QED cascade saturation in extreme high fields.

Upcoming ultrahigh power lasers at 10 PW level will make it possible to experimentally explore electron-positron (ee) pair cascades and subsequent relativistic ee jets formation, which are supposed to occur in extreme astrophysical environments, such as black holes, pulsars, quasars and gamma-ray bursts. In the latter case it is a long-standing question as to how the relativistic jets are formed and what their temperatures and compositions are. Here we report simulation results of pair cascades in two counter-propagating QED-strong laser fields.

Tunable synchrotron-like radiation from centimeter scale plasma channels.

Synchrotron radiation (SR) sources are immensely useful tools for scientific researches and many practical applications. Currently, the state-of-the-art synchrotrons rely on conventional accelerators, where electrons are accelerated in a straight line and radiate in bending magnets or other insertion devices. However, these facilities are usually large and costly.

Prostate cancer identification: quantitative analysis of T2-weighted MR images based on a back propagation artificial neural network model.

Computer-aided diagnosis (CAD) systems have been proposed to assist radiologists in making diagnostic decisions by providing helpful information. As one of the most important sequences in prostate magnetic resonance imaging (MRI), image features from T2-weighted images (T2WI) were extracted and evaluated for the diagnostic performances by using CAD. We extracted 12 quantitative image features from prostate T2-weighted MR images.

Optimal contouring of seminal vesicle for definitive radiotherapy of localized prostate cancer: comparison between EORTC prostate cancer radiotherapy guideline, RTOG0815 protocol and actual anatomy.

Background: Intermediate- to-high-risk prostate cancer can locally invade seminal vesicle (SV). It is recommended that anatomic proximal 1-cm to 2-cm SV be included in the clinical target volume (CTV) for definitive radiotherapy based on pathology studies. However, it remains unclear whether the pathology indicated SV extent is included into the CTV defined by current guidelines.

[Analysis of the clinical information of 1,066 cases undergoing prostate magnetic resonance examination].

Objective: To evaluate the variation of clinical data and referred purpose of prostate magnetic resonance (MR) examination in the past 12 years in Peking University First Hospital.

Methods: One thousand and sixty-six patients underwent prostate MR examination (1,296 exams) from May 1992 to Sept. 2004.