61 resultados para Geometria tubular
Resumo:
This paper presents the development of a prototype of a tubular linear induction motor applied to onshore oil exploitation, named MAT AE OS (which is the Portuguese acronym for Tubular Asynchronous Motor for Onshore Oil Exploitation). The function of this motor is to directly drive the sucker-rod pump installed in the down hole of the oil well. Considering the drawbacks and operational costs of the conventional oil extraction method, which is based on the walking beam and rod, string system, the developed prototype is intended to become a feasible alternative from both technical and economic points of view. At the present time, the MAT AE OS prototype is installed in a test bench at the Applied Electromagnetism Laboratory at the Escola Politecnica da Universidade de Sao Paulo. The complete testing system is controlled and supervised by special software, enabling good flexibility in operation, data acquisition, and performance analysis. The test results indicate that the motor develops a constant lift force along the pumping cycle, as shown by the measured dynamometric charts. Also, the evaluated electromechanical performance seems to be superior to that obtained by the traditional method. The system utilizing the MAT AE OS prototype allows the complete elimination of the rod string sets required by the conventional equipment, indicating that the new system may advantageously replace the surface mechanical components presently utilized.
Resumo:
The processes that govern the rate of particle recovery in a flotation cell include the following sub-processes: collision, attachment, and stability of the aggregate formed by particles and bubbles. Collision is controlled by bulk hydrodynamics inside the flotation cell, while attachment is largely dominated by variables that belong to the domain of surface chemistry (contact angle, induction time). As for the stability of the particle/bubble aggregate, its efficiency depends on both hydrodynamics plus surface chemistry variables of the system. The flotation recovery of coarse particles of apatite and glass spheres was measured by micro-flotation and batch flotation tests in which hydrodynamic parameters were evaluated, such as impeller rotational speed, diameter, and geometry, as well as particle size and density. Results revealed that a proper impeller rotational speed yielded turbulence levels, which enabled to keep particles fully suspended, this way optimizing the collision efficiency between particles and bubbles, without jeopardizing the stability of the particle-bubble aggregates.
Resumo:
In the present work, the sensitivity of NIR spectroscopy toward the evolution of particle size was studied during emulsion homopolymerization of styrene (Sty) and emulsion copolymerization of vinyl acetate-butyl acrylate conducted in a semibatch stirred tank and a tubular pulsed sieve plate reactor, respectively. All NIR spectra were collected online with a transflectance probe immersed into the reaction medium. The spectral range used for the NIR monitoring was from 9 500 to 13 000 cm(-1), where the absorbance of the chemical components present is minimal and the changes in the NIR spectrum can be ascribed to the effects of light scattering by the polymer particles. Off-line measurements of the average diameter of the polymer particles by DLS were used as reference values for the development of the multi-variate NIR calibration models based on partial least squares. Results indicated that, in the spectral range studied, it is possible to monitor the evolution of the average size of the polymer particles during emulsion polymerization reactions. The inclusion of an additional spectral range, from 5 701 to 6 447 cm(-1), containing information on absorbances (""chemical information"") in the calibration models was also evaluated.
Resumo:
The behavior of S. platensis was investigated in this study through fed-batch pulse-feeding cultures performed at different carbon dioxide feeding rates (F = 0.44-1.03 g L-1 d(-1)) and photosynthetic photon flux density (PPFD = 80-250 mu mol photons m(-2) s(-1)) in a bench-scale helical photobioreactor. To achieve this purpose, an inorganic medium lacking the carbon source was enriched by gaseous carbon dioxide from a cylinder. The maximum cell concentration achieved was 12.8 g L-1 at PPFD = 166 mu mol photons m(-2) s(-1) and F= 0.44 g L-1 d(-1) of CO2. At PPFD = 80 and 125 mu mol photons m(-2) s(-1), the carbon utilization efficiency (CUE) reached maximum values of 50 and 69%, respectively, after about 20 days, and then it decreased, thus highlighting a photolimitation effect. At PPFD = 166 mu mol photons m(-2) s(-1), CUE was >= 90% between 20 and 50 days. The photosynthetic efficiency reached its maximum value (9.4%) at PPFD = 125 mu mol photons m(-2) s(-1). The photoinhibition threshold appeared to strongly depend on the feeding rate: at high PPFD, an increase in the amount of fed CO2 delayed the inhibitory effect on biomass growth, whereas at low PPFD, excess CO2 addition caused the microalga to stop growing. (c) 2007 Elsevier B.V. All rights reserved.
Resumo:
Inflorescence and floral development of two tropical legume trees, Dahlstedtia pinnata and Dahlstedlia pentaphylla, occurring in the Atlantic Forest of south-eastern and southern Brazil, were investigated and compared with other papilionoids. Few studies have been made of floral development in tribe Millettieae, and this paper is intended to fill that gap in our knowledge. Dahlstedtia species have an unusual inflorescence type among legumes, the pseudoraceme, which comprises axillary units of three or more flowers, each with a subtending bract. Each flower exhibits a pair of opposite bractcoles. The order of flower initiation is acropetal; inception of the floral organs is as follows: sepals (5), petals (5), carpel (1) plus outer stamens (5) and finally inner stamens (5). Organ initiation in sepal, petal and inner stamen whorls is unidirectional; the carpel cleft is adaxial. The vexillum originates from a tubular-shaped primordium in mid-development and is larger than other petals at maturity, covering the keels. The filament tube develops later after initiation of inner-stamen primordia. Floral development in Dahlstedtia is almost always similar to other papilionoids, especially species of Phaseoleae and Sophoreae. But one important difference is the precocious ovule initiation (open carpel with ovules) in Dahlstedtia, the third citation of this phenomenon for papilionoids. No suppression, organ loss or anomalies occur in the order of primordia initiation or structure. Infra-generic differences in the first stages of ontogeny are rare; however, different species of Dahlstedtia are distinguished by the differing distribution pattern of secretory cavities in the flower. (C) 2009 Elsevier GmbH. All rights reserved.
Resumo:
Eight hundred and seventy-nine patients with acute kidney injury were retrospectively studied over year and eleven months for evaluation of urine volume as a risk factor for death. They were divided into five groups, according to the 24 h urine volume (UV): anuric (UV <= 50 mL/24 h, group 1), oliguric (UV > 50 mL/24 h and < 400 mL/24 h, group 2), and non-oliguric (UV >= 400 mL/24 h). Nonoliguric group was subdivided in three subgroups: UV > 400 mL/24 h and <= 1000 mL/24 h (group 3, reference group), UV > 1000 mL/24 h and <= 2000 mL/24 h (group 4), and UV > 2000 mL/24 h (group 5). Linear tendency test (Mantel extension) pointed out a significant increase in mortality with UV decrease (p < 0.001), confirmed by multivariate analysis. Anuric and oliguric patients had increased risk of respectively 95% and 76% times for death compared to controls (p < 0.05). Patients from groups 4 and 5 presented a reduced risk for death of 50% and 70%, respectively, p = 0.004 and p = 0.001. In conclusion, urine volume was a strong independent factor for mortality in this cohort of AKI patients.
Resumo:
A 50-year-old woman presented with pancreatitis, fluctuant jaundice, weight loss, and abdominal pain. Contrast-enhanced computed tomography and abdominal ultrasound showed slight dilatation of the biliary tree and gallbladder without calculi. Endoscopy demonstrated a tumor protruding from the papilla of Vater. First endoscopically biopsy diagnosed no tumor, and a second biopsy diagnosed as papillary adenocarcinoma. The patient underwent duodenopancreatectomy. The specimen was fixed in formalin (10%). The tissue was processed routinely, and paraffin sections were stained with hematoxylin-eosin and periodic acid Schiff. Gross examination showed two tumors seen as prolapsed nodules growing isolated from the minor and major duodenal papillae measuring 1.5 and 1.0 cm, respectively, both covered by duodenal mucosa and the histologic study of both lesions demonstrated a moderately differentiated tubular adenocarcinoma, which invaded duodenal wall. After surgery, she is alive 24 months without evidence of recurrence.
Resumo:
In animal models, interstitial angiotensin II (ang II) and AT1 receptor (AT1R) are key mediators of renal inflammation and fibrosis in progressive chronic nephropathies. We hypothesized that these molecules were overexpressed in patients with progressive glomerulopathies. In this observational retrospective study, we described the expression of ang II and AT1R by immunohistochemistry in kidney biopsies of 7 patients with minimal change disease (MCD) and in 25 patients with progressive glomerulopathies (PGPs). Proteinuria, serum albumin, and serum creatinine were not statistically different between MCD and PGP patients. Total expression of ang II and AT1R was not statistically different between MCD (108.7 +/- 11.5 and 73.2 +/- 13.6 cells/mm(2), respectively) and PGN patients (100.7 +/- 9.0 and 157.7 +/- 13.8 cells/mm(2), respectively; p>0.05). Yet, interstitial expression of ang II and AT1R (91.6 +/- 16.0 and 45.6 +/- 5.4 cells/mm(2), respectively) was higher in patients with PGN than in those with MCD (22.0 +/- 4.1 and 17.9 +/- 2.9 cells/mm(2), respectively, p<0.05), as was the proportion of interstitial fibrosis (11.0 +/- 0.7% versus 6.1 +/- 1.2%, p<005). In patients with MCD, ang II and AT1R expressions predominate in the tubular compartment (52% and 36% of the positive cells, respectively). In those with PGP, the interstitial expression of ang II and AT1R predominates (58% and 45%, respectively). In conclusion, interstitial expression of ang II and AT1R is increased in patients with progressive glomerulopathies. The relationship of these results and interstitial fibrosis and disease progression in humans warrants further investigations.
Resumo:
Inflammation is currently recognized as a key mechanism in the pathogenesis of renal ischemia-reperfusion (I/R) injury. The importance of infiltrating neutrophil, lymphocytes, and macrophage in this kind of injury has been assessed with conflicting results. Annexin 1 is a protein with potent neutrophil anti-migratory activity. In order to evaluate the effects of annexin A1 on renal I/R injury, uninephrectomized rats received annexin A1 mimetic peptide Ac2-26 (100 mu g) or vehicle before 30 min of renal artery clamping and were compared to sham surgery animals. Annexin A1 mimetic peptide granted a remarkable protection against I/R injury, preventing glomerular filtration rate and urinary osmolality decreases and acute tubular necrosis development. Annexin A1 infusion aborted neutrophil extravasation and attenuated macrophage infiltration but did not prevent tissue lymphocyte traffic. I/R increased annexin A1 expression (assessed by transmission electron microscopy) in renal epithelial cells, which was attenuated by exogenous annexin A1 infusion. Additionally, annexin A1 reduced I/R injury in isolated proximal tubules suspension. Annexin A1 protein afforded striking functional and structural protection against renal I/R. These results point to an important role of annexin A1 in the epithelial cells defense against I/R injury and indicate that neutrophils are key mediators for the development of tissue injury after renal I/R. If these results were confirmed in clinical studies, annexin A1 might emerge as an important tool to protect against I/R injury in renal transplantation and in vascular surgery.
Resumo:
Complications related to renal transplants have been widely reported in the literature. The most common complications include acute tubular necrosis, rejection, perirenal fluid collections, vascular complications, and urinary tract obstruction, which are promptly identified by imaging studies. Here we report a case of a patient with a rare cause of obstruction: a ureteral inguinal hernia. This is the sixth report of this condition, and, to our knowledge, no previous case has been reported in which sonography played an important role in promptly identifying the underlying condition and allowing additional less hazardous studies, therefore aiding case management.
Resumo:
Alouatta guariba clamitans (brown howler monkey) is an endemic primate from the southeastern Brazil tropical forests, classified as near threatened by the IUCN Red List 2007. The genus Aloualta is one of the most difficult New World monkeys to breed and rear in captivity. In this study we examined the macroscopic and histological aspects of the female genital tract of wild brown howler monkeys to provide baseline information for future reproduction research. The anatomical relationship between the vagina, uterus, broad ligament, oviducts and ovaries are those of a typical primate reproductive tract. The fundic portion of the uterus is globoid, the cervix is well developed, which confers to the uterus an elongated shape, and the vagina is a long flattened channel. Histological analysis conducted in females in the follicular phase revealed large quantities of interstitial luteinized tissue in the ovaries, a stratified nonkeratinized vaginal epithelium, lack of glands in the vaginal mucosa and simple tubular endometrial glands. The observed anatomical features should be considered in the adaptation and application of assisted reproductive techniques aimed at improving captive reproduction for species conservation. Am. J. Primatol. 71:145-152, 2009. (C) 2008 Wiley-Liss, Inc.
Resumo:
This study was conducted to analyze the participation of tenascin and fibronectin, components of the extracellular matrix. in different types of carcinoma ex pleomorphic adenoma (CXPA). Seventeen cases of CXPA, classified according to the presence of epithelial and myoepithelial cells and the degree of invasion-intracapsular, minimally, and frankly invasive carcinoma-were immunohistochemically labeled for tenascin and fibronectin. Normal salivary gland included in the specimens showed tenascin only around the excretory duct, and fibronectin slightly expressed all over the stroma of the gland. In reminiscent pleomorphic adenoma, tenascin and fibronectin were observed around tubular structures and in the stroma. Both tenascin and fibronectin were expressed in all the CXPA studied. In areas of in situ carcinoma of the intracapsular type, the expression of these extracellular matrix proteins was enhanced compared with areas of residual pleomorphic adenoma. In intracapsular and minimally invasive types of CXPA, some areas of the tumor border presented tenascin and no fibronectin, pattern that may represent the real invasive front. In frankly invasive CXPA type with only epithelial component, fibronectin was strongly observed in a fibrillar network pattern, and tenascin was only focal. In frankly invasive type with myoepithelial component, tenascin staining was very strong and diffuse. This study showed different patterns of expression of tenascin and fibronectin along the process of tumorigenesis and tumor progression in CXPA, a fact that might play a role in invasion properties of these tumors.
Resumo:
Gemcitabine is a chemotherapy agent that may cause unpredictable side effects. In this report, we describe a fatal gemcitabine-induced pulmonary toxicity in a patient with gallbladder metastatic adenocarcinoma. A 72-year-old patient was submitted to an elective laparoscopic cholecystectomy, and a tubular adenocarcinoma in the gallbladder was incidentally diagnosed. CT scan and ultrasound before the surgery did not show any tumor. After the surgery a Pet scan was positive for a hot-spot in the left colon. The colonic lesion was conveniently removed and the histology evaluation confirmed the diagnosis of adenocarcinoma tubular. The patient was then submitted to three sections of 1,600 mg/m(2) of gemcitabine with intervals of 1 week. Three weeks later he developed severe respiratory distress. A helicoidal CT scan showed diffuse and severe interstitial pneumonitis, and lung biopsy confirmed accelerated usual interstitial pneumonia consistent with drug-induced toxicity. The patient presented unfavorable evolution with progressive worsening of respiratory function, hypotension, and renal failure. He died 1 month later in spite of methylprednisolone pulse therapy, large spectrum antimicrobial therapy, and full support of respiratory, hemodynamic and renal systems. Gemcitabine-induced pulmonary toxicity is usually a dramatic condition. Physicians should suspect pulmonary toxicity in patients with respiratory distress after gemcitabine chemotherapy, mainly in elderly patients.
Resumo:
Aims: Histological grade is one of the most important prognostic factors in breast carcinomas, but poorly differentiated neoplasms still have quite heterogeneous biological behaviour, since they can be genetically classified as basal-like, HER2+ or even luminal. The aim was to analyse the frequency of oestrogen receptor (ER), progesterone receptor (PR) and HER2 expression profiles among breast carcinomas with < 10% tubular formation, and their correlation with classic prognostic factors. Methods and results: One hundred and thirty-four samples of paraffin-embedded tumours were studied retrospectively. The tumours were classified in to four groups by their ER/PR/HER2 profile: (i) ER+ and/or PR+ but HER2-; (ii) ER+ and/or PR+ and HER2+; (iii) ER- and/or PR- but HER2+; and (iv) ER-, PR- and HER2- (triple-negative). The histological features of triple-negative and HER2+ carcinomas overlap. The only difference was the expression of basal cytokeratins (basal CK), which was more frequent among triple-negative carcinomas. Basal-CK expression defined a more aggressive group of tumours, according to the pathological features, regardless of the immunohistochemical profile. Conclusions: Group 1 and 2 tumours (ER+ and/or PR+ tumours with or without HER2 expression) were not statistically different, suggesting that poorly differentiated carcinomas with hormone receptors correspond to the luminal B type of tumour. Among poorly differentiated breast carcinomas, the classic profile associated with basal-CK identifies distinct subtypes equivalent to those seen by genetic classification.
Resumo:
This work characterizes the effects of ambient levels of urban particulate matter (PM(2.5)) from the city of Sao Paulo on spermatogenesis using mice exposed during the embryo-fetal and/or postnatal phases of development. Parental generations (BALB/c mice) were exposed to air pollution in chambers with or without filtering PM(2.5) for 4 months. Animals were mated, and half of the 1-day-old offspring were moved between chambers, which yielded prenatal and postnatal groups. Remaining offspring comprised the non-exposed and pre+postnatal exposed groups. After 90 days, the animals were sacrificed for testis collection and weighing. Optical microscopy was used for the morphometric analyses of the cell counts, spermatogenic cycle, proliferation, and apoptosis. Prenatally exposed animals presented reduced body and testicular weight with an increased gonadosomatic index (GSI). Testicular volume also decreased, as well as the tubular diameter in testes of the same animals. Proliferation, apoptosis, and spermatogenic cycle analyses showed no significant differences among groups. However, the tubules at stage VII of pre- and postnatal animals presented a reduced number of elongated spermatids. Pre+postnatal group presented higher spermatid head retention at stages VIII-XII. These results show that ambient levels of PM(2.5) from Sao Paulo city affect spermatogenesis by damaging sperm production.