22 resultados para Clarendon, George William Frederick Villiers, Earl of, 1800-1870.
Resumo:
PURPOSE Management of ureteral stones remains controversial. To determine whether optimizing extracorporeal shock wave lithotripsy (ESWL) delivery rates improves treatment of solitary ureteral stones, we compared outcomes of two SW delivery rates in a prospective, randomized trial. MATERIALS AND METHODS From July 2010 to October 2012, 254 consecutive patients were randomized to undergo ESWL at SW delivery rates of either 60 pulses (n=130) or 90 pulses (n=124) per min. The primary endpoint was stone-free rate at 3-month follow-up. Secondary endpoints included stone disintegration, treatment time, complications, and the rate of secondary treatments. Descriptive statistics were used to compare endpoints between the two groups. Adjusted odds ratios and 95% confidence intervals were calculated to assess predictors of success. RESULTS The stone-free rate at 3 months was significantly higher in patients who underwent ESWL at a SW delivery rate of 90 pulses per min than in those receiving 60 pulses (91% vs. 80%, p=0.01). Patients with proximal and mid-ureter stones, but not those with distal ureter stones, accounted for the observed difference (100% vs. 83%; p=0.005; 96% vs. 73%, p=0.03; and 81% vs. 80%, p=0.9, respectively). Treatment time, complications, and the rate of secondary treatments were comparable between the two groups. In multivariable analysis, SW delivery rate of 90 pulses per min, proximal stone location, stone density, stone size and the absence of an indwelling JJ stent were independent predictors of success. CONCLUSIONS Optimization of ESWL delivery rates can achieve excellent results for ureteral stones.
Resumo:
BACKGROUND To investigate the impact of perioperative chemo(radio)therapy in advanced primary urethral carcinoma (PUC). PATIENTS AND METHODS A series of 124 patients (86 men, 38 women) were diagnosed with and underwent surgery for PUC in 10 referral centers between 1993 and 2012. Kaplan-Meier analysis with log-rank testing was used to investigate the impact of perioperative chemo(radio)therapy on overall survival (OS). The median follow-up was 21 months (mean: 32 months; interquartile range: 5-48). RESULTS Neoadjuvant chemotherapy (NAC), neoadjuvant chemoradiotherapy (N-CRT) plus adjuvant chemotherapy (ACH), and ACH was delivered in 12 (31%), 6 (15%) and 21 (54%) of these patients, respectively. Receipt of NAC/N-CRT was associated with clinically node-positive disease (cN+; P = 0.033) and lower utilization of cystectomy at surgery (P = 0.015). The objective response rate to NAC and N-CRT was 25% and 33%, respectively. The 3-year OS for patients with objective response to neoadjuvant treatment (complete/partial response) was 100% and 58.3% for those with stable or progressive disease (P = 0.30). Of the 26 patients staged ≥cT3 and/or cN+ disease, 16 (62%) received perioperative chemo(radio)therapy and 10 upfront surgery without perioperative chemotherapy (38%). The 3-year OS for this locally advanced subset of patients (≥cT3 and/or cN+) who received NAC (N = 5), N-CRT (N = 3), surgery-only (N = 10) and surgery plus ACH (N = 8) was 100%, 100%, 50% and 20%, respectively (P = 0.016). Among these 26 patients, receipt of neoadjuvant treatment was significantly associated with improved 3-year relapse-free survival (RFS) (P = 0.022) and OS (P = 0.022). Proximal tumor location correlated with inferior 3-year RFS and OS (P = 0.056/0.005). CONCLUSION In this series, patients who received NAC/N-CRT for cT3 and/or cN+ PUC appeared to demonstrate improved survival compared with those who underwent upfront surgery with or without ACH.
Resumo:
Cathodoluminescence (CL) studies have previously shown that some secondary fluid inclusions in luminescent quartz are surrounded by dark, non-luminescent patches, resulting from fracture-sealing by late, trace-element-poor quartz. This finding has led to the tacit generalization that all dark CL patches indicate influx of low temperature, late-stage fluids. In this study we have examined natural and synthetic hydrothermal quartz crystals using CL imaging supplemented by in-situ elemental analysis. The results lead us to propose that all natural, liquid-water-bearing inclusions in quartz, whether trapped on former crystal growth surfaces (i.e., of primary origin) or in healed fractures (i.e., of pseudosecondary or secondary origin), are surrounded by three-dimensional, non-luminescent patches. Cross-cutting relations show that the patches form after entrapment of the fluid inclusions and therefore they are not diagnostic of the timing of fluid entrapment. Instead, the dark patches reveal the mechanism by which fluid inclusions spontaneously approach morphological equilibrium and purify their host quartz over geological time. Fluid inclusions that contain solvent water perpetually dissolve and reprecipitate their walls, gradually adopting low-energy euhedral and equant shapes. Defects in the host quartz constitute solubility gradients that drive physical migration of the inclusions over distances of tens of μm (commonly) up to several mm (rarely). Inclusions thus sequester from their walls any trace elements (e.g., Li, Al, Na, Ti) present in excess of equilibrium concentrations, thereby chemically purifying their host crystals in a process analogous to industrial zone refining. Non-luminescent patches of quartz are left in their wake. Fluid inclusions that contain no liquid water as solvent (e.g., inclusions of low-density H2O vapor or other non-aqueous volatiles) do not undergo this process and therefore do not migrate, do not modify their shapes with time, and are not associated with dark-CL zone-refined patches. This new understanding has implications for the interpretation of solids within fluid inclusions (e.g., Ti- and Al-minerals) and for the elemental analysis of hydrothermal and metamorphic quartz and its fluid inclusions by microbeam methods such as LA-ICPMS and SIMS. As Ti is a common trace element in quartz, its sequestration by fluid inclusions and its depletion in zone-refined patches impacts on applications of the Ti-in-quartz geothermometer.
Resumo:
William Harvey's discovery of the circulation of the blood is often described as a product of the Scientific Revolution of the Seventeenth Century. Modern research has, however, shown thatHarvey followed the Aristotelian research tradition and thus tried to reveal the purpose of the organs through examination of various animals. His publication of 1628 has to be read as an argument of natural philosophy, or, more precisely, as a series of linked observations, experiments and philosophical reasonings from which the existence of circulation has to be deduced as a logical consequence. Harvey did not consider experiments as superior to philosophical reasoning nor intended he to create a new system of medicine. He believed in the vitality of the heart and the blood and rejected Francis Bacon's empirism and the mechanistic rationalism of Descartes. Harvey's contribution and originality lied less in his single observations and experiments but in the manner how he linked them with critical reasoning and how he accepted, presented and defended the ensuing radical findings.
Resumo:
Axiomatic bases of admissible rules are obtained for fragments of the substructural logic R-mingle. In particular, it is shown that a ‘modus-ponens-like’ rule introduced by Arnon Avron forms a basis for the admissible rules of its implication and implication–fusion fragments, while a basis for the admissible rules of the full multiplicative fragment requires an additional countably infinite set of rules. Indeed, this latter case provides an example of a three-valued logic with a finitely axiomatizable consequence relation that has no finite basis for its admissible rules.