Asymptomatic cholecystitis and its controversial issues in biliary surgery.

Gallbladder stones are present in 10-20 % of the population of Western countries, and the incidence rate has almost tripled over the past 30 years. Asymptomatic cholecystitis is more common than it is mentioned in the literature. Approximately 80 % of the GI have no clinical manifestations.

Experimental insights into increasing laser output at 2.8 µm in Er-doped zinc-tellurite fibers.

In this paper, we provide a new experimental insight into the lasing process in the erbium-doped tellurite glass fiber at high diode-pump powers and pumping pulse durations. It is shown that lasing occurs at two wavelengths. Initially, at a fixed wavelength of 2.

Lasing at 2.72 µm in an Er-doped high-purity tungsten-tellurite glass fiber laser.

This Letter reports the experimental realization, for the first time to our knowledge, of lasing in an erbium-doped tellurite fiber at 2.72 µm. The key to the successful implementation was the use of advanced technology for obtaining ultra-dry preforms of tellurite glasses, as well as the creation of single-mode Er-doped tungsten-tellurite fibers with an almost imperceptible absorption band of hydroxyl groups, with a maximum of ∼3 µm.

Broadband gain performance in the mid-IR using supercontinuum: 2.7 µm gain in high-purity Erdoped tungsten tellurite glass fibers.

This paper presents an experimental study of broadband mid-IR amplification that is carried out, for the first time, to the best of our knowledge, in an erbium-doped tungsten tellurite fiber. A simple, robust supercontinuum source based on a tapered germanate fiber is developed as a seed input in the region of 1.5-3 µm.

Exciton and fermion-pair condensation at non-zero temperature.

A thermodynamic study of a many-particle two-level system with the(2) ⊗(2)-symmetry interaction in the particle-particle and particle-hole channels is carried out. Using the symmetry of the system, its free energy and phase diagram are calculated. It is demonstrated that the superconducting (particle-particle) and excitonic (particle-hole) condensates are both formed in the considered system which undergoes two phase transitions.