Fabrication of tailor-made 2D crystalline and freestanding supramolecular- and metal-organic networks : use of interfacial assembly of amphiphilic calix[4]arenes

This thesis reports new strategies for the fabrication of two-dimensional (2D) free-standing and crystalline tailor-made organic networks via bottom-up assembly of calix[4]arene organic building blocks. Three major areas of work were conducted in this project: 1- Formation of novel 2D metal-organic coordination networks (MOCNs) of calix[4]arene amphiphiles, i.e. a 2D MOCN of C3-p-carboxy-calixarene. 2- Fabrication of the first reported free-standing and crystalline linker-free 2D supramolecular organic network (SON) through dipole-dipole interactions between C3-p-me-cyano-calixarene building units. 3- In-situ synthesis of a bilayered MOCN of C3-p-me-carboxy-calixarene synthons with control over the degree of bilayer formation. The physical and chemical properties of 2D atomically ordered organic and inorganic architectures, including strong in-plane and weak out-of-plane bonding, are unique and distinct to those of the corresponding 3D structures. Thus, 2D materials have both fundamental and applied importance to various applications ranging from superconductors to catalysis.1 Rational design and synthesis of 2D hybrid frameworks that enables control over the resulting structures and functionalities can be achieved by applying the concepts of supramolecular and reticular chemistry.2 Numerous 2D supramolecular organic networks have been produced by taking advantage of non-covalent interactions between organic building units. In addition to supramolecular interactions, coordination bonds have also been employed to link organic building blocks and single metal/metal complex nodes to synthesize 2D architectures, namely 2D MOCNs.3 A wide range of possible organic and inorganic building blocks that possess coordination centers and electron donator/acceptor properties and containing various selective functional groups and catalytic centers have been used to fabricate 2D architectures with desirable structures, properties and functions.3 Several bottom-up techniques for the fabrication of 2D materials have been reported, including wet chemistry synthesis such as direct crystal growth from solvothermal solution, chemical vapor deposition, surfactant-directed synthesis and interfacial self-assembly reactions.2 In bottom-up fabrication methods, the interfaces - where the reaction happens - plays a pivotal role in the nucleation and growth of 2D materials. Interfacial self-assembly is d iii riven by reduction of the interfacial energy between the media.4 Assembly of nanomaterials at interfaces with various geometries (e.g. nanosheets) has led the development of advanced applications in many sectors such as polymer-based photovoltaic devices, magnetic data storage media, polymer composites, oil and mineral refining, coatings, detergents and pharmaceuticals.5 In spite of the great progress in the field of 2D organic networks, there is a lack of practical and versatile strategies to design, fabricate and characterize free-standing and crystalline 2D nano-architectures. The research work described in this thesis led to development of a new approach to produce free-standing and crystalline 2D organic networks of calix[4]arene amphiphilic macrocycles. This work demonstrates 2D organic networks with specific desirable properties and functions can be fabricated by tailoring the structure of the amphiphilic calix[4]arene backbone. Indeed, this technique provides precise control over the organization of the molecular building blocks down to the atomic level, i.e. enables molecular design. The first chapter of this thesis reports the first example of a 2D MOCN of calix[4]arene organic building blocks with tunable crystallinity. We show that carefully functionalized calix[4]arene macrocycles containing carboxy functional groups at the upper rim and propyl chains at the lower rim form a free-standing and crystalline MOCN upon coordination with Cu2+ ions at the air-liquid interface. The second chapter provides the first report of linker-free 2D SON that is stabilized via synergistic interactions of the dipole-dipole forces between calix[4]arene derivative building blocks. A functionalized calix[4]arene synthon bearing methyl cyano functional groups at the upper rim and propyl chains at the lower rim was designed. This amphiphilic calix[4]arene self assembles and forms a crystalline 2D SON at the air-water interface. The crystalline layer can be transferred from the interface onto a solid substrate, while maintaining the homogeneity and crystallinity of the layer. Furthermore, free-standing layers of the 2D SON exhibit high stability and can span perforated substrates with pores as large as 3 × 3 µm. Electron diffraction analysis confirmed the crystallinity of the free-standing 2D SON. The in-situ formation of a bilayered MOCN, at the air-liquid interface, from a functionalized calix[4]arene carrying methyl carboxy groups at the upper rim and propyl chains at the lower rim is reported in the third chapter. Calix[4]arene derivatives are shown to form monolayers or bilayers upon changing the transition metal ion in the subphase. In the presence of Cu2+ ions, a free-standing and crystalline MOCN bilayer forms, in which the degree of bilayer iv formation can be kinetically controlled. Substituting the Cu2+ ions with Ni2+ ions results in formation of a crystalline and free-standing monolayer of MOCN. These observations confirmed that the conformational freedom and flexibility of the modified calix[4]arene building components enable adoption of different coordination geometries in the MOCN, depending on the transition metal ion employed. These highly stable 2D calix[4]arene-based organic networks can potentially be applied as a new generation of sample supports for transmission electron microscopy imaging and X-ray analysis of single biomolecules/assemblies and single-magnetic nanoparticles. Indeed, some examples of biomolecule, assembly and nanoparticle deposition experiments on free-standing coordination networks of calix[4]arene amphiphiles are presented in this thesis. Further work is currently underway to extend this research and define advanced methods to enhance the structural analysis of single biomolecules and the magnetic properties of nanoparticles deposited on free-standing monolayers of calixarenes and related compounds. Keywords: supramolecular chemistry, reticular chemistry, 2D metal-organic coordination network, 2D supramolecular-organic network, self-assembly, Langmuir-Blodgett technique, calix[4]arene amphiphile, amphiphilic bilayers

Natural killer cell biology and its effect on graft versus host disease

Natural killer (NK) cells were originally described in terms of their function. NK cells are of lymphoid origin and are found in the peripheral blood, spleen, and bone marrow, as well as other tissues. These cells are large, radio-resistant and granular lymphocytes that represent an important arm of innate immunity and are thought to play a critical role in the immune surveillance against tumors and virally infected cells. Allogeneic bone marrow transplantation (BMT) has proven to be an effective treatment for hematologic malignancies and some solid tumors. One of the major challenges of allo-stem cell transplantation (SCT) is to reduce the incidence and severity of GVHD while boosting the graft-versus-leukemia (GVL) effect. In the setting of allo-SCT, the reconstitution of NK cells is of notable interest due to their known capability to induce GVL without GVHD. Clinical applications of NK cells have been inspired by recognition of their potent anticancer activity. These studies discussed a solid basis for development of future NK cell trials for cancer therapy by minimizing risks and toxicities

Evaluating the effects of low intensity pulsed ultrasonic waves on experimental tibial fracture healing in

چکیده: زمینه و هدف: ترمیم شکستگی یک روند بیولوژیک پیچیده است که فاکتورهای داخلی و خارجی متعددی روی آن تاثیر می گذارند. یکی از فاکتورهای خارجی، تحریکات مکانیکی امواج اولتراسوند است. هدف از انجام این مطالعه، ارزیابی اثرات اولتراسوند متناوب با شدت پایین روی شکستگی تجربی تیبیای خرگوش نیوزیلندی بود. روش بررسی: در این مطالعه تجربی تعداد 36 سر خرگوش نر بالغ نیوزیلندی را در چهار گروه قرار داده و حیوانات تحت عمل جراحی شکستگی تیبیای راست قرار گرفتند. بعد از بهبود زخم ها، محل شکستگی گروه های آزمایش بترتیب به مدت 2 و 4 هفته تحت تاثیر امواج اولتراسوند قرار داده شدند و گروه های کنترل بدون هیچگونه مداخله ای نگه داری شدند. سپس حیوانات را کشته و تیبیای آنها خارج گردید. بعد از فیکس شدن و پاساژ بافتـــی نمونه ها، از بلوک های پارافین لام تهیه گردیده و با هماتوکسیلین و آئوزین رنگ آمیزی شدند. سپس لام ها برای شاخص های ترمیم استخوان مورد آنالیز استریولوژیک قرار گرفتند و داده ها به کمک آزمون های آماری من ویتنی و کروسکال والیس مورد مقایسه قرار گرفت. یافته ها: نتایج بدست آمده از این مطالعه نشان داد میانگین تغییرات حجمی رشد کالوس غضروفی در خرگوش هایی که تحت تاثیر امواج اولتراسوند قرار داشتند در مقایسه با گروه کنترل به طور معنی داری افزایش یافته بود (05/0>P). اما در سایر شاخص ها (بافت گرانوله و بافت مزانشیمی، بافت استخوانی) اختلاف معنی دار آماری بین گروه های آزمایش و کنترل آنها مشاهده نگردید. نتیجه گیری: امواج اولتراسوند متناوب با فرکانس یک مگا هرتز ممکن است ترمیم شکستگی در تیبیای خرگوش را تسریع نماید

The Relationship Between Strategic Thinking and Hospital Managers’ Productivity in Teaching Hospitals of Shiraz

Background: Using different methods of strategic thinking is essential for organizations such as hospitals; without them, many organizations will not survive. The aim of the present study is to evaluate the relationship between strategic thinking and management productivity in teaching hospitals of Shiraz. Objectives: Because of the importance of strategic management in organizational productivity, the present study is conducted with the goal of assessing the relationship between strategic thinking and hospital managers’ productivity. Patients and Methods: This descriptive-correlational study was conducted in 2015. The statistical population included all managers in different levels in the teaching hospitals of Shiraz (170 persons). Among these, 119 participants were selected through Cochran’s formula and a simple random sampling method. Data were collected by a questionnaire addressing strategic thinking based on Liedtka’s model and Hersey and Blanchard’s theory. Its validity was verified by a panel of experts and its reliability was measured in previous studies. Data analysis was performed in SPSS version 20 using descriptive and analytic statistics (analysis of variance (ANOVA), Pearson’s correlation test and t-test). Results: The average and Standard Deviation of strategic thinking managers was (2.2 ± 0.04), and productivity of management (2.32 ± 0.37) was estimated on the average level. There was a direct meaningful relationship between strategically thinking managers and productivity (r = 0.387, P < 0.001). The results also showed that there is a meaningful correlation between strategic thinking and sustainability, organizational support and understanding of the job. Conclusions: Due to the correlation between strategic thinking and productivity, we recommend educating and training managers in the use of strategic thinking, and that they understand its importance to productivity. Managers should understand that increasing efficiency in a competitive environment today is a necessity for survival

Evaluation of Cefixime Toxicity Treated With Sono-electro-Fenton Process by Bioassay Using Microorganisms

The aim of this study was to determine the toxicity of cefixime in the inlet solution and effluent treated with the sono-electro-Fenton process using standard strains of microorganisms. This research was performed as an experimental study, which was conducted on a laboratory scale. The standard strains of Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) were used for bioassay. First, the stock solution of 1000 mg/L containing Cefixime was prepared, and for each bacterium (gram-positive and gram-negative), 5 samples from the inlet solution of the reactor and 5 samples from effluent treated with the sono-electro-Fenton process were collected under optimal conditions. Finally, each sample was transferred to 10 mL of sterile lactose broth, and a loop of E. coli or S. aureus was dissolved in each sample. Toxicity changes were investigated by calculating the percentage of growth inhibition. The results showed that after 10 hours, the growth rate of both bacteria in the control and the effluent samples was higher, while the growth of bacteria in the inlet solution was lower and had higher toxicity. Based on the results of the study, the toxicity rate for E. coli was reduced from 70% in the inlet solution to 9.3% in the effluent (86.7% reduction in toxicity), and in the case of S. aureus, it was diminished from 25.3% in the inlet solution to 7% in the effluent (72.3% reduction in toxicity) after 10 hours. Based on the results of the present study, bioassay using microorganisms is an effective and useful method to study changes in the toxicity of cefixime

Identifying Factors Affecting Beekeepers Empowerment of Alborz Province

The modern agricultural industry relies extremely on pollination, especially pollination of the major horticultural crops. Reducing bee colonies causes recognition of factors determining activity of bee colony and helps beekeepers to better understand why bee colonies are destroyed sometimes and how they should concern about beehives to breed them in proper way for producing better honey. This research aimed at identifying factors affecting empowerment of beekeepers of Alborz province. The researcher used factor analysis to determine effective factors. Population of the research was beekeepers of Alborz province in which from among them 250 individuals were selected as the sample of the study using Morgan table. Results of factor analysis showed that about 62.846% of total changes occurred in four factors including queen bee, modern packaging, population of hives, and sub-products of honey bee and organic honey production determines the empowerment of beekeeping that was studied in this research

Coordination-Driven Monolayer-to-Bilayer Transition in 2D Metal-Organic Networks

We report on monolayer-to-bilayer transitions in 2D metal−organic networks (MONs) from amphiphiles supported at the water−air interface. Functionalized calix[4]arenes are assembled through the coordination of selected transition metal ions to yield monomolecular 2D crystalline layers. In the presence of Ni(II) ions, interfacial self-assembly and coordination yields stable monolayers. Cu(II) promotes 2D coordination of a monolayer which is then diffusively reorganizing, nucleates, and grows a progressive amount of second layer islands. Atomic force microscopic data of these layers after transfer onto solid substrates reveal crystalline packing geometries with submolecular resolution as they are varying in function of the building blocks and the kinetics of the assembly. We assign this monolayer-to- bilayer transition to a diffusive reorganization of the initial monolayers owing to chemical vacancies of the predominant coordination motif formed by Cu2+ ions. Our results introduce a new dimension into the controlled monolayer-to-multilayer architecturing of 2D metal− organic networks

Specific immune responses induced by multi-epitope DNA derived from Mycobacterium tuberculosis DosR antigens

One third of the world population are latently infected with Mycobacterium tuberculosis and are at the risk of reactivation of tuberculosis (TB). The most effective strategy for control of TB worldwide is the development of a vaccine that inhibits progression of latent TB to active infection. In this study, two optimized constructs consisting of multi-epitopes DNA derived from three latency antigens Rv2029c, Rv2031c, and Rv2627c fused with or without light chain 3 (LC3) are synthetized. The immunogenicity effectiveness of two DNA constructs was evaluated in the mouse model. LC3-fused multi-epitope DNA construct induced strong specific Th1 immune responses with high increase in IFN-γ+ CD4+ and IL-2+ CD4+ T cell populations (both with p + IL-2+ CD4+ T cell population (p + CD8+ T cell population (p + and CD8+ T cell populations. The results indicated that LC3-fused multi-epitope DNA construct has a potential to be investigated for future development of a new TB vaccine

Self-Assembly and Magnetic Order of Bi-Molecular 2D Spin Lattices of M(II,III) Phthalocyanines on Au(111)

Single layer low-dimensional materials are presently of emerging interest, including in the context of magnetism. In the present report, on-surface supramolecular architecturing was further developed and employed to create surface supported two-dimensional binary spin arrays on atomically clean non-magnetic Au(111). By chemical programming of the modules, different checkerboards were produced combining phthalocyanines containing metals of different oxidation and spin states, diamagnetic zinc, and a metal-free 'spacer'. In an in-depth, spectro-microscopy and theoretical account, we correlate the structure and the magnetic properties of these tunable systems and discuss the emergence of 2D Kondo magnetism from the spin-bearing components and via the physico-chemical bonding to the underlying substrate. The contributions of the individual elements, as well as the role of the electronic surface state in the bottom substrate, are discussed, also looking towards further in-depth investigations

Development of technology to extract beta-carotene natural colors from Azolla (Azolla filiculoides)

The present project was aimed at determining the content, quality, and purity of β-carotene extracted from Azolla filiculoides in the Anzali Wetland, comparing it with synthetic β-carotene, and measuring its economic value. One treatment had β-carotene derived from Azolla filiculoides in the Anzali Wetland through the alkaline hydrolysis method in the summer of 2014. Treatments were kept at 4°C for one year. Synthetic β-carotene was used as the control. The quality of the treatments was assessed by applying some chemical tests, including the measurement of the content and quality of β-carotene, colorimetry using the Hunter-LAB method, determination of the purity and vitamin A employing high-performance liquid chromatography (HPLC), estimation of the dwell-time duration at 5°C, and measurement of the solubility of β-carotene in water. Beta carotene of Azolla in the spring extracted to alkaline hydrolysis was11853 mg/kg, in summer was 9935mg/kg, in autumn was 11256 mg/kg and in winter was 11245 mg /kg. Beta carotene of Azolla in the spring extracted to organic solvent was 8347 mg/kg, in summer was 6648 mg/kg, in autumn was 7543 mg/kg and in winter was 7539 mg/kg. The amount of beta-carotene is extracted using organic solvents and alkaline hydrolysis in the summer compared to other seasons showed a significant reduction (P0.05). The extracted amounts of beta-carotene in organic solvents compared to alkaline hydrolysis method in seasons spring, summer, autumn and winter was difference significant (P0.05). According to the harvesting Azolla of wetland is not requires special equipment and in terms of time a lot of Azolla can be harvested in a short time and also for the extraction of beta-carotene from Azolla Anzali Lagoon is not requires special equipment, too, have no economic value of raw material, does not require special conditions for growing, doubling in three days, Azolla is rich in beta-carotene, beta-carotene extraction of large quantities of small amounts of starting material, the cost of chemical materials, labor, fuel, Laboratory equipment required and the cost of importing small packages beta-carotene, beta-carotene into the country in terms of economic cost compared to the cost of imported Sigma beta carotene is economical. As shown in Table 5 in the samples prepared by alkaline hydrolysis in comparison with synthetic chemical manufactured by Sigma in terms of colorimetric tests, purity, composition and solubility of vitamins significant difference was not observed (P>0.05). But, in samples prepared by organic solvents in comparison with synthetic chemical manufactured by Sigma in terms of colorimetric tests, purity, composition and solubility of vitamins significant difference was observed (P<0.05). According to significant differences between the amount of betacarotene extracted from Azoula wetland compared to other seasons in spring and autumn and winter plant growth in spring Azoula alkaline hydrolysis method for the extraction of beta-carotene wetland and wetland Azolla is recommended