Platelet-Rich Plasma Injection Is More Effective than Hyaluronic Acid in the Treatment of Knee Osteoarthritis Injekce plazmy obohacené destičkovým koncentrátem je efektivnější než kyselina hyaluronová v léčbě gonartrózy

ABSTRAcT PURPOSE OF THE STUDy There is increasing use of platelet-rich plasma (PRP) in orthopaedics as it is a simple, cheap and minimally invasive technique. This study aimed to compare the effects of the use of PRP and hyaluronic acid (HA) injections in the knee of patients diagnosed with and being followed-up for degenerative arthritis. MATERIALS AnD METHODS This prospective study included 90 patients with complaints of knee pain with findings of mild or moderate degenerative arthritis. In the PRP group (n = 45), one intra-articular injection was applied and in the HA group (n = 45), three doses of intra-articular injection were applied. Clinical evaluation was made by Knee Injury and Osteoarthritis Outcome Score (KOOS) and a visual pain scale. RESULTS no severe adverse events was observed. Statistically significant better results in the KOOS score and visual pain scale was determined in PRP group than HA group at 3 months and 6 months follow up. The cost of the application for the PRP group was lower than that of the HA group. COnCLUSIOn The results of this study have shown the application of single dose PRP to be a safe, effective and low-cost method for treating OA. However, further studies are required for a more clear result

An inventory problem with two randomly available suppliers

This paper considers a stochastic inventory model in which supply availability is subject to random fluctuations that may arise due to machine breakdowns, strikes, embargoes, etc. It is assumed that the inventory manager deals with two suppliers who may be either individually ON (available) or OFF (unavailable). Each supplier's availability is modeled as a semi-Markov (alternating renewal) process. We assume that the durations of the ON periods for the two suppliers are distributed as Erlang random variables. The OFF periods for each supplier have a general distribution. In analogy with queuing notation, we call this an Es1[Es2]/G1[G2] system. Since the resulting stochastic process is non-Markovian, we employ the "method of stages" to transform the process into a Markovian one, albeit at the cost of enlarging the state space. We identify the regenerative cycles of the inventory level process and use the renewal reward theorem to form the long-run average cost objective function. Finite time transition functions for the semi-Markov process are computed numerically using a direct method of solving a system of integral equations representing these functions. A detailed numerical example is presented for the E2[E2]/M[M] case. Analytic solutions are obtained for the particular case of "large" (asymptotic) order quantity, in which case the objective function assumes a very simple form that can be used to analyze the optimality conditions. The paper concludes with the discussion of an alternative inventory policy for modeling the random supply availability problem

REVISITING MULTIVARIATE LIKELIHOOD RATIO ORDERING RESULTS FOR ORDER STATISTICS

In this article, we establish some results concerning the likelihood ratio order of random vectors of order statistics in the case of independent but not necessarily identically distributed observations and for the case of possible dependent observations. Applications of these results to provide comparisons of conditional order statistics are also given

Effect of sex steroids on bone formation in an orthopedically expanded suture in rats : An immunohistochemical and computed tomography study.

OBJECTIVE: The purpose of this work was to evaluate the effects of sex steroids on bone formation in response to midpalatal suture expansion by means of histological and immunohistochemical examinations and computed tomography (CT). MATERIALS AND METHODS: A total of 32 male and 32 female 12-week-old Wistar rats were divided into four groups per gender. Testosterone was administered to the castrated experimental male rats, estrogen to castrated experimental female rats. Saline solution was given subcutaneously to the male and female control, sham, and castration groups during expansion and retention periods, which lasted 7 and 5 days, respectively. The expansion amount was measured with a digital caliper. The density of the new bone in the expansion area was measured via CT. RESULTS: Histological and CT evaluation revealed that the number of osteoblasts and density of the new bone was higher in male and female experimental groups than in all the other groups. When scores of staining intensity were compared, the experimental groups demonstrated statistically significant greater immunoreactivity in the osteoblasts compared to castrated-only groups. Bone density was higher in the female experimental group than in the others, and higher in the male experimental group than in the others. Expansion amounts in the castrated groups were higher than in the others (p < 0.05). CONCLUSION: Raising the levels of sex steroids in rats revealed positive effects on bone formation in the midpalatal suture in response to expansion. Increased sex steroid levels can reduce the time needed for retention

The analysis of thermoluminescent glow peaks of natural zircon after ß-irradiation

The additive dose (AD), Tm(Ea)-Tstop, repeated initial rise (RIR), peak shape (PS) and computerized glow curve deconvolution (CGCD) methods were used to analyze the thermoluminescence (TL) glow peaks in natural zircon after ß-irradiation between the dose level 0.015 Gy and ? 10 kGy. The CGCD and Ea-Tstop methods indicate that the glow curve of this material is the superposition of at least seven glow peaks, which were referred to as P1-P7, in the temperature range between room temperature (RT) and 400 °C. The dose responses and fading process of individual TL peaks of this material were also examined. The dose response behaviors of all peaks are different from each other and they are saturated at different dose levels. Peaks 1 and 2 completely disappeared after 1 month storage in the dark room at RT. On the other hand, the intensity of peaks 3 + 4 was approximately reduced to 80% of its original value whereas the other peaks (P5-P7) were not sufficiently affected during this period. © 2006 Elsevier B.V. All rights reserved.This work has been supported in part by Mersin University under contract no. BA FBE. FB(SG) 2005-1TL. The authors are also grateful for the financial supports from the Research Fund of Gaziantep University and TUBITAK