893 resultados para Curved Graded Multilayers
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Objectives: Resternotomy is a common part of cardiac surgical practice. Associated with resternotomy are the risks of cardiac injury and catastrophic hemorrhage and the subsequent elevated morbidity and mortality in the operating room or during the postoperative period. The technique of direct vision resternotomy is safe and has fewer, if any, serious cardiac injuries. The technique, the reduced need for groin cannulation and the overall low operative mortality and morbidity are the focus of this restrospective analysis. Methods: The records of 495 patients undergoing 546 resternotomies over a 21-year period to January 2000 were reviewed. All consecutive reoperations by the one surgeon comprised patients over the age of 20 at first resternotomy: M:F 343:203, mean age 57 years (range 20 to 85, median age 60). The mean NYHA grade was 2.3 [with 67 patients (1), 273 (11),159 (111), 43 (IV), and 4 (V classification)] with elective reoperation in 94.6%. Cardiac injury was graded into five groups and the incidence and reasons for groin cannulation estimated. The morbidity and mortality as a result of the reoperation and resternotomy were assessed. Results: The hospital/30 day mortality was 2.9% (95% Cl: 1.6%-4.4%) (16 deaths) over the 21 years. First (481), second (53), and third (12) resternotomies produced 307 uncomplicated technical reopenings, 203 slower but uncomplicated procedures, 9 minor superficial cardiac lacerations, and no moderate or severe cardiac injuries. Direct vision resternotomy is crystalized into the principle that only adhesions that are visualized from below are divided and only sternal bone that is freed of adhesions is sewn. Groin exposure was never performed prophylactically for resternotomy. Fourteen patients (2.6%) had such cannulation for aortic dissection/aneurysm (9 patients), excessive sternal adherence of cardiac structures (3 patients), presurgery cardiac arrest (1 patient), and high aortic cannulation desired and not possible (1 patient). The average postop blood loss was 594 mL (95% CI:558-631) in the first 12 hours. The need to return to the operating room for control of excessive bleeding was 2% (11 patients). Blood transfusion was given in 65% of the resternotomy procedures over the 21 years (mean 854 mL 95% Cl 765-945 mL) and 41% over the last 5 years. Conclusions: The technique of direct vision resternotomy has been associated with zero moderate or major cardiac injury/catastrophic hemorrhage at reoperation. Few patients have required groin cannulation. In the postoperative period, there was acceptable blood loss, transfusion rates, reduced morbidity, and moderate low mortality for this potentially high risk group.
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Event-related potentials (ERPs) were recorded while subjects made old/new recognition judgments on new unstudied words and old words which had been presented at study either once ('weak') or three times ('strong'). The probability of an 'old' response was significantly higher for strong than weak words and significantly higher for weak than new words. Comparisons were made initially between ERPs to new, weak and strong words, and subsequently between ERPs associated with six strength-by-response conditions. The N400 component was found to be modulated by memory trace strength in a graded manner. Its amplitude was most negative in new word ERPs and most positive in strong word ERPs. This 'N400 strength effect' was largest at the left parietal electrode (in ear-referenced ERPs). The amplitude of the late positive complex (LPC) effect was sensitive to decision accuracy (and perhaps confidence). Its amplitude was larger in ERPs evoked by words attracting correct versus incorrect recognition decisions. The LPC effect had a left > right, centro-parietal scalp topography (in ear-referenced ERPs). Hence, whereas, the majority of previous ERP studies of episodic recognition have interpreted results from the perspective of dual-process models, we provide alternative interpretations of N400 and LPC old/new effects in terms of memory strength and decisional factor(s). (C) 2002 Elsevier Science Ltd. All rights reserved.
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Nine classes of integrable open boundary conditions, further extending the one-dimensional U-q (gl (212)) extended Hubbard model, have been constructed previously by means of the boundary Z(2)-graded quantum inverse scattering method. The boundary systems are now solved by using the algebraic Bethe ansatz method, and the Bethe ansatz equations are obtained for all nine cases.
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Objective - To assess the relationship between infrarenal aortic diameter and subsequent all-cause mortality in men aged 65 years or older. Methods and Results - Aortic diameter was measured using ultrasound in 12 203 men aged 65 to 83 years as part of a trial of screening for abdominal aortic aneurysms. A range of cardiovascular risk factors was also documented. Mortality over the next 3 to 7 years was assessed using record linkage. Initial aortic diameter was categorized into 10 intervals, and the relationship between increasing diameter and subsequent mortality was explored using Cox proportional hazard models. Median diameter increased from 21.4 mm in the youngest men to 22.1 mm in the oldest men. The cumulative all-cause mortality increased in a graded fashion with increasing aortic diameter. Using the diameter interval 19 to 22 mm as the reference, the adjusted hazard ratio for all-cause mortality increased from 1.26 (95% CI: 1.09, 1.44; P = 0.001) for aortic diameters of 23 to 26 mm to 2.38 (95% CI: 1.22, 4.61; P = 0.011) for aortic diameters of 47 to 50 mm. Analysis of causes of death indicated that cardiovascular disease was an important contributor to this increase. Conclusion - Infrarenal aortic diameter is an independent marker of subsequent all-cause mortality.
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Layered Double Hydroxides are a class of materials that can be described as positively charged layers of divalent and trivalent cations in the centre of edge-sharing octahedra. Cholesterol derivatives such as cholic acid are substances that play an important role in the digestion of fat components by the organism. This work presents a study on the intercalation of cholate anions in calcined MgAl-CO(3)-HDL. Isotherm experiments were performed at three different temperatures to evaluate the capacity of anion removal by sorption in the calcined LDH. The plateau was reached in all conditions. Increasing temperature results in decreasing cholate sorption. Characteristic peaks of LDH regenerated with OH(-) anions were observed at lower cholate concentrations. A peak in 2 theta equals to 7.5 degrees and peaks between 15 degrees and 20 degrees are observed. Those peaks are the same as the ones observed in the pure sodium cholate PXRD. At higher cholate concentrations the sorbed solids present PXRD related to an additional layered phase, which is related to intercalation of cholate anions with basal spacing equal to 34.3 angstrom. Thus, the cholate anions are also intercalated with a bilayer molecular arrangement at equilibrium concentrations at the isotherms plateau. (C) 2009 Elsevier Ltd. All rights reserved.
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Despite extensive research in the last 150 years, the regional tectonic reconstruction of the Western Alps has remained controversial. The curved orogenic belt consists of several ribbon-like continental terranes (Sesia/Austroalpine, Internal Crystalline Massifs, Brianconnais), which are separated by two or more ophiolitic sutures (Piemonte, Valais, Antrona?, Lanzo/ Canavese?). High-pressure (HP) metamorphism of each terrane occurred during distinct orogenic episodes: at similar to65 Ma in the Sesia/Austroalpine, at similar to45 Ma in the Piemonte zone and at similar to35 Ma in the Internal Crystalline Massifs. It is suggested that these events reflect individual accretionary episodes, which together with kinematic indicators and the speed and direction of plate motions, provide constraints for the discussed reconstruction model. The model involves a prolonged orogenic history that took place during relative convergence of Europe and Adria (here considered as a promontory of the African plate). The first accretionary event involved the Sesia/Austroalpine terrane. Final closure of the Piemonte Ocean occurred during the Eocene (similar to45 Ma) and involved ultra-high-pressure (UHP) metamorphism of the Piemonte oceanic crust. Incorporation of the Brianconnais terrane in the accretionary wedge occurred thereafter, possibly during or after subduction of the Valais Ocean in the late Eocene (45-35 Ma). This subduction was terminated at ca. 35 Ma, when the Internal Crystalline Massifs (i.e. the assumed internal parts of the Brianconnais terrane) were buried into great depths and underwent HP and UHP metamorphism. (C) 2004 Elsevier B.V. All rights reserved.
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Considering that mycobacterial heat-shock protein 65 (hsp65) gene transfer can elicit a profound antitumoral effect, this study aimed to establish the safety, maximum-tolerated dose (MTD) and preliminary efficacy of DNA-hsp65 immunotherapy in patients with advanced head and neck squamous cell carcinoma (HNSCC). For this purpose, 21 patients with unresectable and recurrent HNSCC were studied. Each patient received three ultrasound-guided injections at 21-day intervals of: 150, 600 or 400 mu g of DNA-hsp65. Toxicity was graded according to CTCAE directions. Tumor volume was measured before and after treatment using computed tomography scan. The evaluation included tumor mass variation, delayed-type hypersensitivity response and spontaneous peripheral blood mononuclear cell proliferation before and after treatment. The MTD was 400 mg per dose. DNA-hsp65 immunotherapy was well tolerated with moderate pain, edema and infections as the most frequent adverse effects. None of the patients showed clinical or laboratory alterations compatible with autoimmune reactions. Partial response was observed in 4 out of 14 patients who completed treatment, 2 of which are still alive more than 3 years after the completion of the trial. Therefore, DNA-hsp65 immunotherapy is a feasible and safe approach at the dose of 400 mg per injection in patients with HNSCC refractory to standard treatment. Further studies in a larger number of patients are needed to confirm the efficacy of this novel strategy.
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Objectives: The high incidence of respiratory disorders is one of the main problems in perinatal medical care. With the increased use of intubation, the incidence of laryngeal injury causing stenosis has also increased. The principal constriction point in the infant`s larynx is the midcricoid area. We sought to provide detailed morphometric data on the anatomy of the cricoid cartilage and its relationship with growth and body characteristics of fetuses at 5 to 9 months of gestational age. Methods: Nineteen larynges obtained from 17 stillborn infants and 2 newborn infants ranging in gestational age from 5 to 9 months were studied. Measurements of the cricoid cartilage were made with a millimeter-graded caliper. Results: Weight was the variable most correlated with cricoid measurements. The cricoid lumen configuration showed an almost elliptic shape and did not change with gestational age. The mean inner subglottic cricoid area was 19.27 +/- 9.62 mm(2) and was related to weight and body surface area. Cricoid growth was more pronounced at the outer portion of the cartilage. Conclusions: The cricoid lumen configuration was elliptic, and its mean area was smaller than that of available endotracheal tubes. This lumen area was most influenced by weight and height.
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To evaluate the usefulness of intraoral ultrasonography (IOUS) as a tool for predicting neck metastasis. Squamous cell carcinoma (SCC) of the tongue is aggressive and has a great propensity to metastasize to cervical lymph nodes. SCC of the oral cavity has a worse prognosis when associated with metastatic cervical nodes. Therefore, the metastatic potential of tongue carcinoma should be graded preoperatively to help determine the requirement for neck dissection. Nineteen patients (11 men, 8 women) between 36 and 79 years of age (mean age 60) with T1 to T4a TNM-stage tongue carcinomas were evaluated preoperatively with IOUS. Clinical and pathological TNM classifications were performed. The average tumor thicknesses measured using histological sections were significantly (p < 0.01) lower than those with IOUS (1.3 vs. 1.6 cm, respectively). A significant correlation was observed between the tumor thickness measured using ultrasonography and that measured using histological sections (pathology). Based on this greater accuracy, the cutoff point of tumor thickness based on IOUS evaluation for predicting neck metastasis was determined to be 1.8 cm. Some factors may influence neck metastasis. A knowledge of these would help to avoid unnecessary surgical intervention for N0 patients. The results of this study indicates that there is a significant correlation between neck metastasis and tumor thickness. Intraoral ultrasonography is useful tool for identifying tongue tumors and measuring their thickness, with the thickness measured by IOUS showing a very good correlation with histological measurements. Moreover, IOUS provides prognostic information prior to surgical treatment since tumor thickness can predict the chance of recognizing metastatic cervical nodes.
Determination of the solution structures of conantokin-G and conantokin-T by CD and NMR spectroscopy
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Conantokin-G and conantokin-T are two paralytic polypeptide toxins originally isolated from the venom of the fish-hunting cone snails of the genus Conus. Conantokin-G and conantokin-T are the only naturally occurring peptidic compounds which possess N-methyl-D-aspartate receptor antagonist activity, produced by a selective non-competitive antagonism of polyamine responses, They are also structurally unusual in that they contain a disproportionately large number of acid labile post-translational gamma-carboxyglutamic acid (Gla) residues, Although no precise structural information has previously been published for these peptides, early spectroscopic measurements have indicated that both conantokin-G and conantokin-T form alpha-helical structures, although there is some debate whether the presence of calcium ions is required for these peptides to adopt this fold, We now report a detailed structural study of synthetic conantokin-G and conantokin-T in a range of solution conditions using CD and H-1 NMR spec troscopy. The three-dimensional structures of conantokin-T and conantokin-G were calculated from H-1 NMR-derived distance and dihedral restraints. Both conantokins were found to contain a mixture of alpha- and 3(10) helix, that give rise to curved and straight helical conformers. Conantokin-G requires the presence of divalent cations (Zn2+, Ca2+, Cu2+, Or Mg2+) to form a stable iv-helix, while conantokin-T adopts a stable alpha-helical structure in aqueous conditions, in the presence or absence of divalent cations (Zn2+, Ca2+, Cu2+, Or Mg2+).
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Purpose: The bladder is normally impermeable to possible hostile environmental factors and toxic urinary wastes. Any disruption of the permeability barrier would permit the leakage of urine constituents into the underlying cells layers and subsequent inflammation. Protamine sulfate, which increases urothelial permeability, is used in experimental models of cystitis. We examined whether protamine sulfate alone could cause bladder inflammation or if the association of protamine sulfate and urine is needed for this condition. Materials and Methods: Female Wistar rats (Center for the Development of Experimental Models for Medicine and Biology, Federal University of Sao Paulo, Sao Paulo, Brazil) had the bladder catheterized and instilled with protamine sulfate (10 mg) or sterile saline for 30 minutes. To exclude urine other groups of rats underwent bilateral nephrectomy and the same procedure was used. One day after instillation the bladders were removed for histopathology. Edema and vascular congestion were graded from 0-none to 3-severe. Polymorphonuclear and mast cells were counted. The Kruskal-Wallis test was performed for statistical analysis. Results: Intravesical instillation of protamine sulfate in nonnephrectomized rats led to inflammation, in contrast to findings in rats instilled with saline. On the other hand, nephrectomized rats showed no inflammatory changes following the instillation of protamine sulfate or saline. The mast cell count was similar in all groups. Conclusions: Bladder inflammation in this experimental model of urothelial injury was not due to protamine sulfate alone. The association of protamine sulfate and urine was necessary to trigger the inflammatory cascade. Thus, urine indeed has an important role in the development of bladder inflammation in an environment of higher urothelial permeability.
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Abnormal heart-rate (HR) response during or after a graded exercise test has been recognized as a strong and an independent predictor of all-cause mortality in healthy and diseased subjects. The purpose of the present study was to evaluate the HR response during exercise in women with systemic lupus erythematosus (SLE). In this case-control study, 22 women with SLE (age 29.5 perpendicular to 1.1 years) were compared with 20 gender-, BMI-, and age-matched healthy subjects (age 26.5 +/- 1.4 years). A treadmill cardiorespiratory test was performed and HR response during exercise was evaluated by the chronotropic reserve (CR). HR recovery (Delta HRR) was defined as the difference between HR at peak exercise and at both first (Delta HRR1) and second (Delta HRR2) minutes after exercising. SLE patients presented lower peak VO(2) when compared with healthy subjects (27.6 perpendicular to 0.9 vs. 36.7 perpendicular to 1.1 ml/kg/min, p = 0.001, respectively). Additionally, SLE patients demonstrated lower CR (71.8 +/- 2.4 vs. 98.2 +/- 2.6%, p = 0.001), Delta HRR1 (22.1 +/- 2.5 vs. 32.4 +/- 2.2%, p = 0.004) and Delta HRR2 (39.1 +/- 2.9 vs. 50.8 +/- 2.5%, p = 0.001) than their healthy peers. In conclusion, SLE patients presented abnormal HR response to exercise, characterized by chronotropic incompetence and delayed Delta HRR. Lupus (2011) 20, 717-720.
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Introduction: Xenotransplantation and multivisceral transplantation are advanced therapeutic methods that still require a scientific basis. There are no experimental models of multivisceral transplantation available, particularly not the monitoring by endoscopy. Here, we describe the endoscopic features in a model of multivisceral xenotransplantation. Methods: The distal esophagus, stomach, intestine, colon, liver, pancreas, and the kidneys with a common vascular pedicle were harvested from rabbits and implanted in swine (group I, n = 9) or in rabbits (group II, n = 4). Endoscopy was performed in the stomach, jejunum, and ascending colon at four consecutive time points (immediate after surgery and 10, 90, and 180 min after reperfusion). Lesions were macroscopically graded as mild, moderate, and severe. Biopsies were taken following sacrifice at 180 min after reperfusion. Results: In group I, the stomach, jejunum, and colon manifested a progression of lesions with predominance of mild lesions after 10 min, mild to moderate lesions after 90 min, and moderate to severe lesions after 180 min. In animals from group II, endoscopy showed normal features at all time points after reperfusion. Histopathologic analysis confirmed the diagnosis of hyperacute rejection in group I. Grafts from group II animals presented normal or mild ischemic/reperfusion injury. Conclusion: All animals subjected to multivisceral xenotransplantation showed a progression of endoscopic lesions with time after transplantation, while animals subjected to allotransplantation showed no aberrations in endoscopy. We conclude that endoscopy is a useful tool in the assessment of hyperacute rejection of a xenograft.
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Objectives: To evaluate the genotoxic risk to hairdressers exposed daily to chemical substances such as hair dyes, waving and straightening preparations and manicurists` products by the Comet assay test (single-cell gel electrophoresis). Methods: The Comet assay was performed on blood samples from 69 female hairdressers (36.4 +/- 10.7 years old) currently employed in 21 different beauty institutes in Sao Paulo, Brazil, and on 55 female control blood donors (32.6 +/- 10.0 years old) from the Sao Paulo University Clinical Hospital blood bank. All the control subjects had occupations other than hairdresser. Comet assays were performed by evaluating 100 blood lymphocytes per individual and graded by visual score according to comet tail length. Results: The hairdressers showed a higher frequency of DNA damage revealed by Comet Score (159.8 +/- 71) when compared to the control group (125.4 +/- 64.1), and the difference was statistically significant by the Student`s t-test (P = 0.005). Multiple regression analysis showed that in addition to the hairdressers` profession, tobacco use contributed to the higher frequency of cells with comets (P < 0.05). Conclusions: The observed DNA damage could be associated with the hairdressers` occupational environment, where different chemicals are chronically manipulated and inhaled. Considering that this profession in many countries, including Brazil, is not officially regulated, more attention should focus on these professionals not only by legislative bodies but also by multidisciplinary teams able to develop and implement risk prevention and control strategies for chemical, physical and biological agents to which hairdressers are exposed.
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Purpose: To evaluate the effects of oral azithromycin in patients with posterior blepharitis. Methods: Twenty-six eyes of 13 patients with posterior blepharitis diagnosed by a qualified ophthalmologist were enrolled in this study. Patients were instructed to use oral azithromycin 500 mg per day for 3 days in 3 cycles with 7-day intervals. Subjective clinical outcomes were graded and scored 1 day before and 30 days after the end of the treatment (53 days after initiating the treatment) based on severity scores of: (1) eyelid debris; (2) eyelid telangiectasia; (3) swelling of the eyelid margin; (4) redness of the eyelid margin; and (5) ocular mucus secretion. For the assessment of global efficacy, patients were asked by the investigator to rate the subjective symptoms (eyelid itching, ocular itching, eyelid hyperemia, ocular hyperemia, ocular mucus secretion, photophobia, foreign body sensation, and dry eye sensation) on a scale of 0 (no symptoms) to 5 (severe symptoms). Break-up time, Schirmer I test, corneal fluorescein staining score, and rose bengal staining score were also performed in all patients. Results: All clinical outcomes scoring showed statistically significant improvement after oral azithromycin, except for eyelid swelling. Average subjective symptom grading improved statistically after treatment with oral azithromycin, except for eyelid hyperemia, photophobia, and foreign body sensation. Average tear film break-up time values showed statistically significant improvement after the treatment with oral azithromycin. No statistically significant improvement was observed on average values of Schirmer I test, corneal fluorescein staining score, and rose bengal staining score. Conclusions: The combination of multiple clinical parameters shown in this study supports the clinical efficacy of pulsed oral azithromycin therapy for the management of posterior blepharitis.