abdullah amini

Several experimental studies have displayed positive result for laser radiation on stimulating bone regeneration in recent years. The purpose of this experimental study was to determine low-level laser (LLL) effects on partial bone defects in hypothyroidism male rat.
Forty male Wistar rats were randomly distributed as below groups: hypothyroidism laser (Hypo laser), hypothyroidism (Hypo), and control. Four weeks after surgery, the tibia bone was removed. Biomechanical and histological examinations were performed immediately.
Our results showed significant reduction in the absorption of energy, resistance in bending deformation (bending stiffness), maximum force, high stress load, trabecular bone volume, and number of osteocytes, osteoblasts and osteoclasts in the osteotomy site in hypothyroidism rats compared to hypothyroidism laser group (P The results indicated that using laser may improve fracture regeneration and it may accelerate bone healing in hypothyroidism rat.

The principle of sufficient reason is one of the most significant philosophical principles. Arthur Schopenhauer, the well-known German philosopher, has emphasized on this principle and taken it as the entrance key element to his philosophical system. He tries to characterize the limits and conditions of application of this principle, and to avoid the inappropriate use of this principle outside the phenomenal reality domain. In his philosophical system, this principle governs the relations between phenomena and objects. Furthermore, the mentioned principle is not equal to the principle of causality, but it is more general than that. For the principle of causality is only one of the four forms of the principle of sufficient reason. This paper tries to discuss the content, application domain and importance of this principle in Schopenhauer ׳s philosophy.

Arthur Schopenhauer, the German idealist, is well-known for his atheism, pessimism, misogyny and fluent style. Additionally, the notion of the genius is significant in his thought. It is important to discuss the notion within Schopenhauer's whole system, because it can not be well grasped without fully understanding his system. The main purpose of this paper is to show briefly the genius ׳s position and its relation to art and artist in Schopenhauer ׳s thought. Finally, it will be noticed that some of Schopenhauer ׳s ideas on the relationship between the genius and the artist are controversial.

Leibniz initially believed in the absoluteness of time and place, but later he changed his idea. His true and final view is that time and place are relative and subjective concepts, whereas Newton believed that they are absolute and have a real and objective existence independent of other phenomena. In his correspondence with Samuel Clark, he refers to the weak points of the views of Newton and Clark and presents several philosophical and theological arguments to reject them. Time and place are treated in his philosophy ontologically, and their existence is relative. Epistemologically speaking, these concepts correspond to phenomena and depend on external phenomena and objects. From a psychological point of view, these concepts are formed in the mind through observing the relations among objective phenomena. Time and place are attributes of phenomena rather than monads or simple substances.In contrast to Newton's idea, the existence of an empty place or vacuum is impossible and in contradiction to Leibniz's accepted principles. He has presented some metaphysical and theological arguments on rejecting this issue in most of his works.

The aim of this study was to determine indications of keratoplasty during 7 years (1999–2006) in Emam-Rreza and Vali-Asr teaching hospitals of Birjand University of medical sciences.

Medical records of all patients who underwent penetrating keratoplasty (PK) in teaching hospitals of Birjand University of Medical Sciences from 1999 to 2006 were investigated retrospectively. The recorded data covered sex, age, indication, job and place of life of the patient. This data were analyzed regarding statistical significance was determined using X2 analysis.

During a 7-year period, total number of 120 patients were operated. The most common indication for PK was corneal opacity (62%), followed by keratoconus 20% and other 18% (Bolus keratopathy plus corneal dystrophia). The major job group for keratoplasty was farmer and the keratoplasty in patients that live in village (56%) was more than the city (44%).

Corneal opacity was the leading indication for PK. The major cause of corneal scarring was trauma with Thorn barberry and corneal infection in our study.