 hours after the procedure in the ICU. The mass was initially inte1preted as pancreatic pseudocyst. Ultrasonography may provide enough evidence to differentiate a pancreatic pseudocyst. from an obstructed afferent loop, by the presence of a peripancreatic cystic mass or debris within the mass or the absence of the keyboard sign, suggesting effacement of the valvulae conniventes of the small bowel. Howewer, CT scan of the abdomen has been suggested to be highly characteristic, if not pathognomonic, for an obstructed afferent loop and should be considered first in patients with pancreatitis after Billroth II gastrectomy. A history of previous gastrectomy, recurrent or severe abdominal pain, hyperamylasemia with characteristic tomography, and endoscopic findings will establish the diagnosis and necessitate surgical evaluation and intervention.

Perfuração gástrica por tricobezoar

Bezoars are uncommon foreign bodies found in the stomach and intestines. They are usually secundary to "strange" or "weird" alimentary habits. The contents may include hait; stones, vegetal fibers and others. Diagnosis is generally made due to complications, mainly parcial or complete obstruction of the segment affected. Bleeding and peiforation may also occur: This paper describes a case of a 14-years-old female patient, who presented herself to lhe Emergency Room and was diagnosed as having a gastric peiforation due to a trichobezoar that was 15 cm long and weighted 900g. A review of lhe literature and comments about diagnosis and management are presented.

Adenoma viloso da ampola de Vater

The aim of this paper is to present a case of a 37-year-old female patient with a benign tumor of the Ampulla of Vater and a brief review of the literature. The patient presented with progressive obstructive jaundice and weigth loss due to the presence of two adenomas of the second portion of duodenum. Laboratory tests confirmed the presence of obstruction of the biliary tree. Ultrasound and CT scan of the abdomen revealed bile duct dilatation. ERCP showed a tumor at the site of the Ampulla of Vater. The biopsies revealed tubular adenoma. She was submitted to local resection of the tumors and sphincteroplasty, since the frozen biopsy at the time of surgery showed no malignancy. During the post-operative follow-up she presented recurrence of symptoms. An upper GI endoscopy revealed a tumor at the Ampulla of Vater. She was then submitted to Whipple procedure with an uneventful recovery.

Adenocarcinoma primário de duodeno

Primary adenocarcinoma of the duodenum is an extremely rare disease, and represents only 0.35 % of all gastrointestinal malignies. Early detection of the disease is dificult because doesn't have pathognomonic simptoms. The Whipple procedure is the optimal method of treatment. The authors relate one case of a adenocarcinoma of the duodenum in a 65- year-old white female with a history of abdominal pain for a six-month period, associated with postprandial fullness, vomiting and weight loss. Endoscopy showed a elevated tumor in the second part of the duodenum, with partial obstruction of the lumen. Histological study of endoscopic biopsies reveled a moderare differentiated adenocarcinoma of the duodenum. The treatment was surgical. The authors comment on the more important aspects of this pathology.

Prolapso jejunal em gastroenteroanastomose

The autors report a case of jejunal mucosa prolapse after gastroenteroanastomosis, a rare postoperative complication. In the late postcholecistectomy period the patient had persistent vomit. Upper digestive endoscopy (UDE) showed obstruction of the second portion of duodenum, and a gastrojejunal anastomosis was performed. Soon after that, the patient had persistent vomit and upper digestive endoscopy (UDE) showed invagination of the jejunal mucosa. She was reoperated, a Roux Y gastrectomy was performed and the patient had a good evolution. The treatment for this complication is basically surgical, which intends to realieve the obstructive symptomatology.

Íleo biliar colônico

Colonic obstruction is a very rare complication of gallstone disease. We describe two cases of colonic obstruction by gallstone in old age women, in which the final diagnosis was made on surgery. In one it was found a cholecystocolic fistula and a stone impacted in the sigmoid colon which was milked until the cecum, where it was removed through a cecolithotomy. In the other there was a cholecystoduodenal fistula, the stone was impacted in the sigmoid colon and in association there was a colonic necrosis, treated by colectomy, ileostomy and mucous fistula, During colonic mobilization a colecystoduodenal fistula was exposed, making necessary to perform a cholecystectomy and fistula repair. Both patients died in sepsis.

Estenose esofagiana congênita por coristoma

Oesophageal choristomas are a very uncommon cause of congenital oesophageal stenosis. A high index of suspection is necessary for differential diagnosis with commoner causes of oesophageal suboclusion in childhood, mainly acquired oesophageal obstruction caused by gastroesophageal reflux. We present a case report and review the clinical, endoscopic and radiologic features of the disease and consider the need for padronization of surgical techniques to treat this condition, which is still controversial.

Síndrome de chilaiditi associada a megaduodeno e megacólon transverso

Chilaiditi syndrome is a rare abnormality, uncommon in children, whith an incidence increasing with the age, ranging from 0.025% to 0.28% in the general population usually affecting males. The patients are usually asymptomatics and the syndrome is incidently discover through radiologic exams. However, abdominal pain and distention, nauseas, vomits and changes in intestinal habits, and even intestinal obstruction can occur. The authors report a case of a patient with Chilaiditi's syndrome associated to megastomach, megaduodenum and megacolon.

Tuberculose entérica

The authors reports two patients with operated from enteric tuberculosis. Tuberculosis involving the intestinal tract may be due to either Mycobacterium tuberculosis or M. bovis. In the former situation, the disease is primary to the lungs and is carried to the intestinal tract by swallowing sputum. The latter organism produces infection associated with swallowed nonpasteurized milk. This condition is extremely unusual in most western countries, since pasteurization of milk is standardized. The diagnosis was performed through laparotomy because of symptoms suggestive of intestine obstruction. Inflammatory reactions were observed on the small intestine (jejunum-ileum) in both cases. The presence of tuberculosis of the lungs was observed in one patient. The chemotherapic treatment was estabilished after the histopathologic diagnosis. The distinction between tuberculosis and Crohn's disease may not be possible by radiography or endoscopy. Videolaparoscopy has been found to be an useful procedure for the early diagnosis of Enteric Tuberculosis. In spite of the epidemiology knowledge, clinical control and improvement in treatment, extra pulmonary tuberculosis rate from concealed focus has been increased, due to AIDS poverty in certain populational groups and immigration from Asia to wertern countries. Compared with immunocompetent patients, the proportion of extrapulmonary tuberculosis is much higher in patients with AIDS, justfying the increased frequency of reports of intestinal tuberculosis in these patients.

Síndrome da artéria mesentérica superior

The Superior Mesenteric Syndrome is a rare and controversial disease. The compression of the duodenum by the mesenteric artery and aorta causes an intermitent obstruction. Preoperative diagnosis is very difficult.We present one case of this syndrome in a pacient with severe weight loss and signs of high intestinal obstruction. The diagnosis was based on clinical and radiologic findings. A duodenojejunostomy was performed after medical treatment failure.This patient died on the 20th posoperative day due to cardiac complications. This syndrome must be remembered in cases of high obstruction in chronic ill patients.

Adenomioma da papila de vater em adulto jovem

The authors report a case of adenomyoma of papilla of Vater in a young adult, a rare pathology in this age and site. The commonest clinical findings are abdominal pain, dyspepsia and jaundice, as in this case in which the patient referred these symptoms for several months. The diagnosis is usually difficult before surgery, because the radiological and endoscopic appearances are difficult to interpret, since they may only show obstruction and enlargement of the biliary tract; in this way, the endoscopic biopsy may be useful. In the present case the computed tomography, abdominal scan and intraoperative cholangiography only demonstrated obstruction and enlargement of the biliary tract, without the presence of gallstones. The treatment is usually lesion resection according to its size, performing the total resection in those cases of extensive involvement of the digestive tract, as it was performed in this case, due to the dimension of the lesion and its malignant appearance. The patient was discharged from hospital on the thirteenth postoperative day, with a histological diagnosis of adenomyoma of papilla of Vater. Three months after the procedure the patient was asymptomatic.