Comparative analysis of three mode-selection methods for solid-state lasers

In the Nd3+:YAG pulsed Q-switched laser system, the selective output of several low order modes of TEM00, TEM01 and TEM11 is realized by adding a iris diaphragm, a telescope or a Gaussian mirror at an appropriate position in the resonator, and the three are compared and analyzed.

Clinical and Functional Outcomes of Lens-Iris Diaphragm Implantation with Simultaneous Subtotal Penetrating Keratoplasty: a 15-Year Follow-Up Case Report

Combined traumatic injuries of the anterior eye segment are attributed to the severe consequences of the injured organ of vision. Iris defects result in spherical and chromatic aberrations, diplopia, flares, severe photophobia, cosmetic defects, and significantly reduced visual acuity after the injury. The literature describes various methods to restore visual functions impaired as a result of aniridia. Use of an artificial iris together with an intraocular lens pathology results in optimal reconstruction and recovery of normal anterior segment anatomy and topography. In this paper, we provide a report on a patient followed up for 15 years after combined reconstruction eye surgery for an off-the-job penetrating eye injury sustained in 2003. A complex intervention was required due to the involvement of the cornea, iris, and lens. In 2004, the patient underwent a lens-iris diaphragm implantation combined with penetrating keratoplasty. The diaphragm implantation was followed by an improvement in visual acuity and elimination of photophobia and flares. There were no intra- or postoperative complications. Two years later, LASIK refractive surgery was performed on the corneal transplant to eliminate induced ametropia. The patient retained good eye function, with a stable position of the lens-iris diaphragm, for many years after the diaphragm implantation, keratoplasty, and refractive surgery. In 2018, he had an intravitreal implant impregnated with dexamethasone, as changes in the retina had developed. The long-term follow-up in this case demonstrates that the implantation of a lens-iris diaphragm resulted in an elimination of undesirable optical events associated with aniridia and produced an optimal functional result, while also improving the patient’s quality of life with a good aesthetic effect.

Electron cryo-tomography provides insight into procentriole architecture and assembly mechanism

Centriole is an essential structure with multiple functions in cellular processes. Centriole biogenesis and homeostasis is tightly regulated. Using electron cryo-tomography (cryoET) we present the structure of procentrioles from Chlamydomonas reinhardtii. We identified a set of non-tubulin components attached to the triplet microtubule (MT), many are at the junctions of tubules likely to reinforce the triplet. We describe structure of the A-C linker that bridges neighboring triplets. The structure infers that POC1 is likely an integral component of A-C linker. Its conserved WD40 β-propeller domain provides attachment sites for other A-C linker components. The twist of A-C linker results in an iris diaphragm-like motion of the triplets in the longitudinal direction of procentriole. Finally, we identified two assembly intermediates at the growing ends of procentriole allowing us to propose a model for the procentriole assembly. Our results provide a comprehensive structural framework for understanding the molecular mechanisms underpinning procentriole biogenesis and assembly.

Electron Cryo-Tomography Provides Insight into Procentriole Architecture and Assembly Mechanism

SummaryCentriole is an essential structure with multiple functions in cellular processes. Centriole biogenesis and homeostasis is tightly regulated. Using electron cryo-tomography (cryoET) we present the structure of procentrioles from Chlamydomonas reinhardtii. We identified a set of non-tubulin components attached to the triplet microtubule (MT), many are at the junctions of tubules likely to reinforce the triplet. We describe structure of the A-C linker that bridges neighboring triplets. We find that POC1 is an integral component of the A-C linker. Its conserved WD40 β-propeller domain provides sites for attachment to other A-C linker components. The twist of A-C linker results in an iris diaphragm-like motion of the triplets in the longitudinal direction of procentriole. Finally, we identified two assembly intermediates at the growing ends of procentriole allowing us to propose a model for the procentriole assembly. Our results provide a comprehensive structural framework for understanding the molecular mechanisms underpinning procentriole biogenesis and assembly.