This regimen of stereotactic CK monotherapy for low- to intermediate-risk prostate cancer with excellent dose coverage of the prostate was well tolerated. Data collection is ongoing for further assessment of toxicity and PSA response.

The dynamics of monoatomic steps on the Au(l 10) surface was studied with a scanning tunneling microscope from room temperature to 590 K. The time dependence of the position fluctuations of steps was measured as a function of temperature and kink density. The mean-square displacement of the position was found to be proportional to the square root of time. The proportionality constant exhibits Arrhenius behavior and varies linearly with the kink density. The step dynamics is dominated by the diffusion of geometrical kinks that cannot pass each other.PACS numbers: 68.35.Fx, 05.40.+J, 61.16.Ch Steps play a major role in many surface phenomena. For instance, they can act as nucleation sites for the growth of new layers and can provide preferred adsorption and reaction sites. The dynamics of steps is of crucial importance for mass transport in growth and erosion phenomena, as well as for surface phase transitions such as surface roughening, deconstruction, and faceting. A scanning tunneling microscope (STM) provides the means to study step dynamics on the atomic scale [1-4]. The atomic mechanism underlying the thermal movements of steps is not yet fully understood. Up to now, the STM has been used to investigate the so-called "frizziness" of steps on metal surfaces, for instance on Cu(001) and Ag(l 11) [1][2][3]. Frizziness is the phenomenon that a step appears rough in the STM due to an undersampling of the step in time. The results on the frizzy steps have been interpreted in terms of the thermal creation of kink pairs. In this scenario a pair of kinks of opposite direction is formed when one or more atoms either depart from or attach to a previously straight section of the step.In this Letter, we present a direct observation and a temperature-dependent statistical analysis of step dynamics on Au(llO) performed with a high-speed, hightemperature STM. The individual snapshot observations show that the step fluctuates due to the diffusion of preexisting kinks along the step and that thermal kink generation plays no role of importance in the step dynamics at the investigated temperatures. The dependence of the mean-square displacement of the step on time and kink density indicates that the kinks move due to the exchange of atoms between kink sites and adatom sites on the adjacent terraces. From the temperature dependence we derive the activation energy for the movement of a single kink.The experiments were performed in ultrahigh vacuum (p < 1 x 10 ~1 0 mbar) with a STM specially designed for use at high temperatures. This instrument has been used to image various metal and semiconductor surfaces with atomic resolution up to 750 K. The STM tip was prepared by electrochemical etching of a 0.25 mm diame-ter W wire and annealing in vacuum. The tip was further prepared in situ by field electron emission and Ar ion sputtering. The Au sample was chemically etched and mechanically polished. It was cleaned in situ by cycles of Ar ion sputtering and annealing to 550 K. The cycles were optimized to produce a sharp (1x2) low-en...

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We present a high-speed scanning tunneling microscope ͑STM͒ study of the energetics and the thermal roughening transition of the Ag͑115͒ surface. Using a statistical analysis of large numbers of STM images we directly determine the kink creation energy and the step interaction energy. From these two energies we predict the roughening temperature after the terrace-ledge-kink model of Villain et al. This prediction is compared with an experimental estimate of the roughening temperature, obtained from STM observations at elevated temperatures. In addition, we derive an interaction energy for two neighboring kinks.

Erratum: "A high-speed variable-temperature ultrahigh vacuum scanning tunneling microscope" [Rev. Sci.In this article we introduce a novel scanning tunneling microscope ͑STM͒, which operates in a sample temperature range from 60 to at least 850 K. The most important new feature of this STM is that, while one selected part of the surface is kept within the microscope's field of view, the sample temperature can be varied over a wide range of several hundreds of degrees during actual imaging. The extremely low drift of the scanner and sample was achieved by the combination of a thermal-drift compensated piezoelectric scanner design with a newly developed sample stage. The design of the sample stage defines a fixed center from which thermal expansions, in all three directions, are forced outwards. The performance of the microscope is demonstrated for several surfaces including Au͑110͒, on which we follow one particular surface region over a temperature range of more than 270 K.