Use of Cloud Technologies in a Modern Scalable Web Application

The goal of this project is to implement a web-based conference management system using a modern web development stack based on Cloud technology, allowing easy resource management and scaling on demand, while offering a sophisticated set of tools with a high level of abstraction. Amazon Web Services will be used as the basis of most of the tools and services used in the project

Effect of different treatment on Surface Morphology of laser bleached teeth: SEM Evaluation

Objective: The aim of this study was to evaluate and compare the effect of dental surface treatment with Er:YAG , Nd:YAG ,CO2 lasers and sodium ascorbate to recently laser bleached enamel by scanning electron microscope (SEM).Methods: 15caries-free extracted human third molars were selected for this study. The samples were bleached by Heydent JW power activated by diode laser 810 nm. After 7 day, the bleaching procedure was repeated as same as first time. Then, the samples were divided to five groups randomly as follow: Group 1: treated using Nd:YAG laser with output power of 1 W, Group 2: treated using Er:YAG laser with output power of 0.5 W, Group 3: treated using CO2 laser with output power of 0.5 W, Group 4: sodium ascorbate 10%, Group 5: no surface treatment. After treatments, the surfaces were evaluated using Scanning Electron Microscope (SEM) analysis.Results: The surfaces treated by Nd:YAG laser showed some melting area but the surface treated by Er:YAG laser showed irregular and micro porous surface. CO2 laser treatment of surfaces resulted in melting of superficial layer of dental substrate and micro cracks. Sodium ascorbate did not change the surface except changes raised from bleaching.Conclusion: Laser conditioning of laser-bleached teeth can be beneficial for enhancing bond  strength of resin material to recently bleached enamel

The Effect of Incorporation of 0.5 %wt. Silica Nanoparticles on the Micro Shear Bond Strength of a Resin Modified Glass Ionomer Cement

Statement of the Problem: The clinical success of glass ionomer restorations depends on the strength of resin-modified glass ionomer (RMGI) cement bonding to dentin and there is limited information available regarding the bond strength of resin modified glass ionomers containing silica nanoparticles to dental structures. Purpose: The aim of this study was to compare the microshear bond strength (µSBS) of RMGI with and without silica (SiO2) nanoparticles to dentin of permanent teeth. Materials and Method: in this experimental study, the occlusal surfaces of 30 freshly extracted intact third molars were ground to expose the flat dentin and after conditioning with 20% poly acrylic acid, were randomly assigned to two main groups (n=15). The first group was filled with RMGI (Fuji II LC, GC) and the second group was filled with RMGI plus 0.5%wt. silica nanoparticles. Then, each main group was divided into three subgroups, and then stored in an incubator at 37 oC with 100% humidity for 1, 7, and 30 days. The µSBS test was performed using a universal testing machine (1 mm/min). The data were analyzed by t-test, repeated measures ANOVA and Tukey test (p< 0.05). Results: There were no statistically significant differences between the mean µSBS of the groups with and without nanoparticles along the different storage periods (p> 0.05). There was significant difference in µSBS values among the three different storage periods in all the tested materials (p< 0.05). Conclusion: Incorporation of 0.5 %wt. silica nanoparticles did not compromise the µSBS of Fuji II LC RMGI to dentin

Duty-Cycle Division Multiplexing (DCDM): towards the largest optical networks capacity

Demultiplexing concept of Duty-Cycle Division Multiplexing (DCDM) technique is tested in the back-to-back connection and after transmission over copper wire and optical fiber. Three different lengths of copper wire are tested with the total loss of 3.3, 6.6, and 9.9 dB respectively. Even though the sampling points and threshold values were not dy- namic, the demultiplexing process for the case of back-to-back, and after transmission over the links with 3.3, and 6.6 dB losses, was successful without experiencing any errors. This can be witnessed when the recovered data is compared against the transmitted bits. However, the errors are recorded in the link with 9.9 dB losses, which was mainly due to the non-optimized sampling points and threshold values. In experiment over 60 km Standard Single Mode Fiber, successful transmission was demonstrated. The receiver sensitivity is calculated off-line by using bit error rate analysis. These results confirm the validity of DCDM demultiplexer structure including the sampling process and the data recovery rules

Investigating the Relationship Between High Levels of Angiotensin II in Plasma and the Rate of Deterioration in Hypertensive Patients to COVID-19

Introduction: The COVID-19 crisis poses a heightened risk to vulnerable populations. Considering factors influencing deterioration, complications, and mortality, it is especially important to pay attention to these groups, including persons with hypertension (HTN) and diabetes. This study aimed to investigate the correlation between the angiotensin II (ANG II) level and the disease severity and clinical course in COVID-19 patients. Methods: A cross-sectional study was conducted on 50 COVID-19 patients (mean age 59.1±20) admitted to Sinai hospital in Hamedan. The blood samples of the patients were taken during hospitalization and discharge, and the plasma ANG II level was measured using an enzyme-linked immunosorbent assay kit. The quantitative comparison was analyzed with paired t test and qualitative comparison with the chi-square test. The correlation of variables was checked with the Pearson test, and P<0.05 was considered statistically significant. Results: Overall, 44%, 16%, and 10% of COVID-19 patients had HTN, cardiovascular disease (CVD), and 10% diabetes, respectively. The oxygen level of 82% of the patients was below 90, of which 68% were intubated, and the lowest oxygen levels were observed in patients with HTN and CVD with 2 deaths. The primary and secondary examination of the ANG II level demonstrated that its level was significantly higher during illness compared to full recovery and decreased during recovery. Conclusion: The ANG II level is related to the severity of the disease in the early stages of 2019- nCoV infection. Therefore, HTN or other diseases that affect the level of ANG II in the blood can increase the severity of the disease

70-Gb/s amplitude-shift-keyed system with 10-GHz clock recovery circuit using duty cycle division multiplexing

The performance of ASK over DCDM for up to seven channels is reported. The aggregate bit rate of 70 Gb/s is achieved with only 160-GHz modulation bandwidth. The clock and data recovery are realized at 10-GHz clock rate, which is very economic and efficient. At 7 × 10 Gb/s, the worst receiver sensitivity of −10 dBm, OSNR of 41.5 dB and chromatic dispersion tolerance of ±7 ps/nm are achieved. Whereas, for the best channel, the receiver sensitivity, OSNR, and chromatic dispersion tolerance are −23.5 dBm, 29 dB, and ±36 ps/nm, respectively

THE FATE OF PATENTS: AN EXPLORATORY ANALYSIS OF PATENTS AS IPO SIGNALS OF REPUTATIONAL ADVANTAGE

Drawing on the reputation literature and signaling theory, this article builds on work that looks at patents as reputation signals. We build a multi-industry database of patents that expire due to lack of maintenance fee payments and test for a relationship between these patents and the firm’s IPO date. We find a significant and positive relationship between the likelihood of patents expiring due to lack of maintenance fee payments and the time to IPO. We also find that patents associated with firms which are not venture capital backed, are more likely to expire. Our findings suggest that patents that are used for signaling intentions are more likely to be underutilized. Implications for research and policy are discussed

The Fate of Patents : An Exploratory Analysis of Patents as Signals of Reputational Advantage

Drawing on the reputation literature and signaling theory, this article builds on work that looks at patents as reputation signals.We build a multi-industry database of patents that expire due to lack of maintenance fee payments and test for a relationship between these patents and the firm’s IPO date.We find a significant and positive relationship between the likelihood of patents expiring due to lack of maintenance fee payments and the time to IPO. We also find that patents associated with firms which are not venture capital backed,are more likely to expire. Our findings suggest that patents that are used for signaling intentions are more likely to be underutilized.Implications for research and policy are discussed.QC 20160408</p

Bonding Durability of Four Adhesive Systems

Objectives: This study aimed to compare the durability of four adhesive systems by assessing their microtensile bond strength (MTBS) and microleakage during six months of water storage. Materials and Methods: A total of 128 human third molars were used. The adhesives tested were Scotch Bond Multipurpose (SBMP), Single Bond (SB), Clearfil-SE bond (CSEB), and All-Bond SE (ABSE). After sample preparation for MTBS testing, the microspecimens were subjected to microtensile tester after one day and six months of water storage. For microleakage evaluation, facial and lingual class V cavities were prepared and restored with composite. After thermocycling, microleakage was evaluated. Bond strength values were subjected to one-way ANOVA and Tamhane’s test, and the microleakage data were analyzed by the Kruskal-Wallis, Dunn, Mann Whitney and Wilcoxon tests (P<0.05). Results: Single Bond yielded the highest and ABSE yielded the lowest bond strength at one day and six months. Short-term bond strength of SBMP and CSEB was similar. After six months, a significant decrease in bond strength was observed in ABSE and SBMP groups. At one day, ABSE showed the highest microleakage at the occlusal margin; however, at the gingival margin, there was no significant difference among groups. Long-term microleakage of all groups at the occlusal margins was similar, whilst gingival margins of SBMP and SB showed significantly higher microleakage. Conclusion: The highest MTBS and favorable sealability were obtained by Clearfil SE bond. Water storage had no effect on microleakage of self-etch adhesives at the gingival margin or MTBS of CSEB and SB.