Currents in Biochemical Research 1956

PEDIATRICS ◽  
1958 ◽  
Vol 21 (4) ◽  
pp. 699-699
Author(s):  
SAMUEL J. FOMON
Keyword(s):  
Electron Transfer ◽  
Enzyme Activity ◽  
Chemical Reactions ◽  
The Past ◽  
Recent Developments ◽  
Living Organisms ◽  
Biochemical Research ◽  
Prosthetic Groups ◽  
Kinetics Of

Because most chemical reactions occurring in living organisms are catalyzed by enzymes and because recent developments in methodology have given great impetus to studies of these substances, it is perhaps not surprising that enzyme chemistry is prominently featured in a collection of essays recounting important advances in biochemical research during the past 10 years. The mechanism of synthesis of enzymes and of interaction between enzyme and substrate, the importance of certain of the prosthetic groups, co-enzymes and co-factors, electron transfer and kinetics of enzyme activity are all considered.

scholarly journals Analytical applications of oscillatory chemical reactions: Determination of some pharmaceuticaly and biologically important compounds

2012 ◽  
Vol 66 (2) ◽  
pp. 153-164 ◽  
Author(s):  
Natasa Pejic ◽  
Slobodan Anic ◽  
Ljiljana Kolar-Anic
Keyword(s):  
Chemical Reactions ◽  
Stirred Tank ◽  
Analyte Concentration ◽  
Tank Reactor ◽  
The Past ◽  
Quantitative Characteristics ◽  
Oscillatory Chemical ◽  
Kinetics Of ◽  
Made In

Novel analytical methods for quantitive determination of analytes based on perturbations of oscillatory chemical reactions realized under open reactor conditions (continuosly fed well stirred tank reactor, CSTR), have been developed in the past twenty years. The proposed kinetic methods are generally based on the ability of the analyzed substances to change the kinetics of the chemical reactions matrix. The unambiguous correlation of quantitative characteristics of perturbations, and the amount (concentration) of analyte expressed as a regression equation, or its graphics (calibration curve), enable the determination of the unknown analyte concentration. Attention is given to the development of these methods because of their simple experimental procedures, broad range of linear regression ( 10-7 10-4 mol L-1) and low limits of detection of analytes ( 10-6 10-8 mol L1, in some cases even lower than 10-12 mol L-1). Therefore, their application is very convenient for routine analysis of various inorganic and organic compounds as well as gases. This review summarizes progress made in the past 5 years on quantitative determination of pharmaceutically and biologically important compounds.

Recent Developments in Mechanisms and the Kinetics of Deformation Twinning in Titanium Alloys

2010 ◽  
Vol 654-656 ◽  
pp. 863-866 ◽  
Author(s):  
Zane Wyatt ◽  
Sreeramamurthy Ankem
Keyword(s):  
Diffusion Process ◽  
Titanium Alloys ◽  
Time Dependent ◽  
Deformation Mechanisms ◽  
Strain Rate Effects ◽  
The Past ◽  
Shear Process ◽  
Rate Effects ◽  
Recent Developments ◽  
Kinetics Of

Within the past decade, it has been shown that twinning in α, β, and α + β titanium alloys can occur at speeds much lower than the speed of sound by many orders of magnitude. This is related to the twinning deformation mechanisms controlled by the diffusion of oxygen as compared to simply a shear process. Very recent developments, such as strain-rate effects on twinning, support a recent hypothesis that the twinning in these materials is controlled by a slow diffusion process, resulting in time-dependent twinning. These recent developments, along with the ramifications of the findings will be outlined in this article.

scholarly journals Critical aspects in exploring time analysis for the voltammetric estimation of kinetic parameters of surface electrode mechanisms coupled with chemical reactions

2021 ◽  
Vol 40 (1) ◽  
pp. 1
Author(s):  
Rubin Gulaboski ◽  
Valentin Mirceski ◽  
Milivoj Lovric
Keyword(s):  
Electron Transfer ◽  
Chemical Reactions ◽  
Accurate Determination ◽  
Frequency Variation ◽  
Main Concern ◽  
Square Wave ◽  
Transfer Step ◽  
Independent Analysis ◽  
Kinetics Of ◽  
Critical Aspects

The accurate determination of the rate constant related to the electron transfer step of so-called “surface redox active compounds” by voltammetric measurements is very important because it is linked to the reactivity and stability of many biological and chemical systems such as redox enzymes, vitamins, hormones, and many more. Evaluation of the kinetics of the electron transfer is often challenging, especially when chemical equilibria are coupled to the electron transfer step. In this work, we theoretically consider some critical aspects of the time-related methodologies in square-wave voltammetry (SWV), which is designed to analyze the kinetics of the electron transfer step of surface mechanisms coupled with chemical reactions. We demonstrate with a series of simulated scenarios that caution must be taken when exploring the time-related analysis for kinetic characterizations for both surface CE and EC mechanisms. The main concern stems from the fact that the SW frequency simultaneously affects both the kinetics of electron transfer and that of chemical reactions as well. Under defined conditions, the SW frequency variation in the case of surface EC and CE mechanisms may produce unexpected features of the voltammetric patterns. In many scenarios, time-independent analysis, such as those related to the square-wave amplitude and potential increment, are seen as alternative tools to evaluate the rate parameter of electrode reactions.

Light guided chemoselective olefin metathesis reactions

2017 ◽  
Vol 89 (6) ◽  
pp. 829-840 ◽  
Author(s):  
Ofer Reany ◽  
N. Gabriel Lemcoff
Keyword(s):  
Chemical Reactions ◽  
Olefin Metathesis ◽  
Lessons Learned ◽  
The Past ◽  
Metathesis Reactions ◽  
Catalytically Active ◽  
Recent Developments ◽  
Metathesis Catalysts ◽  
External Stimuli ◽  
Careful Design

AbstractAn appealing concept in synthetic chemistry is photo-induced catalysis; where dormant complexes become catalytically active upon activation with light. The ruthenium-based olefin metathesis complexes founded on the original Grubbs catalyst have probably been one of the most widely studied families of catalysts for the past 25 years. Greater stability and versatility of these olefin-metathesis catalysts has been achieved by careful design of the ligand sphere, including latent catalysts which are activated by external stimuli. This article describes our recent developments towards light-induced olefin metathesis reactions based on photoactive sulfur-chelated ruthenium benzylidene catalysts. Alternative chemical reactions, be it photo-induced olefin metathesis or other direct photochemical processes, by using light of different frequencies were studied in chemoselective chromatic orthogonal pathways. The lessons learned during the development of these reactions have given birth to selective photo-deprotection sequences and novel pathways for stereolithographic applications.

Wilfred Ethier. Modern International Economics. New York: W. W. Norton and Company. 1983. xviii + 588 pp.

1988 ◽  
Vol 27 (1) ◽  
pp. 81-83
Author(s):  
Nadeem A. Burney
Keyword(s):  
International Economic ◽  
New York ◽  
Economic Theory ◽  
International Economics ◽  
International Monetary System ◽  
International Markets ◽  
The Past ◽  
Monetary System ◽  
Recent Developments

Its been long recognized that various economies of the world are interlinked through international trade. The experience of the past several years, however, has demonstrated that this economic interdependence is far greater than was previously realized. In this context, the importance of international economic theory as an area distinct from general economics hardly needs any mentioning. What gives international economic theory this distinction is international markets for some goods and effects of national sovereignty on the character of economic activity. Wilfred Ethier's book, which incorporates recent developments in the field, is an excellent addition to textbooks on international economics for one- or twosemester undergraduate courses. The book mostly covers standard topics. A distinguishing feature of this book is its detailed analysis of the flexible exchange rates and a discussion of the various approaches used for their determination. Within each chapter, the author has extensively used facts, figures and major events to clarify the concepts in the light of the theoretical framework. The book also discusses, in a fair amount of detail, the existing international monetary system and the role of various international organizations.

Developments in sugarcane processing over the past 15 years

2019 ◽  
pp. 451-458
Author(s):  
Peter W. Rein
Keyword(s):  
Environmental Conditions ◽  
Energy Value ◽  
The Past ◽  
Recent Developments ◽  
Technology Of Production ◽  
Sugarcane Processing

Developments in the technology of production of sugar from sugarcane tend to be incremental improvements in an effort to reduce costs and boost revenue. Nonetheless the developments are significant and contribute to sustainable sugarcane enterprises. Some technologies have adapted to changing environmental conditions, and more attention is being given to boosting revenue through associated activities, particularly in enhancing the potential for sugarcane operations to exploit the energy value of sugarcane. This paper outlines recent developments of interest in processing sugarcane.

Performing States-Of-In-Between: Dogs, Parrots, and Other Humans in Recent Austrian Performances

2017 ◽  
Vol 40 (3) ◽  
pp. 295-310
Author(s):  
Sabine Wilke
Keyword(s):  
Fine Arts ◽  
Specific Form ◽  
Cultural Critique ◽  
Contemporary Society ◽  
Dramatic Effect ◽  
The Past ◽  
Violent Content ◽  
The World ◽  
The Sixties ◽  
Recent Developments

Every late spring since 1951, the Wiener Festwochen bring performers from around the world to Vienna for an opportunity to share recent developments in performance styles and present them to a Viennese public that seems to be increasingly open to experimentation. These festival weeks solidify a specific form of Viennese self-understanding and self-representation as a culture that is rooted in performance. This essay seeks to link two recent Austrian performances—one of them was part of the Wiener Festwochen in 2016, the other was staged in downtown Linz during the past few years—to this Austrian and specifically Viennese culture of performance by reading them as contemporary articulations of a tradition of radical performance art that can be traced back to the Viennese Actionism of the sixties and later feminist articulations in the seventies and eighties. They play on the dramatic effect of these actions, specifically their joy in cruelty, chaos, and orgiastic intoxication, by staging regressions and thus making visible what has been dammed up and repressed in contemporary society.1 Just as their historical models, these two performances merge the performing and the fine arts and they highlight provocative, controversial, and, at times, violent content. But they do it in an interspecies context that adds an entire layer of complexity to the project of societal and cultural critique.

The Medicinal Chemistry of Therapeutic Peptides: Recent Developments in Synthesis and Design Optimizations

2019 ◽  
Vol 26 (13) ◽  
pp. 2330-2355 ◽  
Author(s):  
Anutthaman Parthasarathy ◽  
Sasikala K. Anandamma ◽  
Karunakaran A. Kalesh
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Therapeutic Potential ◽  
The Past ◽  
Recombinant Production ◽  
Tremendous Progress ◽  
Recent Developments ◽  
Therapeutic Peptides ◽  
Development Processes ◽  
Delivery Strategies

Peptide therapeutics has made tremendous progress in the past decade. Many of the inherent weaknesses of peptides which hampered their development as therapeutics are now more or less effectively tackled with recent scientific and technological advancements in integrated drug discovery settings. These include recent developments in synthetic organic chemistry, high-throughput recombinant production strategies, highresolution analytical methods, high-throughput screening options, ingenious drug delivery strategies and novel formulation preparations. Here, we will briefly describe the key methodologies and strategies used in the therapeutic peptide development processes with selected examples of the most recent developments in the field. The aim of this review is to highlight the viable options a medicinal chemist may consider in order to improve a specific pharmacological property of interest in a peptide lead entity and thereby rationally assess the therapeutic potential this class of molecules possesses while they are traditionally (and incorrectly) considered ‘undruggable’.

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