Photo- Responsive Adhesion and De-Adhesion of Polymers and Nanoparticles

Photochromic behavior is not a new concept in chemistry and was mentioned for the first time in literature more than a century ago. This dissertation focused on using photochromic molecules to innovate and develop methods to remotely modify adhesion of thin films to substrates. We explored both photo-induced covalent and non-covalent adhesion. To induce non-covalent adhesion, we hypothesized that if photochromic molecules embedded in a polymer were exposed to light, this could change the properties of the molecule which might lead to the change of polymer adhesion to substrate. We investigated the effect of ultraviolet (UV) and visible light exposure on the adhesion of polystyrene (PS) for a range of photochromic molecules such as, donor-acceptor Stenhouse adducts (DASA), diarylethene derivatives (DAE) and spiropyrans (SP) to glass substrate. We utilized adhesion measurement methods like water detachment, pull-off and the lap shear tests, which were used to detect the increase and decrease of adhesion to the glass surface after light exposure. We also investigated the effects of photochrome concentration, light wavelength, substrate properties, and polymer structure on adhesion and de-adhesion. The innovative part of our final project was to engineer multi-functional nanoparticles and substrates with light-switchable covalent adhesion. Nanoparticles with surface-bound anthracene (AN) were able to undergo [4+4] photocycloaddition reactions to form covalent adhesion. In theory this reaction could help nanoparticles to selectively assemble and make a predesigned structure after being activated by light. Our results demonstrated that under ultraviolet (365 nm) illumination, both unimolecular and bimolecular photochemical reactions led to the loss of surface-bound AN absorbance. These competing reaction pathways decreased the efficiency of the cross-linking dimerization reaction

Modelling potential distribution of fluvial fish species for expanding conservation knowledge: Case study of the genus Barbus in Iran

Species inhabiting fresh waters are severely influenced by anthropogenic factors. Effective management and conservation plans require high accurate and reliable species distribution forecasts. Here, we modelled potential distribution of the genus Barbus in Iran, based on environmental variables using Species Distribution Models (SDMs). Six environmental predictors (i.e. slope, bankfull width, elevation, mean air temperature, range of air temperature and annual precipitation) were applied for modelling. The models were selected among different technique (GLM, GAM, CTA, SRE, GBM, RF, MARS, and FDA) which their results were summarized through ensemble forecasting approaches. According to the TSS (True Skill Statistic), the accuracy of the implemented models was greater than 0.8. The results showed that the projected distributions not only were observed in the same recorded basins but also in the new basins. Presented results deepen the conservation knowledge in Iran and act as a guidance for management decisions aimed at legal identification of critical habitats for species as well as informing them for translocation of threatened or captive-bred populations

ODABIR DLIJETA ZA BUŠENJE STIJENA S RAZLIČITIM TALOŽNIM FACIJESIMA UPORABOM METODE MARKOVLJEVA LANCA: PRIMJER STUDIJE NAFTNOGA POLJA U JUŽNOME IRANU

The selection of a drill bit is an essential issue in well planning. Furthermore, identification and evaluation of sedimentary rocks before well drilling plays a crucial role in choosing the drill bit. Moreover, the Markov chain as a stochastic model is one of the powerful methods for identifying lithological units, which is based on the calculation of the transition probability matrix or transition matrix. The Markov chain experiences transitions from one state (a situation or set of values) to another according to specified probabilistic rules. In this paper, the Markov chain was implemented for bit selection in a formation with different sedimentary facies (such as the Dashtak Formation). Therefore, the proper drill bit was proposed by utilizing the transition matrix of rock facies and the available bits. This process was carried out in two wells where the thicknesses of the Dashtak Formation are 960 meters and 1410 meters. Consequently, the results indicate that the Markov chain is a practical method for selecting bits in a sequence of rock facies based on an acceptable matching between the reality mode (the used bits in the well) and the Markov chain results. Besides, in the case of using an improper bit in a well, and using a bit in a washing and reaming operation, there were differences between the used bits and the Markov chain outputs.Odabir dlijeta iznimno je važan korak u izradi projekta bušotine, a prepoznavanje i procjena taložnih stijena prije početka bušenja ima presudnu ulogu u odabiru dlijeta. Markovljev lanac, kao primjer stohastičkoga modela, jedna je od važnijih metoda za razlikovanje litoloških jedinica. Temelji se na računu matrice vjerojatnosti prijelaza ili matrice prijelaza. Markovljev lanac opisuje prijelaze iz jednoga stanja (situacije ili skupa vrijednosti) u drugo prema određenim vjerojatnosnim pravilima. U ovome je radu prvi put opisana uporaba Markovljeva lanca kod odabira dlijeta za bušenje kroz interval s različitim taložnim facijesima (formacija Dashtak). Stoga su u odabiru odgovarajućega dlijeta korišteni prijelazna matrica stijenskih facijesa i podatci o dostupnim dlijetima. Ovaj postupak proveden je u dvjema bušotinama gdje su debljine formacije Dashtak 960 i 1410 m. Dobiveni rezultati pokazuju da je Markovovljev lanac praktična metoda za odabir dlijeta kod bušenja niza litofacijesa. Zaključak je donesen na temelju stupnja podudaranja između stvarnih podataka (dlijeta korištenih u bušotini) i rezultata dobivenih modelom (Markovljevim lancem). Također, u slučaju uporabe neodgovarajućega dlijeta u bušotini za operacije pročišćavanja i proširenja kanala bušotine pojavile su se razlike između korištenih dlijeta i rezultata dobivenih Markovljevim lancem

Use of lipophilic and hydrophilic polymers in production of sustained release zinc sulfate tablets

Background and aims: Zinc sulfate administered to correct zinc deficiency. Its oral administration has shown serious digestive side effects and sometimes it has led to the lack of use it. The main aim of the present study was to use lipophilic and hydrophilic polymers in production of sustained release zinc sulfate tabletsover an extended period of time. Methods: Sustained release (SR) zinc sulfate tablets were prepared using either lipophilic-based matrix or hydrophilic matrix system or natural polymers by either hot-fusion (HF) granulation or direct compression (DC) method. Physical and chemical features of provided SR tablets including hardness, friability, and weight variation, disintegration time, swelling index, content uniformity and drug release behavior were evaluated. The drug concentration was assayed by an atomic absorption spectrophotometer at 213.8 nm. Results: Most of the prepared formulations showed acceptable physicochemical properties. Among 30 formulations, SR tablets with lipophilic matrix-based showed more predictable release profiles compared to tablets prepared based on hydrophilic or natural matrixes. Tablets containing carnauba wax showed slower release while tablets with hydrogenated castor oil represented faster release profile. A few lipophilic matrix tablets containing zinc sulfate (110 mg), beeswax (or carnauba wax) and Avicel (or Emcompress) were selected as the optimum formulations showing release profiles based on USP criteria for lipophilic-based SR tablets. The mean dissolution time (MDT) and dissolution efficiency (DE8%) of selected formulations were 1.69-1.95 hr and 69.3-71.8%, respectively. Tablet hardness and granule size had no effects on release rate. The drug release kinetic followed Higuchi model. Conclusion: Lipophilic based SR tablets of zinc sulfate is suggested as an alternative for capsule or syrup of the drug whichhave digestive side effects

Effects of fluoride versus amorphous calcium phosphate solutions on enamel microhardness of white spot lesions : an in-vitro study

Development of white spot lesions around orthodontic fixed orthodontic appliances is a common finding, especially in patients with poor oral hygiene. One of the conservative interventions for regression of these lesions is using chemical solutions. The current study aimed to compare the effectiveness of fluoride and amorphous calcium phosphate (ACP) on microhardness improvement of affected enamel. Forty-five intact human incisor teeth were selected and randomly divided into 3 groups of 15. Fluoride group, ACP group and artificial saliva group (control group). Inducing of white spot lesion was done by PH-cycling model. Samples of the first and second group were submerged into 0.05% fluoride and 0.05% ACP solutions respectively for one minute a day. The rest of the time, all specimens were put in artificial saliva, which was incubated in 37 °c temperature. Microhardness of specimens was assessed by Vickers microhardness test in three stages: 1: Baseline microhardness assessment that was done before induction of white spot lesion, 2: Secondary microhardness assessment that was done after induction, 3: Final microhardness assessment that was done after chemical treatment. The SPSS 11.5 software was used for statistical analysis and p< 0.05 was considered as significant. Microhardness of specimens in the fluoride and ACP groups had significantly improved after the treatment (between secondary assessment and final assessment). In the control group, no significant improvements were observed. In final assessment, there were significant differences between the ACP and control groups, but no significant differences were found neither between the fluoride and ACP, nor the Fluoride and control groups. According to the current study, both 0.05% ACP and 0.05% fluoride solutions enhanced enamel micro-hardness in treatment of white spot lesion

Effect of Nanomicelle Curcumin on Quality of Life and Sleep in Patients With Parkinson’s Disease: A Double-Blind, Randomized, and Placebo-Controlled Trial

Background: Considering the evidence indicating the neuronal protective effects of curcumin in previous studies, this double-blind, randomized, placebo-controlled, and parallel-group trial was aimed at exploring the possible nanomicelle curcumin (SinaCurcumin®, nano-micellar soft gel)-mediated impact on sleep, fatigue, and quality of life (QoL) in patients with Parkinson’s disease (PD).Methods: A sample of 50 PD patients were recruited and randomly divided into experimental (25) and control groups (25). Sleep quality, fatigue, and QoL were assessed based on the Pittsburgh Sleep Quality Index (PSQI), Fatigue Severity Scale (FSS), and the Parkinson’s Disease Questionnaire–39 (PDQ-39), respectively, at the beginning and the end of the study. The groups were treated for three months by 80 mg of nano-micellar soft gel twice a day.Results: Nanomicelle curcumin significantly increased sleep quality and QoL compared with placebo (P values = 0.0001 and 0.0002, respectively) in PD patients. This significant difference has not influenced by the duration of the disease, the severity of disease progression (Hoehn &amp; Yahr scale), and the cumulative dose of levodopa. This supplement did not have a significant effect on the fatigue severity of patients compared to placebo.Conclusion: It has proposed that the nanomicelle curcumin can be used to improve sleep quality and QoL in PD patients

Segmenting breast cancerous regions in thermal images using fuzzy active contours

Breast cancer is the main cause of death among young women in developing countries. The human body temperature carries critical medical information related to the overall body status. Abnormal rise in total and regional body temperature is a natural symptom in diagnosing many diseases. Thermal imaging (Thermography) utilizes infrared beams which are fast, non-invasive, and non-contact and the output created images by this technique are flexible and useful to monitor the temperature of the human body. In some clinical studies and biopsy tests, it is necessary for the clinician to know the extent of the cancerous area. In such cases, the thermal image is very useful. In the same line, to detect the cancerous tissue core, thermal imaging is beneficial. This paper presents a fully automated approach to detect the thermal edge and core of the cancerous area in thermography images. In order to evaluate the proposed method, 60 patients with an average age of 44/9 were chosen. These cases were suspected of breast tissue disease. These patients referred to Tehran Imam Khomeini Imaging Center. Clinical examinations such as ultrasound, biopsy, questionnaire, and eventually thermography were done precisely on these individuals. Finally, the proposed model is applied for segmenting the proved abnormal area in thermal images. The proposed model is based on a fuzzy active contour designed by fuzzy logic. The presented method can segment cancerous tissue areas from its borders in thermal images of the breast area. In order to evaluate the proposed algorithm, Hausdorff and mean distance between manual and automatic method were used. Estimation of distance was conducted to accurately separate the thermal core and edge. Hausdorff distance between the proposed and the manual method for thermal core and edge was 0.4719 ± 0.4389, 0.3171± 0.1056 mm respectively, and the average distance between the proposed and the manual method for core and thermal edge was 0.0845± 0.0619, 0.0710 ± 0.0381 mm respectively. Furthermore, the sensitivity in recognizing the thermal pattern in breast tissue masses is 85 % and its accuracy is 91.98 %.A thermal imaging system has been proposed that is able to recognize abnormal breast tissue masses. This system utilizes fuzzy active contours to extract the abnormal regions automatically

Application of Radiation and Genetic Engineering Techniques to Improve Biocontrol Agent Performance: A Short Review

Biological control is a potential nonchemical method to manage plant pathogens by beneficial microorganisms. To improve antagonistic potential of biocontrol agents, mutation by radiations, chemicals, and genetic manipulations has been used. Genetic techniques and ionizing radiation containing direct or indirect emissions play the greatest role for selection of useful microorganisms to enhance the efficiency of biological systems. Indeed, genetic engineering has a main role in increasing antimicrobial metabolites, host colonization ability, and endurance in micro-ecosystem. Genetic improvement can be achieved by protoplast fusion, genetic modification (GM), and chemical (genotoxic agents) and physical mutations. However, ultraviolet light and ionizing radiations can induce modifications in the genome of an organism. Irradiation, particularly gamma rays, is also applied for controlling postharvest diseases. Indeed, irradiation cannot completely eliminate pathogens, but it might result in cell injury and directly damage the chromosomal DNA of a living cell. This technology has been used for many reasons including disinfestation of foods, reducing foodborne pathogens, and extending shelf life many fruits, vegetables, and nuts. In the current review, we discuss advances in the radiation and molecular genetic techniques with the aim to improve antagonistic potential of microorganisms as it is applied to the suppression of plant pathogens