Magnetic resonance imaging (MRI) in rectal cancer: a comprehensive review

Magnetic resonance imaging (MRI) has established itself as the primary method for local staging in patients with rectal cancer. This is due to several factors, most importantly because of the ability to assess the status of circumferential resection margin. There are several newer developments being introduced continuously, such as diffusion-weighted imaging and imaging with 3 T. Assessment of loco-regional lymph nodes has also been investigated extensively using different approaches, but more work needs to be done. Finally, evaluation of tumours during or after preoperative treatment is becoming an everyday reality. All these new aspects prompt a review of the most recent advances and opinions. In this review, a comprehensive overview of the current status of MRI in the loco-regional assessment and management of rectal cancer is presented. The findings on MRI and their accuracy are reviewed based on the most up-to-date evidence. Optimisation of MRI acquisition and relevant regional anatomy are also presented, based on published literature and our own experience

Improved uniformity of contact resistance in GaAs MESFET using Pd/Ge/Ti/Au ohmic contacts

Improved contact resistance uniformity, with a low resistance on high-low doped GaAs MESFET, was demonstrated using a Pd/Ge/Ti/Au ohmic contact. The lowest contact resistivity obtained was 2.8 x 10(-6) Ohm-cm(2). The average value and standard deviation (Delta Rc) of the contact resistance (Rc) were 0.73 and 0.07 Ohm-mm, respectively, which were more uniform than those for AuGe/Ni contacts with an average Rc of 0.77 Ohm-mm and Delta Rc of 0.16 Ohm-mm. The improved uniformity was attributed to the uniform penetration of the ohmic junction into the buried high-doped channel layer by solid-state reactions, resulting in the improved uniformity of device performance.X118sciescopu

Microstructural evolution of Co2GaAs thin film on GaAs substrate

X11sciescopu

Non-equilibrium microstructure and thermal stability of plasma-sprayed Al-Si coatings

A splat-quenched, thick Al-Si deposit was manufactured by low-pressure plasma spraying (LPPS) and investigated in terms of microstructural inhomogeneity, Si solid solubility in α-Al, formation of metastable phases, and thermal stability. The LPPS Al-Si deposit had an inhomogeneous, layered microstructure consisting of splat-quenched lamellae and the incorporation of unmelted or partially melted particles. The splat-quenched Al-Si lamellae were formed by deposition of a fully liquid droplet and had an almost featureless microstructure at relatively low magnifications. There was a significant reduction in the α-Al lattice parameter in the LPPS Al-Si deposit because of extended Si solubility in the α-Al matrix. Transmission electron microscopy investigations showed that the splat quenching of liquid Al-Si droplet led to (i) columnar grain growth of α-Al(Si), (ii) formation of nano-sized Si precipitates in the Al matrix which was supersaturated with Si; and (iii) formation of amorphous Si phase embedded in the crystalline Al matrix. On reheating, the amorphous Si transformed into fine crystalline Si by interdiffusion of Al and Si atoms. Simultaneously, Si precipitation occurred in the supersaturated α-Al matrix. The overall activation energy for the Si crystallization/precipitation was estimated as ∼81 kJ/mol from a modified Kissinger analysis. © 2005 Materials Research Society

Conducting Polymer Dough for Deformable Electronics

A simple strategy for changing a brittle conducting polymer (PEDOT:PSS) into a solution-processed highly deformable viscoelastic polymer is presented. Rapid self-healing of conductivity, customer-designed LEDs with complex micropatterns, and foldable stretchable LEDs are demonstrated.115514sciescopu

Mosaic structure of various oriented grains in CoSi2/Si(001)

We investigated the mosaic structure of CoSi2/Si(001) film in a synchrotron x-ray scattering experiment. The CoSi2 film, formed by thermal reaction of a 120 Angstrom Co film on Si(001), was composed largely of epitaxial grains of various orientations. In particular, the twin oriented (B-type) CoSi2(111) grains were grown epitaxially on the Si(lll) facets that were generated during annealing. Two distinct mosaic structures were observed in the CoSi2 grains; the epitaxial grains of the same orientation with the Si substrate, such as the CoSi2(001) [the CoSi2(111)] grains lying on the Si(001) [the Si(lll) facets], showed a small mosaicity of similar to 0.5 degrees full width at half maximum (FWHM), while those of different orientations demonstrated a rather broad mosaicity of similar to 2.5 degrees FWHM. We attributed the smaller mosaicity of the epitaxial grains of the same orientation to the reduced interfacial energy due to higher coincidence site density. (C) 2000 American Vacuum Society. [S0734-2101(00)03403-7].open111sciescopu

Coating on a Cold Substrate Largely Enhances Power Conversion Efficiency of the Bulk Heterojunction Solar Cell

Spin-coating a mixture solution of P3HT and PCBM on a cold substrate largely enhanced the power conversion efficiency (PCE) of the bulk heterojunction (BHJ) solar cells. This concept was based on the abrupt decrease in the solubility of P3HT as solution temperature decreased. The selective precipitation of P3HT on the PEDOT:PSS-coated cold substrate facilitated a desirable rich composition of P3HT at the interface with the PEDOT:PSS layer. The high crystallinity of P3HT suppressed the movement of PCBM during thermal annealing, preventing aggregation of PCBM. The morphological excellence of the pristine film gave a comparable PCE to that made by the conventional fabrication process. After thermal annealing, the device made via coating on a cold substrate showed above 30% increase in PCE from the BHJ solar cells made by the conventional method.111111sciescopu

A microstructural and electrical investigation of Pd/Ge/Ti/Au ohmic contact to n-type GaAs

Interfacial microstructure and elemental diffusion of Pd/Ge/Ti/Au ohmic contact to n-type GaAs have been investigated using x-ray diffraction(XRD), Auger electron spectroscopy(AES), and cross-sectional transmission electron microscopy(XTEM), and their results are used to interpret the electrical properties. The lowest contact resistance of 0.43 Omega mm is obtained after annealing at 380 degrees C. The contact is thermally stable even after isothermal annealing for 5h at 400 degrees C. The good Pd/Ge/Ti/Au ohmic contact is due to the formation of both AuGa and TiO compounds. The AuGa compound enhances the creation of more Ga vacancies, followed by incorporation of Ge into Ga vacancies and TiO compound suppresses As outdiffusion from GaAs substrate, respectively.open11sci