Abstract: A discontinuously double-threaded bone screw includes a drive head and anchoring body consisting of a cylindro-conical core over which extend at least two cylindro-conical threads, the anchoring body including anchoring portions of different profiles, ensuring an anchoring corresponding to different bone hardnesses and strengths, the anchoring body including, below the drive head, a first anchoring portion with a conical core and two threads with cylindrical profile and identical pitch, a second anchoring portion with a cylindrical core and a single cylindrical thread over ¼ turn, a third anchoring portion with a cylindrical core and two threads with cylindrical profile over ½ turn, a fourth anchoring portion including a cylindrical core and a single thread with cylindrical profile n turn based on total length of the bone screw, and a fifth anchoring portion including a conical core and two threads with conical profile forming the tip of the bone screw.

Abstract: A discontinuously double-threaded bone screw includes a drive head and anchoring body consisting of a cylindro-conical core over which extend at least two cylindro-conical threads, the anchoring body including anchoring portions of different profiles, ensuring an anchoring corresponding to different bone hardnesses and strengths, the anchoring body including, below the drive head, a first anchoring portion with a conical core and two threads with cylindrical profile and identical pitch, a second anchoring portion with a cylindrical core and a single cylindrical thread over ¼ turn, a third anchoring portion with a cylindrical core and two threads with cylindrical profile over ½ turn, a fourth anchoring portion including a cylindrical core and a single thread with cylindrical profile over n turn based on total length of the bone screw, and a fifth anchoring portion including a conical core and two threads with conical profile forming the tip of the bone screw.

Abstract: Disclosed is a polyaxial screw including a friction element (12) positioned between the head (3) of the threaded bone anchoring portion (2) and the head (9) of the mechanical thread anchoring portion (4) on the one hand, and a retaining element (13, 18) ensuring that the anchoring portions (2, 4) cannot separate from each other while guaranteeing that the anchoring portion with the mechanical thread (4) is free to move in vertical translation and angular pivoting with respect to the threaded bone anchoring portion (2) so as to be able to axially preposition the mechanical thread anchoring portion (4) with respect to the axial anchoring position of the threaded bone anchoring portion (2).

Abstract: Disclosed is a polyaxial screw including a friction element (12) positioned between the head (3) of the threaded bone anchoring portion (2) and the head (9) of the mechanical thread anchoring portion (4) on the one hand, and a retaining element (13, 18) ensuring that the anchoring portions (2, 4) cannot separate from each other while guaranteeing that the anchoring portion with the mechanical thread (4) is free to move in vertical translation and angular pivoting with respect to the threaded bone anchoring portion (2) so as to be able to axially preposition the mechanical thread anchoring portion (4) with respect to the axial anchoring position of the threaded bone anchoring portion (2).

Abstract: A support grid, formed as a grid including a number of longitudinal support rods and a number of transverse support rods, is used to support a number of lighting fixtures, each of which projects light emitted from an end of a fiber optic tail. The fiber optic tails are joined into a fiber optic bundle illuminated by a light source. The support grid allows placement of the fixtures to be located in the longitudinal and transverse directions to light various objects within chamber of a museum display case, while the light source is held outside the chamber.

Abstract: A boro-silicate-glass (BSG) is deposited on a silicon substrate coated with a bottom SiO2 and an overlying Si3N4 layer by LPCVD using an O3/TEB/TEOS mixture at low pressure (less than 300 mTorr), low temperature (less than 500° C.) and a TEB flow which is adjusted to have a boron concentration in the BSG layer less than 10% (in weight). The BSG material deposited that way has been found to be resistant to aggressive silicon dry etch chemistries and is easily and rapidly etched in standard BSG etchants. However, very high etch rates are obtained with a HF/ethylene glycol wet chemistry. The disclosed BSG deposition method finds a valuable application in the fabrication of the buried plate in deep trench cell capacitors because no undercuts are produced in the bottom SiO2 layer sidewall exposed in the trench during the BSG layer removal.