Articoli di riviste: "Macro-initiator"

1

Nakamura, Kohki, Keiji Fujimoto e Haruma Kawaguchi. "Dispersion polymerization of methyl methacrylate using macro-azo-initiator". Colloids and Surfaces A: Physicochemical and Engineering Aspects 153, n. 1-3 (agosto 1999): 195–201. http://dx.doi.org/10.1016/s0927-7757(98)00531-7.

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Xu, Yuan Qing, Tao Ding, Xiao Min Fang, Hao Xu e Yan Rong Ren. "Living Radical Polymerization of Methyl Methacrylate Mediated by Tris-(4-Acetyphenyl)Methane". Advanced Materials Research 933 (maggio 2014): 91–96. http://dx.doi.org/10.4028/www.scientific.net/amr.933.91.

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Abstract (sommario):

Pseudo-living radical polymerization and reverse atom transfer radical polymerization (RATRP) of methyl methacrylate (MMA) were reported, utilizing tris-(4-acetyphenyl) methane (TAcPM) as the thermal iniferter and initiator, respectively. The polymerization of MMA using TAcPM as thermal iniferter possesses pseudo-living characteristics: Mnincreases with conversion in a certain range, and the resulted polymer can be used as the macro-initiator for chain extension. The RATRP using TAcPM as the initiator shows linear kinetic plot, linear increase of Mnwith conversion and narrow polydispersity indice (PDI) of the resultant polymers.

3

Xu, Yuan Qing, Xiao Min Fang, Tao Ding e Yan Rong Ren. "Living Radical Polymerizations of Methyl Methacrylate Mediated by Tris-(4-Carboxyphenyl) Methane". Advanced Materials Research 631-632 (gennaio 2013): 3–8. http://dx.doi.org/10.4028/www.scientific.net/amr.631-632.3.

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Pseudo-living radical polymerization and reverse atom transfer radical polymerization (RATRP) of methyl methacrylate (MMA) were reported, utilizing tris-(4-carboxyphenyl)methane (TCOPM) as the thermal iniferter and initiator, respectively. The polymerization of MMA using TCOPM as thermal iniferter possesses pseudo-living characteristics: Mn increases with conversion in a certain range, and the resulted polymer can be used as the macro-initiator for chain extension. The RATRP using TCOPM as the initiator shows linear kinetic plot, linear increase of Mn with conversion and narrow polydispersity indice (PDI) of the resultant polymers. Effects of temperature on both polymerizations were investigated.

4

Handayani, Aniek S., Is Sulistyati Purwaningsih, Muhamad Chalid, Emil Budianto e Dedi Priadi. "Synthesis of Amylopectin Macro-Initiator for Graft Copolymerization of Amylopectin-g-Poly(Methyl Methacrylate) by ATRP (Atom Transfer Radical Polymerization)". Materials Science Forum 827 (agosto 2015): 306–10. http://dx.doi.org/10.4028/www.scientific.net/msf.827.306.

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Graft copolymer of Amylopectin and PMMA was synthesized by atom transfer radical polymerization (ATRP) method. The hydroxyl groups of amylopectin partially substituted with tert-butyl a-bromoisobutyrate to form tert-butyl a-bromoisobutyrate (TBBiB ) groups. This compound is known as an efficient macro-initiator for ATRP process. This research, aimed to obtain a bio based polymer of Amylopectin, in which the amylopectin was used as macro-initiator in the ATRP of MMA. The experiment was carried out in the homogeneous system under temperature range of 40 – 70°C in DMSO solution using TEA as catalyst. The modified amylopectin-TBBiB then was grafted to methyl methacrylate trough ATRP. Product characterization indicates that the graft copolymer Amylopectin-g-PMMA is efficient and the obtained product owns well defined structures

5

Kovačič, Sebastijan, e Christian Slugovc. "Ring-opening Metathesis Polymerisation derived poly(dicyclopentadiene) based materials". Materials Chemistry Frontiers 4, n. 8 (2020): 2235–55. http://dx.doi.org/10.1039/d0qm00296h.

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This review article summarises the academic work in the fields of initiator development, polymer chemistry and physics, composites, self-healing composites, novel processing opportunities and macro-as well as microporous materials.

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Shen, Shao Hua, Ying Xiang Duan, Qing Quan Liu e Qiu Guao Xiao. "Preparation and Characterization of Poly (vinylbenzyl chloride)-b-poly (lactide) Copolymers via Nitroxide-Mediated Controlled Radical and Ring-Opening Polymerization". Advanced Materials Research 554-556 (luglio 2012): 295–98. http://dx.doi.org/10.4028/www.scientific.net/amr.554-556.295.

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Hydroxyl-terminated poly(vinylbenzyl chloride) (PVBCOH) were synthesized using nitroxide-mediated controlled radical polymerization. Then, PVBCOH was used as a macro-initiator for ring-opening polymerization of lactide (LA) in the presence of stannous octanoate (Sn(Oct)2) as a catalyst. The structures, molecular weights and polydispersity index (PDI) of PVBCOH and PVBC-b-PLA were characterized by 1H-NMR, and GPC, respectively. The results indicated that PDI of PVBCOH and PVBC-b-PLA was 1.63 and 1.27, respectively. Moreover, the molecular weight and PDI of PVBCOH and PVBC-b-PLA could be well tuned by changing monomer-to-initiator ratio.

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Chalid, Mochamad, Aniek Sri Handayani e Emil Budianto. "Functionalization of Starch for Macro-Initiator of Atomic Transfer Radical Polymerization (ATRP)". Advanced Materials Research 1051 (ottobre 2014): 90–94. http://dx.doi.org/10.4028/www.scientific.net/amr.1051.90.

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Using of petro-polymers such as polymethylmethacrylate, polypropylene and polyethylene in the world has been undergoing a critical problem due to significantly decreasing of petroleoum stock as monomer sources. Therefore reducing of the petro-polymer usage should be performed by using natural resources such as modified starches.This study reported addition of an acyl bromide compound to substitute hydroxyl groups on the starch obtains a macro initiator for graft-copolymerizing polymethylmethacrylate (PMMA) onto the functionalized starch as starch-g-PMMA through atomic transfer radical polymerization (ATRP) method. The starch activation through the substitution of the hydroxyl functional group creates ability of the starch to transfer a radical atom onto a petro-monomer such an alkylmethacrylate which furthermore polymerize into starch-g-PMMA at mild condition. This paper reported study of the starch activation describing about screening catalysts and acyl bromide compounds, optimizing process variables such as amount ratio of a selected acyl bromide compound to starch and temperature. The functionalized starchs were analysed by 13-CNMR, FTIR, titration and their morphology was observed by FE-SEM.

8

Liu, Xiaohong, Ming Li, Xuemei Zheng, Elias Retulainen e Shiyu Fu. "Dual Light- and pH-Responsive Composite of Polyazo-Derivative Grafted Cellulose Nanocrystals". Materials 11, n. 9 (14 settembre 2018): 1725. http://dx.doi.org/10.3390/ma11091725.

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As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.

9

Hazer, Baki, Elif Ayyıldız e Faruk Bahadır. "Synthesis of PNIPAM–PEG Double Hydrophilic Polymers Using Oleic Acid Macro Peroxide Initiator". Journal of the American Oil Chemists' Society 94, n. 9 (19 luglio 2017): 1141–51. http://dx.doi.org/10.1007/s11746-017-3020-0.

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Aswale, Suraj, Minji Kim, Dongwoo Kim, Aruna Kumar Mohanty, Heung Bae Jeon, Hong Y. Cho e Hyun-jong Paik. "Synthesis and Characterization of Spirocyclic Mid-Block Containing Triblock Copolymer". Polymers 15, n. 7 (28 marzo 2023): 1677. http://dx.doi.org/10.3390/polym15071677.

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Polymers containing cyclic derivatives are a new class of macromolecular topologies with unique properties. Herein, we report the synthesis of a triblock copolymer containing a spirocyclic mid-block. To achieve this, a spirocyclic polystyrene (cPS) mid-block was first synthesized by atom transfer radical polymerization (ATRP) using a tetra-functional initiator, followed by end-group azidation and a copper (I)-catalyzed azide-alkyne cycloaddition reaction. The resulting functional cPS was purified using liquid chromatography techniques. Following the esterification of cPS, a macro-ATRP initiator was obtained and used to synthesize a poly (methyl methacrylate)-block-cPS-block-poly (methyl methacrylate) (PMMA-b-cPS-b-PMMA) triblock copolymer. This work provides a synthetic strategy for the preparation of a spirocyclic macroinitiator for the ATRP technique and as well as liquid chromatographic techniques for the purification of (spiro) cyclic polymers.

11

Lou, Yu, Dong Jian Shi, Wei Fu Dong e Ming Qing Chen. "Synthesis and Self-Assemble Behavior of Block Copolymerization of Vinyl Acetate and N-Vinylacetamide". Advanced Materials Research 645 (gennaio 2013): 10–14. http://dx.doi.org/10.4028/www.scientific.net/amr.645.10.

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Polymerizations of VAc was carried out using AIBN as the initiator and DIP as the MADIX agent precursor. Then, block copolymer PVAc-b-PNVA had been synthesized by RAFT radical polymerization in the presence of PVAc-DIP as macro CTA. The length of blocks could be tuned by changing the molar ratio of NVA and VAc. Block copolymer PVAc-b-PNVA self-assembled into micelles in solution, and underwent microphase separation in bulk state.

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Myrzakhanov, M. M., El-Sayed Negim, Mohammad Nasir e K. M. Azzam. "Synthesis and application of nonionic graft copolymers P(mPEG-g-MMA)". Kompleksnoe Ispolʹzovanie Mineralʹnogo syrʹâ/Complex Use of Mineral Resources/Mineraldik Shikisattardy Keshendi Paidalanu 1, n. 324 (6 settembre 2022): 64–70. http://dx.doi.org/10.31643/2023/6445.09.

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The goal of this research is to prepare novel amphiphilic graft copolymers (nonionic) based on hydrophilic poly (ethylene glycol) methyl ether (mPEG) and hydrophobic methyl methacrylate (MMA) at room temperature and pressure. To generate P(mPEG-g-MMA) grafts, poly (ethylene glycol) methyl ether (mPEG) was synthesized and grafted with varied ratios of methyl methacrylate (MMA) in the existence of benzoyl peroxide as an initiator utilizing a macro-free radical initiator procedure under the effect of heating in toluene. The research discussed in this paper looked at the possibility of using the synthesized graft copolymer P(mPEG-g-MMA) as a nonionic demulsifier in Petroleum Crude Oil Emulsions. The produced nonionic surfactants were assessed as water demulsifiers in oil emulsions that were noticeable at varying oil: water ratios at 60oC. According to the demulsifier chemical compositions as well as concentrations, the testing findings revealed that the dehydration rate of the prepared demulsifiers reached 100%. The optimal demulsifier dose was 300 ppm.

13

UEDA, Akira, Masayuki SHIMADA, Yasuyuki AGARI e Susumu NAGAI. "Synthesis of Poly(vinylpyrrolidone)-Polystyrene Block Copolymers by the Use of a Macro-Azo-Initiator." KOBUNSHI RONBUNSHU 51, n. 7 (1994): 453–58. http://dx.doi.org/10.1295/koron.51.453.

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Singh, Shane P., e Jaroslav Tir. "Partisanship, Militarized International Conflict, and Electoral Support for the Incumbent". Political Research Quarterly 71, n. 1 (16 settembre 2017): 172–83. http://dx.doi.org/10.1177/1065912917727369.

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Comparative politics scholarship often neglects to consider how militarized interstate disputes (MIDs) shape political behavior. In this project, we advance an argument that considers voter responses to international conflict at the individual level. In particular, we consider how the well-known conditioning effects of partisanship manifest in relation to militarized international conflict. Examining individual- and macro-level data across ninety-seven elections in forty-two countries over the 1996–2011 period, we find consistent evidence of militarized conflict impacting vote choice. This relationship is, however, moderated by partisanship, conflict side (initiator or target), and conflict hostility level. Among non-copartisan voters, the incumbent benefits the most electorally from initiating low-hostility MIDs or when the country is a target of a high-hostility MID; the opposite scenarios (initiator of a high-hostility MID or target of a low-hostility MID) lead to punishment among this voter group. Copartisans, meanwhile, tend to either maintain or intensify their support in most scenarios we examine; when a country is targeted in a low-hostility MID, copartisan support erodes mildly.

15

XU Qi, 徐奇, 周宗明 ZHOU Zong-ming, 张玉良 ZHANG Yu-liang e 汪映寒 WANG Ying-han. "Effect of Main-Chain Flexibility of Macro-Initiator on Electro-Optical Properties of Polymer Dispersed Liquid Crystal". Chinese Journal of Liquid Crystals and Displays 28, n. 4 (2013): 484–89. http://dx.doi.org/10.3788/yjyxs20132804.0484.

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Tsunematsu, Hiroki, Junpei Miyake, Junji Watanabe e Yoshiyuki Ikeda. "Synthesis of a Macro-initiator Based on Poly(trimethylene carbonate) and Its Functionalization toward Living Radical Polymerization". Transactions of the Materials Research Society of Japan 36, n. 4 (2011): 561–64. http://dx.doi.org/10.14723/tmrsj.36.561.

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Park, Hee-Woong, Hyun-Su Seo, Kiok Kwon, Jung-Hyun Lee e Seunghan Shin. "Enhanced Heat Resistance of Acrylic Pressure-Sensitive Adhesive by Incorporating Silicone Blocks Using Silicone-Based Macro-Azo-Initiator". Polymers 12, n. 10 (19 ottobre 2020): 2410. http://dx.doi.org/10.3390/polym12102410.

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To improve the heat resistance of acrylic-based pressure-sensitive adhesive (PSA), silicone-block-containing acrylic PSAs (SPSAs) were synthesized using a polydimethylsiloxane (PDMS)-based macro-azo-initiator (MAI). To evaluate the heat resistance of the PSA films, the probe tack and 90° peel strength were measured at different temperatures. The acrylic PSA showed that its tack curves changed from balanced debonding at 25 °C to cohesive debonding at 50 °C and exhibited a sharp decrease. However, in the case of SPSA containing 20 wt% MAI (MAI20), the balanced debonding was maintained at 75 °C, and its tack value hardly changed with temperature. As the MAI content increased, the peel strength at 25 °C decreased due to the microphase separation between PDMS- and acryl-blocks in SPSA, but the shear adhesion failure temperature (SAFT) increased almost linearly from 41.3 to 122.8 °C. Unlike stainless steel substrate, SPSA showed improved peel strength on a polypropylene substrate due to its low surface energy caused by PDMS block. Owing to the addition of 20 wt% silicone-urethane dimethacrylate oligomer and 200 mJ/cm2 UV irradiation dose, MAI20 showed significantly increased 90° peel strength at 25 °C (548.3 vs. 322.4 gf/25 mm for pristine MAI20). Its heat resistance under shear stress assessed by shear adhesion failure test (SAFT) exhibited raising in failure temperature to 177.3 °C when compared to non-irradiated sample.

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Kumar, Dinesh, A. K. Saikia, Bikramjit Kaur e Uttam Kumar Mandal. "Preparation of Thermoresponsive Nanosize Magnetic Hydrogel in In-Situ Polymerization of N-Isopropylacrylamide Using PEG as Macro-Initiator". Advanced Science, Engineering and Medicine 9, n. 10 (1 ottobre 2017): 803–9. http://dx.doi.org/10.1166/asem.2017.2067.

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Quilitzsch, M., e M. Ulbricht. "Low-Fouling UF Membranes for Water Treatment by Surface Modification with Hydrogel Layers via a New Macro-Initiator". Procedia Engineering 44 (2012): 1521–22. http://dx.doi.org/10.1016/j.proeng.2012.08.852.

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Wang, Guohao, e Liying Yu. "Analysis of Enterprise Sustainable Crowdsourcing Incentive Mechanism Based on Principal-Agent Model". Sustainability 12, n. 8 (16 aprile 2020): 3238. http://dx.doi.org/10.3390/su12083238.

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The utilization of crowdsourcing to acquire distant knowledge is increasing. In the new product development process, sustainable crowdsourcing is an effective way to exploit both external and internal resources to boost enterprise innovation quality and the efficiency of the competitive edge of macro tasks in a relatively long cycle. The challenge of sustainable crowdsourcing is how to design a proper incentive mechanism to achieve the maximum initiator profit and, at the same time, satisfy the solver’s motivation so that they can continuously participate in the innovation process. In two situations, including a single motivation and multiple motivations of the solver, this paper analyzed the impact of a few factors on the initiator’s profit and the incentive coefficient for the solver based on the Principal–Agent Model. From the model and simulation results, the solver’s incentive coefficient is positively correlated to the solver’s work quality and negatively correlated to the uncertainty of the enterprise operation, the solver’s Effort Cost, the solver’s degree of risk aversion, etc. If the initiator is more sensitive to the benefits of the solver’s intrinsic motivation, the monetary incentive will be higher. The research results provide a theoretical basis to quantify the initiator’s expected profit and design a proper incentive plan for the solver. Finally, the conclusions offer practical guidance for enterprise to execute incentive plans for sustainable crowdsourcing from the perspective of the solver’s motivation.

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Robles Grana, Alvaro Leonel, Hortensia Maldonado-Textle, José Román Torres-Lubián, Claude St Thomas, Ramón Díaz de León, José Luis Olivares-Romero, Luis Valencia e Francisco Javier Enríquez-Medrano. "Controlled (Co)Polymerization of Methacrylates Using a Novel Symmetrical Trithiocarbonate RAFT Agent Bearing Diphenylmethyl Groups". Molecules 26, n. 15 (30 luglio 2021): 4618. http://dx.doi.org/10.3390/molecules26154618.

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Herein, we report a novel type of symmetrical trithiocarbonate chain transfer agent (CTA) based diphenylmethyl as R groups. The utilization of this CTA in the Reversible Addition-Fragmentation chain Transfer (RAFT) process reveals an efficient control in the polymerization of methacrylic monomers and the preparation of block copolymers. The latter are obtained by the (co)polymerization of styrene or butyl acrylate using a functionalized macro-CTA polymethyl methacrylate (PMMA) previously synthesized. Data show low molecular weight dispersity values (Đ < 1.5) particularly in the polymerization of methacrylic monomers. Considering a typical RAFT mechanism, the leaving groups (R) from the fragmentation of CTA should be able to re-initiate the polymerization (formation of growth chains) allowing an efficient control of the process. Nevertheless, in the case of the polymerization of MMA in the presence of this symmetrical CTA, the polymerization process displays an atypical behavior that requires high [initiator]/[CTA] molar ratios for accessing predictable molecular weights without affecting the Đ. Some evidence suggests that this does not completely behave as a common RAFT agent as it is not completely consumed during the polymerization reaction, and it needs atypical high molar ratios [initiator]/[CTA] to be closer to the predicted molecular weight without affecting the Đ. This work demonstrates that MMA and other methacrylic monomers can be polymerized in a controlled way, and with “living” characteristics, using certain symmetrical trithiocarbonates.

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Hui, Jia, Yan Shi e Zhi Feng Fu. "Synthesis and Characterization of well Defined Polychloroprene by RAFT Polymerization". Advanced Materials Research 787 (settembre 2013): 241–44. http://dx.doi.org/10.4028/www.scientific.net/amr.787.241.

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Well defined polychloroprene has been synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization with 2-(ethoxycarbonyl) prop-2-yl dithiobenzoate (EPDTB) as RAFT agent, AIBN as initiator, Chloroprene as monomer. Polymerization with two different feed ratios of monomer to RAFT agent were carried out. The sampling products at different reaction times were characterized using GPC and 1H-NMR. The GPC results demonstrated the molecular weight distributions (Mw/Mn) were narrow, and the number average molecular weight (Mn) was developed linearly with monomer conversion. All the characteristic signals of polychloroprene with the EPDTB as terminal groups were clearly observed in the 1H-NMR spectrum. In addition, the chain-extended polymers were also obtained successfully using the macro-RAFT agent, which indicated the active nature of the chain end.

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Nguyen, Duc, Vien T. Huynh, Algirdas K. Serelis, Tim Davey, Olga Paravagna, Chris H. Such e Brian S. Hawkett. "Janus particles by simplified RAFT-based emulsion polymerization process for polymer coating". Colloid and Polymer Science 300, n. 4 (11 gennaio 2022): 341–49. http://dx.doi.org/10.1007/s00396-021-04939-x.

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AbstractWe describe a simplified method to synthesize film forming polymer Janus particles by phase separation during RAFT-based free radical emulsion polymerization. Fully crosslinked snowman- or football-shaped polystyrene Janus particles (PSJPs) were first produced in a one-step batch process using amphiphilic triblock macro-RAFT copolymers as stabilizers. Such particles were in turn employed as seeds in a continuous emulsion polymerization in which a monomer mixture of methyl methacrylate (MMA) and butyl acrylate (BA) (1/1 by weight) was constantly injected into the reaction in the presence of a water soluble initiator. The added monomers wetted seed particle surface and their polymerization led to formations of 93-nm film forming single- or two-headed Janus particles. The resulted latex was successfully used to disperse and encapsulate solid calcite extender. Graphical abstract

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Wei, Qiangbing, Xiaolong Wang e Feng Zhou. "A versatile macro-initiator with dual functional anchoring groups for surface-initiated atom transfer radical polymerization on various substrates". Polymer Chemistry 3, n. 8 (2012): 2129. http://dx.doi.org/10.1039/c2py20148h.

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Kim, Keon Hyeong, Jungahn Kim e Won Ho Jo. "Preparation of hydrogel nanoparticles by atom transfer radical polymerization of N-isopropylacrylamide in aqueous media using PEG macro-initiator". Polymer 46, n. 9 (aprile 2005): 2836–40. http://dx.doi.org/10.1016/j.polymer.2005.02.009.

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Schmücker, Simon, e Dirk Kuckling. "Stimuli-responsive coil-rod-coil block copolymers synthesized by using a bis-alkoxyamine-functionalized poly(para-phenylene) macro initiator". European Polymer Journal 85 (dicembre 2016): 363–74. http://dx.doi.org/10.1016/j.eurpolymj.2016.10.042.

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Zhang, Yu-liang, Ai-lin Qin e Ying-han Wang. "EFFECT OF MOLECULAR WEIGHT OF MACRO-INITIATOR ON ELECTRO-OPTICAL PROPERTIES OF POLYMER DISPERSED LIQUID CRYSTAL BASED ON GRAFT POLYMERS". Acta Polymerica Sinica 012, n. 5 (4 luglio 2012): 534–38. http://dx.doi.org/10.3724/sp.j.1105.2012.11255.

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Uyanik, Nursel? "Synthesis and characterization of five-block copolymers prepared by vinyl pyrrolidinone and a macro initiator with poly(dimethylsiloxane) and polycaprolactone". Journal of Applied Polymer Science 64, n. 10 (6 giugno 1997): 1961–69. http://dx.doi.org/10.1002/(sici)1097-4628(19970606)64:10<1961::aid-app11>3.0.co;2-0.

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Komjaty, Andrei, Elena Stela Wisznovszky (Muncut) e Lavinia Ioana Culda. "Study on the influence of technological parameters on 3D printing with sla technology". MATEC Web of Conferences 343 (2021): 01003. http://dx.doi.org/10.1051/matecconf/202134301003.

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The influence of the technological parameters of the printing through the SLA (Stereolithography) technology is presented. This printing technology is based on the use of a photosensitive resin, which polymerizes in contact with UV rays with a wavelength of 405nm. An Anycubic Photon Mono printer is used, on which parts are printed, in which the dimensional accuracy and the condition of the resulting surfaces will be analyzed. It will study the influence of the polymerization time of the resin (5s - 10s), of the advance step between the successively deposited layers (0.05mm - 0.2mm), as well as the influence of the placement positioning of the reference mark for printing. A Black basic type, monomer with photo-initiator photosensitive resin will be used made by Anycubic,. A Sony alpha 37 DSLR camera with Sony SAL-100M28 100mm F / 2.8 AF Macro lens will be used to capture images for the resulting surfaces.

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Gao, Jie, e Guangqun Zhai. "Poly(tertiary amine) as a surface-active multifunctional macro-initiator in Cu2+–amine redox-initiated radical emulsion polymerization of methyl methacrylate". Polymer Bulletin 76, n. 7 (8 ottobre 2018): 3403–22. http://dx.doi.org/10.1007/s00289-018-2534-4.

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Saikia, Ajoy Kumar, e Uttam Kumar Mandal. "A COMPARATIVE STUDY OF PARTICLES CHARACTERISTICS, TEMPERATURE SENSITIVITY AND MORPHOLOGY OF PEG/POLY (NIPAM-CO-AMPS) MICROGELS". Journal of Advanced Scientific Research 13, n. 01 (10 febbraio 2022): 252–62. http://dx.doi.org/10.55218/jasr.202213129.

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The temperature sensitive copolymer of microsize hydrogels consist of N-isopropylacrylamide (NIPAM) and 2- acrylamido-2 methylpropanesulphonic acid (AMPS) have been synthesized by soap free emulsion polymerization method in the presence of polyethylene glycol (PEG) as macro initiator and N, N´-methylenebisacrylamide (NMBA) as crosslinker. In this work, Dynamic Light Scattering (DLS), Transmission Electron Microscope (TEM) and Atomic Force Microscope (AFM) technique were used for structural analysis of microgels. It was found that particle size observed by TEM and AFM were spherical with a diameter around 103.0 nm to 133.1 nm and 121.1 nm to 189.0 nm. While DLS measurement shows narrow particle size distribution with hydrodynamic diameter from 343.6nm to 528 nm at a temperature 25°C and 132.5nm to 414.4nm at temperature 50°C depending on the AMPS content in Microgels samples. The surface roughnesses of particles were observed to be increasing with increased AMPS content. Moreover, decrease in hydrodynamic diameter from 25°C to 50°C revealed the temperature sensitivityproperty of microgels.

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Mohamed, Mohamed Gamal, Wei-Shih Hung, Ahmed F. M. EL-Mahdy, Mahmoud M. M. Ahmed, Lizong Dai, Tao Chen e Shiao-Wei Kuo. "High-Molecular-Weight PLA-b-PEO-b-PLA Triblock Copolymer Templated Large Mesoporous Carbons for Supercapacitors and CO2 Capture". Polymers 12, n. 5 (23 maggio 2020): 1193. http://dx.doi.org/10.3390/polym12051193.

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High-molecular-weight PLA440-b-PEO454-b-PLA440 (LEL) triblock copolymer was synthesized through simple ring-opening polymerization (ROP) by using the commercial homopolymer HO-PEO454-OH as the macro-initiator. The material acted as a single template to prepare the large mesoporous carbons by using resol-type phenolic resin as a carbon source. Self-assembled structures of phenolic/LEL blends mediated by hydrogen bonding interaction were determined by FTIR and SAXS analyses. Through thermal curing and carbonization procedures, large mesoporous carbons (>50 nm) with a cylindrical structure and high surface area (>600 m2/g) were obtained because the OH units of phenolics prefer to interact with PEO block rather than PLA block, as determined by FTIR spectroscopy. Furthermore, higher CO2 capture and good energy storage performance were observed for this large mesoporous carbon, confirming that the proposed approach provides an easy method for the preparation of large mesoporous materials.

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Quilitzsch, Mathias, Ronald Osmond, Michaela Krug, Martin Heijnen e Mathias Ulbricht. "Macro-initiator mediated surface selective functionalization of ultrafiltration membranes with anti-fouling hydrogel layers applicable to ready-to-use capillary membrane modules". Journal of Membrane Science 518 (novembre 2016): 328–37. http://dx.doi.org/10.1016/j.memsci.2016.07.007.

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El-Fattah, Ahmed Abd, Elizabeth Grillo Fernandes, Federica Chiellini e Emo Chiellini. "Amphiphilic Pentablock Copolymers Prepared from Pluronic and ε-Caprolactone by Enzymatic Ring Opening Polymerization". International Journal of Molecular Sciences 23, n. 3 (26 gennaio 2022): 1390. http://dx.doi.org/10.3390/ijms23031390.

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Amphiphilic copolymers are appealing materials because of their interesting architecture and tunable properties. In view of their application in the biomedical field, the preparation of these materials should avoid the use of toxic compounds as catalysts. Therefore, enzymatic catalysis is a suitable alternative to common synthetic routes. Pentablock copolymers (CUC) were synthesized with high yields by ring-opening polymerization of ε-caprolactone (ε-CL) initiated by Pluronic (EPE) and catalyzed by Candida antarctica lipase B enzyme. The variables to study the structure–property relationship were EPEs’ molecular weight and molar ratios between ε-CL monomer and EPE macro-initiator (M/In). The obtained copolymers were chemically characterized, the molecular weight determined, and morphologies evaluated. The results suggest an interaction between the reaction time and M/In variables. There was a correlation between the differential scanning calorimetry data with those of X-ray diffraction (WAXD). The length of the central block of CUC copolymers may have an important role in the crystal formation. WAXD analyses indicated that a micro-phase separation takes place in all the prepared copolymers. Preliminary cytotoxicity experiments on the extracts of the polymer confirmed that these materials are nontoxic.

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Xin, Ting-Ting, Tongqi Yuan, Shu Xiao e Jing He. "Synthesis of cellulose-graft-poly(methyl methacrylate) via homogeneous ATRP". BioResources 6, n. 3 (20 giugno 2011): 2941–53. http://dx.doi.org/10.15376/biores.6.3.2941-2953.

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Cellulose-graft-poly(methylmethacrylate) (cellulose-g-PMMA) copolymers were prepared by homogeneous atom transfer radical polymerization (ATRP) under mild conditions, in an attempt to develop an efficient way to modify the surface of cellulose. A cellulose macro-initiator was successfully synthesized by direct homogeneous acylation of cellulose with 2-bromopropionyl bromide in a room temperature ionic liquid (RTIL), 1-allyl-3-methylimidazolium chloride ([AMIM]Cl). Copolymers were obtained via ATRP of methyl methacrylate (MMA) with CuBr/penta-methyldiethylenetriamine (PMDETA) as catalyst and N,N-dimethyl-formamide (DMF) as solvent without homopolymer byproduct. The grafting copolymers were characterized by 1H-NMR, 13C-NMR, and FTIR. The grafted PMMA chain was obtained by the hydrolysis of the cellulose backbone and analyzed by GPC and TGA measurements. In addition, the assemblies or aggregates formed by cellulose-g-PMMA copolymers were studied by means of TEM and AFM. The results indicated that the graft polymerization occurred from the cellulose backbone and the obtained copolymers had grafted polymer chains with well-controlled molecular weight and polydispersity; the cellulose graft copolymer in solution could aggregate and self-assemble into sphere-like structures.

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Fortună, Maria E., Elena Ungureanu, Răzvan Rotaru, Alexandra Bargan, Ovidiu C. Ungureanu, Carmen O. Brezuleanu e Valeria Harabagiu. "Synthesis and Properties of Modified Biodegradable Polymers Based on Caprolactone". Polymers 15, n. 24 (17 dicembre 2023): 4731. http://dx.doi.org/10.3390/polym15244731.

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In this paper, the synthesis and characterization of two polycaprolactone-polydimethylsiloxane (PDMS-CL) copolymers with biodegradable properties are reported. A comparative study was carried out using an aminopropyl-terminated polydimethylsiloxane macro-initiator (APDMS) with two different molecular weights. The copolymers (PDMS-CL-1 and PDMS-CL-2) were obtained by ring-opening polymerization of ɛ-caprolactone using APDMS as initiators and stannous 2-ethylhexanoate as a catalyst. The copolymer’s structures were confirmed by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H-NMR) spectra, and energy dispersion spectroscopy (EDX). Surface morphology was investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The hydrophobic properties of the copolymers were demonstrated by the water contact angle and water vapor sorption capacity. Additionally, biological tests were conducted on San Marzano type tomato plants (Lypercosium esculentum) to assess the synthesized copolymers’ susceptibility to the environment in terms of biological stability and metabolic activity. The biodegradation of PDMS-CL-1 and PDMS-CL-2 copolymers does not have a dangerous effect on the metabolic activity of plants, which makes it a convenient product in interaction with the environment.

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Kitov, V. A. "PIONEER OF INFORMATION SCIENCE AND CYBERNETICS <i>ON THE 100TH ANNIVERSARY OF THE BIRTH OF ACADEMICIAN V.M. GLUSHKOV</i>". Вестник Российской академии наук 93, n. 10 (1 ottobre 2023): 996–1005. http://dx.doi.org/10.31857/s0869587323100079.

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The article is devoted to the life and work of the outstanding Soviet scientist, pioneer of informatics and cybernetics, initiator of the development of a nationwide automated management information system, Academician of the Academy of Sciences of the USSR Viktor Mikhailovich Glushkov (1923–1982). The author tells about the main stages of his biography, focusing on the scientific achievements: the solution of the fifth generalized Hilbert problem, the creation of the USSR’s largest Institute of Cybernetics of the Academy of Sciences of the Ukrainian SSR, the development of the theory of digital automata, the first personal computers for engineering calculations, the most powerful supercomputers in the USSR with a new macro-pipeline architecture, contribution to cybernetics and computer science, programming theory and systems of algorithmic algebras, to the creation of artificial intelligence systems. Attention is paid to the role of V.M. Glushkov as an ideologist and one of the creators of the industry of management information systems in the USSR, scientific director of large industrial management information systems. Particular attention is paid to the National Automated System for the Collection and Processing of Information proposed by him for accounting, planning and management of the national economy.

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Zenati, Athmen, e Yang-Kyoo Han. "Synthesis and characteristics of novel azo-based diblock copolymers and their self-assembly behavior via solvents and thermal annealing". e-Polymers 17, n. 6 (26 ottobre 2017): 523–35. http://dx.doi.org/10.1515/epoly-2017-0042.

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AbstractA series of azo-based diblock copolymers (DBCs) with various compositions were successfully synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization in anisole with PCAEMA-CTA (macro-CTA), DOPAM (new acrylamide monomer) and AIBN (initiator). Kinetic studies on diblock copolymerization manifested a controlled/living manner with good molecular weight control. Structures and properties of monomers and DBCs were determined by 1H nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). Liquid crystalline (LC) phases and morphological properties were investigated using optical polarizing microscope (OPM), atomic force microscopy (AFM), scanning electron microscopy (SEM) and small-angle X-ray scattering (SAXS). Experimental results demonstrated that the prepared PCAEMA-CTA and DBCs possessed low polydispersity index (≤1.37). All DBCs revealed sharp endothermic transition peaks corresponding to the smectic-to-nematic phase. DBCs with high azo contents showed batonnet textures of the smectic phase whereas DBCs of low azo segments displayed threaded textures of the nematic phase. DBC with 49 wt% of azo side-chains generated a lamellar compared to DBCs with low azo block (≤41 wt%) or non-azo block (≤38 wt%) which produced hexagonal-type nanostructures. In addition, all DBCs exhibited reversible trans-cis photoisomerization behavior under UV irradiation and dark storage at different intervals of time.

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Zioło, Aleksandra, Beata Mossety-Leszczak, Małgorzata Walczak, Beata Strachota, Adam Strachota, Kamil Awsiuk, Natalia Janiszewska e Joanna Raczkowska. "Synthesis and Morphology Characteristics of New Highly Branched Polycaprolactone PCL". Molecules 29, n. 5 (24 febbraio 2024): 991. http://dx.doi.org/10.3390/molecules29050991.

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A simple and efficient method for the synthesis of biodegradable, highly branched polycaprolactone (PCL) is presented. The solvent-free (bulk) reaction was carried out via ring opening polymerization (ROP), catalyzed by tin octanoate Sn(Oct)2, and it employed hyperbranched polyamide (HPPA) as a macro-initiator. The core–shell structure of the obtained products (PCL-HPPA), with the hyperbranched HPPA core and linear PCL chains as shell, was in the focus of the product characterization. 1H nuclear magnetic resonance (1H NMR) and elemental analysis confirmed the covalent incorporation of the HPPA in the products, as well as a high degree of grafting conversion of its amino functional groups. Confocal Raman Micro spectroscopy, and especially Time-of-Flight Secondary Ion Mass Spectrometry, further supported the existence of a core–shell structure in the products. Direct observation of macromolecules by means of cryogenic transmission electron microscopy, as well as gel permeation chromatography (GPC), suggested the existence of a minor ‘aggregated’ product fraction with multiple HPPA cores, which was attributed to transesterification reactions. Differential scanning calorimetry, as well as X-ray diffraction, demonstrated that the PCL-HPPA polymers displayed a similar degree of crystallinity to linear neat PCL, but that the branched products possessed smaller and less regular crystallites.

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Li, Tiantian, Zhenyu Cui, Qifa Zhang, Shuhao Qin, Benqiao He e Jianxin Li. "Synthesis of chlorinated polypropylene grafted poly(methyl methacrylate) using chlorinated polypropylene as macro-initiator via atom transfer radical polymerization and its application in lithium ion battery". Materials Letters 176 (agosto 2016): 64–67. http://dx.doi.org/10.1016/j.matlet.2016.04.079.

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Guan, Xinghua, Xiaoyan Ma, Hualong Zhou, Fang Chen e Zhiguang Li. "Synthesis and thermal decomposition kinetics of poly(methyl methacrylate)-b-poly(styrene) block copolymers". Journal of Thermoplastic Composite Materials 30, n. 5 (14 ottobre 2015): 691–706. http://dx.doi.org/10.1177/0892705715610406.

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Two diblock copolymers of poly(methyl methacrylate)- block-poly(styrene) with chlorine as terminal group (PMMA- b-PS-Cl) were synthesized via two-step atom transfer radical polymerization. The structures of the block copolymers were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and gel permeation chromatography. Thermal properties including glass transition temperature ( Tg) and thermal stability were studied by differential scanning calorimetry and thermogravimetric analysis (TGA), respectively. The block copolymers of PMMA- b-PS-Cl exhibited two glass transitions, which were attributed to the Tgs of PMMA and PS segments, respectively. According to TGA, thermal decompositions of PMMA macro-initiator and PMMA- b-PS-Cl block copolymers had two stages. The weight loss ratio in the second stage was more significant than that in the first stage, which may be attributed to the separation of the halogen atom from the terminal group and the formation of a double bond. The breaking down of the backbone dominates in the second stage in which the weight loss ratio was more than 70%, represented the main stage of pyrolysis. It was found that the introduction of the PS chain remarkably enhanced the thermal stability of the copolymer, thus endowing the block copolymers high activation energy for thermal decomposition. On the other hand, the remaining two pyrolysis procedures further indicated that thermodynamic mechanism didn’t change due to the introduction of PS segments.

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Xu, Jing, Benkai Qin, Shujuan Luan, Peilan Qi, Yingying Wang, Kai Wang e Shiyong Song. "Acid-labile poly(ethylene glycol) shell of hydrazone-containing biodegradable polymeric micelles facilitating anticancer drug delivery". Journal of Bioactive and Compatible Polymers 33, n. 2 (marzo 2018): 119–33. http://dx.doi.org/10.1177/0883911517715658.

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Biodegradable pH-sensitive amphiphilic block polymer (mPEG-Hyde-PLGA) was synthesized via ring-opening polymerization, initiated from a hydrazone-containing macro-initiator. In this way, a pH-sensitive hydrazone bond was inserted into the backbone of block copolymer, linking hydrophilic poly(ethylene glycol) segment and hydrophobic poly(lactic-co-glycolic acid) segment. The copolymer self-assembled to form stable micelles with mean diameters below 100 nm and served as a drug delivery system for doxorubicin, with drug loading content of 5.3%. pH sensitivity of the hydrazone-containing micelles was investigated by changes in diameter and size distribution observed by dynamic light scattering measurements when the micelles were encountered to acidic medium. Small pieces and larger aggregates were found by transmission electron microscopy resulting from the disassociation of the micelles in acidic conditions. It was also noted that doxorubicin release from the pH-sensitive micelles is significantly faster at pH 4.0 and pH 5.0 compared to pH 7.4, while almost no difference was detected in the case of pH non-sensitive micelles. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays on HepG-2 and MCF-7 cells revealed that doxorubicin-loaded pH-sensitive micelles had higher antitumor activity than pH-insensitive ones. This pH-sensitive drug delivery system based on hydrazone-containing block copolymer has been proved as a promising drug formulation for cancer therapy.

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Guo, Guangming, Si Wu, Guoshan Liu, Fuyong Zhang e Luyan Wang. "Synthesis and Performance of HPEG-AA-AMPS-HPA Polycarboxylate Superplasticizer". Journal of Physics: Conference Series 2737, n. 1 (1 marzo 2024): 012007. http://dx.doi.org/10.1088/1742-6596/2737/1/012007.

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Abstract An clay-resistance and slump-retaining polycarboxylate superplasticizer (PCE-RC) was synthesized using macro-monomer HPEG with different molecular weight, acrylic acid (AA), 2-acrylamide-2-methacrylic acid (AMPS) and 2-hydroxy-1-methylethyl acrylate (HPA) via H2O2-NaHSO3 redox initiator system. Effects of the acid-ether ratio, HPEG molecular weight, the amount of AMPS and HPA on the properties of PCE-RC in cement were discussed and the optimal molar ratio of HPEG3000, AA, AMPS and HPA was 1:4.5:0.1:0.1. As-synthesized polycarboxylate superplasticizer PCE-RC was characterized by GPC and FTIR. The performance of the cement paste doped with 2.0wt% montmorillonite (MMT) and concrete with cement containing MMT were tested in the presence of PCE. Results showed that cement doped with MMT performed superior fluidity and fluidity retention with the addition of PCE-RC. Compared with commercially available superplasticizer AS-KN, PCE-RC in concrete containing MMT presented better clay resistance and slump retaining performance due to the introduction of AMPS and HPA. Herein the negative charged sulfonic groups provided by AMPS could promote more PCE-RC to adsorb on MMT surface, resulting in the decrease of intercalated PCE-RC amount, which is in favor of clay resistance. While the usage of HPA monomer is beneficial for the slump-retaining ability of PCE-RC in cement due to the introduction of ester group.

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Devlaminck, Dries, Paul Van Steenberge, Marie-Françoise Reyniers e Dagmar D’hooge. "Modeling of Miniemulsion Polymerization of Styrene with Macro-RAFT Agents to Theoretically Compare Slow Fragmentation, Ideal Exchange and Cross-Termination Cases". Polymers 11, n. 2 (13 febbraio 2019): 320. http://dx.doi.org/10.3390/polym11020320.

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A 5-dimensional Smith-Ewart based model is developed to understand differences for reversible addition-fragmentation chain transfer (RAFT) miniemulsion polymerization with theoretical agents mimicking cases of slow fragmentation, cross-termination, and ideal exchange while accounting for chain length and monomer conversion dependencies due to diffusional limitations. The focus is on styrene as a monomer, a water soluble initiator, and a macro-RAFT agent to avoid exit/entry of the RAFT leaving group radical. It is shown that with a too low RAFT fragmentation rate coefficient it is generally not afforded to consider zero-one kinetics (for the related intermediate radical type) and that with significant RAFT cross-termination the dead polymer product is dominantly originating from the RAFT intermediate radical. To allow the identification of the nature of the RAFT retardation it is recommended to experimentally investigate in the future the impact of the average particle size (dp) on both the monomer conversion profile and the average polymer properties for a sufficiently broad dp range, ideally including the bulk limit. With decreasing particle size both a slow RAFT fragmentation and a fast RAFT cross-termination result in a stronger segregation and thus rate acceleration. The particle size dependency is different, allowing further differentiation based on the variation of the dispersity and end-group functionality. Significant RAFT cross-termination is specifically associated with a strong dispersity increase at higher average particle sizes. Only with an ideal exchange it is afforded in the modeling to avoid the explicit calculation of the RAFT intermediate concentration evolution.

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Vakhabova, V. E., e K. G. Guliev. "Synthesis, homopolymerization and properties of p-aminopyridine methacrylate". Proceedings of Universities. Applied Chemistry and Biotechnology 13, n. 3 (29 settembre 2023): 333–39. http://dx.doi.org/10.21285/2227-2925-2023-13-3-333-339.

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For the first time, p-aminopyridine methacrylate was synthesized by a reaction between p-aminopyridine and methacryloyl chloride. IR and NMR spectroscopy сonfirmed the obtained compound structure. Radical homopolymerization of synthesized p-aminopyridine methacrylate was carried out either in bulk or in benzene solution (initiator – AIBN). The study of radical polymerization regularities of p-aminopyridine methacrylate discovered no side reactions and induction period of the reported process under the created conditions with a maximum yield of 92%. It was found that p-aminopyridine methacrylate is a more reactive monomer in radical polymerization as compared to methyl methacrylate. The structure of the obtained monomer and polymer was investigated by IR and NMR spectroscopy. Based on these data, the polymerization proceeds by a double bond, with substituents in the side macro chain remaining unreacted. The study of the synthesized monomer polymerization in the bulk indicated the presence of the gel effect. The autoacceleration begins at ~25% monomer conversion during the polymerization process, which agrees with the literature data. It was discovered that the polymerization of p-aminopyridine methacrylate proceeds at a rate higher than that of methyl methacrylate. This observation is likely to be connected with the substituent contribution to the electronic state of the entire monomer molecule. Hence, the electron density of the vinyl group changes and the growing radical becomes stabilized with the substituent –M-effect. The polymer synthesized possesses high antimicrobial properties.

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Ma, Jun, Chong Cheng e Karen L. Wooley. "The Power of RAFT for Creating Polymers Having Imbedded Side-Chain Functionalities: Norbornenyl-Functionalized Polymers and their Transformations via ROMP and Thiol-ene Reactions". Australian Journal of Chemistry 62, n. 11 (2009): 1507. http://dx.doi.org/10.1071/ch09243.

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Robust, efficient and orthogonal chemistries are becoming increasingly important tools for the construction of increasingly sophisticated materials. In this article, the selectivity of reversible addition–fragmentation chain transfer (RAFT)-based radical polymerization of bifunctional monomers is exploited for the preparation of statistical and block copolymers that contain imbedded side-chain functionalities, which are then shown to exhibit two different orthogonal types of chemical reactivity to afford discrete nanoscale objects and functional derivative structures. Based on the radical reactivity ratios calculated from Alfrey–Price theory, a bifunctional monomer 4-(5′-norbornene-2′-methoxy)-2,3,5,6-tetrafluorostyrene (1) was designed and synthesized, for its highly reactive tetrafluorostyrenyl group relative to its norbornene (Nb) group. Selective RAFT copolymerization of 1 with styrene (St) afforded copolymers with over 50 mol-% structural units having a pendent norbornenyl functionality while maintaining narrow molecular weight distribution (polydispersity index (PDI) = 1.23). Diblock copolymers (PDI = 1.09–1.23) with Nb side-chain substituents regioselectively placed along one segment of the block copolymer structure were also prepared by RAFT copolymerizations of 1 with St or 2,3,4,5,6-pentafluorostyrene, using either polystyrene or poly(styrene-alt-maleic anhydride)-based macro chain-transfer agents. A well-defined star block copolymer (PDI = 1.23) having a poly(norbornene)-based core and polystyrene arms was obtained by ring-opening metathesis polymerization using the regioselective diblock copolymer PSt-b-P(1-co-St) as the multifunctional macromonomer and Grubbs’ catalyst (first generation) as the initiator. Photo-induced thiol-ene reactions of Nb-functionalized polymers with thiols were fast and efficient, yielding polymers with new side-chain structures.

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Klimek-Jankowska, Dorota. "Variation in Aspect Usage in General-Factual Contexts: New Quantitative Data from Polish, Czech, and Russian". Languages 7, n. 2 (7 giugno 2022): 146. http://dx.doi.org/10.3390/languages7020146.

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This study aims to account for the variation in aspect choices in factual imperfective contexts in Polish, Czech, and Russian. A series of online questionnaires were conducted wherein the native speakers of the tested languages were asked to fill in the missing verbs for two types of existential contexts (neutral and resultative) and four types of presuppositional factual contexts (weakly and strongly resultative with a focus on the initiator or the result state of the past event). We show that neutral existential factual contexts generally elicited significantly more imperfective choices than resultative existential factual contexts. Additionally, there was a trend towards a higher usage of imperfective in weakly resultative presuppositional contexts as compared to strongly resultative presuppositional contexts, suggesting that the less emphasis is placed on the result state the more likely the choice of imperfective aspect is for the expression of the temporal indefiniteness of factual contexts. Russian showed a significantly higher proportion of imperfective uses than Polish and Czech, with Czech being intermediate. We argue that these observations result from the fact that in all types of factual contexts (both existential and presuppositional) there is an interaction between two types of TEMPORAL (IN)DEFINITENESS of the past event: (i) temporal (in)definiteness at the micro-level (first phase syntax-vP) (depending on the position of the time variable within the temporal event of the past complex event) and (ii) (in)definiteness of the past event at the macro-level (second phase syntax–AspP and TP) (related to the position of the past event relative to the utterance time). We show that both discourse-level information and verb-level information interact in determining these two types of (in)definiteness, and they do it differently in Polish, Czech, and Russian.

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Zapsha, Halyna, Olga Orlova-Kurilova, Svetlana Limarenko e Anastasia Yatsun. "Resource Support for the Effectiveness of Strategic Management of Innovation Infrastructure in the Formation of Competitive Advantages and Socio-economic Guarantees in the Context of Economic Globalization". Central Ukrainian Scientific Bulletin. Economic Sciences, n. 6(39) (2021): 9–16. http://dx.doi.org/10.32515/2663-1636.2021.6(39).9-16.

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The aim of the article is to study the resource provision of the effectiveness of strategic management of innovation infrastructure in the formation of competitive advantages and socio-economic guarantees in the context of economic globalization. In the conditions of transformation of the national economy, there is a need to form such objects of innovation infrastructure that will stimulate the implementation of the innovation process at any stage of production. Such facilities must support the most promising business idea, innovative projects or ideas, in order to turn them into a product or service. The main purpose of economical use of innovation potential is to create and maintain the existing innovation infrastructure, able to position itself as a communicative channel for the transfer and exchange of knowledge, resources, ideas and technologies between stakeholders of innovative entrepreneurship. Proposals for further development of innovation infrastructure as a determining driver of positive changes in the institutional environment and a source of formation of positive synergy of innovative development of entrepreneurship have been developed. The stages of formation of such infrastructure according to the life cycle of the innovation project are marked, in the course of which due to achievement of complementarity of infrastructural elements impulses for the further stimulation of the economy based on diffusion of innovations are formed. This allows the state, as the initiator of regulation, to determine the directions of renewal of innovation infrastructure taking into account modern conditions. The necessity of reserve accumulation of resource potential of innovative entrepreneurship is noted and the directions of its use according to the stages of realization of the innovative project are determined. These actions are important for increasing innovative development at the macro level and forming a further strategy for innovative development of business stakeholders. The conclusion is made about the need for rational and economic use of resources. This need is due to the rapid involvement of resources in periods of transformation of the national economy, as well as the emergence of crisis trends in the domestic business environment.

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Kostromina, S. N., L. A. Darinskaia, N. L. Moskvicheva e A. F. Filatova. "Approbation and Validation of the «Index of Autonomous Functioning» (IAF) in the Russian Sample". Психологическая наука и образование 28, n. 5 (14 dicembre 2023): 168–83. http://dx.doi.org/10.17759/pse.2023280513.

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<p>One of the key issues in contemporary psychology is a correlation between determinism and indeterminism in understanding human behaviour. Autonomy as self-determined behaviour, as an individual's autonomous choice of behaviour, is one of the most significant and sought-after constructs in the study of personality functioning. In E. Deci and R. Ryan's self-determination theory (SDT), the need for autonomy is one of the basic innate needs of the personality, and this confirms the need for a person to feel as an actor, an initiator, the cause of one's own life and to act in harmony with one's integrated Self. The article presents the procedure of adaptation of the Russian-language version of the “Index of Autonomous Functioning” (IAF) developed within the macro-theory of self-determination by E. Deci and R. Ryan. The methodology assesses the need for autonomy, including such characteristics as authorship in life, self-interest and susceptibility to external control. In the article we studied the results of reliability and accuracy assessment (Cronbach's coefficient – 0,774) on a sample of 689 university students in Saint Petersburg. The structure of the questionnaire had three scales: authorship, susceptibility to control, and interest. Correlation analysis confirmed the correlation of the scales with other methods of measuring autonomous behavior, such as "Subjective Quality of Choice", "The Existence Scale", "World Assumptions Scale" and "Stolin Self-Relationship Questionnaire". Testing of diagnostic sensitivity of the Russian version of the questionnaire showed positive results, revealing significant level differences between three clusters: respondents with high, medium and low autonomous functioning index, as well as significant differences in gender and level of education of the respondents. A positive correlation was found between the overall IAF score, the interest-taking subscale, and the age of respondents (within Russian sample). According to the results, the Russian-language version of the “Index of Autonomous Functioning” has good psychometric characteristics and can be used as a qualitative research tool.</p>

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Brummel-Ziedins, Kathleen E., Philip Lam, Eric Gauthier e David Schneider. "Depletion of Systemic Concentrations of Coagulation Factors in Blood From Patients with Atherosclerotic Vascular Disease". Blood 118, n. 21 (18 novembre 2011): 1231. http://dx.doi.org/10.1182/blood.v118.21.1231.1231.

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Abstract Abstract 1231 Introduction. Thrombosis complicating the rupture of atherosclerotic plaques leads to arterial occlusion. Tissue factor (Tf), a membrane-bound glycoprotein, is expressed to a greater extent in atherosclerotic plaques and is likely a key mediator of micro and macro thrombosis. Atherosclerotic vascular disease is a widespread process that can lead to stroke, myocardial infarction and peripheral artery occlusion. Because thrombosis consumes coagulation factors, the goal of the present study was to determine whether the extent of atherosclerosis correlated with the concentration or activity of coagulation factors in blood and to relate, using novel computational approaches, the thrombin generation potential of the arterial blood to the extent of atherosclerosis. Methods. Patients scheduled for diagnostic cardiac catheterization (n=57) for clinical indications were enrolled. The average age was 65 (range 35–92) with a predominance of males (71%). Most patients were treated with aspirin (54/57 – 95%) and a small group had been treated with both aspirin plus clopidogrel (7/57 – 12%). After review of their angiograms, patients were divided into 3 groups based on their maximal extent of stenosis, 1) no coronary artery disease (no CAD, n=10), 2) coronary arterial stenosis <50% (CAD<50%, n=9), and 3) coronary arterial stenosis >50% (CAD>50%, n=38). For patients with CAD>50%, we evaluated those not treated with clopidogrel (n=31) separately from the group taking clopidogrel (n=7). Blood was taken from catheters placed in the femoral artery before administration of anticoagulants. Thrombin and factor Xa generation was assessed computationally based on measurements of plasma coagulation factors (II, V, VII, IX, X) and inhibitors (antithrombin and free tissue factor pathway inhibitor, TFPI) in all patients. Results. Plasma composition was not significantly different between individuals with no CAD versus CAD. In individuals with CAD, the concentrations of fX and prothrombin were significantly less in blood from patients with more than 50% stenosis. This difference was apparent in both those taking clopidogrel and those not taking clopidogrel. Thrombin and fXa generation after a 5 pM Tf initiator was significantly increased in all individuals compared to a physiologic control. Individuals with >50% CAD had significantly lower total thrombin then individuals with CAD<50% (83±16μM.s vs. 96 ±20μM.s, respectively). Kinetic analysis suggested that depletion of fX and prothrombin would decrease the amount of thrombin generated in patients with CAD>50%. To determine whether selected factors influenced the generation of fXa and thrombin, linear regression analysis was performed. The concentrations in blood of TFPI and fVIII were strongly associated (R2=0.5) with the time to the maximum rate of thrombin generation and maximum concentration of fXa generated. In simulations performed with increasing Tf concentrations (12.5 pM and 25 pM) TFPI and fVIII continued to correlate with thrombin and fXa generation. Also, at increasing Tf concentrations, fXa generation had greater (11 fold range) power to resolve each individual's thrombin generation profile (4 fold range). Conclusions. In summary, a reduced concentration of prothrombin and fX was observed in patients with more severe CAD, which could reflect greater consumption of these coagulation factors, reduced production or some combination. The computational analyses indicated important roles for TFPI and fVIII in the thrombin generation potential of individuals with CAD. The kinetics of fXa and thrombin generation suggests that the lower concentrations of fX and prothrombin may have functional implications consistent with clinical observations of patients with severe CAD having a narrower therapeutic window when treated with vitamin K antagonists. Disclosures: No relevant conflicts of interest to declare.

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