155 research outputs found
Development of Biodegradable and Stimuli-Responsive Macromolescules and Their Assemblies
Polymersomes are potentially multifunctional soft materials constructed by the self-assembly of amphiphilic block copolymers in aqueous medium. While much research has focused on controlling the assembly and encapsulation properties of polymersomes, their surface functionalization has been relatively unexplored. This is important because it plays a critical role in determining their properties such as toxicity and biodistribution behavior. The work described in this thesis involves the development of a biocompatible and biodegradable polymersome systems based on poly(ethylene oxide)-b-polycaprolactone (PEO-PCL) block copolymers with azide surface groups as a novel scaffold for various biomedical applications. The surface functionalization of these polymersomes with polyester dendrons bearing alkyne focal points with different peripheral groups, such as amines and guanidines, as well as a small molecule rhodamine dye is accomplished and their conjugation yields are compared to each other. Moreover, dendritic and non-dendritic polymersome-based MRI contrast agents, with the highest currently reported longitudinal relaxivity for a polymersome system, are developed by decorating PEO-PCL polymerosomes\u27 surfaces with both non-dendritic and dendritic Gd(III)-based contrast agents. In addition, PEO-PCL polymersomes were employed to develop a multifunctional system with the potential to interfere with the viral infection process at two levels. In addition to their use as materials for functionalizing the surfaces of nanomaterials, dendrimers and their assemblies have been widely used as drug delivery vehicles. In order to enable a new level of control over drug release, backbone photodegradable dendrimers and dendrons are synthesized by incorporation of a monomer unit based on o-nitrobenzyl esters and 2,2-bis(hydroxymethyl)propionic acid. It is shown that these dendrimers undergo effective photolysis to release only small molecules upon irradiation with UV light. Finally, these dendrons are incorporated into amphiphilic Janus dendrimer structures and their self-assembly to dendrimersomes followed by their photodegradation are discussed
Development of Molecular Beacon method to detect of JAK2 V617F mutation
V617F mutation of JAK2 gene is a point mutation of Somatic cells leading to permanent phosphorylation and protein kinase activity of the JAK2 protein. This mutation is a valuable marker in the diagnosis of myeloid neoplasms. Development of new techniques can be effective and highly sensitive for the detection of the mutation. The aim of this study is designing and executing a molecular beacon probe-based real-time PCR detect to V617F mutation. Test results were reviewed from a set of wild type and cloned JAK2 exon 12 mutated allele genes into plasmid vector and through amplification by Real-Time PCR system. The sensitivity and specificity of Molecular Beacon probes design were tested. The results showed that the Real-Time PCR system has %100 specificity and % 0.001 sensitivity. Based on the results obtained from the molecular beacon probe-based real-time PCR, it was proved that the system is able to detect normal and mutant alleles of JAK2 V617F position with high accuracy and a short time in a closed tube syste
Dendritic surface functionalization of nanomaterials: controlling properties and functions for biomedical applications
Uma grande variedade de nanomateriais tem demonstrado aplicações médicas promissoras, tais como liberação de fármacos e em imagens. Nestas aplicações, a superfÃcie quÃmica dos materiais é crÃtica, uma vez que exerce papel importante na determinação da toxicidade e comportamento de biodistribuição do material. Aqui, nós revisamos a funcionalização de nanomateriais, como dendrons, como método eficiente de alterar a superfÃcie quÃmica destes compostos, introduzindo novas propriedades e funções. Descritos aqui estão nanopartÃculas superparamagnéticas de óxido de ferro (do inglês, SPIO), com guanidinas dendrÃticas para aumentar seu transporte para o interior das células, úteis em imagens de ressonância magnética. A introdução de dendrons contendo hidroxilas, aminas, guanidinas, carboidratos e quelatos de Gd(III) periféricos em vesÃculas poliméricas (polymersomes) também está descrita. Esses grupos dendrÃticos permitem a modulação de toxicidade, captura celular, ligação à proteÃna e eficiência como agente de contraste, enquanto que, ao mesmo tempo, permitem a manutenção da estabilidade das vesÃculas poliméricas. Assim, essa abordagem é promissora para o desenvolvimento de grande variedade de materiais multifuncionais para aplicações farmacêuticas.A wide variety of nanomaterials have demonstrated promise in medical applications such as drug delivery and imaging. In these applications, the surface chemistry of the materials is critical as it plays an important role in determining the toxicity and biodistribution behavior of the material. We review here the functionalization of nanomaterials with dendrons as an efficient method to alter the surface chemistry of the materials, introducing new properties and functions. Described here is the functionalization of superparamagnetic iron oxide nanoparticles (SPIO) with dendritic guanidines to enhance their transport into cells for magnetic resonance imaging applications. The introduction of dendrons bearing peripheral hydroxyls, amines, guanidines, carbohydrates and Gd(III) chelates to polymer vesicles (polymersomes) is also described. These dendritic moieties allow for modulation of toxicity, cell uptake, protein binding, and contrast agent efficiency, while at the same time allowing the stabilities of the polymersomes to be maintained. Thus, this approach holds promise for the development of a wide range of multifunctional materials for pharmaceutical applications
A Self-healing Architecture based on RAINBOW for Industrial Usage
Over recent decades computer and software systems become more and more complex because of the applications’
and user’s requirements. The complexity makes the software systems more vulnerable to the error and bugs. Also, environmental situations affect software systems which do not react to the environmental activities. Self-healing architectures have been proposed in order to make systems defeat these problems and to make systems capable of reacting to the environmental activity. Hence, these architectures help system to become dynamic and more robust, but finding a proper architecture which can support and cover system’s requirements is an issue. This is particularly true in industrial environments, which consist of some known and some unknown parameters.
This paper presents an architecture that can be used in some industrial environment to facilitate the process of adapting the system to unpredicted situations. This architecture has been developed over the base of RAINBOW infrastructure and it is compliant to the MAPE control loop (Autonomic Computing control loop). The paper reports also about the practical experience of implementing this architecture for a painter robot in an automotive factory, which deals with problems in painted part by itself. The proposed architecture uses rule-based reasoning and it actualizes the method of environmental modeling by using a rule-based system as the model extractor. The results of the implementation shows huge benefits in reusability and even in the quality of painting process
Population genetic study on common kilka (Clupeonella cultriventris Nordmann, 1840) in the Southwest Caspian Sea (Gilan Province, Iran) using microsatellite markers
This study represents population genetic analysis of the common kilka Clupeonella cultriventris (Nordmann, 1840) in the southwest Caspian Sea (Gilan Province). A total of 60 specimens of adult common kilka were sampled from two seasons (spring and summer), 2010. Fifteen pairs of microsatellites previously developed for American shad (Alosa sapidissima), Pacific herring (Clupea pallasi), Atlantic herring (Clupea harengus) and Sardine (Sardina pilchardus) were tested on genomic DNA of common kilka. Alleles frequencies, the fixation index RST, observed and expected heterozygosity were determined at disomic loci amplified from fin tissue samples. Five pairs of primers (Cpa6, Cpa8, Cpa104, Cpa125 and AcaC051) as polymorphic loci were used to analyze the genetic variation of the common kilka population. Analyses revealed that an average of alleles per locus was 14.4 (range 5 to 21 alleles per locus in regions). All sampled regions contained private alleles. The average observed and expected heterozygosity were 0.153 and 0.888, respectively. All loci significantly deviated from Hardy-Weinberg equilibrium (HWE). Based on AMOVA, RST values was found to be 0.113 (Nm=1.96, P<0.01). The genetic distance between populations was 0.344, which indicates that the genetic difference among the studied populations is pronounced. These results support the existence of different genetic populations along the Caspian Sea coast (Guilan Province).Key words: Population genetic, Southwest Caspian Sea, microsatellite, Clupeonella cultriventris
Mycobacterium tuberculosis Detection based on mpt64 amplification by Nested-PCR in Sputum samples
Introduction: Tuberculosis (TB) is an old problem that is currently considered as a great challenge, mostly in developing countries. It may be a lethal disease. Thus, rapid diagnosis of Mycobacterium tuberculosis (MTB) infection plays a critical role in controlling the spread of TB, whereas conventional methods may take up to several weeks or longer to diagnose the infection. Hence, nested polymerase chain reaction (NCR) assay was applied for direct identification of the MTB DNA presence in sputum samples. The aim of the study was the development of a direct NCR method using mpt64 specific primers for rapid diagnosis of MTB infection.
Materials and Methods: To development of study, eight positive and negative sputum specimens obtained from Masih Daneshvari hospital pulmonary TB center, were studied. After smear preparation genomic DNA was extracted and mpt64 was amplified using NCR method. While doing work we paying attention to PCR standardization and precautions to avoid sample contamination.
Results: After evaluation gained appropriate results from purified genomic DNA by AGE and biophotometer, the standardized NCR products were evaluated by Agarose Gel Electrophoresis. Five of 7 positive samples were positive, and one of the negative samples was negative using our NCR assay. Conclusion: Based on the results of this study, we could be successful in the NCR technique’s optimization to our system for disese detection, while it can be apply as a more rapid, accurate, inexpensive, and specific diagnostic assay for direct detection of MTB DNA
A Low-Cost and Energy-Effcient Wearable Device For Posture Monitoring
Millions of Americans suffer every year from back problems, now imagine if there was a way to help track and prevent back problems. Our solution to this problem is PostureBot a device that will help its users to correct their back posture and maintain good back posture.In doing so this device can help elevate and prevent people from developing minor and serious back problems in their future
Gas absorption in mobile beds of spherical packings
Experiments have been conducted to investigate the hydrodynamics
and mass transfer performance of some alternative mobile bed packings.
The polypropylene packings used in this work were 50 x 38 mm oblate
spheroids, 38 mm diameter plain spheres, 25 mm diameter plain spheres
and 25 mm diameter slotted spheres.
The perspex column was 22 cm internal diameter and 144 cm high and
was fitted with a supporting grid having 72% open area.
In the hydrodynamics studies, air and water were passed counter
currently through the column. Bed pressure drop, mean expanded bed
height, minimum expanding gas velocity and volume of liquid hold up for
all of the packings were measured at different air and water rates and
with two bed static heights of 10.5 and 16.5 cm.
The general hydrodynamic behaviour of the fluidized packings has
been observed and factors influencing pressure drop, liquid hold up,
expanded bed height and minimum expanding velocity have been identified.
Evidence for gas and liquid flow through the interiors of the slotted
packings and giving rise to higher liquid hold up and a smoother quality
of fluidization as compared with the other packings has been found.
Plain spheres and oblate spheroid packings appeared to have almost
identical hydrodynamic behaviour, although the oblate spheroid was found
to show more slugging fluctuation in the bed height at high gas
veloci ti e s .
In mass transfer studies, dilute C02 (2% voV Vol) was absorbed
into sodium hydroxide solutions and the interfacial area and liquid film
transfer coefficient were thereby established employing the pseudo first
order reaction model for the rate of absorption (known generally as the
Danckwerts' model) (41).
The experimental results on the Danckwerts' plot lay on a straight
line and therefore confirmed the applicability of the Danckwerts' model
from which (kL) and (a) could be estimated.
The interfacial area per unit volume of expanded bed (a) and per
unit volume static bed (as) was found to be higher for the slotted
packings than for the plain sphere packings and the oblate spheroid
packi ngs.
The interfacial area per unit volume of liquid hold up (aL) was
higher for the plain sphere packing than for the oblate spheroid and the
slotted sphere packings, however, the (a) and (as) for the plain sphere
packings were higher than for the oblate spheroid packings.
The liquid film transfer coefficient for the slotted sphere
packings was higher than for the other packings and was found to be
almost the same for the plain sphere and the oblate spheroid packings.
The operational mass transfer efficiency (defined as the ratio of
the volumetric liquid film mass transfer coefficient to the fluid energy
consumption in the bed) for the oblate spheroid packings was found to be
higher than for the plain and slotted sphere packings. This efficiency
ratio was also found to be higher for the slotted packings than for the
plain sphere packings. Finally, the slotted packings appear to offer
high volumetric mass transfer coefficients with a smoother quality of
fluidization and homogeneous contacting of gas and liquid
The Possible Impact of Problem-solving Method of Instruction on Exceptional Students’ Creativity
The current study aimed at investigating the possible impact of the problem-solving method of instruction on the exceptional students’ creativity. A sample of 50 male exceptional (Mild intellectual disability) students studying in the third grade of junior high school was chosen and divided into two equal groups. Both groups filled out the Torrance Test of Creative Thinking (TTCT) in pre- and post-test stages. They also completed the Raven Standard Progressive Matrices (RSPM) as a covariate variable. The results of covariance analysis revealed that the mean value for creativity score was higher for the students provided with the problem-solving method of instruction than that of their counterparts provided with the traditional method of instruction while the effect of intelligence was controlled. The scores obtained for the factors including fluency, flexibility, originality, and elaboration also increased through problem-solving method of instruction
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