DISPOSITIVO PARA EXTRAÇÃO LÍQUIDO-LÍQUIDO EM SISTEMAS DE ANÁLISES EM FLUXO

AbstractA device comprising a lab-made chamber with mechanical stirring and computer-controlled solenoid valves is proposed for the mechanization of liquid-liquid extractions. The performance was demonstrated by the extraction of ethanol from biodiesel as a model of the extraction of analytes from organic immiscible samples to an aqueous medium. The volumes of the sample and extractant were precisely defined by the flow-rates and switching times of the valves, while the mechanic stirring increased interaction between the phases. Stirring was stopped for phase separation, and a precise time-control also allowed a successful phase separation (i.e., the absence of the organic phase in the aqueous extract). In the model system, a linear response between the analytical response and the number of extractions was observed, indicating the potential for analyte preconcentration in the extract. The efficiency and reproducibility of the extractions were demonstrated by recoveries of ethanol spiked to biodiesel samples within 96% and 100% with coefficients of variation lower than 3.0%.

Identification of Rhizoctonia solani associated with soybean in Brazil by rDNA-ITS sequences

The aim of this study was to identify isolates of Rhizoctonia solani causing hypocotyl rot and foliar blight in soybean (Glycine max) in Brazil by the nucleotide sequences of ITS-5.8S regions of rDNA. The 5.8S rDNA gene sequence (155 bp) was highly conserved among all isolates but differences in length and nucleotide sequence of the ITS1 and ITS2 regions were observed between soybean isolates and AG testers. The similarity of the nucleotide sequence among AG-1 IA isolates, causing foliar blight, was 95.1-100% and 98.5-100% in the ITS1 and ITS2 regions, respectively. The nucleotide sequence similarity among subgroups IA, IB and IC ranged from 84.3 to 89% in ITS1 and from 93.3 to 95.6% in ITS2. Nucleotide sequence similarity of 99.1% and 99.3-100% for ITS1 and ITS2, respectively, was observed between AG-4 soybean isolates causing hypocotyl rots and the AG-4 HGI tester. The similarity of the nucleotide sequence of the ITS-5.8S rDNA region confirmed that the R. solani Brazilian isolates causing foliar blight are AG-1 IA and isolates causing hypocotyl rot symptoms are AG-4 HGI. The ITS-5.8S rDNA sequence was not determinant for the identification of the AG-2-2 IIIB R. solani soybean isolate.

A novel postharvest rot of okra pods caused by Rhizoctonia solani in Brazil

Okra pods with unusual brown lesions and rot were collected in a local supermarket in Brasília DF. The objective of this paper was to characterize the causal agent, to fulfill Koch's postulates and to determine some conditions conducive to disease. The pathogen was identified as Rhizoctonia solani based on morphological characteristics which fitted the fungus description, such as pale to brown hyphae, with nearly right-angled side branches constricted at the base, hyphal cells 6-10 µm wide with a septum near the base. Five isolates were obtained from infected pods and identified as AG 1-IB anastomosis group. Wounded or unwounded okra pods cv. Santa Cruz 47 were inoculated with mycelium disks of R. solani and kept in humid chambers at 12 ºC or 25 ºC. After seven days at 25 ºC, both wounded and unwounded pods were completely rotted and brown, while those kept at 12 ºC showed small lesions ranging from 0.6 to 1.0 mm only in wounded pods. The pathogen was able to grow in different materials used for assembling crates and packs of horticultural products, such as pinewood, corrugated carton, plastic, Styrofoam and newspaper sheets when kept in humid chambers (24 ºC, 96 % RH). The disease occurrence can be related to careless handling practices and to the transmission of R. solani propagules by infected plant debris or soil particles. This is the first report of Rhizoctonia solani causing postharvest rot in okra pods in Brazil.

DFMA-ohjeistuksen laatiminen tuulivoimateollisuuden mekaniikkasuunnittelijoille

Osien hyvä valmistettavuus on aina asettanut haasteita suunnittelulle. Yritysten verkostoituminen lisää haasteellisuutta, kun tuotteiden suunnittelu tehdään erillään kokoonpanosta ja osavalmistus tapahtuu alihankintana. Tällöin on ensiarvoisen tärkeää, että suunnittelulla on tarvittavat perustiedot eri valmistusmenetelmistä, jotta suunniteltujen osien valmistus ja kokoonpano luonnistuu ongelmitta. Työn alun kirjallisuusosiossa käsitellään suunnittelun teoriaa, joka toimii perustana hyvälle osasuunnittelulle. Teorian lisäksi työssä käsitellään eri työmenetelmiä koskevat rajoitukset ja mahdollisuudet. Oikein suunniteltu osa on työstömenetelmien kannalta hyvin valmistettavissa, työ voidaan tehdä taloudellisilla työmenetelmillä ja kokoonpanossa osat sopivat yhteen ilman sovitustyötä. Käytännön osuudessa on käsitelty The Switch Drive Systems Oy:n tuotteiden valmistettavuuden kehityskohteita, joilla tuotteiden valmistettavuutta voidaan parantaa. Kehityskohteiden perusteella on laadittu valmistusmenetelmäkohtainen suunnittelun ohjeistus, jonka avulla kehitetään The Switchin suunnittelua vastaamaan paremmin laitetoimittajien tarpeisiin. Näiden ohjeistuksien avulla voidaan kehittää suunnittelutyötä siten, että osien valmistettavuus sekä laatu paranevat ja kokoonpano nopeutuu.

Harmonical oscillator and electro-mechanical analogy: an interdiscinary experiment to high precision mass variation measurements

In general, the traditional Physics courses needs examples of the aplications of the Physics concepts in other areas such as Chemistry and Biology. This lacks tend to demotivate Chemistry and Biology students regarding to deal with Physical concepts developed in classroom. In this work, the analogy among mechanic and electric oscillators is investigated to be applied in Chemistry and Biology areas, showing to be valuable due to its aplication in techniques that aims to measure mass variation with high precision. This measure could be made in a direct or indirect way. These techniques are known as electrogravimetric techniques and they are important in biosensor aplications. Thus, this paper explores the electromechanic analogy in an interdisciplinary way involving areas like Physics, Chemistry and Biology. Based on this analogy, it is proposed an experiment that can be applied in different ways, i.e. by an basic approach or more deeper, depending on the students specific formation, in other words, Physics, Chemistry or Biology.

Estenose arterial pós-transplante hepático: tratamento com angioplastia transluminal percutânea

Vascular complications after liver transplantation include oclusion or stenosis at the sites of anastomosis in the hepatic artery, portal vein, and vena cava. Balloon angioplasty of these stenosis carries little risk and is a useful procedure for the treatment of these problems. The purpose of this paper was to assess whether percutaneous transluminal angioplasty can help to prolong allograft survival and impruve allograft function in patient with hepatic artery stenosis after liver transplantation. We report a 43-year-old mate with stenosis of hepatic artery anastomosis after liver transplantation. An abrupt elevation of liver enzymes and serum bilirrubin levels was noted on the fifth postoperative month. The patient underwent percutaneous liver biopsy, which revealed important ductal depletion due to hypoperfusion, even though Doppler ultrasound examination demonstrated arterial flow. An angiogram confirmed severe stenosis of the arterial anastomosis with poor intraparenchymal arterial perfusion pattern. In an attempt to preserve the graft, a percutaneous transluminal angioplasty was performed using microballoons mounted on a hydrophylic micro guidewire. Intervention proceeded without complications. Liver enzimes and bilirrubin levels decreased within twenty-four hours of angioplasty. Normal levels were achieved after one week. Seven month after angioplasty, the patient is in a optimal clinical condition with no signs of graft impairment. We conclude that percutaneous transluminal angioplasty of hepatic artery stenosis after liver transplantation is relatively safe and may help decrease allograft loss.

Trombose mesentérica como complicação da colecistectomia videolaparoscópica

Intestinal complications after laparoscopic cholecystectomy are rare and usually caused by direct injury sustained on trocar insertion. However, intestinal ischaemia has been reported as an unusual complication of the pneumoperitoneum. We describe a 55-years-old patient who underwent an uneventful laparoscopic cholecystectomy after an episode of acute cholecystitis. Initial recovery was complicated by development of increasing abdominal pain which led to open laparotomy on day 2. Gangrene of the distal ileum and right-sided colon was detected and small bowel resection with right colectomy and primary anastomosis was performed. Histological examination of the resected ileum showed features of venous hemorragic infarction and trombosis. In view of the proximity of the operation it is assumed that ileal ischaemia was precipitated by carbon dioxide pneumoperitoneum. Some studies have been demonstrated that, within 30 minutes of establishing a pneumoperitoneum at an intraabdominal pressure of 16 mmHg, cardiac output, blood flow in the superior mesenteric artery and portal vein decrease progressively. Carbon dioxide pneumoperitoneum may lead to mechanical compression of the splanchnic veins and mesenteric vasoconstriction as a result of carbon dioxide absortion. The distribution of the ischaemic segment of intestine is also unusual as the most precarious blood supply is traditionally at the splenic flexure of the colon. It has been suggested that intermittent decompression of the abdomen reduces the risk of mesenteric ischaemia during penumoperitoneum especially in patients with predisposing clinical features for arteriosclerosis intestinal. In present patient was observed intestinal venous infarction what remains unclear but we think the carbon dioxide pneumoperitoneum have been related to it.

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.

Fistula gastrocólica

A case of gastrocolic fistula(GCF) in a patient with duodenal stenosis who had previously undergone gastroenteric anastomosis is reported. The patient went through hemigastrectomy, partial colectomy and segmental enterectomy with bloc resection. Reconstruction was carried out through Billroth II gastrojejunostomy, jejunojejunostomy and end-to-end anastomosis of the colon. The patient had good post-operative evolution and was discharged from hospital seven days after surgery. GCF should be suspected in patients presenting weight loss, diarrhea and fecal vomiting, mainly with history of peptic ulcer surgery, gastric or colonic malignancy and use of steroidal and nonsteroidal antiinflamatory drugs. Barium enema is the choice test for diagnosis, however, the benign or malignant nature of the lesion should always be evaluated through high digestive endoscopy. Clinical treatment with oral H2-antagonists and discontinuing ulcerogenic medications might be indicated in some cases; surgical treatment is indicated in cases of malignant disease and might be indicated in cases of peptic disease as it treats GCF and also the baseline disease. Some advise upwards colostomy at first. The most used technique is bloc resection, including the fistulous tract, hemigastrectomy and partial colectomy. Gastrectomy, fistulous tract excision and colon suturing may be performed in some cases. The mortality rate is related to metabolic disorders and the recurrence with the use of antiinflammatory drugs.

Istoadenoma do ducto biliar comum

Biliary duct cystoadenomas are rare neoplasms, with about 120 cases described in the literature, including cystoadenomas and cystoadenocarcinomas. The authors report a case of cystoadenoma of the common bile duct in a 45-year-old woman with history of jaundice. Ultrasound revealed a cystic mass located in the common bile duct. Endoscopic retrograde cholangiopancreatography showed a negative filling defect in the proximal third of the common bile duct, a finding unique to our case. Total excision of the mass, cholecystectomy and an end-total anastomosis with a T-tube choledochostomy, were performed. Histological examination revealed a multicystic lesion with cavities lined by mucinous columnar non-ciliated epithelium, with surrounding densely cellular stroma resembling ovarian stroma. Six years after surgery the patient is alive and well, with no complains referring to the hepatobiliary tract. No abnormalities are presently detected in the biliary tree, ultrasonographically.

Anastomose duodenoduodenal na pancreatoduodenectomia por pancreatite crônica

Literature has been showing a tendency of reducing the limits of Whipple's resection. The main technical advance was the pylorus preserving resection, technique proposed by Traverso and Longmire in 1978. The pancreticoduodenectomy for chronic pancreatitis, is probably the best opportunity to apply this type of procedure. In these specific patients, the author preserved the pylorus and the third portion of the duodenum. The gastrointestinal transit was reconstructed by the duodenumduodenal anastomosis and the bile duct and the pancreas were drained in a Roux-en-way loop . Follow-up showed no important complication, with no problems related to gastric emptying and without pain.

Hepaticojejunostomia em "y" de roux videoassistida

Management of common bile duct stones in the era of laparoscopic surgery is controversial. The biliary anastomosis is indicated in case of large common bile duct, recurrent stones, giant stones and concomitant common bile duct stricture and duct stones. The development of laparoscopic techniques permits to perform this type of surgery laparoscopically as well as the open procedure.

Utilização da veia esplênica para restabelecer o fluxo sangüíneo mesentérico-porta após ressecção de veia mesentérica superior durante duodenopancreatectomia

Superior mesenteric vein invasion has historically been considered a contraindication for pancreatic cancer resection. Several studies have shown that in selected cases vascular resection can be performed safely. Many techniques have been used to reconstruct the venous flow. We describe one case of mesenteric superior vein resection and reconstrution of mesenteric-portal venous flow using the splenic vein during a pancreatoduodenectomy for pancreatic adenocarcinoma. The patient presented an extensive involvement of the superior mesenteric vein. A segmental resection with an end-to-end anastomosis of this vein and the splenic vein was accomplished after splenectomy. The patient had histologically confirmed negative margins. There was no hospital complications. These results show that the splenic vein can be an option for venous flow reconstruction when a segmental vascular resection is required during at pancreaticoduodenectomy.

Hemorragia digestiva baixa devido a melanoma maligno metastático

A case of lower gastrointestinal bleeding due to metastatic malignant melanoma in a man, in which the final diagnosis was made only on surgery, is reported. The patient underwent a segmentary enterectomy with primary anastomosis and he was discharged on tenth postoperative day.

Tratamento cirúrgico do schwannoma traqueal

Schwannoma is a rare benign tumor of the proximal tracheobronchial tree. The aim of the present study is to report a case of tracheal schwannoma causing airway obstruction. A 16-year-old woman complained of cough, wheezing and dyspneia. Bronchoscopy and computerized tomography showed a polypoide intratracheal mass obstructing approximately 80% of the lumen. The treatment consisted of tracheal resection and primary anastomosis. Histological analysis revealed a tracheal schwannoma. The postoperative course was uneventful and the patient remains well twelve months after surgery.