Vernier spectrometer using counterpropagating soliton microcombs

Determination of laser frequency with high resolution under continuous and abrupt tuning conditions is important for sensing, spectroscopy, and communications. We show that a single microresonator provides rapid and broadband measurement of optical frequencies with a relative frequency precision comparable to that of conventional dual-frequency comb systems. Dual-locked counterpropagating solitons having slightly different repetition rates were used to implement a vernier spectrometer, which enabled characterization of laser tuning rates as high as 10 terahertz per second, broadly step-tuned lasers, multiline laser spectra, and molecular absorption lines. Besides providing a considerable technical simplification through the dual-locked solitons and enhanced capability for measurement of arbitrarily tuned sources, our results reveal possibilities for chip-scale spectrometers that exceed the performance of tabletop grating and interferometer-based devices.

Two port video-assisted gastrostomy and jejunostomy: technical simplification and clinical results

BACKGROUND: Patients presenting upper gastrointestinal obstruction, difficulty or inability in swallowing, may need nutritional support which can be obtained through gastrostomy and jejunostomy. AIM: To describe the methods of gastrostomy and jejunostomy video-assisted, and to compare surgical approaches for video-assisted laparoscopy and laparotomy in patients with advanced cancer of the esophagus and stomach, to establish enteral nutritional access. METHODS: Were used the video-assisted laparoscopic techniques for jejunostomy and gastrostomy and the same procedures performed by laparotomies. Comparatively, were analyzed the distribution of patients according to demographics, diagnosis and type of procedure. RESULTS: There were 36 jejunostomies (18 by laparotomy and 17 laparoscopy) and 42 gastrostomies (21 on each side). In jejunostomy, relevant data were operating time of 132 min vs. 106 min (p=0.021); reintroduction of diet: 3.3 days vs 2.1 days (p=0.009); discharge: 5.8 days vs 4.3 days (p= 0.044). In gastrostomy, relevant data were operative time of 122.6 min vs 86.2 min (p= 0.012 and hospital discharge: 5.1 days vs 3.7 days (p=0.016). CONCLUSION: The comparative analysis of laparotomy and video-assisted access to jejunostomies and gastrostomies concluded that video-assisted approach is feasible method, safe, fast, simple and easy, requires shorter operative time compared to laparotomy, enables diet start soon in compared to laparotomy, and also enables lower length of stay compared to laparotomy.

Version of Surgical Tactics for Spondyloptosis Treatment

Tactics of surgical treatment of spondyloptosis including use of transpedicular external fixation device is presented. There were 4 patients with L5 spondyloptosis. The tactics is characterized by minor traumatization of lumbosacral spine with external fixation device, decrease of neurologic complications rate owing to gradual L5 reduction, possibility of spine deformity elimination, significant technical simplification of internal transpedicular osteosynthesis performance. Clinical results showed normalization of anatomic interrelation in lumbosacral spine, elimination of vertebroradicular conflict, restoration of trunk balance and anthropometric proportion as well as stabilization of L5-S1 segment by osteo-metalic block.