Advances in [1,2]-Sigmatropic Rearrangements of Onium Ylides via Carbene Transfer Reactions

Synthesis ◽  
2021 ◽  
Author(s):  
Claire Empel ◽  
Sripati Jana ◽  
Rene M. Koenigs
Keyword(s):  
Review Article ◽  
Transfer Reactions ◽  
The Past ◽  
Sigmatropic Rearrangements ◽  
Carbene Transfer ◽  
Formation Step ◽  
Made In

This review article summarizes progress made in [1,2]-sigmatropic rearrangements using carbenes in the ylide formation step. While other rearrangements, such as the [2,3]-sigmatropic, Doyle-Kirmse, or Sommelet-Hauser rearrangements, have been studied in detail over the past decades, studies on [1,2]-sigmatropic rearrangements are still limited. Based on the application of diazoalkanes as carbene precursors, research on diazoalkanes in ylide formation reactions started flourishing in the 1990s. This review covers milestones from the beginning of [1,2]-sigmatropic rearrangements using carbenes to generate ammonium, oxonium and other ylide species and should serve as an overview to further promote research in this area.

REVIEW ARTICLE

PEDIATRICS ◽  
1956 ◽  
Vol 17 (6) ◽  
pp. 897-924
Author(s):  
Lytt I. Gardner
Keyword(s):  
Adrenal Tumor ◽  
Review Literature ◽  
Review Article ◽  
Adrenal Hyperplasia ◽  
The Past ◽  
Developing Area ◽  
Arbitrary Selection ◽  
Selection Of ◽  
Colorimetric Methods ◽  
Made In

THE IDENTIFICATION and measurement of adrenocortical steroids in body fluids over the past 2 decades have made possible an extensive exploration of adrenal function. This review is restricted to adrenocortical metabolism in the fetus, infant and child. No attempt will be made to cover all of this rapidly developing area of endeavor. Certain aspects have been treated in other review articles, to which the reader is referred. The reviews by Moore on fetal endorinology, Klein on neonatal adrenal physiology, Lieberman and Teich and Roberts and Szego on steroid biochemistry, White and Wettstein and Anner on adrenal cortical hormones, Ingle on cortisone and Gaunt, Renzi and Chart on aldosterone are especially useful. The books by Wilkins and by Talbot and colleagues contain helpful treatments of this area. Due to the prolific nature of even the review literature, it is necessary to make a rather arbitrary selection of material. NEWER METHODOLOGY Within recent years a number of methods have been developed for the estimation of hormones in urine and plasma. Several techniques for the chromatographic separation of the 17-ketosteroids in urine have been described. Of particular value in the diagnosis of virilizing adrenal tumor has been the development of colorimetric methods for the estimation of dehydroepiandrosterone in urine. Some progress has been made in the estimation of corticosteroids in the urine. Techniques for the measurement of 11-oxygenated neutral 17-ketosteroids, pregnanetriol and pregnanediol in the urine of patients with congenital adrenal hyperplasia have been described. There has been a blossoming of methods for estimating steroids in plasma. Several varieties of techniques are now available for the measurement of corticosteroids and 17-ketosteroids in plasma.

South Asian Developmental Crisis (Review Article)

1973 ◽  
Vol 12 (2) ◽  
pp. 181-188
Author(s):  
Rafiq Ahmad
Keyword(s):  
Second World War ◽  
World War ◽  
The Past ◽  
The Great Depression ◽  
Political Independence ◽  
Integrated Theory ◽  
Pass Through ◽  
Developed World ◽  
Second World ◽  
Made In

Like nations and civilizations, sciences also pass through period of crises when established theories are overthrown by the unpredictable behaviour of events. Economics is passing through such a crisis. The challenge thrown by the Great Depression of early 1930s took a decade before Keynes re-established the supremacy of economics. But this supremacy has again been upset by the crisis of poverty in the vast under-developed world which attained political independence after the Second World War. Poverty had always existed but never before had it been of such concern to economists as during the past twenty five years or so. Economic literature dealing with this problem has piled up but so have the agonies of poverty. No plausible and well-integrated theory of economic development or under-development has emerged so far, though brilliant advances have been made in isolated directions.

Literacy and Education: Fifth Release From the 1961 Census of Pakistan (Review Article)

1963 ◽  
Vol 3 (3) ◽  
pp. 424-442
Author(s):  
Jamila Akhtar
Keyword(s):  
Population Growth ◽  
Urban Areas ◽  
Review Article ◽  
Interim Report ◽  
Educational Levels ◽  
Rural And Urban Areas ◽  
The Past ◽  
Review Articles ◽  
Rural And Urban ◽  
Age And Sex

This review of the Literacy and Education Bklletin1 of the 1961 Census is fourth in the series of review articles published in this journal2. The Bulletin under review forms a part of the interim report on the characteristics of the population of Pakistan. It gives information on the number of illiterate and literate persons by age and sex for rural and urban areas on division and district basis; illiterate and literate.population in selected cities and towns; and the educational levels attained by the literate population by age and sex for divisions and districts. Relevant statistical notes and statements precede the tables in the Bulletin. The objective of this review is to describe the meaningfulness and significance of literacy statistics. To this end, a distinction is made between formal and functional levels of literacy. Comparisons of the 1951 and 1961 census figures are undertaken to indicate the progress of literacy and education during the past decade with reference to the effect of intercensal rate of population growth on such progress. Certain questions regarding the reliability of data are raised, which emphasize the need for caution in the interpretation of literacy statistics.

Mass Spectrometry Techniques: Principles and Practices for Quantitative Proteomics

2020 ◽  
Vol 21 ◽  
Author(s):  
Rocco J. Rotello ◽  
Timothy D. Veenstra
Keyword(s):  
Mass Spectrometry ◽  
Quantitative Proteomics ◽  
Protein Identification ◽  
Dynamic Nature ◽  
Complete Coverage ◽  
The Past ◽  
Proteome Level ◽  
A Cell ◽  
Quantitative Changes ◽  
Made In

: In the current omics-age of research, major developments have been made in technologies that attempt to survey the entire repertoire of genes, transcripts, proteins, and metabolites present within a cell. While genomics has led to a dramatic increase in our understanding of such things as disease morphology and how organisms respond to medications, it is critical to obtain information at the proteome level since proteins carry out most of the functions within the cell. The primary tool for obtaining proteome-wide information on proteins within the cell is mass spectrometry (MS). While it has historically been associated with the protein identification, developments over the past couple of decades have made MS a robust technology for protein quantitation as well. Identifying quantitative changes in proteomes is complicated by its dynamic nature and the inability of any technique to guarantee complete coverage of every protein within a proteome sample. Fortunately, the combined development of sample preparation and MS methods have made it capable to quantitatively compare many thousands of proteins obtained from cells and organisms.

Nucleosides and Nucleoside Analogues as Emerging Antiviral Drugs

2020 ◽  
Vol 17 ◽  
Author(s):  
Mohamed Ibrahim Elzagheid
Keyword(s):  
Significant Role ◽  
Mode Of Action ◽  
Crucial Role ◽  
Viral Infections ◽  
Antiviral Drugs ◽  
Review Article ◽  
Nucleoside Analogues ◽  
The Past ◽  
Nucleoside Drugs

: Nucleosides and their analogues have been in use for many years and have become essential for treating patients with viral infections. Many additional nucleoside drugs have been approved over the past decades. This strongly demonstrates how important these compounds are and the crucial role they play. Given that a significant amount of research and literature has been documented regarding nucleoside analogues, this review article mainly focuses the discussion on nucleosides and nucleoside analogous that have proven to play significant role or be emerging in the treatment of known viral infections. This covers the names, structures, applications, toxicity, and mode of action of relevant nucleoside analogues.

Formation of Carbon-Oxygen Bond Mediated by Hypervalent Iodine Reagents Under Metal-free Conditions

2020 ◽  
Vol 17 ◽  
Author(s):  
Ayesha Jalil ◽  
Yaxin O Yang ◽  
Zhendong Chen ◽  
Rongxuan Jia ◽  
Tianhao Bi ◽  
...  
Keyword(s):  
Natural Products ◽  
Bond Formation ◽  
Building Blocks ◽  
Review Article ◽  
Hypervalent Iodine ◽  
Metal Free ◽  
Bioactive Natural Products ◽  
The Past ◽  
Oxygen Bond ◽  
Privileged Scaffolds

: Hypervalent iodine reagents are a class of non-metallic oxidants have been widely used in the construction of several sorts of bond formations. This surging interest in hypervalent iodine reagents is essentially due to their very useful oxidizing properties, combined with their benign environmental character and commercial availability from the past few decades ago. Furthermore, these hypervalent iodine reagents have been used in the construction of many significant building blocks and privileged scaffolds of bioactive natural products. The purpose of writing this review article is to explore all the transformations in which carbon-oxygen bond formation occurred by using hypervalent iodine reagents under metal-free conditions

Evidence-based Assessment

2010 ◽  
pp. 76-98
Author(s):  
John Hunsley ◽  
Eric J. Mash
Keyword(s):  
Decision Making ◽  
Clinical Assessment ◽  
Assessment Process ◽  
Evidence Based ◽  
The Past ◽  
Specific Assessment ◽  
The Many ◽  
Selection Of ◽  
Made In

Evidence-based assessment relies on research and theory to inform the selection of constructs to be assessed for a specific assessment purpose, the methods and measures to be used in the assessment, and the manner in which the assessment process unfolds. An evidence-based approach to clinical assessment necessitates the recognition that, even when evidence-based instruments are used, the assessment process is a decision-making task in which hypotheses must be iteratively formulated and tested. In this chapter, we review (a) the progress that has been made in developing an evidence-based approach to clinical assessment in the past decade and (b) the many challenges that lie ahead if clinical assessment is to be truly evidence-based.

The Role of Histones and Heparin in Sepsis: A Review

2021 ◽  
pp. 088506662199232
Author(s):  
Xiaojuan Zhang ◽  
Xin Li
Keyword(s):  
Septic Shock ◽  
Multiple Organ ◽  
Clinical Settings ◽  
The Past ◽  
Life Saving ◽  
Extracellular Histones ◽  
Sepsis And Septic Shock ◽  
Development And Management ◽  
Made In

Septic shock with multiple organ failure is a devastating situation in clinical settings. Through the past decades, much progress has been made in the management of sepsis and its underlying pathogenesis, but a highly effective therapeutic has not been developed. Recently, macromolecules such as histones have been targeted in the treatment of sepsis. Histones primarily function as chromosomal organizers to pack DNA and regulate its transcription through epigenetic mechanisms. However, a growing body of research has shown that histone family members can also exert cellular toxicity once they relocate from the nucleus into the extracellular space. Heparin, a commonly used anti-coagulant, has been shown to possess life-saving capabilities for septic patients, but the potential interplay between heparin and extracellular histones has not been investigated. In this review, we summarize the pathogenic roles of extracellular histones and the therapeutic roles of heparin in the development and management of sepsis and septic shock.

Mapping Logistical Capitalism

2021 ◽  
pp. 026327642199042
Author(s):  
Eugene Brennan
Keyword(s):  
Critical Theory ◽  
20Th Century ◽  
Social Life ◽  
Review Article ◽  
Global Capitalism ◽  
Racial Capitalism ◽  
The Past ◽  
Black Lives Matter ◽  
Class Composition

This review article engages with a rich field of scholarship on logistics that has gathered momentum over the past decade, focusing on two new publications by Laleh Khalili and Martín Arboleda. It contextualizes how and why logistics is bound up with the militarization of contemporary political and social life. I argue that the later 20th century rise of logistics can be better understood as both a response to and symptom of capitalist crisis and I situate this scholarship on war and logistics in relationship to Giovanni Arrighi’s account of crisis and ‘unravelling hegemony’. I also show how logistics provides essential critical and visual resources that contribute to efforts to map global capitalism and to debates on totality and class composition in contemporary critical theory. Finally, contemporary events such as the ongoing Coronavirus crisis and the reemergence of Black Lives Matter are considered in light of this analysis with reference to the centrality of logistics to racial capitalism.

Some Experiments on the Extra-Corporeal Hatching of the Eggs of Ascaris suum

1939 ◽  
Vol 17 (2) ◽  
pp. 69-82 ◽  
Author(s):  
D. W. Fenwick
Keyword(s):  
Hydrochloric Acid ◽  
Digestive Tract ◽  
Sodium Carbonate ◽  
Ascaris Suum ◽  
The Body ◽  
Very Old ◽  
The Past ◽  
Pancreatic Fluid ◽  
Sand Cultures ◽  
Made In

Numerous attempts have been made in the past to induce the eggs of Ascaris suum to hatch outside the body of the host. Extra-corporeal hatching has been observed under a variety of conditions by different workers. Kondo (1920, 1922), Asada (1921) and others record hatching in water, charcoal and sand cultures. Wharton (1915) states that hatching will occur in alkaline digestive juices, while Martin (1913) records a similar phenomenon in pancreatic fluid. Many different explanations have been offered to explain this hatching. Wharton suggested that the interaction of algae and sand might have some effect. Ohba (1923), who found that hatching would occur in 0·2% hydrochloric acid and 0·2% sodium carbonate believed that extra-corporeal hatching was limited to very old cultures of eggs. Many workers are of the opinion that some stimulus normally present in the digestive tract is necessary for hatching.

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