All-fiber tunable devices based on high-index photonic crystal fibers filled with liquid crystals.

In this paper we present all-in fiber tunable devices based on specially designed and optimized high-index photonic crystal fibers filled with nematic liquid crystals. A special host microstructured optical fibers have been designed and manufactured to ensure low-loss index guiding and mode field diameter matching to SMF-28 fiber, ensuring low losses on interconnections with leading in-out FC/PC connectorized pigtails. We present four types of tunable all-fiber devices: tunable retarders with tuning range as high as 20 λ, tunable polarizers with variable axis of polarization and continuously tunable polarization dependent losses, tunable and fully controllable polarization controller and finally indeterministic depolarizer in which depolarization is caused by random thermodynamic process. We also present a cost-effective method to achieve change in the direction of the steering electric field, which was controlled by custom-made programable controllers. Finally, we present a method for effective packaging for the proposed devices.

The role of galectin-3 in atrial fibrillation.

Numerous risk factors for atrial fibrillation (AF) progression have been identified. However, the biomarkers mentioned in the guidelines do not have any clinically relevant predictive value. Some research groups investigated the potential utility of galectin-3 (gal-3) as a diagnostic, prognostic, and predictive biomarker in AF. In this review, we have thoroughly summarized the current data on the role of gal-3 in AF based on the original research in this field. Patients suffering from AF present with increased levels of gal-3. The concentration of gal-3 differs between patients with AF depending on the type of AF - it is higher in patients with persistent AF than in patients with paroxysmal AF. Multiple studies investigating the reappearance of AF in patients who underwent ablation have shown that gal-3 is a promising biomarker to predict the outcome of this therapy. Patients with increased levels of gal-3 are at higher risk of AF recurrence. Although the research considered in this work addressed many aspects of the role of gal-3 in AF, most of it has been conducted on a small group of patients. Therefore, further research and extensive clinical trials confirming described findings are highly warranted.

Catamenial pneumothorax - a review of the literature.

Catamenial pneumothorax should be defined as recurrent accumulation of air in the pleural cavity in reproductive-age women without concomitant respiratory diseases. The sine qua non criterion is the occurrence of the pneumothorax in the period of 72 hours before or after the menses. Additional criteria include characteristic pleural lesions, right-sided occurrence, and coexistence of endometriosis. There are no radiological or pathological conditions allowing an exact confirmation of catamenial pneumothorax. In the case of catamenial pneumothorax, treatment failure most commonly consists in disease recurrence. It may occur even as late as several years after the initial treatment. The recurrence rate in patients undergoing surgery ranges from 8% to 40%. Finding and resecting the visible pleural lesions is of key importance during surgical treatment. Reconstruction of the diaphragm must be performed in every patient in whom diaphragmatic perforations are found. Hormonal therapy seems to be effective in sustaining the effects of surgical treatment.

Improving the electric field sensing capabilities of the long-period fiber grating coated with a liquid crystal layer.

The hybrid liquid crystal long-period fiber grating structure presented here uses the 1702 liquid crystal as a thin layer on the bare long-period fiber grating. To achieve the highest long-period fiber grating sensitivity to the liquid crystal layer presence, a UV-induced host grating, with a relatively short period of 226.8 µm, was chosen. This design makes it possible to couple light from the propagating core mode to a cladding mode at a wavelength near the phase-matching turning point. This phenomenon is exploited here for the first time to measure the thermal and electric field responses of the liquid crystal long-period fiber grating structure. All experimental results achieved in this work are supported by theoretical analysis.