950 resultados para Free radical generation


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CONTEXT Although open radical cystectomy (ORC) is still the standard approach, laparoscopic radical cystectomy (LRC) and robot-assisted radical cystectomy (RARC) are increasingly performed. OBJECTIVE To report on a systematic literature review and cumulative analysis of pathologic, oncologic, and functional outcomes of RARC in comparison with ORC and LRC. EVIDENCE ACQUISITION Medline, Scopus, and Web of Science databases were searched using a free-text protocol including the terms robot-assisted radical cystectomy or da Vinci radical cystectomy or robot* radical cystectomy. RARC case series and studies comparing RARC with either ORC or LRC were collected. A cumulative analysis was conducted. EVIDENCE SYNTHESIS The searches retrieved 105 papers, 87 of which reported on pathologic, oncologic, or functional outcomes. Most series were retrospective and had small case numbers, short follow-up, and potential patient selection bias. The lymph node yield during lymph node dissection was 19 (range: 3-55), with half of the series following an extended template (yield range: 11-55). The lymph node-positive rate was 22%. The performance of lymphadenectomy was correlated with surgeon and institutional volume. Cumulative analyses showed no significant difference in lymph node yield between RARC and ORC. Positive surgical margin (PSM) rates were 5.6% (1-1.5% in pT2 disease and 0-25% in pT3 and higher disease). PSM rates did not appear to decrease with sequential case numbers. Cumulative analyses showed no significant difference in rates of surgical margins between RARC and ORC or RARC and LRC. Neoadjuvant chemotherapy use ranged from 0% to 31%, with adjuvant chemotherapy used in 4-29% of patients. Only six series reported a mean follow-up of >36 mo. Three-year disease-free survival (DFS), cancer-specific survival (CSS), and overall survival (OS) rates were 67-76%, 68-83%, and 61-80%, respectively. The 5-yr DFS, CSS, and OS rates were 53-74%, 66-80%, and 39-66%, respectively. Similar to ORC, disease of higher pathologic stage or evidence of lymph node involvement was associated with worse survival. Very limited data were available with respect to functional outcomes. The 12-mo continence rates with continent diversion were 83-100% in men for daytime continence and 66-76% for nighttime continence. In one series, potency was recovered in 63% of patients who were evaluable at 12 mo. CONCLUSIONS Oncologic and functional data from RARC remain immature, and longer-term prospective studies are needed. Cumulative analyses demonstrated that lymph node yields and PSM rates were similar between RARC and ORC. Conclusive long-term survival outcomes for RARC were limited, although oncologic outcomes up to 5 yr were similar to those reported for ORC. PATIENT SUMMARY Although open radical cystectomy (RC) is still regarded as the standard treatment for muscle-invasive bladder cancer, laparoscopic and robot-assisted RCs are becoming more popular. Templates of lymph node dissection, lymph node yields, and positive surgical margin rates are acceptable with robot-assisted RC. Although definitive comparisons with open RC with respect to oncologic or functional outcomes are lacking, early results appear comparable.

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BACKGROUND Patients with muscle-invasive urothelial carcinoma of the bladder have poor survival after cystectomy. The EORTC 30994 trial aimed to compare immediate versus deferred cisplatin-based combination chemotherapy after radical cystectomy in patients with pT3-pT4 or N+ M0 urothelial carcinoma of the bladder. METHODS This intergroup, open-label, randomised, phase 3 trial recruited patients from hospitals across Europe and Canada. Eligible patients had histologically proven urothelial carcinoma of the bladder, pT3-pT4 disease or node positive (pN1-3) M0 disease after radical cystectomy and bilateral lymphadenectomy, with no evidence of any microscopic residual disease. Within 90 days of cystectomy, patients were centrally randomly assigned (1:1) by minimisation to either immediate adjuvant chemotherapy (four cycles of gemcitabine plus cisplatin, high-dose methotrexate, vinblastine, doxorubicin, and cisplatin [high-dose MVAC], or MVAC) or six cycles of deferred chemotherapy at relapse, with stratification for institution, pT category, and lymph node status according to the number of nodes dissected. Neither patients nor investigators were masked. Overall survival was the primary endpoint; all analyses were by intention to treat. The trial was closed after recruitment of 284 of the planned 660 patients. This trial is registered with ClinicalTrials.gov, number NCT00028756. FINDINGS From April 29, 2002, to Aug 14, 2008, 284 patients were randomly assigned (141 to immediate treatment and 143 to deferred treatment), and followed up until the data cutoff of Aug 21, 2013. After a median follow-up of 7·0 years (IQR 5·2-8·7), 66 (47%) of 141 patients in the immediate treatment group had died compared with 82 (57%) of 143 in the deferred treatment group. No significant improvement in overall survival was noted with immediate treatment when compared with deferred treatment (adjusted HR 0·78, 95% CI 0·56-1·08; p=0·13). Immediate treatment significantly prolonged progression-free survival compared with deferred treatment (HR 0·54, 95% CI 0·4-0·73, p<0·0001), with 5-year progression-free survival of 47·6% (95% CI 38·8-55·9) in the immediate treatment group and 31·8% (24·2-39·6) in the deferred treatment group. Grade 3-4 myelosuppression was reported in 33 (26%) of 128 patients who received treatment in the immediate chemotherapy group versus 24 (35%) of 68 patients who received treatment in the deferred chemotherapy group, neutropenia occurred in 49 (38%) versus 36 (53%) patients, respectively, and thrombocytopenia in 36 (28%) versus 26 (38%). Two patients died due to toxicity, one in each group. INTERPRETATION Our data did not show a significant improvement in overall survival with immediate versus deferred chemotherapy after radical cystectomy and bilateral lymphadenectomy for patients with muscle-invasive urothelial carcinoma. However, the trial is limited in power, and it is possible that some subgroups of patients might still benefit from immediate chemotherapy. An updated individual patient data meta-analysis and biomarker research are needed to further elucidate the potential for survival benefit in subgroups of patients. FUNDING Lilly, Canadian Cancer Society Research.

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Procurement of fresh tissue of prostate cancer is critical for biobanking and generation of xenograft models as an important preclinical step towards new therapeutic strategies in advanced prostate cancer. However, handling of fresh radical prostatectomy specimens has been notoriously challenging given the distinctive physical properties of prostate tissue and the difficulty to identify cancer foci on gross examination. Here, we have developed a novel approach using ceramic foam plates for processing freshly cut whole mount sections from radical prostatectomy specimens without compromising further diagnostic assessment. Forty-nine radical prostatectomy specimens were processed and sectioned from the apex to the base in whole mount slices. Putative carcinoma foci were morphologically verified by frozen section analysis. The fresh whole mount slices were then laid between two ceramic foam plates and fixed overnight. To test tissue preservation after this procedure, formalin-fixed and paraffin-embedded whole mount sections were stained with hematoxylin and eosin (H&E) and analyzed by immunohistochemistry, fluorescence, and silver in situ hybridization (FISH and SISH, respectively). There were no morphological artifacts on H&E stained whole mount sections from slices that had been fixed between two plates of ceramic foam, and the histological architecture was fully retained. The quality of immunohistochemistry, FISH, and SISH was excellent. Fixing whole mount tissue slices between ceramic foam plates after frozen section examination is an excellent method for processing fresh radical prostatectomy specimens, allowing for a precise identification and collection of fresh tumor tissue without compromising further diagnostic analysis.

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The frontal eye field (FEF) is known to be involved in saccade generation and visual attention control. Studies applying covert attentional orienting paradigms have shown that the right FEF is involved in attentional shifts to both the left and the right hemifield. In the current study, we aimed at examining the effects of inhibitory continuous theta burst (cTBS) transcranial magnetic stimulation over the right FEF on overt attentional orienting, as measured by a free visual exploration paradigm. In forty-two healthy subjects, free visual exploration of naturalistic pictures was tested in three conditions: (1) after cTBS over the right FEF; (2) after cTBS over a control site (vertex); and, (3) without any stimulation. The results showed that cTBS over the right FEF-but not cTBS over the vertex-triggered significant changes in the spatial distribution of the cumulative fixation duration. Compared to the group without stimulation and the group with cTBS over the vertex, cTBS over the right FEF decreased cumulative fixation duration in the left and in the right peripheral regions, and increased cumulative fixation duration in the central region. The present study supports the view that the right FEF is involved in the bilateral control of not only covert, but also of overt, peripheral visual attention.

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Klebsiella pneumoniae of sequence type (ST) 11 is a hyper-epidemic nosocomial clone spreading worldwide among humans and also emerging in pets. In this report, we describe a clinical case of fatal sepsis due to this multidrug-resistant (MDR) pathogen in a Eurasian beaver. The isolate showed resistance to six different classes of antimicrobials including third generation cephalosporins and fluoroquinolones. This is the first report describing the detection of a MDR K. pneumoniae ST11 in a free-ranging animal. Our finding highlights the potential for environmental dissemination of hyper-epidemic clones of K. pneumoniae and possible spread in wildlife and cause epizootics.

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This paper presents an algorithm for generating scale-free networks with adjustable clustering coefficient. The algorithm is based on a random walk procedure combined with a triangle generation scheme which takes into account genetic factors; this way, preferential attachment and clustering control are implemented using only local information. Simulations are presented which support the validity of the scheme, characterizing its tuning capabilities.

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Manufacturing technologies as injection molding or embossing specify their production limits for minimum radii of the vertices or draft angle for demolding, for instance. These restrictions may limit the system optical efficiency or affect the generation of undesired artifacts on the illumination pattern when dealing with optical design. A novel manufacturing concept is presented here, in which the optical surfaces are not obtained from the usual revolution symmetry with respect to a central axis (z axis), but they are calculated as free-form surfaces describing a spiral trajectory around z axis. The main advantage of this new concept lies in the manufacturing process: a molded piece can be easily separated from its mold just by applying a combination of rotational movement around axis z and linear movement along axis z, even for negative draft angles. The general designing procedure will be described in detail

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We demonstrate generating complete and playable card games using evolutionary algorithms. Card games are represented in a previously devised card game description language, a context-free grammar. The syntax of this language allows us to use grammar-guided genetic programming. Candidate card games are evaluated through a cascading evaluation function, a multi-step process where games with undesired properties are progressively weeded out. Three representa- tive examples of generated games are analysed. We observed that these games are reasonably balanced and have skill ele- ments, they are not yet entertaining for human players. The particular shortcomings of the examples are discussed in re- gard to the generative process to be able to generate quality games

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We experimentally investigate high-frequency microwave signal generation using a 1550 nm single-mode VCSEL subject to two-frequency optical injection. We first consider a situation in which the injected signals come from two similar VCSELs. The polarization of the injected light is parallel to that of the injected VCSEL. We obtain that the VCSEL can be locked to one of the injected signals, but the observed microwave signal is originated by beating at the photodetector. In a second situation we consider injected signals that come from two external cavity tunable lasers with a significant increase of the injected power with respect to the VCSEL-by-VCSEL injection case. The polarization of the injected light is orthogonal to that of the free-running slave VCSEL. We show that in this case it is possible to generate a microwave signal inside the VCSEL cavity. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

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A novel scheme for depth sequences compression, based on a perceptual coding algorithm, is proposed. A depth sequence describes the object position in the 3D scene, and is used, in Free Viewpoint Video, for the generation of synthetic video sequences. In perceptual video coding the human visual system characteristics are exploited to improve the compression efficiency. As depth sequences are never shown, the perceptual video coding, assessed over them, is not effective. The proposed algorithm is based on a novel perceptual rate distortion optimization process, assessed over the perceptual distortion of the rendered views generated through the encoded depth sequences. The experimental results show the effectiveness of the proposed method, able to obtain a very considerable improvement of the rendered view perceptual quality.

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Performance of heave plates used in offshore structures is strongly influenced by their added mass and damping, which are affected by proximity to a boundary. A previous paper by the authors presented numerical simulations of the flow around a circular solid disk oscillating at varying elevations from seabed [1]. The force calculated was used to evaluate the added mass and damping coefficients for the disk. The simulations suggest that as the structure moves closer to the seabed the added mass and damping coefficients (Ca and Cb) increases continuously. In order to understand the physics behind the added mass and damping trends, when a heave plate is moving near a seabed or closer to the free surface, the flow characteristics around the heave plate are examined numerically in this paper. Flow around oscillating disks is dominated by generation and development of phase-dependent vortical structures, characterized by the KC number and the distance from the seabed or free surface to the heave plate. Numerical calculations presented in this paper have comprised the qualitative analysis of the vortex shedding and the investigation of the links between such vortex shedding and, on one hand the damping coefficient, and on the other hand, pairing mechanisms such as the shedding angle.

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Entre 1966 y 1967 un pequeño grupo de jóvenes arquitectos recién titulados en la Facultad de Arquitectura de Florencia escenifican en dos actos programados en las ciudades de Pistoia y Módenala exposición Superarchitettura, con la que sin saberlo inauguran un corto pero intenso periodo de experimentación arquitectónica que convulsionaría Italia durante los 10 años posteriores, dinamitados por multitud de propuestas que darán lugar a la última arquitectura con aspiraciones socio-políticas responsable de un vibrante legado teórico que proclamaba la vuelta a las raíces olvidadas de la profesión y que se mostraba más preocupada por reflexionar sobre sus fundamentos que por perpetuar la práctica de un oficio ahora puesto en crisis. Ambos eventos suponen también el nacimiento simultáneo de Superstudio y Archizoom, dos de los colectivos más influyentes de la arquitectura experimental italiana de estos años, convertidos en protagonistas de un agitado periodo de transición en el que una generación estaba dando paso a la siguiente a través de la sustitución de los principios doctrinarios recibidos de la modernidad por una jugosa incertidumbre desmitificadora ligada a una nueva realidad económica, política y social que marcaría los inicios de la posmodernidad. La experiencia italiana surge aprovechando la efervescencia de un fenómeno que posteriormente algunos críticos etiquetaron como Arquitectura Radical con la intención de unificar el trabajo de un heterogéneo y atomizado grupo de arquitectos fundamentalmente europeos – individualmente comprometidos con el replanteamiento total de la definición y objetivos de la disciplina, al tiempo que participaban en una particular cruzada existencial mediante la que pretendían, si no cambiar el mundo, al menos romper la dinámica estéril de la arquitectura profesional y tecnológica heredada. La presente tesis fomenta la recuperación interesada de este breve momento radical como un ambicioso proyecto de modernización inacabado, pero no solo para analizar las causas de su precipitado final, sino sobre todo para mostrar las razones de su gran éxito internacional, convirtiendo para ello el trabajo de Superstudio, ejemplo paradigmático de la actitud crítica compartida por el resto de operadores contemporáneos, en el catalizador adecuado a partir del cual interpretar y extrapolar su legado con el fin de narrar el cambio trascendental que este episodio supuso para la práctica arquitectónica, alejándola del diseño de edificios y centrándola en la adopción y aplicación de multitud de actividades no tectónicas en un intento por separarse de lo que era percibido como una disciplina corrupta. A lo largo de su corta carrera en común, los seis miembros de Superstudio sustituyeron la construcción convencional por la explotación intensiva de medios alternativos desde el diseño de mobiliario e iluminación y algunos experimentos en torno a la “arquitectura eléctrica”, hasta la expansión mediática de su trabajo a través de revistas, películas, exposiciones y conferencias contribuyendo así a una provocativa destrucción y posterior expansión de los límites dentro de los que hasta ese momento se había mantenido cómodamente instalada la arquitectura. Esta investigación descubre la trascendencia de considerar aquello que ocupó gran parte de la actividad de Superstudio y de sus colegas radicales (muebles, revistas, instalaciones, películas, labor teórica y docente, etc.) como nuevas formas de arquitectura con las que construir un nuevo lenguaje crítico, en un intento por contribuir a renovar y reforzar la relevancia y responsabilidad social de una profesión llamada a expandirse más allá de lo construido para nutrirse e interactuar con todos los ámbitos de nuestro entorno diario. ABSTRACT Between 1966 and 1967 a small group of newly qualified young architects from the Faculty of Architecture of Florence staged in two events planned in the cities of Pistoia and Modena the Superarchitettura exhibition, with which unwittingly inaugurated a short but intense period of architectural experimentation that convulse Italy during the following 10 years, blown up by a multitude of proposals that will result in the latest architecture with socio political aspirations responsible for a vibrant theoretical legacy proclaiming a return to forgotten roots of the profession and that was more concerned with reflect on its fundamentals than perpetuate the practice of a profession now put into crisis. Both events also involve the simultaneous birth of Superstudio and Archizoom, two of the most influential groups of Italian experimental architecture of these years, turned into protagonists of an hectic period of transition in which a generation was giving way to the next through replacing the received doctrinal principles of modernity by a juicy demystifying uncertainty linked to a new reality economic, political and social that would mark the beginning of postmodernism. The Italian experience arises taking advantage of the commotion of a phenomenon that later some critics labeled as Radical Architecture with the intention of unifying the work of a diverse and fragmented group of architects mainly European individually committed to the total rethinking of the definition and objectives of the discipline, while participating in a particular existential crusade with which they sought to, if not change the world, at least break out of the sterile dynamic of professional and technological architecture inherited. This doctoral thesis promotes an interested recovery of in this short radical time as an ambitious modernization project unfinished, but not only to analyze the causes of its precipitous end, but above all to show the reasons for it’s international success, turning the work of Superstudio, a paradigmatic example of the critical attitude shared by the rest of contemporary operators, into the suitable catalyst from which to interpret and extrapolate it’s legacy in order to recount the significant change that this episode marked for architectural practice, moving it away from building and focusing it on the adoption and implementation of many nonLtectonic activities in an attempt to separate from what was perceived as a corrupt discipline. Throughout their short career in common, the six members of Superstudio replaced conventional construction by intensive exploitation of alternative means L from furniture and lighting design and some experiments around the "electric architecture", to the media expansion of their work through magazines, films, exhibitions and lectures thus contributing to a provocative destruction and subsequent expansion of the limits within which architecture had remained ensconced until then. This dissertation finds out the importance of considering what occupied much of the activity of Superstudio and their radical colleagues (furniture, magazines, installations, films, theoretical and educational work, etc.) as new forms of architecture that build a new critical language, in an attempt to help renew and reinforce the relevance and social responsibility of a profession call to expand beyond the built to nourish and interact with all areas of our everyday environment.

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Damage from free radicals has been demonstrated in susceptible neuronal populations in cases of Alzheimer disease. In this study, we investigated whether iron, a potent source of the highly reactive hydroxyl radical that is generated by the Fenton reaction with H2O2, might contribute to the source of radicals in Alzheimer disease. We found, using a modified histochemical technique that relies on the formation of mixed valence iron complexes, that redox-active iron is associated with the senile plaques and neurofibrillary tangles—the pathological hallmark lesions of this disease. This lesion-associated iron is able to participate in in situ oxidation and readily catalyzes an H2O2-dependent oxidation. Furthermore, removal of iron was completely effected using deferoxamine, after which iron could be rebound to the lesions. Characterization of the iron-binding site suggests that binding is dependent on available histidine residues and on protein conformation. Taken together, these findings indicate that iron accumulation could be an important contributor toward the oxidative damage of Alzheimer disease.

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Mutations in superoxide dismutase 1 (SOD1; EC 1.15.1.1) are responsible for a proportion of familial amyotrophic lateral sclerosis (ALS) through acquisition of an as-yet-unidentified toxic property or properties. Two proposed possibilities are that toxicity may arise from imperfectly folded mutant SOD1 catalyzing the nitration of tyrosines [Beckman, J. S., Carson, M., Smith, C. D. & Koppenol, W. H. (1993) Nature (London) 364, 584] through use of peroxynitrite or from peroxidation arising from elevated production of hydroxyl radicals through use of hydrogen peroxide as a substrate [Wiedau-Pazos, M., Goto, J. J., Rabizadeh, S., Gralla, E. D., Roe, J. A., Valentine, J. S. & Bredesen, D. E. (1996) Science 271, 515–518]. To test these possibilities, levels of nitrotyrosine and markers for hydroxyl radical formation were measured in two lines of transgenic mice that develop progressive motor neuron disease from expressing human familial ALS-linked SOD1 mutation G37R. Relative to normal mice or mice expressing high levels of wild-type human SOD1, 3-nitrotyrosine levels were elevated by 2- to 3-fold in spinal cords coincident with the earliest pathological abnormalities and remained elevated in spinal cord throughout progression of disease. However, no increases in protein-bound nitrotyrosine were found during any stage of SOD1-mutant-mediated disease in mice or at end stage of sporadic or SOD1-mediated familial human ALS. When salicylate trapping of hydroxyl radicals and measurement of levels of malondialdehyde were used, there was no evidence throughout disease progression in mice for enhanced production of hydroxyl radicals or lipid peroxidation, respectively. The presence of elevated nitrotyrosine levels beginning at the earliest stages of cellular pathology and continuing throughout progression of disease demonstrates that tyrosine nitration is one in vivo aberrant property of this ALS-linked SOD1 mutant.

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Genetic recombination of plus-strand RNA viruses is an important process for promoting genetic variation. By using genetically marked poliovirus RNAs, we have demonstrated that genetic recombination can occur in a cell-free system that generates infective virus from added poliovirus RNA. Recombinant polioviruses were isolated, and the region of crossing over was roughly mapped. Recombinants could be isolated even under conditions where the yield of viruses from one of the parental RNAs was depressed to levels comparable to or less than the yield of recombinant viruses, an observation suggesting that only one of the recombining RNAs needs to be replication-competent. The generation of poliovirus recombinants in a cell-free system offers new possibilities for studying recombination and evolution of RNA viruses.