In silico designing and creation a new generation of reteplase with more fibrin specificity

Introduction: Reteplase is a fibrin-specific thrombolytic drug and non-glycosylated modified recombinant form of human tissue plasminogen activator (t-PA). It is containing kringle-2 and serine protease domains but the epidermal growth factor and fibronectin finger domains are absent. The lack of finger domain in reteplase cause decrease fibrin specificity. Since the enhancing fibrin specificity is one of the aim for development new thrombolytic drug, due to decreasing side effect such as hemorrhage, also reteplase is non-glycosylated and can be produced in bacterial system at low cost, in this study a new generation of reteplase designed with more fibrin specificity.  Methods and Results: According to the sequence of protein drugswith more fibrin specificity, mutations in reteplase sequence consist of substitution mutation in Kringle 2 domains and adding sequence of mutated finger domain to reteplase sequence. 3D structure of this new reteplase was created by Modeller9.17 software and then simulated by Gromacs 5 software for 20 ns. Docking simulation was performed between new and wild reteplase with fibrin by HADDOCK server separately. The results showed that new reteplase has better interaction with fibrin compared with wild type (table1). Parameter Wild reteplase New  reteplase HADDOCK score* -35.8 +/- 8.3 -43.2 +/- 21.3             *More negative score is better score  Conclusions: In this study a new generation of reteplase with more fibrin specificity was designed in silico. Since the production of reteplase has low cost compared with tPA, improvement its structure to desirable features such as increasing fibrin specificity, can be a way to achieve a favorable thrombolytic drug

Push-out bond strength of quartz fibre posts to root canal dentin using total-etch and self-adhesive resin cements

Objectives: Several adhesive systems are available for cementation of fibre posts into the root canal. The aim of the present study was to investigate the push-out bond strengths of quartz fibre posts to root dentin with the use of different total-etch and self-adhesive resin cements. Study Design: Ninety single-rooted human premolars were endodontically treated and standardized post-spaces were prepared. Fibre posts were cemented with different luting agents: total-etch (Nexus NX3, Duo-Link, and RelyX ARC) and self-adhesive resin cements (Maxcem Elite, BisCem, and RelyX Unicem). Three post/dentin sections (coronal, middle and apical) were obtained from each specimen, and push-out bond strength test was performed in each section at a cross-head speed of 0.5 mm/min. Data was analyzed with two-factor and one-way analysis of variance and a post-hoc Tukey test at a significance level of p < 0.05. Results: Cement type, canal region, and their interaction significantly influenced bond strength. Significantly higher bond strength values were observed in the apical region of self-adhesive cements. Only Duo-Link and RelyX ARC cements resulted in homogeneous bond strengths. Conclusions: Cementation of quartz fibre posts using self-adhesive cements provided higher push-out bond strengths especially in the apical region, while total-etch cements resulted in more uniform bond strengths in different regions of the root canal. © Medicina Oral

Lymphoma infectious mononucleosis by Epstein-Barr virus: A case report

Background: Epstein-Bar virus (EBV) causes infectious mononucleosis in more than 90% of children. Rarely, mononucleosis may lead to malignancy. The aim the current study was to introduce a child with mononucleosis and persistent adenopathy. Case report: A 4-year-old male patient presented with complaints of fever, shortness of breath and sore throat. He was treated with antibiotics and prednisolone. Normal flora was grown by pharynx and blood cultures. Due to the high clinical suspicion (persistent large lymph nodes), open biopsy of cervical lymph nodes was done after 3 weeks and Non-Hodgkin lymphoma disease was diagnosed in the biopsy. Conclusions: Atypical presentation should be considered for every child and biopsy is inevitable in larger and persistent lymphadenopathy after 2 weeks. Because of poor prognosis and high mortality rate, early detection of lymphoma is very important

Effect of pre-heating on the mechanical properties of silorane-based and methacrylate-based composites

Background: The use of composites in dental restoration has been commonly criticized, due to their underwhelming mechanical properties. This problem may be solved partially by preheating. The present research aims to determine the effect of preheating on the mechanical properties of two different classes of composites. Material and Methods: A Silorane-based (Silorane) and a Methacrylate-based (Z250) composite were preheated to different temperatures (25, 37, and 68 °C) and afterwards were tested with the appropriate devices for each testing protocol. The materialâ s flexural strength, elastic modulus, and Vickers microhardness were evaluated. Two-way ANOVA, and Tukeyâ s post hoc were used to analyze the data. Results: Microhardness and elastic modulus increased with preheating, while flexural strength values did not increase significantly with preheating. Furthermore the methacrylate-based composite (Z250) showed higher values compared to the Silorane-based composite (Silorane) in all the tested properties. Conclusions: Preheating Silorane enhances the compositeâ s microhardness and elastic modulus but does not affect its flexural strength. On the other hand, preheating Z250 increases its microhardness but does not change its flexural strength or elastic modulus. In addition, the Z250 composite shows higher microhardness and flexural strength than Silorane, but the elastic modulus values with preheating are similar. Therefore Z250 seems to have better mechanical properties making it the better choice in a clinical situation

Chemical composition and antibacterial activity of some herbal essential oils against Streptococcus mutans

Background and aims: One of the most common chronic diseases in the world is tooth decay. A variety of bacteria are involved in this disorder of which Streptococcus mutants is the most common. Essential oils are considered as new natural compounds for use in combating drug-resistant bacteria. This study was aimed to evaluate the antibacterial activity of some essential oils prepared from Eucalyptus caesia Benth, Cuminum cyminum L. and Satureja hortensis L. on S. mutants. Methods: In this study, essential oils were extracted by hydrodistillation method. E. caesia Benth, C. cyminum L. and S. hortensis L. were characterized by using gas chromatography‒mass spectrophotometry (GC‒MS). Antibacterial activity indices including minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and zone of inhibition for the above essential oils against Streptococcus mutans were determined using broth macro-dilution and disk diffusion methods. Data analysis was performed using one-way ANOVA and Tukey test. Results:Results showed that all three extracts had antibacterial activity against S. mutants. S. hortensis L. essential oil with the lowest MIC and MBC value (13.2 and 18.4 µg/ml, respectively) and the biggest inhibition zone showed the strongest antibacterial effect against S. mutants in all exposure times and at all concentrations, compared with two other essential oils. Furthermore, C. cyminum L. essential oil had higher anti-bacterial activity against S. mutant than E. caesia Benth essential oil. Conclusions:The essential oils used in the present study with different components showed antibacterial activity (especially S. hortensis L essential oil), and therefore they can be used as a new antibacterial substance. Keywords: Dental caries, Streptococcus mutans, Essential oils, Antimicrobial

The Effects of an Herbal Mixture on the Clinical Symptoms of Women with Polycystic Ovary Syndrome

Background & Objective: Polycystic ovary syndrome is the most common endocrine disorder in women. Multiple-drug treatments and prolonged treatments often cause patients to discontinue the treatment. Considering the side-effects of chemical drugs, the present study aimed to investigate the effects of the combination of cumin and fennel extract on the clinical symptoms of women with polycystic ovary syndrome. Materials and Methods: This clinical trial was conducted on 70 patients with polycystic ovary syndrome, who were selected randomly from the patients referring to the teaching hospitals in Shahrekord, Iran. The patients were randomly divided into two groups of intervention and control. The intervention group received capsules containing fennel and black cumin, and the control group received placebo twice per day for four months. Before and after the intervention, the clinical symptoms of the subjects were evaluated in both groups. Data analysis was performed in SPSS. Results: In the intervention group, a significant reduction was observed in hirsutism, while the menstrual duration increased compared to the control group (P0.05). Conclusion: According to the results, the combination of fennel and cumin extract could effectively improve the clinical symptoms of the patients with polycystic ovary syndrome. Therefore, the herbal mixture could be used as a non-toxic medication for the treatment of these patients. Keywords: Cumin, Fennel, Polycystic Ovary Syndrome, Clinical Symptom

Accessibility of grafted functional groups limits reactivity of covalent graphene derivatives

Graphene derivatives are an emerging and important class of promising materials because they can bear a wide variety of functional groups, rendering them suitable for a plethora of applications, ranging from energy storage to sensorics. Further functionalisation of these materials requires a thorough understanding of their reactivity at the molecular level because the organic functional groups are close to an effectively infinite surface, which may affect their reactivity. Nitrile groups grafted on a graphene can be easily hydrolysed to carboxyl groups, but they are resistant to reduction by LiAlH4. Here, we combine theoretical and experimental methods to explain the resistance of CN groups grafted on the graphene surface in terms of the limited accessibility of these groups for the reduction agent. We highlight that such mechanistic aspects, i.e., steric hindrance of the reaction centres and surface-solvent interactions, play a crucial role in the reactivity of 2D materials.Web of Science598art. no. 15379

Magnetic polaron states in photoluminescent carbon dots enable hydrogen peroxide photoproduction

Photoactivation of aspartic acid-based carbon dots (Asp-CDs) induces the generation of spin-separated species, including electron/hole (e−/h+) polarons and spin-coupled triplet states, as uniquely confirmed by the light-induced electron paramagnetic resonance spectroscopy. The relative population of the e−/h+ pairs and triplet species depends on the solvent polarity, featuring a substantial stabilization of the triplet state in a non-polar environment (benzene). The electronic properties of the photoexcited Asp-CDs emerge from their spatial organization being interpreted as multi-layer assemblies containing a hydrophobic carbonaceous core and a hydrophilic oxygen and nitrogen functionalized surface. The system properties are dissected theoreti cally by density functional theory in combination with molecular dynamics simulations on quasi-spherical assemblies of size-variant flakelike model sys tems, revealing the importance of size dependence and interlayer effects. The formation of the spin-separated states in Asp-CDs enables the photoproduc tion of hydrogen peroxide (H2O2) from water and water/2-propanol mixture via a water oxidation reaction.Web of Science1932art. no. 220658

Optimization Based Analysis of Desalination Technologies for Unconventional Oil and Gas Produced Water Treatment

Hydraulic fracturing of shale oil and gas reservoirs is associated with significant environmental sustainability issues regarding water management. Large volume of water, known as produced water, with relatively high total dissolved solids (TDS), is produced during well production. Difficult to treat, these hypersaline brines could contaminate surface freshwater resources and ground water reservoirs. Advanced desalination technologies offer a promising way to provide fresh water while treating the hypersaline produced water. However, the overall performance of desalination systems operating with hypersaline brines has not been thoroughly studied using systems-level approaches. As such, it is necessary to address this knowledge gap by comprehensive analysis of technologies deemed suitable for produced water treatment. This work investigates the technoeconomic feasibility of several well-established as well as novel technologies for treatment of produced water. This is accomplished through module scale mathematical modeling of thermodynamic processes and technoeconomic nonlinear programming optimization. The technologies studied include 1) air gap, direct contact, permeate gap, conductive gap, sweeping gas, and vacuum membrane distillation (MD) systems, 2) single effect, backward feed, forward feed, and parallel feed multi-effect mechanical vapor recompression (MVR) systems, and 3) brine reflux, consecutive loops, split feed, and cascading osmotically assisted reverse osmosis (OARO) systems. This work show that air gap MD has the lowest treatment cost of all MD configurations when the gap size is small, and the Reynolds number is low. For OARO systems, brine-reflux configuration outperforms all others in terms of cost, energy consumption, and design simplicity. Additionally, single effect MVR outperforms multi-effect MVR when the temperature difference across the evaporator is well constrained. Across the studied technologies, brine reflux OARO has the smallest work of separation, followed by air gap MD and MVR. However, brine reflux OARO requires significant investment and replacement of large-area membranes, whereas airgap MD is the least expensive in terms of capital costs. MVR is also associated with high capital costs of compressor and evaporator. Under ideal operating conditions, air gap MD has the lowest cost for produced water treatment. Furthermore, when operational complexities are considered, or feed is at lower salinities, alternative technologies may offer more viable options

The Effect of Peer Education on Practical Skills Training of Dentistry Students in Restorative Preclinic

Introduction: Peer education can be a useful adjunctive method for clinical skills training. This study was performed to evaluate the effect of peer education on practical skill training of dental students in restorative preclinic. Methods: In this quasi-experimental study which was performed in years 2009-10, all 34 dental students of Tabriz School of Dentistry (admission year:2006), who enrolled in practical restorative I course and met inclusion criteria were randomly divided into two groups as intervention and control. Peer education method was used for intervention group besides the conventional method for running practical restorative I course, while in control group, the course ran conventionally. At the end of the semester, the mean rank of students’ scores in the course in the two groups were compared. For this purpose, SPSS software and Mann-Whitney U test were used at a significance level of P<0.05. Results: The mean scores in practical restorative I was 15.73±1.69 in the intervention group and 14.69±2.67 in the control group. There was no significant difference in the mean rank of scores between the two groups. Conclusion: Practical skill of students who had used peer education method was the same as the students in the control group. It is suggested that peer education method be considered as a supplementary educational method in education of restorative dentistry preclinical course