scholarly journals Biological Active Esters of the Isovaleric Acid

2014 ◽  
Vol 16 (4) ◽  
Author(s):  
Kh.A. Suerbaev ◽  
G.Zh. Zhaksylykova ◽  
N.O. Appazov

<p>Hydroalkoxycarbonylation of olefins with carbon monoxide and alcohols under condition of homogeneous –catalysis with transition metal complexes allows facile one-step synthesis of practically <br /> useful carbon acid esters. Many of them have biological activity and are constituents of drugs or valuable intermediate products in drug synthesis. Hydroalkoxycarbonylation of isobutylene with carbon monoxide and alcohols in the presence of catalytic system Pd(PPh<sub>3</sub>)<sub>4</sub>-PPh<sub>3</sub>-TsOH was applied for preparing of biological active isovaleric acid esters: <em>1</em>-menthylisovalerate (main active component of the spasmolytic medicine “Validolum”), ethylisovalerate (intermediate product for obtaining sedative and spasmolytic medicines “Ethyl ester of <em>α</em>-bromisovaleric acid” and “Corvalolum”), cyclohexylisovalerate (bactericide activity) and benzylisovalerate (bactericide and antifungus activity). Hydroalkoxycarbonylation reaction of isobutylene with carbon monoxide and alcohols (ethanol, cyclohexanol, l-menthol, benzyl alcohol) in the presence Pd(PPh<sub>3</sub>)<sub>4</sub>-PPh<sub>3</sub>-TsOH system carried out at conditions: temperature 100 °C; CO pressure 2.0 MPa; reaction time 4 h; reactants and catalyst components ratio [alcohol]:[isobutylene]:[Pd(PPh<sub>3</sub>)<sub>4</sub>]:[PPh<sub>3</sub>]:[TsOH] = 435:550:1:3:12. The yields of the products were 71-95% (on converted alcohols). The selectivity in linear reaction products was 100%. Such a high regioselectivity is apparently provided both by the structure of the starting alkene (isobutylene) and by the reaction mechanism. The most probable is a hydride mechanism. Due to the more advanced technology of production the Medicines will have better qualitative characteristics. The cost of production of the Medicines with the use of new technologies is 2-3 times lower as compared to the medicines produced by existing at the present traditional technologies.</p>

2019 ◽  
pp. 30-41 ◽  
Author(s):  
E.P. Sannikova ◽  
A.V. Malysheva ◽  
F.A. Klebanov ◽  
D.G. Kozlov

The capacity of yeast to produce the highly active variants of PLA2 has been confirmed. The high-active variants were based on the original enzyme from the strain А-2688 of Streptomyces violaceoruber. To reduce the enzyme toxicity and to increase its expression, various approaches were tested including point mutations, construction of artificial N- and/or C-end pro-regions, hybridization with other proteins and engineering or inactivation of glycosylation sites. As a main result, the modified PLA2 enzymes were obtained which have the same secretion level as their low-active predecessors, but specific activity of which was at least tenfold higher. As the main feature, the selected mutants were characterized by a lower affinity for Ca2+ that probably accounts for their low toxicity (and high expression capacity) at the stage of biosynthesis and their ability to activate under special conditions, e.g. during the egg yolk fermentation. The data obtained can provide a basis for the cost reduction of highly active PLA2 enzyme preparations in industries where the application of high calcium concentrations is allowed. recombinant phospholipase А2, Streptomyces violaceoruber, yeasts, secretion, producer strain The work was initiated by the Innovation Center Biriuch - New Technologies, Ltd., and was supported within the framework of the State Assignment no. 595-00004-18 PR.


1990 ◽  
Vol 55 (7) ◽  
pp. 1678-1685
Author(s):  
Vladimír Stuchlý ◽  
Karel Klusáček

Kinetics of CO methanation on a commercial Ni/SiO2 catalyst was evaluated at atmospheric pressure, between 528 and 550 K and for hydrogen to carbon monoxide molar ratios ranging from 3 : 1 to 200 : 1. The effect of reaction products on the reaction rate was also examined. Below 550 K, only methane was selectively formed. Above this temperature, the formation of carbon dioxide was also observed. The experimental data could be described by two modified Langmuir-Hinshelwood kinetic models, based on hydrogenation of surface CO by molecularly or by dissociatively adsorbed hydrogen in the rate-determining step. Water reversibly lowered catalyst activity and its effect was more pronounced at higher temperature.


Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 882
Author(s):  
M. Munzer Alseed ◽  
Hamzah Syed ◽  
Mehmet Cengiz Onbasli ◽  
Ali K. Yetisen ◽  
Savas Tasoglu

Civil wars produce immense humanitarian crises, causing millions of individuals to seek refuge in other countries. The rate of disease prevalence has inclined among the refugees, increasing the cost of healthcare. Complex medical conditions and high numbers of patients at healthcare centers overwhelm the healthcare system and delay diagnosis and treatment. Point-of-care (PoC) testing can provide efficient solutions to high equipment cost, late diagnosis, and low accessibility of healthcare services. However, the development of PoC devices in developing countries is challenged by several barriers. Such PoC devices may not be adopted due to prejudices about new technologies and the need for special training to use some of these devices. Here, we investigated the concerns of end users regarding PoC devices by surveying healthcare workers and doctors. The tendency to adopt PoC device changes is based on demographic factors such as work sector, education, and technology experience. The most apparent concern about PoC devices was issues regarding low accuracy, according to the surveyed clinicians.


Informatics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 30
Author(s):  
Mansoor Ahmed Soomro ◽  
Mohd Hizam-Hanafiah ◽  
Nor Liza Abdullah ◽  
Mohd Helmi Ali ◽  
Muhammad Shahar Jusoh

Industry 4.0 revolution, with its cutting-edge technologies, is an enabler for businesses, particularly in reducing the cost and improving the productivity. However, a large number of organizations are still too in their infancy to leverage the true potential of Industry 4.0 and its technologies. This paper takes a quantitative approach to reveal key insights from the companies that have implemented Industry 4.0 technologies. For this purpose, 238 technology companies in Malaysia were studied through a survey questionnaire. As technology companies are usually the first in line to adopt new technologies, they can be studied better as leaders in adopting the latest technologies. The findings of this descriptive study surfaced an array of insights in terms of Industry 4.0 readiness, Industry 4.0 technologies, leadership, strategy, and innovation. This research paper contributes by providing 10 key empirical insights on Industry 4.0 that can be utilized by managers to pace up their efforts towards digital transformation, and can help the policymakers in drafting the right policy to drive the digital revolution.


Author(s):  
R E Pauls ◽  
B Pease

Abstract An ionic liquid (IL) 111 column was compared with other commonly employed stationary phases including polydimethyl siloxane and polyethylene glycol for the separation of fatty acid monomethyl and dimethyl esters. The fatty acid esters employed in this study were derived from metathesis reactions of vegetable oils both with and without olefins. The IL 111 column demonstrated enhanced performance compared with conventional columns for the separation of these esters. These advantages included significantly enhanced retention of dimethyl esters relative to monomethyl esters, excellent cis/trans isomer separation and the ability to analyze higher carbon number dimethyl esters. As a result, these columns are highly suited for the analysis of mixtures of mono- and dimethyl fatty acid esters found in lipid metathesis reaction products or to determine monofunctional impurities in samples of commercial dimethyl esters.


2000 ◽  
Vol 287 (2) ◽  
pp. 349-352 ◽  
Author(s):  
Vincent W.S. Liu ◽  
Phillip Nagley ◽  
Hextan Y.S. Ngan

2015 ◽  
Vol 2 (1-2) ◽  
pp. 55-70
Author(s):  
Sean Foley

For decades, many scholars have contended that Saudi Arabia is a fixed political system, where a conservative monarchy uses advanced technology, oil revenues, and religion to dominate the people. Such a system is often portrayed as inherently unstable, a seemingly never-ending series of collisions between an unchanging traditional political structure seeking to hold on to power at any cost and a dynamic modernity—a view encapsulated in a phrase expressed at virtually every public discussion of the Kingdom in the West: ‘you must admit that Saudi Arabia must change’. Ironically this phrase confirms what this article argues is a secret to the success of Saudi Arabia in the contemporary era: the ability to legitimize transformation without calling it change. No society is static, including Saudi Arabia. Throughout the Kingdom’s history, the defining social institutions have repeatedly utilized Tajdīd (Revival) and Iṣlāḥ (Reform) to respond to new technologies and the changing expectations of a diverse society. While Muslim scholars are most often entrusted to arbitrate this process, ordinary Saudis use this process to guide their actions in the various social spaces they encounter both at home and abroad. Critically, this process reflects the response of King Abdulaziz and the founders of the third Saudi state in the early twentieth century to the factors that had brought down previous Saudi states in the nineteenth century.


2021 ◽  
Vol 2021 (23) ◽  
pp. 31-42
Author(s):  
Anatolii Tsynka ◽  
◽  
Andrii Hrinchuk ◽  
Ivan Rakovych ◽  
◽  
...  

Introduction. In the modern conditions of the pricing system in the construction of Ukraine, the key value have the estimated norms, which are presented in separate collections, the main purpose of which is to determine the standard quantity of resources required to perform a particular type of work as a basis for the transition to the cost indicators. In order to determine the cost of road work objectively and accurately, it is essential that the indicators of estimated norms meet the requirements of regulatory documents and modern methods of execution of road works.Problematics. In connection with the active improvement of the regulatory base of the road construction industry, permanent upgrade of road organizations technique fleet, the introduction of new technologies and materials in construction and operation of roads, improving the methods of work there is a discrepancy between the existing resource element of estimated norms and the actual conditions of work in terms of built-up labor costs, the operation time of machines and mechanisms and the range of materials. Accordingly, it affects the reliability and accuracy of determining the cost of road works.Purpose. Improvement and harmonization with actual working conditions and requirements of regulatory documents of industry regulatory and estimate base of resource elementary estimated norms for work performed during construction, reconstruction, repair and operational maintenance of roads and bridges to ensure reliable and valid technical, economic and estimated calculations.Materials and methods. During work performance the analysis of the regulatory documentation, establishing the requirements to the technology of road works and materials has been carried out. A number of chronometric observations with the measurement of time of road works in full-scale conditions was carried out. The obtained data were summarized, averaged and on their basis the indicators of the resource element of the estimated norms were estimated.Results. A review of the main amendments and additions, which came into force after the approval of Amendment No 2 SOU 42.1-37641918-035:2018 [1] and Amendment No 2 SOU 42.1-37641918-071:2018 [2], which were developed to improve the regulatory-estimate base for the calculation of road works, taking into account the requirements and provisions of existing regulatory documents taking into account the current state of scientific and technological progress in the road sector.Conclusions. The above analysis of the amendments that came into force with the approval of [1]. and [2] will systematize the innovations provided by the requirements of current regulatory documents on the calculation of the cost of road works and the development of relevant documents at all stages of the investment process, planning and organization of road works, as well as the writing-off of material resources. Review and systematization of recent improvements in the estimated regulatory documents for road works will provide an opportunity to optimally plan the use of available material, labor and financial resources, often limited.Keywords: public road, operational maintenance, investment documentation, overhaul and current repairs, machine, mechanism, regulatory document, resource element estimate norm, Standard of Organization of Ukraine.


Author(s):  
Robert F. Steele ◽  
Dale C. Paul ◽  
Torgeir Rui

Since the early 1990’s there have been significant changes in the gas turbine, and power generation market place. The ‘F-Class’ Gas Turbines, with higher firing temperatures, single crystal materials, increased compressor pressure ratios and low emission combustion systems that were introduced in the early 1990’s have gained significant field experience. Many of the issues experienced by these new product introductions have been addressed. The actual reliability growth and current performance of these advanced technology machines will be examined. Additionally, the operating profiles anticipated for many of the units installed during this period has been impacted by both changes in the anticipated demand and increases in fuel costs, especially the cost of natural gas. This paper will review how these changes have impacted the Reliability, Availability, and Maintainability performance of gas turbines. Data from the ORAP® System, maintained by Strategic Power Systems, Inc, will be utilized to examine the actual RAM performance over the past 10 to 15 years in relation to goals and expectations. Specifically, this paper will examine the reliability growth of the F-Class turbines since the 1990’s and examine the reliability impact of duty cycle on RAM performance.


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