scholarly journals Structure, morphology, size and application of iron phosphate

2020 ◽  
Vol 59 (1) ◽  
pp. 538-552
Author(s):  
Xiaoxing Zhang ◽  
Li Zhang ◽  
Hui Liu ◽  
Binxia Cao ◽  
Libo Liu ◽  
...  

AbstractIron phosphates have rich chemical structures with various morphologies and sizes. Since they are environment friendly with good biocompatibility, they have good performances in the fields of catalysis and battery electrode material rising in recent years, as well as in the traditional fields like agriculture and steel. They also have important applications in adsorption, separation and concentration due to their unique structural characteristics. In this paper, iron phosphates are classified based on their common characteristics such as structure, morphology and size, and their application in the past two decades is reviewed, with emphasis on their application in adsorption, separation and concentration of different species. Further, their application in adsorption, separation and concentration of heavy metals is prospected.

2019 ◽  
Vol 23 (11) ◽  
pp. 1214-1238 ◽  
Author(s):  
Navjeet Kaur ◽  
Pranshu Bhardwaj ◽  
Meenu Devi ◽  
Yamini Verma ◽  
Neha Ahlawat ◽  
...  

Due to special properties of ILs (Ionic Liquids) like their wide liquid range, good solvating ability, negligible vapour pressure, non-inflammability, environment friendly medium, high thermal stability, easy recycling and rate promoters etc. they are used in organic synthesis. The investigation for the replacement of organic solvents in organic synthesis is a growing area of interest due to increasing environmental issues. Therefore, ionic liquids have attracted the attention of chemists and act as a catalyst and reaction medium in organic reaction with high activity. There is no doubt that ionic liquids have become a major subject of study for modern chemistry. In comparison to traditional processes the use of ionic liquids resulted in improved, complimentary or alternative selectivities in organic synthesis. The present manuscript reported the synthesis of multiple nitrogen containing five-membered heterocyclic compounds using ionic liquids. This review covered interesting discoveries in the past few years.


Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 330
Author(s):  
Timofey V. Malyarenko ◽  
Alla A. Kicha ◽  
Valentin A. Stonik ◽  
Natalia V. Ivanchina

Sphingolipids are complex lipids widespread in nature as structural components of biomembranes. Commonly, the sphingolipids of marine organisms differ from those of terrestrial animals and plants. The gangliosides are the most complex sphingolipids characteristic of vertebrates that have been found in only the Echinodermata (echinoderms) phylum of invertebrates. Sphingolipids of the representatives of the Asteroidea and Holothuroidea classes are the most studied among all echinoderms. In this review, we have summarized the data on sphingolipids of these two classes of marine invertebrates over the past two decades. Recently established structures, properties, and peculiarities of biogenesis of ceramides, cerebrosides, and gangliosides from starfishes and holothurians are discussed. The purpose of this review is to provide the most complete information on the chemical structures, structural features, and biological activities of sphingolipids of the Asteroidea and Holothuroidea classes.


2019 ◽  
Vol 23 (07n08) ◽  
pp. 797-812 ◽  
Author(s):  
Sonja Merkaš ◽  
Mladen Žinić ◽  
Régis Rein ◽  
Nathalie Solladié

During the past years, we focused on exerting control over the position and distance of porphyrins along our specifically designed oligonucleotidic scaffold. Indeed, in naturally occurring light-harvesting complexes, biopolymer scaffolds hold pigments at intermolecular distances that optimize photon capture, electronic coupling, and energy transfer. To this end, four uridine-porphyrin conjugates (a monomer, a dimer, a tetramer and an octamer) were subjected to a comprehensive conformational analysis by using NMR spectroscopy. The collected NOE NMR data highlighted characteristic and strong interactions indicating that the glycosidic angle between the ribose and uracil base is anti. In order to further investigate the conformation of this family of molecules, NMR experiments were carried out at variable temperatures. At low temperature, the signals of the porphyrinic protons decoalesce, showing two sets of [Formula: see text]-pyrrolic protons. Similar observations are made for signals corresponding to sugar moieties and especially the H1′ protons, indicating molecular motions within our porphyrin-uridin arrays. These results testify in favor of the existence of a dynamic process between C3′-endo and C2′-endo conformations.


2019 ◽  
Vol 11 (3) ◽  
pp. 471-488 ◽  
Author(s):  
Liu Shouying

Purpose The purpose of this paper is to analyze the structure and changes of China’s land system. To achieve this aim, the paper is divided into four parts. The first part gives a brief introduction to the structural characteristics of the Chinese land institutional arrangements; the second part analyzes the reform process of the land system in the past 40 years and its path of change; the third part engages the discussion about the historic contribution made by the land institutional change to rapid economic growth and structural changes; and the final part is conclusion and some policy implications. Design/methodology/approach After 40 years of reforms and opening up, China has not only created a growth miracle unparalleled for any major country in human history, but also transformed itself from a rural to an urban society. Behind this great transformation is a systemic reform in land institutions. Rural land institutions went from collectively owned to household responsibility system, thereby protecting farmers’ land rights. This process resulted in long-term sustainable growth in China’s agriculture, a massive rural-urban migration and a historical agricultural transformation. The conversion of agricultural land to non-agricultural uses and the introduction of market mechanisms made land a policy tool in driving high economic growth, industrialization and urbanization. Findings Research shows that the role of land and its relationship with the economy will inevitably change as China’s economy enters a new stage of medium-to-high speed growth. With economic restructuring, low-cost industrial land will be less effective. Urbanization is also shifting from rapid expansion to endogenous growth so that returns on land capitalization will decrease and risks will increase. Therefore, China must abandon land-dependent growth model through deepening land reforms and adapt a new pattern of economic development. Originality/value This paper gives a brief introduction to the structural characteristics of the Chinese land institutional arrangements, analyzes the reform process of the land system in the past 40 years and its path of change, and evaluates the historic contribution made by the land institutional change to rapid economic growth and structural changes.


Marine Drugs ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. 610
Author(s):  
Junjie Yan ◽  
Weiwei Liu ◽  
Jiatong Cai ◽  
Yiming Wang ◽  
Dahong Li ◽  
...  

Phenazines are a large group of nitrogen-containing heterocycles, providing diverse chemical structures and various biological activities. Natural phenazines are mainly isolated from marine and terrestrial microorganisms. So far, more than 100 different natural compounds and over 6000 synthetic derivatives have been found and investigated. Many phenazines show great pharmacological activity in various fields, such as antimicrobial, antiparasitic, neuroprotective, insecticidal, anti-inflammatory and anticancer activity. Researchers continued to investigate these compounds and hope to develop them as medicines. Cimmino et al. published a significant review about anticancer activity of phenazines, containing articles from 2000 to 2011. Here, we mainly summarize articles from 2012 to 2021. According to sources of compounds, phenazines were categorized into natural phenazines and synthetic phenazine derivatives in this review. Their pharmacological activities, mechanisms of action, biosynthetic pathways and synthetic strategies were summarized. These may provide guidance for the investigation on phenazines in the future.


2006 ◽  
Vol 973 ◽  
Author(s):  
Shijun Wang ◽  
M. Stanley Whittingham

ABSTRACTThis study focusses on optimizing the parameters of the hydrothermal synthesis to produce iron phosphates for lithium ion batteries, with an emphasis on pure LiFePO4 with the olivine structure and compounds containing a higher iron:phosphate ratio. Lithium iron phosphate (LiFePO4) is a promising cathode candidate for lithium ion batteries due to its high theoretical capacity, environmentally benign and the low cost of starting materials. Well crystallized LiFePO4 can be successfully synthesized at temperatures above 150 °C. The addition of a reducing agent, such as hydrazine, is essential to minimize the oxidation of ferrous (Fe2+) to ferric (Fe3+) in the final compound. The morphology of LiFePO4 is highly dependent on the pH of the initial solution. This study also investigated the lipscombite iron phosphates of formula Fe1.33PO4OH. This compound has a log-like structure formed by Fe-O octahedral chains. The chains are partially occupied by the Fe3+ sites, and these iron atoms and some of the vacancies can be substituted by other cations. Most of the protons can be ion-exchanged for lithium, and the electrochemical capacity is much increased.


2011 ◽  
Vol 15 (01) ◽  
pp. 97-121
Author(s):  
Neeraj Dwivedi ◽  
Arvinder Singh

The case presents a decision situation facing the Vice President of strategic planning at Piramal Diagnostics Limited, who has to formulate the future growth strategy and decide on the roadmap. The company is the largest player in the organized medical diagnostics industry in India and has shown attractive growth in the past few years. The case describes the structural characteristics of the medical diagnostics industry in India and follows it with a description of the strengths and weaknesses of Piramal Diagnostics and the strategies adopted by it. The Vice President is expected to choose an appropriate strategic option to help the company achieve its ambitious growth target.


2021 ◽  
Vol 08 ◽  
Author(s):  
Adarsh Sahu

Background: 1,2,3-triazole is considered widely explored scaffolds by medicinal chemists because of their therapeutic importance. The structural characteristics of 1,2,3-triazoles allow this to mimic certain functional groups demonstrating its utility to prepare new medicinal compounds using the concept of bioisosterism and molecular hybridization. Centered on Huisgens cycloaddition reaction, over the past decade and a half, click chemistry approaches were developed to furnish triazole derivatives with various applications ranging from drugs to bioconjugation linkers. Objective: In the present review, we aim to highlight the different approaches developed for the synthesis of 1,2,3-triazole derivatives and in particular advances in synthetic methods for the last 16 years. This review is also intended to help researchers for finding potential future directions and scope in the development of synthetic strategies. Conclucion: As summarized through the compilation of recent advances for 1,2,3-triazole synthesis, it is clear that these protocols have numerous advantages such as cleaner reaction profile, shorter reaction times, excellent product yields, environmentally benign milder reactions, and safe operations.


2019 ◽  
Vol 28 (3) ◽  
pp. 280-304
Author(s):  
Reiko Ikeo

Over the past decade, more and more writers have used the present tense as the primary tense for their fictional narratives. This article shows that contemporary present-tense fiction has more lexical and syntactic characteristics which are similar to spoken discourse than past-tense fiction by comparing lexis and structures in two corpora: a corpus consisting of present-tense narratives and a corpus of past-tense narratives. It also discusses how the use of the present tense affects the management of viewpoint in narrative by relating its lexical, structural characteristics to the presentation of characters’ speech and thoughts.


Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 129
Author(s):  
Dario Matulja ◽  
Maria Kolympadi Markovic ◽  
Gabriela Ambrožić ◽  
Sylvain Laclef ◽  
Sandra Kraljević Pavelić ◽  
...  

Gorgonian corals, which belong to the genus Eunicella, are known as natural sources of diverse compounds with unique structural characteristics and interesting bioactivities both in vitro and in vivo. This review is focused primarily on the secondary metabolites isolated from various Eunicella species. The chemical structures of 64 compounds were divided into three main groups and comprehensively presented: a) terpenoids, b) sterols, and c) alkaloids and nucleosides. The observed biological activities of depicted metabolites with an impact on cytotoxic, anti-inflammatory, and antimicrobial activities were reviewed. The most promising biological activities of certain metabolites point to potential candidates for further development in pharmaceutical, cosmetic, and other industries, and are highlighted. Total synthesis or the synthetic approaches towards the desired skeletons or natural products are also summarized.


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