Temperature-dependent phonon dynamics of Ag3PO4 microcrystals.

In this work, we present the study of the temperature-dependent behavior of silver orthophosphate (Ag3PO4) microcrystals using in situ Raman scattering. The Ag3PO4 as-synthesized microcrystals were prepared by the precipitation method and characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and infrared spectroscopy, and differential scanning calorimetry (DSC). Temperature-dependent phonon dynamics were performed on Ag3PO4 microcrystals and pointed to a first-order phase transition in the temperature range 500-515 °C: Phase I (25-500 °C) â†’ Phase II (515-590 °C). The phase transition is reversible and a temperature hysteresis was observed during the heating - cooling process: Phase II (590-470 °C) â†’ Phase I (455-25 °C). The reversible phase transition is related to the distortion of the tetrahedral symmetry of PO4 caused by the decrease in the crystalline order. DSC analysis confirmed the results of temperature-dependent Raman spectroscopy.

Functional properties of yam bean (Pachyrhizus erosus) starch.

The study was carried out in order to determine and establish the functional characters of starch extracted from yam bean (Pachyrhizus erosus (L) Urban) compared with cassava starch. Yam bean is a tropical tuber legume easily grown and holds a great potential as a new source of starch. Yam bean starch shows functional properties which are peculiar to those of most starch root crops. Gelatinization temperature (53-63 degrees C) and the pasting temperature (64.5 degrees C) are less than those of cereal starch, however, the swelling power is high (54.4 g gel/g dried starch). Yam bean starch paste presents a high viscosity profile, high retrogradation tendency and low stability on cooking. The functional properties of yam bean starch, similar to those of cassava starch, allows yam bean to be used as a potential new source of starch.

Progressive outer retinal necrosis syndrome: successful treatment with a new combination of antiviral drugs.

PURPOSE: To describe a case of progressive outer retinal necrosis syndrome, successfully treated with a new combination of antiviral drugs. METHODS: The patient was treated with a combined therapy of antiviral drugs that includes: intravenous acyclovir 10 mg/kg, three intravitreal injections of foscarnet (1200 microg) and a ganciclovir implant in the right eye. RESULTS: The progressive outer retinal necrosis appeared to response dramatically with the combination of antiviral agents used over a period of 2 weeks with a final visual acuity of 20/80 at 3 months of follow up. CONCLUSIONS: Intravitreal foscarnet combined with i.v. acyclovir and ganciclovir implant may represent an effective alternative treatment for PORN.

Management of posteriorly dislocated introcular lens: a new technique.

Many surgical techniques have been described in the management of posteriorly dislocated intraocular lens (IOLs). Lifting the IOL off the retina is a critical step during the surgical procedure. We describe a new simple and effective technique using an extrusion cannula that offers many advantages to lift the IOL in a safer and more controlled way.

Dye-enhanced cataract surgery. Part 1: anterior capsule staining for capsulorhexis in advanced/white cataract.

PURPOSE: To evaluate anterior capsule staining using 3 dyes to perform continuous curvilinear capsulorhexis (CCC) in postmortem human eyes with advanced/white cataract. SETTING: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS: In experimental closed-system surgery, CCC was performed in 12 postmortem human eyes with cataract after the anterior capsule was stained with 3 capsule dyes (fluorescein sodium 2%, indocyanine green [ICG] 0.5%, and trypan blue 0.1%). Two commonly used techniques for capsule staining were also compared: staining within an air bubble and intracameral subcapsular injection of dye. RESULTS: In all globes, CCC was uneventful using the 3 dyes and with both techniques. With the intracameral subcapsular injection, the dye remained trapped in the subcapsular space in contact with the posterior surface of the anterior capsule, allowing enough time to perform any maneuver. The staining provided by ICG, at the concentration used, was slightly superior to that of the other dyes. Leakage of fluorescein sodium into the vitreous cavity was seen using the Miyake-Apple posterior video/photographic technique. CONCLUSION: Intracameral subcapsular injection of ICG allowed the easiest recognition of the capsular flap by staining the posterior surface of the anterior capsule and without leaking into the vitreous cavity.

Macular translocation: histopathologic findings in swine eyes.

PURPOSE: Macular translocation has been proposed as an alternative technique in the treatment of some cases of choroidal neovascularization. The purpose of the paper is to report the histopathologic findings in the retina of swine eyes undergone macular translocation. METHODS: Ten eyes of ten Yucatan pigs underwent posterior pars plana vitrectomy and scleral imbrication to achieve macular translocation. Mattress sutures were preplaced at the equator of the eyes. After a pars plana vitrectomy, balanced saline solution was injected under the temporal retina to produce a retinal detachment. Scleral imbrication was achieved by tightening the mattress sutures. An air-fluid exchange was performed and the eye was filled with sulfur hexafluoride 18%. The eyes were enucleated 2, 4, 8 and 12 weeks after surgery and analyzed under light and electron microscopy. RESULTS: Macular translocation was achieved in all cases. The major findings consist of a minimal decrease in the number of photoreceptors outer segments; also a change in the morphology was noted. This included some degree of loss of vertical alignment and an increase in the interphotoreceptor space. There was a recovery in the morphology of the photoreceptors over time. CONCLUSIONS: Minimal changes in the photoreceptors and retinal pigment epithelium are observed when macular translocation is performed with recovery of these changes over time. Scleral imbrication is an effective technique to achieve translocation of the fovea.

Estudo clinico e laboratorial de 30 casos de anemia hemolitica auto-imune. / Clinical and laboratorial study of 30 cases of autoimmune hemolytic anemia

Os autores analisam 30 casos de anemia hemolitica auto-imune estudados entre os anos 1953 e 1980, procurando avaliar sua incidencia quanto ao sexo, faixa etaria e raca. Os sinais, sintomas e parametros hematologicos mais frequentes, etiologia e estudo imuno-hematologico sao tambem apresentados, bem como a evolucao clinica e a terapeutica empregada e sua avaliacao quanto a eficacia. A incidencia mostrou-se maior em pacientes do sexo feminino, sem preferencia por raca, e mais incidente na terceira decada da vida. Quanto a clinica e ao laboratorio, os exames hematologicos e bioquimicos apresentaram-se com alteracoes comuns a todo processo hemolitico agudo; os exames imuno-hematologicos revelaram predominancia de auto-anticorpos frios de natureza inespecifica. Houve prevalencia de casos de etiologia idiopatica (60%). A terapeutica mais frequentemente empregada e com mais sucesso foi a prednisona. A L-asparaginase apresentou sucesso terapeutico nos 3 casos em que foi empregada. Dos 30 pacientes, 5 foram submetidos a esplenectomia por nao haverem respondido satisfatoriamente ao tratamento clinico; destes 5 pacientes, 60% apresentaram melhora do quadro clinico e hamatologico e em 1 deles a reacao de Coombs direta tornou-se negativa