High efficiency radio frequency antennas for amplifier free quantum sensing applications.

Radio frequency (RF) signals are frequently used in emerging quantum applications due to their spin state manipulation capability. Efficient coupling of RF signals into a particular quantum system requires the utilization of carefully designed and fabricated antennas. Nitrogen vacancy (NV) defects in diamond are commonly utilized platforms in quantum sensing experiments with the optically detected magnetic resonance (ODMR) method, where an RF antenna is an essential element. We report on the design and fabrication of high efficiency coplanar RF antennas for quantum sensing applications. Single and double ring coplanar RF antennas were designed with -37 dB experimental return loss at 2.87 GHz, the zero-field splitting frequency of the negatively charged NV defect in diamond. The efficiency of both antennas was demonstrated in magnetic field sensing experiments with NV color centers in diamond. An RF amplifier was not needed, and the 0 dB output of a standard RF signal generator was adequate to run the ODMR experiments due to the high efficiency of the RF antennas.

Open subintimal angioplasty of the superficial femoral and distal arteries.

PURPOSE: To describe an open approach to subintimal angioplasty. TECHNIQUE: Through a subinguinal incision and arteriotomy over the superficial femoral artery origin, the opening of a subintimal channel is created surgically. The subintimal plane is advanced distally with a guidewire, and this neolumen is expanded with sequential balloon dilations. The atherosclerotic core is dissected proximally in the common femoral artery and tacked down to ensure inflow. A patch graft closes the arteriotomy. CONCLUSIONS: Open subintimal angioplasty is a simple, minimally invasive alternative treatment for complete SFA occlusion. Long-term follow-up in a large group of patients will be necessary to determine the durability of the false arterial lumen.

Surgical treatment of spontaneous internal carotid dissection.

Spontaneous dissection of the internal carotid artery is rarely submitted to surgery. We report a case successfully operated on with complete restoration of the cerebral blood flow. A 43-year-old male was admitted to our hospital 10 days after an episode of amaurosis fugax of the left eye, left sided headache and paresis of the right arm of a few hours duration. A diagnosis of dissection of the left internal carotid artery was made by duplex and triplex ultrasound examination and was confirmed by cerebral arteriography in contrast to magnetic resonance angiography which was misleading. Due to the slow arterial flow from the right to the left cerebral hemisphere through only the posterior communicating arteries we envisaged the possibility of a cerebral infarction if the dissection were to be extended. For this reason a surgical procedure was performed by excising the dissected segment and inserting a venous graft for the re-establishment of the arterial flow. Surgical treatment of spontaneous internal carotid dissection should be considered very carefully when the clinical and laboratory findings suggest the possibility of an impending stroke.