Birthday, Revisited.

In this paper, the philosophical concept of birth will be discussed from an uncommon point of view presented by M. A. Taheri

Christmas, A Mirror.

Christmas, A Mirror. It is important what is the concept behind our actions. It is important how we are looking at our roles as human beings, and where and to what extent we are seeking that. Besides, after finding our roles, we need to know that this is only the beginning of a long path of bringing that concept into practice

Influence of Low Temperature Degradation on Microstructural Integrity of Zirconia Dental Implants

Zirconia dental implants have become more popular in the field of implant dentistry. However, concerns have been raised regarding low temperature degradation and its influence on phase stability and micro-structural integrity in terms of increased micro-crack formation. In the case of dental implants, this could possibly result in delamination and interference with bone to implant contact and eventually lead to loss of integration and failure. Nevertheless, no study has reported the effects on commercially available Zirconia dental implants. The primary aims of this study was to determine if there is a correlation between ageing duration and 1) depth of tetragonal-monoclinic phase transformation (t-m transformation), 2) micro-crack formation of commercially available Zirconia dental implants. A secondary aim was to compare the depth of t-m transformation, micro-crack formation as the result of ageing between different commercially available Zirconia dental implants. Accelerated aging at increased temperature, moisture and pressure were performed using an autoclave technique to artificially age Zirconia dental implants. There were a total of 36 implants from four companies, three of which were commercially available. Each group had nine implants, with three samples evaluated prior to aging and three at 15 and 30 hours of aging. Focused ion beam-scanning electron microscopy analysis was performed to determine the microstructural features of the surface and bulk of as-received implants and to investigate the aging effect on microstructural integrity defined by the t-m transformation and formation of micro-cracks on the aged implants. Pre-existing grain transformation around surface porosities and micro-cracks were most evident in types A, B, C and were significantly higher in A compared to C (p ≤ 0.05). No significant differences were found among groups at 15 hours. At 30 hours, the depth of the t-m transformation and quantity of micro-cracks increased for A, C and D and a significantly higher transformation was found for type A compared to type B (p ≤ 0.05). Type B microstructure seemed to be least affected by LTD at 30 hours. A strong correlation between ageing duration and depth of t-m transformation at 15 and 30 hours was found (p ≤ 0.01) for all implants combined. Within the limitations of this study we concluded that aging led to loss in micro-structural integrity described by transformation of grains and increased number of porosities and microcracks for types A, C and D, a finding most apparent at 30 hours. The effect of aging on microstructural integrity is likely more related to composition and structural details of implants, than their surface treatment

The Study of the Effects of Knowledge Management on Innovation and Organizational Performance: A Case Study in Small and Medium Enterprises in Qom

This study aimed to evaluate the effects of knowledge management oninnovation and organizational performance. The study was conducted by using descriptivemethod. The sample consisted of experts and managers of small and medium enterprisesin Qom province that were selected by using stratified random sampling method. 160questionnaires were distributed and 150 questionnaires were received and evaluated.  The survey questionnaire was used to gatherinformation. Cronbach's alpha was used to assess reliability. The results showthat knowledge management has a positive and significant impact on innovation andfirm performance of Qom province

Determination of isolated Aeromonas hydrophila antibiotic resistance profile from farmed common carp (Cyprinus carpio) in Khuzestan Province

Aeromonas are an example of emerging bacterial pathogens. Even though they have been recognized as primary fish and human pathogens. Aeromonas hydrophila are opportunistic pathogens that are at the same time infectious and enterotoxigenic and multiple antibiotic resistances (MAR) among Aeromonas hydrophila strains has been reported from many parts of the world. Under these circumstances, it will be worthwhile to find out the prevalence of antibiotic resistance of the Aeromonas hydrophila strains. The one hundred pieces of fish samples were collected from 4 common carp training pool in Khuzestan province. The part of intestine was collected in sterile plate and was homogenized. The samples were cultured in blood agar and incubated in 37centigrade degree temperature. Three to five Aeomonas hydrophila suspected colony, were selected from any plate and purified in blood agar. After initial evaluation of each colony by catalase, oxidase and gram staining, suspected strains DNA was extracted by boiling. Aeromonas hydrophila strains were confirmed by PCR assay and using of genus and species specific primers. Finally, multiple antibiotic resistance (MAR) of confirmed Aeromonas hydrophila isolates was evaluated by Kirby-Bauer disc diffusion method. Twenty Aeromonas hydrophila strains of Aeromonas suspected colonies were confirmed by PCR assay and the most of isolates had a multiple resistance. The least and the most resistance was observed regarding to cefotaxim and ciprofloxacin (<25%), vancomycin and clindamycin (90%), respectively. Compared with results of other studies, antibiotic resistance pattern of these bacterial strains is variable in different geographical areas; therefore resistant pattern of each group of bacteria must be determined in each area

Scanning Electron Microscope (SEM) Evaluation of Tooth Surface Irradiated by Different Parameters of Erbium: Yttrium Aluminium Garnet (Er:YAG) Laser

INTRODUCTION: The aim of this study was to investigate the Scanning Electron Microscope (SEM) analysis of tooth surface irradiated by different parameters of Er:YAG laser.METHODS: 15 caries-free extracted human third molars were used in this study. The teeth were put into 5 groups for laser irradiation as follows: Group 1 (power: 2.5 W, Energy: 250 mJ); Group 2(power: 3 W, Energy: 300 mJ); Group 3 (power: 3.5 W, Energy: 350 mJ); Group 4 (power: 4 W, Energy: 400 mJ); Group 5 (power: 4.5 W, Energy: 450 mJ). All samples were prepared by repetition rate of 10 Hz. Then,the samples were prepared for SEM examination.RESULTS: The SEM images showed cleaned ablated surface and exposed dentinal tubules, without production of smear layer.CONCLUSION: It can be concluded that Er:YAG laser can be an alternative technique for surface treatment and can be considered as safe as the conventional methods,like turbine and bur

Molecular diagnosis of Mycoplasma spp. Arthritis by PCR

Background: Arthritis is one of the most common inflammatory diseases worldwide. It is characterized by symptoms such as systemic inflammation and autoantibody production. The molecular mechanisms in pathogenesis of arthritis are not fully understood. Studies show that many microorganisms, including Mycoplasmas, play a role in arthritis. The PCR method is a fast and accurate molecular method for the detection of Mycoplasma genus. The main objective of this study is the detection of Mycoplasma spp arthritis by PCR method.Methods: In this study, 70 samples of synovial fluid collected from Shariati hospital. DNA samples were extracted by phenol-chloroform standard method. Using several Mycoplasma standard strains and 16S rRNA gene target optimized PCR test of Mycoplasma spp. Sensitivity and specificity test were performed on the basis of standard methods and then performed on the DNA extracted of samples.Results: PCR product was amplified by 272 bp and was observed on 2% gel electrophoresis. Specificity test with DNA of other microorganisms showed 100% specificity of these primers. The limit of detection was evaluated 100 copy/reaction. From 70 samples of synovial fluid, 2 samples (3%) were positive and 68 cases (97%) were negative.Conclusion: This study showed that a number of infectious arthritis are Mycoplasma spp at the same time, and the PCR technique can be used as a sensitive and accurate way of early detection of Mycoplasma spp arthritis. 

Evaluation of PCR for the Identification of Mycoplasma spp. and Mycoplasma genitalium congenital infection in cord blood

Background: Congenital infections are the most important threat to human fetal health caused by bacterial, viral, and fungal agents. In this study, PCR diagnostic method has been used on umbilical cord samples to diagnose bacterial agents such as Mycoplasmas, especially Mycoplasma genitalium. Materials and Methods: This study was performed on 100 cord blood samples from cesarean section patients. Limit of detection (LOD) and specificity tests of both PCR was performed. DNA samples were extracted by the DNG plus method and amplified by the PCR technique. The optimized PCR product of 715 bp for Mycoplasma spp. and 427 bp for M. genitalium was amplified and observed on 1.5% gel electrophoresis. DNA specificity testing of seven other organisms revealed a 100% specificity of these primers. The detection limit was set at 100 copy / reaction for Mycoplasma.spp and 1000 copy / reaction for M. genitalium. Results: Of the 100 samples examined, 5 samples were positive for Mycoplasma spp, and no positive cases were observed for M. genitalium. Maternal infections can have important consequences on the fetus. Conclusion: Molecular methods such as PCR could be used for rapid identification of important factors in congenital infections, such as mycoplasma, and provide a good prognosis. &nbsp