We have developed a simple and reliable method for preparing single-atom tips. Electrochemical techniques are applied to deposit a noble metal film on the W < 111 > tip. With the protection of the metal film, the tip can be stored and transferred in the ambient condition. After a gentle annealing of the plated tip in vacuum, a thermally and chemically stable nano-pyramid with single atom sharpn...

This paper describes attempts to localize the site of perception of low temperatures (0-10 degrees C) during thermoinduction in Thlaspi arvense L. Reproductive development (stem elongation and flower formation) was observed when shoots were cooled to 4 degrees C for 4 weeks and then returned to 21 degrees C while maintaining the roots constant 21 degrees C. However, chilling the roots was ineff...

We show that strong optical field gradients can be created at the tip apex of a local probe microscope illuminated by an external light source. We demonstrate that these confined fields can be easily, precisely and continuously tuned by changing the polarization and the incidence of the external field. We also investigate the topology of the field intensity in the tip–surface junction. © 1997 A...

In an attempt to compensate for their sessile nature, plants have developed growth responses to deal with the copious and rapid changes in their environment. The process by which plant roots expand in soil involves water uptake through osmosis and imbibition, and an overall increase in size by cell division. Each root apex has sensors to get information from the environment, which is then trans...

Using a simple mathematical formulation, the relationship between the position of the lag screw tip (relevant to both intramedullary and extramedullary devices) and the concept of tip-apex distance (TAD) was derived. TAD is widely used in operating theaters as a surgical guideline in relation to the fixation of trochanteric fractures, and in clinical studies as a predictor of lag screw cut-out....

This paper describes the fine structure of the spermatozoan apex and its morphological changes during the process of fertilization in Ciona intestinalis. At the apex of the head an acrosome is present in the form of a flattened vesicle containing moderately electron-dense material with an electron-dense plate in its centre. Contiguous to the acrosome, an apical substance is located in the anter...

Intertrochanteric fractures (ITFs) are the most common type of fractures requiring surgical intervention. They also have the highest surgical mortality among orthopedic operations. Among the many different techniques used for fixation of this type of fracture, use of the Dynamic Hip Screw (DHS) has gained wide acceptance. This current study was designed to assess positive predictive value of ti...

Intense multiphoton electron emission is observed from sharp (∼ 20 nm radius) metallic tips illuminated with weak 100 pJ, 7-fs light pulses. Local field enhancement, evidenced by concurrent nonlinear light generation, confines the emission to the tip apex. Electrons are emitted from a highly excited nonequilibrium carrier distribution, resulting in a marked change of the absolute electron flux ...

The price of single point diamond tools with a sharp tip is very high due to complex machining process and highly expensive machining equipments. Yet, the performance is not quite satisfactory. In this paper, we have presented a very simple and cost effective machining process for the sharpening and polishing of diamond stylus using low energy reactive ion beam machining (RIBM). In our method, ...