Attaching single biomolecules selectively to the apex of AFM tips for measuring specific interactions.

We present a general approach for preparing well-defined AFM tips for probing single target molecules. We demonstrated that carboxylic acid groups could be generated by electrochemical oxidation selectively at the apex of an AFM tip that is coated with a monolayer of oligo(ethylene glycol) derivatives for resisting nonspecific interactions. These carboxylic acid groups were used as handles to tether only one ligand molecule, such as biotin, to the tip apex for measurement of specific interactions with biomolecules.

Using movie clips in PowerPoint presentations: part 1, compatibility issues.

Objective: The purpose of this article is to discuss common compatibility issues relating to the use of movie clips in PowerPoint presentations.

Conclusion: Our investigations found that successful display of movie clips in PowerPoint depends on the following three factors: movie file format, codec selection, and cross-platform compatibility. These factors primarily result from the rapid change in today's computer operating systems.

The N-terminal regulatory domain of cyclin A contains redundant ubiquitination targeting sequences and acceptor sites.

Cyclin A is destroyed during mitosis by the ubiquitin-proteasome system. Like cyclin B, a destruction box (D-box) motif is required for the destruction of cyclin A. However, cyclin A degradation is more complicated than cyclin B because cyclin A's D-box motif is more extensive and proteolysis involves complex signaling in some organisms.

Using PowerPoint to create high-resolution images for journal publications.

Objective: In this article, I describe the essential steps for using PowerPoint to create high-resolution images for radiology journal publications.

Conclusion: PowerPoint 2003 can be used as an alternative to create high-resolution images for journal publications without the need for other image-processing software.

Comparison of resistance to protein adsorption and stability of thin films derived from alpha-hepta-(ethylene glycol) methyl omega-undecenyl ether on HSi(111) and HSi(100) surfaces.

Oligo(ethylene glycol)-terminated thin films were prepared by photo-induced hydrosilylation of alpha-hepta-(ethylene glycol) methyl omega-undecenyl ether (EG(7)) on hydrogen-terminated silicon (111) and (100) surfaces. Their resistance to protein adsorption, and stabilities (from hours to days) under a wide variety of conditions, such as air, water, biological buffer, acid, and base, were investigated using contact-angle goniometry and ellipsometry techniques. Results indicated higher stability of the films chemisorbed on Si(111) than on Si(100).

Preparation and heck reaction of multidentate carbosilane films derived from focally functionalized and allyl-terminated dendrons on hydrogen-terminated silicon(111) surfaces.

Multidentate carbosilane films were prepared by thermally induced hydrosilylation of allyl-terminated carbosilane dendrons of generations 0, 1, and 2 (G0-G2) on hydrogen-terminated silicon(111) surfaces. The dendron molecules contain three (G0), nine (G1), and twenty-seven (G2) allyl groups at the periphery, and a bromophenyl functional group at the focal point. The dendron films were characterized by contact-angle goniometry, ellipsometry, Fourier transform infrared spectroscopy in the attenuated total reflection mode, and X-ray photoelectron spectroscopy (XPS).

Projecting PowerPoint presentations with a PDA.

Objective: This article describes the use of a personal digital assistant (PDA) as a projection device for PowerPoint presentations.

Conclusion: Advances in hardware and software have made PDA devices capable of storing, accessing, retrieving, and sharing data, and their use is becoming increasingly evident in the health care arena. In this article, I describe a use for the PDA that will further increase its value and efficiency in daily academic and teaching activities.

A simple method for displaying cine images on web-based teaching files.

Objective: Our objective was to develop a simple method for displaying dynamic cine images on Web-based teaching files.

Conclusion: We developed a simple method for displaying cine images on Web-based teaching files using an open-source utility, the Java applet. This interactive utility offers improved 3D visualizations compared with the traditional approach using thumbnail and static images.

Development of a radiology report monitoring system for case tracking.

Objective: The objective was to develop an automated system to monitor and collect radiology reports for case-tracking purposes.

Conclusion: The system we developed allows users to automate the case-tracking process for either clinical follow-up or teaching purposes. With this system, radiologists can initiate the tracking of a case by dictating a keyword into the report.

Use of personal digital assistants in diagnostic radiology resident education.

Rationale And Objectives: Personal digital assistants (PDAs) are gaining widespread use in the medical community. We introduced a PDA-based mobile system that provides departmental and educational information with a seamless connection to the intranet. The objective of this study is to determine the impact a PDA has on educational resources (learning or data reference) brought to work and used at home by a radiology resident based on user surveys.

Comprehensive innovative solution for resident education using the Intranet Journal of Chest Radiology.

Rationale And Objectives: Because of the rapid increase in clinical workload in academic radiology departments, time for teaching rotating residents is getting more and more limited. As a solution to this problem, we introduced the Intranet Journal of Chest Radiology as a comprehensive innovative tool for assisting resident education.

Materials And Methods: The Intranet Journal of Chest Radiology is constructed using Microsoft FrontPage version 2002 (Microsoft Corp, Redmond, WA) and is hosted in our departmental web server (Beth Israel Deaconess Medical Center, Boston, MA).

Protein-resistant monolayers prepared by hydrosilylation of alpha-oligo(ethylene glycol)-omega-alkenes on hydrogen-terminated silicon (111) surfaces.

Atomically flat, homogeneous, and protein-resistant monolayers can be readily prepared on H-Si(111) surfaces by photo-induced hydrosilylation of alpha-oligo(ethylene glycol)-omega-alkenes.

A Web-based ACR index for radiological diagnoses.

Objective: We created an online computer system that allows radiologists to access the American College of Radiology (ACR) index for radiologic diagnoses from any Web browser.

Conclusion: A total of 11,260 indexes (10 anatomic, 722 pathologic, 90 subanatomic, and 10,438 subpathologic) were integrated into this online system. Users can navigate the entire ACR hierarchic indexing structure with easy-to-use cascading dropdown lists.

A simple method for extracting DICOM images from a magnetooptic disk.

Objective: Our objective was to develop a simple and easy-to-use method to extract DICOM images from magnetooptic (MO) disks to the computer desktop for research purposes.

Conclusion: The method we developed allows users to extract DICOM images directly from MO disks to a PC desktop. The hardware component that we used is commercially available and is plug-and-play.

Nanometric protein arrays on protein-resistant monolayers on silicon surfaces.

We present a novel approach for preparation of nanometric protein arrays, based on binding of avidin molecules to nanotemplates generated by conductive AFM lithography on robust oligo(ethylene glycol)-terminated monolayers on silicon (111) surfaces that are protein-resistant. We showed that only biotinated-BSA but not the native BSA bind to the avidin arrays and that the resulting arrays of biotinated BSA could bind avidin to form protein dots with a feature size of approximately 30 nm. This result demonstrates that the avidin array may serve as templates for preparation of nanoarrays of a wide variety of biotin-tagged proteins for studying their interactions with other protein molecules at nanoscale.

A mobile solution: PDA-based platform for radiology information management.

Objective: We describe how our radiology department set up, integrated, and deployed a personal digital assistant-based mobile platform to deliver updated critical departmental and educational material to our residents.

Conclusion: We have implemented and described a robust mobile solution that maintains a seamless connection with the departmental intranet. Resident feedback regarding the use of the mobile solution program has confirmed our belief that using this mobile technology is a feasible and clinically practical alternative for accessing time-sensitive and educational materials.

Reproducibility of linear tumor measurements using PACS: comparison of caliper method with edge-tracing method.

The aim of this study was to evaluate inter- and intra-observer reproducibility when making electronic caliper linear tumor measurements on picture archiving and communications systems (PACS) and compare them with linear measurements obtained from circumferential tracing of tumor perimeter. Three radiologists measured 64 masses from 30 patients on body CT scans in two separate settings. Long axis and perpendicular short axis were measured using electronic calipers.

Modification of silicon AFM cantilever tips with an oligo(ethylene glycol) derivative for resisting proteins and maintaining a small tip size for high-resolution imaging.

We demonstrate that silicon AFM tips can be modified by etching with 2% HF solution followed by reaction with an alpha,omega-oligo(ethylene glycol)alkene. Tips properly modified by this technique maintain a small tip size and effectively reduce the nonspecific interaction with fibrinogen and bovine serum albumin, resulting in greatly improved image resolution and contrast for high-coverage fibrinogen films.

A temperature-sensitive mutation in the nodal-related gene cyclops reveals that the floor plate is induced during gastrulation in zebrafish.

The floor plate, a specialized group of cells in the ventral midline of the neural tube of vertebrates, plays crucial roles in patterning the central nervous system. Recent work from zebrafish, chick, chick-quail chimeras and mice to investigate the development of the floor plate have led to several models of floor-plate induction. One model suggests that the floor plate is formed by inductive signalling from the notochord to the overlying neural tube.

Cyclin A in cell cycle control and cancer.

Cyclin A is particularly interesting among the cyclin family because it can activate two different cyclin-dependent kinases (CDKs) and functions in both S phase and mitosis. An embryonic form of cyclin A that is only essential for spermatogenesis is also present in some organisms. In S phase, phosphorylation of components of the DNA replication machinery such as CDC6 by cyclin A-CDK is believed to be important for initiation of DNA replication and to restrict the initiation to only once per cell cycle.

Cyclin F is degraded during G2-M by mechanisms fundamentally different from other cyclins.

Cyclin F, a cyclin that can form SCF complexes and bind to cyclin B, oscillates in the cell cycle with a pattern similar to cyclin A and cyclin B. Ectopic expression of cyclin F arrests the cell cycle in G(2)/M. How the level of cyclin F is regulated during the cell cycle is completely obscure.

CT colonography: colonic distention improved by dual positioning but not intravenous glucagon.

The aim of this study was to determine whether intravenous (IV) glucagon and dual positioning administered prior to CT colonography enhances colonic distention. We assessed the effect of dual positioning and IV glucagon on colonic distention in 96 patients who underwent CT colonography examinations. The CT colonography was performed in both supine and prone positions.

Labelling and binding of poly-(L-lysine) to functionalised gold surfaces. Combined FT-IRRAS and XPS characterisation.

We compare herein the interfacial reactivity of self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA), 1-undecanethiol (UDT) and 11-mercaptoundecanol (MUD) on gold surfaces towards aqueous solutions of poly-(L-lysine) (PL). Liquid-phase labelling of PL with the alkyne dicobalt hexacarbonyl cluster 1 combined with analysis of the substrates by Fourier transform infrared reflection-absorption spectroscopy (FT-IRRAS) and X-ray photoelectron spectroscopy (XPS) revealed that irreversible binding of PL occurred in all cases. However, the mechanism of binding involved differed markedly from one monolayer to the other.