Enzymatic Synthesis and Analysis of Large-Ring Cyclodextrins

2002 ◽  
Vol 55 (2) ◽  
pp. 39 ◽  
Author(s):  
M. Zheng ◽  
T. Endo ◽  
W. Zimmermann
Keyword(s):  
Physicochemical Properties ◽  
Recent Work ◽  
Enzymatic Synthesis ◽  
Degree Of Polymerization ◽  
Reaction Conditions ◽  
Guest Molecules ◽  
Large Ring ◽  
The Past ◽  
Specific Host ◽  
Wide Range

Large-ring cyclodextrins (LR-CD) are cyclic α-1,4-glucans composed of nine to more than several hundred glucopyranose units. Cyclodextrins are able to form highly specific inclusion complexes with a wide range of guest molecules thereby modifying their physicochemical properties. Only in the past 10 years, LR-CD with a degree of polymerization between 9 and 32 have been isolated and characterized. The structures of these LR-CD show novel features distinct from those of the extensively studied α- β-, and γ-CD composed of six, seven, and eight glucopyranose units, respectively. Recent work on the enzymatic synthesis of LR-CD has confirmed the ability of different 4-α-glucanotransferases to form large cyclic α-1,4-glucans from amylose and amylopectin, depending on the specificity of the enzyme used and on the substrate and reaction conditions chosen. The potential of LR-CD for specific host-guest interactions and corresponding applications has been demonstrated.

scholarly journals Thalidomide Embryopathy: An Enigmatic Challenge

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Neil Vargesson
Keyword(s):  
Multiple Myeloma ◽  
Recent Work ◽  
Birth Defects ◽  
Behcet’S Disease ◽  
Molecular Targets ◽  
Species Specificity ◽  
The Past ◽  
Wide Range ◽  
Clinical Conditions ◽  
New Generation

Thalidomide remains one of the world’s most notorious drugs due to the severe birth defects it induced in children between 1957 and 1962. Yet, to some this drug is a lifesaver, as it now enjoys renaissance in the treatment for a wide range of conditions including leprosy, multiple myeloma, Behcet’s disease, and some cancers. However, thalidomide has also been linked to causing a new generation of thalidomide survivors in Brazil, where the drug is used to treat leprosy. Surprisingly how thalidomide causes birth defects and how it acts in the treatment of clinical conditions are still far from clear. In the past decade great strides in our understanding of the actions of the drug, as well as molecular targets, have been made. The purpose of this review is to look at the recent work carried out into understanding how thalidomide causes birth defects, it’s molecular targets and the challenges that remain to be elucidated. These challenges include identifying clinically relevant but nonteratogenic forms of the drug, and the mechanisms underlying phocomelia and species specificity.

Microwave-accelerated Approaches to Diverse Xanthenes: A Review

2020 ◽  
Vol 7 (2) ◽  
pp. 99-111
Author(s):  
Jagmeet Singh ◽  
Ankit Lathwal ◽  
Shalini Agarwal ◽  
Mahendra Nath
Keyword(s):  
Reaction Rates ◽  
Waste Generation ◽  
Reaction Conditions ◽  
Catalytic Systems ◽  
Heterocyclic Molecules ◽  
The Past ◽  
Wide Range ◽  
Pharmaceutical Properties ◽  
Synthetic Methodologies ◽  
High Yields

Microwave-accelerated methods have emerged as powerful tools in organic synthesis to enhance the reaction rates and provide products with high yields, improved selectivity, lower energy consumption, mild reaction conditions and negligible waste generation. Xanthenes are an important class of biologically important oxygen-containing heterocyclic molecules that possess a multitude of pharmaceutical properties. By considering the medicinal and material significance of these molecules, a large number of synthetic methodologies and catalytic systems have been reported for the synthesis of a wide range of xanthenes in the past. However, the focus of the present review is to summarize various microwave-assisted protocols for the synthesis of diversely substituted xanthene analogues.

scholarly journals Feature sampling in categorization and recognition of objects

2002 ◽  
Vol 55 (1) ◽  
pp. 141-154 ◽  
Author(s):  
Koen Lamberts
Keyword(s):  
Recognition Memory ◽  
Recent Work ◽  
Time Course ◽  
Process Models ◽  
Dual Process ◽  
Perceptual Categorization ◽  
The Past ◽  
Wide Range ◽  
Single Process ◽  
Recognition Of Objects

This article presents an overview of some recent work on the time course of perceptual categorization and recognition memory. First, The EGCM-RT, which is a feature-sampling model of the time course of categorization, is described. It is shown that the model explains a wide range of categorization data. Second, an overview is given of a feature-sampling model of the time course of recognition that is derived from the EGCM-RT. This model explains results that have been interpreted in the past as evidence for dual-process models of recognition, and it provides a single-process alternative to dual-process accounts.

Optical Properties of HVEM Accelerators

1975 ◽  
Vol 33 ◽  
pp. 180-181
Author(s):  
A. Strojnik ◽  
J.W. Scholl ◽  
V. Bevc
Keyword(s):  
Optical Properties ◽  
Electron Accelerator ◽  
Systematic Investigation ◽  
Electron Source ◽  
High Brightness ◽  
The Past ◽  
Wide Range ◽  
Optical Behavior

The electron accelerator, as inserted between the electron source (injector) and the imaging column of the HVEM, is usually a strong lens and should be optimized in order to ensure high brightness over a wide range of accelerating voltages and illuminating conditions. This is especially true in the case of the STEM where the brightness directly determines the highest resolution attainable. In the past, the optical behavior of accelerators was usually determined for a particular configuration. During the development of the accelerator for the Arizona 1 MEV STEM, systematic investigation was made of the major optical properties for a variety of electrode configurations, number of stages N, accelerating voltages, 1 and 10 MEV, and a range of injection voltages ϕ0 = 1, 3, 10, 30, 100, 300 kV).

Pursuit of the Abscopal Effect

2020 ◽  
Vol 04 (04) ◽  
pp. 369-372
Author(s):  
Paul B. Romesser ◽  
Christopher H. Crane
Keyword(s):  
Tumor Immunology ◽  
Antitumor Immunity ◽  
Clinical Success ◽  
Immune Recognition ◽  
Immune Modulators ◽  
Cancer Subtypes ◽  
The Past ◽  
Tumor Irradiation ◽  
Wide Range ◽  
Tumor Recognition

AbstractEvasion of immune recognition is a hallmark of cancer that facilitates tumorigenesis, maintenance, and progression. Systemic immune activation can incite tumor recognition and stimulate potent antitumor responses. While the concept of antitumor immunity is not new, there is renewed interest in tumor immunology given the clinical success of immune modulators in a wide range of cancer subtypes over the past decade. One particularly interesting, yet exceedingly rare phenomenon, is the abscopal response, characterized by a potent systemic antitumor response following localized tumor irradiation presumably attributed to reactivation of antitumor immunity.

The Many Pasts of Detective Fiction

2020 ◽  
Vol 1 (2) ◽  
pp. 157-172
Author(s):  
Thomas Leitch
Keyword(s):  
Detective Fiction ◽  
Golden Age ◽  
Public History ◽  
Detective Novel ◽  
Sherlock Holmes ◽  
Detective Story ◽  
The Past ◽  
Wide Range ◽  
Detective Novels ◽  
The Many

Building on Tzvetan Todorov's observation that the detective novel ‘contains not one but two stories: the story of the crime and the story of the investigation’, this essay argues that detective novels display a remarkably wide range of attitudes toward the several pasts they represent: the pasts of the crime, the community, the criminal, the detective, and public history. It traces a series of defining shifts in these attitudes through the evolution of five distinct subgenres of detective fiction: exploits of a Great Detective like Sherlock Holmes, Golden Age whodunits that pose as intellectual puzzles to be solved, hardboiled stories that invoke a distant past that the present both breaks with and echoes, police procedurals that unfold in an indefinitely extended present, and historical mysteries that nostalgically fetishize the past. It concludes with a brief consideration of genre readers’ own ambivalent phenomenological investment in the past, present, and future each detective story projects.

Nine Centuries of Man

2017 ◽  
Keyword(s):  
Twentieth Century ◽  
Diverse Range ◽  
Gender Expectations ◽  
Court Records ◽  
The Past ◽  
Wide Range ◽  
Police Reports ◽  
Late Twentieth ◽  
Scottish History ◽  
Late Twentieth Century

What did it mean to be a man in Scotland over the past nine centuries? Scotland, with its stereotypes of the kilted warrior and the industrial ‘hard man’, has long been characterised in masculine terms, but there has been little historical exploration of masculinity in a wider context. This interdisciplinary collection examines a diverse range of the multiple and changing forms of masculinities from the late eleventh to the late twentieth century, exploring the ways in which Scottish society through the ages defined expectations for men and their behaviour. How men reacted to those expectations is examined through sources such as documentary materials, medieval seals, romances, poetry, begging letters, police reports and court records, charity records, oral histories and personal correspondence. Focusing upon the wide range of activities and roles undertaken by men – work, fatherhood and play, violence and war, sex and commerce – the book also illustrates the range of masculinities that affected or were internalised by men. Together, the chapters illustrate some of the ways Scotland’s gender expectations have changed over the centuries and how, more generally, masculinities have informed the path of Scottish history

Free but fragile: Human relations amidst poverty and HIV in democratic South Africa

2015 ◽  
Vol 2 (2) ◽  
pp. 85-94
Author(s):  
Christina Landman
Keyword(s):  
South Africa ◽  
Predominantly White ◽  
Black People ◽  
Hiv Treatment ◽  
Human Relations ◽  
White People ◽  
Black And White ◽  
The Past ◽  
Wide Range ◽  
Black Township

Dullstroom-Emnotweni is the highest town in South Africa. Cold and misty, it is situated in the eastern Highveld, halfway between the capital Pretoria/Tswane and the Mozambique border. Alongside the main road of the white town, 27 restaurants provide entertainment to tourists on their way to Mozambique or the Kruger National Park. The inhabitants of the black township, Sakhelwe, are remnants of the Southern Ndebele who have lost their land a century ago in wars against the whites. They are mainly dependent on employment as cleaners and waitresses in the still predominantly white town. Three white people from the white town and three black people from the township have been interviewed on their views whether democracy has brought changes to this society during the past 20 years. Answers cover a wide range of views. Gratitude is expressed that women are now safer and HIV treatment available. However, unemployment and poverty persist in a community that nevertheless shows resilience and feeds on hope. While the first part of this article relates the interviews, the final part identifies from them the discourses that keep the black and white communities from forming a group identity that is based on equality and human dignity as the values of democracy.

FROM THE HISTORY OF THE FORMATION AND DEVELOPMENT OF PERIODICALS IN NAMANGAN

2019 ◽  
Vol 20 (2) ◽  
pp. 49-54
Author(s):  
Dildora Alinazarova ◽  
Keyword(s):  
The Past ◽  
Wide Range ◽  
History Of ◽  
Printing House

In this article, based on an analysis of a wide range of sources, discusses the emergence and development of periodicals and printing house in Namangan. The activities of Ibrat- as the founder of the first printing house in Namangan are considered. In addition, it describes the functioning and development of "Matbaai Ishokia" in the past and present

p-Sulfonic acid calix[n]arene catalyzed synthesis of bioactive heterocycles: A review

2020 ◽  
Vol 24 ◽  
Author(s):  
Bubun Banerjee ◽  
Gurpreet Kaur ◽  
Navdeep Kaur
Keyword(s):  
Supramolecular Chemistry ◽  
Sulfonic Acid ◽  
Catalytic Efficiency ◽  
The Other ◽  
Reaction Conditions ◽  
Metal Free ◽  
Bioactive Scaffolds ◽  
Wide Range ◽  
Efficient Alternative ◽  
Bioactive Heterocycles

: Metal-free organocatalysts are becoming an important tool for the sustainable developments of various bioactive heterocycles. On the other hand, during last two decades, calix[n]arenes have been gaining considerable attention due to their wide range of applicability in the field of supramolecular chemistry. Recently, sulfonic acid functionalized calix[n] arenes are being employed as an efficient alternative catalyst for the synthesis of various bioactive scaffolds. In this review we have summarized the catalytic efficiency of p-sulfonic acid calix[n]arenes for the synthesis of diverse biologically promising scaffolds under various reaction conditions. There is no such review available in the literature showing the catalytic applicability of p-sulfonic acid calix[n]arenes. Therefore, we strongly believe that this review will surely attract those researchers who are interested about this fascinating organocatalyst.

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