Incidence, etiology, location, prevention and treatment of positive surgical margins after radical prostatectomy for prostate cancer

PURPOSE: During radical prostatectomy for prostate cancer tumor at the surgical margin is a relatively frequent finding. We summarize the literature on the incidence, etiology, location, prevention and treatment of positive surgical margins after radical prostatectomy. MATERIALS AND METHODS: The literature was reviewed for data on positive margins during radical prostatectomy for prostate cancer. RESULTS: Positive surgical margins may result from artifacts induced by tissue processing, incising inadvertently into the prostate or incising into extraprostatic tumor that has extended beyond the limits of resection. Patients with 10 ng./ml. or greater preoperative prostate specific antigen, biopsy Gleason score 7, multiple positive biopsies, or clinical stage T2b, T2c or T3 cancer have a higher risk of positive margins. Preoperative endorectal magnetic resonance imaging may be useful in staging a select group of patients. Neoadjuvant androgen deprivation reduces the incidence of positive margins but does not appear to delay progression or improve survival. The surgical approach, retropubic or perineal, may influence the location and etiology of positive margins. In general, nerve and bladder neck sparing procedures do not compromise tumor removal in appropriately selected patients. Positive margins increase the risk of progression and correlate with decreased cancer specific and overall survival. There is no consensus on the management of positive margins. External beam radiation and androgen deprivation may be administered as adjuvant therapy or at the time of recurrence. CONCLUSIONS: Tumor at the specimen edge is an adverse prognostic factor. With appropriate patient selection and meticulous surgical technique some positive margins can be prevented. Controlled prospective randomized studies of postoperative therapy are needed before definitive recommendations can be made for treating positive margins.     

The Role of Cations in Some Inorganic Hydrolysis Reactions

Cations which shift certain equilibria from left to right by forming a compound with one of the reaction products were investigated with respect to their kinetic role in the process. Silver ions have no influence on the rate of the hydrolysis of cyanogen iodide. Similarly, cations which form sparingly soluble carbonates do not influence the rate of hydration of carbon dioxide. On the other hand, the hydrolysis of chlorine is accelerated by Ag⁺ and, to a lesser extent, by Cd²⁺ and Fe(III). It is shown that the effect is not due simply to a bimolecular reaction between chlorine and the cation. In the case of Ag⁺, heterogeneous catalysis may play some role, in analogy with the solvolysis of organic halides. In the case of Cd²⁺, there is spectrophotometric evidence for compounds between Cl₂ and HOCl on the one hand, and the cation on the other. It is suggested that these compounds interconvert more rapidly than do the parent substances. A similar mechanism may be operative in the case of Fe(III), and, possibly, also in the case of Ag⁺.     

Scalable and dynamic quorum systems

We investigate issues related to the probe complexity of quorum systems and their implementation in a dynamic environment. Our contribution is twofold. The first regards the algorithmic complexity of finding a quorum in case of random failures. We show a tradeoff between the load of a quorum system and its probe complexity for non adaptive algorithms. We analyze the algorithmic probe complexity of the Paths quorum system suggested by Naor and Wool in [29], and present two optimal algorithms. The first is a non adaptive algorithm that matches our lower bound. The second is an adaptive algorithm with a probe complexity that is linear in the cardinality of the smallest quorum set. We supply a constant degree network in which these algorithms could be executed efficiently. Thus the Paths quorum system is shown to have good balance between many measures of quality. Our second contribution is presenting Dynamic Paths - a suggestion for a dynamic and scalable quorum system, which can operate in an environment where elements join and leave the system. The quorum system could be viewed as a dynamic adaptation of the Paths system, and therefore has low load high availability and good probe complexity. We show that it scales gracefully as the number of elements grows.Published online: 10 December 2004Moni Naor: Incumbent of the Judith Kleeman ProfessorialChair.Research supported in part by the RAND/APX grant from the EU Program IST     

Coping ability of rape victims: Comment on Myers, Templer, and Brown.

Discusses a retrospective study of female rape victims by M. Meyers et al (see record 1984-12510-001) that concluded that these women may have projected to their assailants an image of vulnerability and helplessness that increased the probability of assault. These conclusions are criticized on both methodological and sociopolitical grounds. (2 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of Stress Tensors in thin textured copper films by grazing incidence diffraction

Ion-platted thin copper films were examined for residual stresses and texture by X-ray diffraction. The complete orientation distribution functions were determined and sharp (111)-fibre textures were found. The strains were measured by grazing incidence diffraction. The stress tensors were calculated using both texture-weighted elastic compliances and texture-independent X-ray elastic constants. The importance of the texture measurement for the stress tensor determination is discussed. The found stresses can be interpreted as thermally induced.     

Quantum-confined Stark effect modulators at 1.06 μm on GaAs

Electroabsorption modulation is achieved at or near a wavelength of 1.06 μm with In_xAl_yGa_1-x-yAs/In _xGa_1-xAs multiple-quantum-well (MQW) structures grown on GaAs substrates. The lattice mismatch (close to 2%) between the MQW and the substrate is accommodated by a compositional-step-graded buffer array. A dislocation density of less than 10⁷/cm² is estimated for the MQW region. For 80-to-100 Å well widths, a maximum electroabsorption coefficient of 8000 cm^-1 with an applied voltage of 15 V is obtained     

Photo-electronic properties of InAs0.07Sb0.93 films

The temperature dependent photoconductive and surface barrier photovoltaic spectral responses of InAs_0.07Sb_0.93 films with an impurity density ～5.5×10¹⁵ cm^-3, grown by liquid phase microzone crystallization, are shown to be a function of their fundamental energy bandgaps shifted to values lower than those of InSb. From charge carrier transport measurements their absolute zero bandgap is calculated as ε_g0=0.197 eV, in good agreement with theory. In contrast with previously reported data on InAs_xSb_1-x solid solution bulk and single crystal layers, the electron mobility of InAs_0.07Sb_0.93 films increases with decreasing temperature reaching a value of ～1.32×10⁵ cm²/Vs at 77 K.     

Vibrational excitation of CO2by transfer from thermally excited nitrogen

Fluorescence from CO2molecules excited by transfer from heated nitrogen has been observed. Insofar as thermal excitation of nitrogen can be accomplished by chemical means, this process may be utilized to implement a chemically excited laser.