According to Helmholtz it is nowadays accepted that one of the major reasons for the development of presbyopia is the increasing sclerosis of the crystalline lens. Therefore the investigation of the process of accommodation of the lens is an important field of research. Our aim was to simulate the process of accommodation in-vitro and to measure the changes of geometry of the crystalline lens m...

The anterior face of the mouse lens is covered by a layer of epithelial cells. The epithelial cells serve a barrier function at the lens surface and as a progenitor population from which lens fiber cells, the predominant cell type of the lens, are derived. Decreased epithelial cell density is commonly observed during aging and cataract formation in humans and animal models and may contribute di...

1. A crystalline enzyme capable of digesting yeast nucleic acid has been isolated from fresh beef pancreas. 2. The enzyme called "ribonuclease" is a soluble protein of albumin type. Its molecular weight is about 15,000. Its isoelectric point is in the region of pH 8.0. 3. Ribonuclease splits yeast nucleic acid into fragments small enough to diffuse readily through collodion or cellophane membra...

A method is described for isolating a crystalline protein of high tryptic activity from beef pancreas. The protein has constant proteolytic activity and optical activity under various conditions and no indication of further fractionation could be obtained. The loss in activity corresponds to the decrease in native protein when the protein is denatured by heat, digested by pepsin, or hydrolyzed ...

Discrete lattice systems have had a long and productive history in physics. Examples range from exact theoretical models studied in statistical mechanics to approximate numerical treatments of continuum models. There has, however, been relatively little attention paid to exact lattice models which obey an invertible dynamics: from any state of the dynamical system you can infer the previous sta...

In an earlier study (1) of the amino acid composition of papain, it was assumed that all of the sulfur could be attributed to cysteine and cystine since methionine is absent from this protein. However, because of the sulfhydryl nature of this enzyme, the content of these amino acids is of some importance; we have used the method of Schram, Moore, and Bigwood (2) for this estimation. The results...

Purpose To investigate the relationship between lens power and age as well as the relationship between lens power and axial length (AL) in Chinese children and adolescents. Methods The participants underwent a comprehensive ophthalmic examination that included AL, cycloplegic refraction, and Pentacam measurements. The crystalline lens power was calculated using Bennett's formula and then comp...

Ultrathin transmission metasurface devices are designed on the basis of the Yang-Gu amplitude-phase retrieval algorithm for focusing the terahertz (THz) radiation into four or nine spots with focal spacing of 2 or 3 mm at a frequency of 0.8 THz. The focal properties are experimentally investigated in detail, and the results agree well with the theoretical expectations. The designed THz multi-fo...

Intraocular light scatter is modeled through a stratified medium. It is shown that the eye lens possesses properties of an interference filter. In conditions that may mimic opacification, as found with cataract formation, such a filter may have stop zones with reflectance up to 1 in the band of visible light.

Urogenital myiasis caused by Psychoda spp. involving human are very rare and present with unusual symptoms. Larvae belonging to Psychoda sp. (Diptera: Psychodidae) were found in the urogenital tract of a 9-year-old girl, who lives in Tajoura, Libya, and had suffered from genital pruritus and moving larvae in urine. This is the first record of such case in Libya.