Recent Developments in Asymmetric Hydroformylation

2021 ◽  
Author(s):  
Soumyadeep Chakrabortty ◽  
Ahmad Almasalma ◽  
Johannes G. de Vries
Keyword(s):  
Recent Literature ◽  
Bidentate Ligands ◽  
Recent Developments ◽  
Asymmetric Hydroformylation ◽  
Made In

The recent literature on asymmetric hydroformylation is reviewed from the perspective of the ligand development. Much progress was made in the area of hybrid bidentate ligands containing one P-chiral phosphine...

scholarly journals 3D IMAGING OF INDIVIDUAL PARTICLES: A REVIEW

2012 ◽  
Vol 31 (2) ◽  
pp. 65 ◽  
Author(s):  
Eric Pirard
Keyword(s):  
Literature Review ◽  
Digital Imaging ◽  
Systems Analysis ◽  
3D Imaging ◽  
Materials Science ◽  
Recent Literature ◽  
Three Dimensional ◽  
Shape Estimation ◽  
Individual Particles ◽  
Made In

In recent years, impressive progress has been made in digital imaging and in particular in three dimensional visualisation and analysis of objects. This paper reviews the most recent literature on three dimensional imaging with a special attention to particulate systems analysis. After an introduction recalling some important concepts in spatial sampling and digital imaging, the paper reviews a series of techniques with a clear distinction between the surfometric and volumetric principles. The literature review is as broad as possible covering materials science as well as biology while keeping an eye on emerging technologies in optics and physics. The paper should be of interest to any scientist trying to picture particles in 3D with the best possible resolution for accurate size and shape estimation. Though techniques are adequate for nanoscopic and microscopic particles, no special size limit has been considered while compiling the review.

scholarly journals Recent advances in the electrochemical construction of heterocycles

2014 ◽  
Vol 10 ◽  
pp. 2858-2873 ◽  
Author(s):  
Robert Francke
Keyword(s):  
Heterocyclic Compounds ◽  
Elevated Temperatures ◽  
Ring Formation ◽  
Environmentally Benign ◽  
Heterocyclic Chemistry ◽  
Ambient Conditions ◽  
Recent Developments ◽  
Strong Acids ◽  
Selection Of ◽  
Made In

Due to the fact that the major portion of pharmaceuticals and agrochemicals contains heterocyclic units and since the overall number of commercially used heterocyclic compounds is steadily growing, heterocyclic chemistry remains in the focus of the synthetic community. Enormous efforts have been made in the last decades in order to render the production of such compounds more selective and efficient. However, most of the conventional methods for the construction of heterocyclic cores still involve the use of strong acids or bases, the operation at elevated temperatures and/or the use of expensive catalysts and reagents. In this regard, electrosynthesis can provide a milder and more environmentally benign alternative. In fact, numerous examples for the electrochemical construction of heterocycles have been reported in recent years. These cases demonstrate that ring formation can be achieved efficiently under ambient conditions without the use of additional reagents. In order to account for the recent developments in this field, a selection of representative reactions is presented and discussed in this review.

China’s shadow banking sector: beneficial or harmful to economic growth?

2015 ◽  
Vol 7 (4) ◽  
pp. 421-445 ◽  
Author(s):  
James R. Barth ◽  
Tong Li ◽  
Wen Shi ◽  
Pei Xu
Keyword(s):  
Economic Growth ◽  
Banking Sector ◽  
Commercial Banking ◽  
Global Perspective ◽  
Shadow Banking ◽  
Content Type ◽  
Wide Range ◽  
Recent Developments ◽  
Major Factors ◽  
Made In

Purpose – The purpose of this paper is to examine recent developments pertaining to China’s shadow banking sector. Shadow banking has the potential not only to be a beneficial contributor to continued economic growth, but also to contribute to systematic instability if not properly monitored and regulated. An assessment is made in this paper as to whether shadow banking is beneficial or harmful to China’s economic growth. Design/methodology/approach – The authors start with providing an overview of shadow banking from a global perspective, with information on its recent growth and importance in selected countries. The authors then focus directly on China’s shadow banking sector, with information on the various entities and activities that comprise the sector. Specifically, the authors examine the interconnections between shadow banking and regular banking in China and the growth in shadow banking to overall economic growth, the growth in the money supply and the growth in commercial bank assets. Findings – Despite the wide range in the estimates, the trend in the size of shadow banking in China has been upward over the examined period. There are significant interconnections between the shadow banking sector and the commercial banking sector. Low deposit rate and high reserve requirement ratios have been the major factors driving its growth. Shadow banking has been a contributor, along with money growth, to economic growth. Practical implications – The authors argue that shadow banking may prove useful by diversifying China’s financial sector and providing greater investments and savings opportunities to consumers and businesses throughout the country, if the risks of shadow banking are adequately monitored and controlled. Originality/value – To the authors’ knowledge, this paper is among the few to systematically evaluate the influence of shadow banking on China’s economic growth.

scholarly journals Copper-promoted/copper-catalyzed trifluoromethylselenolation reactions

2020 ◽  
Vol 16 ◽  
pp. 305-316 ◽  
Author(s):  
Clément Ghiazza ◽  
Anis Tlili
Keyword(s):  
Organic Compounds ◽  
Crucial Role ◽  
Copper Catalysis ◽  
Chemistry Major ◽  
Recent Developments ◽  
Made In

Copper catalysis and, more generally, copper chemistry are pivotal for modern organofluorine chemistry. Major advances have been made in the field of trifluoromethylselenolations of organic compounds where copper catalysis played a crucial role. Recent developments in this field are highlighted in this minireview.

scholarly journals Studies on the moss flora of the Bío-Bío region of Chile

2006 ◽  
Vol 28 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Robert R. Ireland ◽  
Gilda Bellolio ◽  
Roberto Rodríguez ◽  
Juan Larraín
Keyword(s):  
South America ◽  
New Taxa ◽  
New Records ◽  
Recent Literature ◽  
Extensive Study ◽  
Central Chile ◽  
Number Of Species ◽  
South Central ◽  
Made In

An extensive study was made on the moss flora of the Bío-Bío Region (VIII Región) in south-central Chile in 2001-2003. Collections were made in all four provinces of the region: Arauco, Bío-Bío, Concepción and Ñuble. Approximately 265 localities in the region were explored with over 6,000 mosses collected in the four provinces. The mosses of this region had not previously been studied to any great extent and with part of the region’s environment being destroyed by the construction of several dams on one of the major rivers, the Bío-Bío, the study of this area seemed of utmost importance. Thus far, a total of 20 taxa were found which are new to Chile, making a total of 877 known for the country, with four new taxa known for South America. An additional 87 taxa are reported new only to the Bío-Bío Region. That number, together with some new records from the recent literature, increases the total for the Region from 190 to 300. It was determined from the 87 new taxa for the Bío-Bío Region that the majority (41) represent northern extensions of taxa, while a much smaller number (10) represent southern extensions. The remainder (36) fill in a gap in the distribution of the taxa between the northern and southern parts of the country. Many difficult species still remain to be identified and the number of species new to science, to Chile and to the Bío-Bío Region, is certain to increase when the remaining specimens are identified.

Ras proteins as therapeutic targets

2018 ◽  
Vol 46 (5) ◽  
pp. 1303-1311 ◽  
Author(s):  
Atanu Chakraborty ◽  
Emily Linnane ◽  
Sarah Ross
Keyword(s):  
Therapeutic Strategies ◽  
Targeted Therapeutics ◽  
Ras Proteins ◽  
Ras Genes ◽  
Small Molecule Drug ◽  
Oncogenic Mutations ◽  
Recent Developments ◽  
Novel Therapeutic Strategies ◽  
Novel Therapeutic ◽  
Made In

Oncogenic mutations in RAS genes underlie the pathogenesis of many human tumours, and there has been intense effort for over 30 years to develop effective and tolerated targeted therapeutics for patients with Ras-driven cancers. This review summarises the progress made in Ras drug discovery, highlighting some of the recent developments in directly targeting Ras through advances in small molecule drug design and novel therapeutic strategies.

The Indian Farming-Community and their Health-Concerns for a Sustainable Agriculture

2022 ◽  
Vol 13 (1) ◽  
pp. 0-0
Keyword(s):  
Developing Countries ◽  
Well Being ◽  
Intervention Strategies ◽  
Health Concerns ◽  
Work Related ◽  
Farming Community ◽  
Recent Developments ◽  
Health Disorders ◽  
The Government ◽  
Made In

The exposure of farmers to agricultural hazards and risks has been increased in their work-places with the recent developments in agricultural sectors in most of the developing countries. This higher expose may be due to the enhanced need in meeting the food as well as monetary demand of farming house-holds. The agricultural-productivity has also been reduced in developing countries because of the exposure of farmers to work-related stresses affecting their well-being. Thus, an attempt was made in this study for exploring the mental-health disorders among the farmers and the farming-community in the state of Odisha in India for undertaking possible intervention strategies by the government and competent authorities.

scholarly journals Recent Advances in Palladium-Catalyzed Isocyanide Insertions

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4906
Author(s):  
Jurriën W. Collet ◽  
Thomas R. Roose ◽  
Bram Weijers ◽  
Bert U. W. Maes ◽  
Eelco Ruijter ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Building Blocks ◽  
Insertion Reactions ◽  
Chemical Reagents ◽  
The Past ◽  
Recent Advances ◽  
Recent Developments ◽  
Palladium Catalyzed ◽  
Made In ◽  
Rapid Incorporation

Isocyanides have long been known as versatile chemical reagents in organic synthesis. Their ambivalent nature also allows them to function as a CO-substitute in palladium-catalyzed cross couplings. Over the past decades, isocyanides have emerged as practical and versatile C1 building blocks, whose inherent N-substitution allows for the rapid incorporation of nitrogeneous fragments in a wide variety of products. Recent developments in palladium catalyzed isocyanide insertion reactions have significantly expanded the scope and applicability of these imidoylative cross-couplings. This review highlights the advances made in this field over the past eight years.

A Discussion on natural strain and geological structure - The finite element method and the solution of some geophysical problems

1976 ◽  
Vol 283 (1312) ◽  
pp. 139-151 ◽  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Geological Structure ◽  
The Finite Element Method ◽  
Recent Developments ◽  
Limited Application ◽  
Discrete Problems ◽  
The Finite Difference Method ◽  
Made In ◽  
Element Method

The finite element method has become established as a powerful tool for the solution of many problems of continuum mechanics where its physical interpretation, by analogy with discrete problems of structural analysis permits the user to exercise a considerable degree of insight and judgement in its use. Further it is now a recognized mathematical procedure of approximation which embraces many older methodologies (such as the finite difference method) as a subclass. In the field of geological studies its impact is fairly recent and only a limited application has been made to date. The techniques used here have been limited to those established over a decade ago in the parallel fields and recent developments and possibilities barely touched upon. In this paper the author therefore attempts to ( a ) outline some of the general mathematical and practical aspects of the method with illustrations from various fields which are relevant to geological problems, ( b ) survey accomplishments already made in geology and geotechnical fields, and ( c ) suggest some possible new extensions of application.

A Review of Recent Developments in the Mechanisms of Antifatigue Agents

1985 ◽  
Vol 58 (2) ◽  
pp. 269-283 ◽  
Author(s):  
Gerald Scott
Keyword(s):  
Structural Design ◽  
Material Design ◽  
The Past ◽  
Truck Tires ◽  
Recent Developments ◽  
Shoulder Region ◽  
Major Factors ◽  
High Level ◽  
Vulcanization Process ◽  
Made In

Abstract In spite of the remarkable advances that have been made in the engineering design of tires during the past two decades, the basic formulations used in vulcanization and protection during service have essentially remained unchanged. This is to a large extent due to two major factors: 1. The versatility of the traditional accelerated sulfur curing system which provides the necessary combination of resilience and strength with good resistance to cyclical stress. 2. The development of diarylamine antidegradants which confer a high level of thermal-oxidative and mechano-oxidative (fatigue) resistance to the rubber. Both of these developments have occurred slowly with small incremental improvements and, probably because of their success, relatively little fundamental work has been published which addresses the questions of why a polysulfide network is so resistant to fatigue and why N-sec-alkyl-N′-phenyl-p-phenylenediamines are so much more successful as antidegradants than other classes of antioxidant. It is becoming evident, however, that if tires are to withstand the increasingly demanding conditions to which they are subjected in service, much more attention must be paid to the material design as opposed to the structural design of tires. Nowhere is this more evident than in aircraft tires. Recent studies have shown that the tires of heavily laden wide-bodied aircraft reach temperatures in excess of 70°C at the relatively modest speed of 32 km/h (20 mph). Similarly, in heavy duty truck tires, temperatures over 100°C are not abnormal in the shoulder region. This leads to extensive restructurization of the fatigue resistant polysulfide network, particularly in the shoulder of the tire, to give a much weaker mono-disulfide structure. It is no coincidence then that failure normally occurs in this region. The practice of multiple retreading exacerbates the change in chemical decomposition of the rubber. It is well known to the rubber scientist that extending the vulcanization process also leads to restructurization of the rubber network from polysulfide to mono- and disulfide. This is shown typically for a HAF-black tire formulation at 140°C in Figure 1. Antidegradants have virtually no effect on anaerobic restructurization (see Figure 2), and indeed, the established antifatigue agent, IPPD (I), actually accelerates the loss of polysulfide crosslinks from the vulcanizate at 140°C. During fatiguing, on the other hand, IPPD effectively retards restructurization (see Figure 3), whereas a typical bisphenol, nonstaining antidegradant, II, has much less effect.

Sign in / Sign up

Export Citation Format

Share Document