scholarly journals Physical, Chemical and Biological Study of Leaf Extracts from Senna obtusifolia: Bibliographic Review

2021 ◽  
Vol 15 (29) ◽  
pp. 82-90
Author(s):  
Mario Omar Calla Salcedo ◽  
Sheylla Susan Moreira da Silva de Almeida
Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 568
Author(s):  
Daniele Fulvio ◽  
Alexey Potapov ◽  
Jiao He ◽  
Thomas Henning

A deep understanding of the origin of life requires the physical, chemical, and biological study of prebiotic systems and the comprehension of the mechanisms underlying their evolutionary steps. In this context, great attention is paid to the class of interstellar molecules known as “Complex Organic Molecules” (COMs), considered as possible precursors of prebiotic species. Although COMs have already been detected in different astrophysical environments (such as interstellar clouds, protostars, and protoplanetary disks) and in comets, the physical–chemical mechanisms underlying their formation are not yet fully understood. In this framework, a unique contribution comes from laboratory experiments specifically designed to mimic the conditions found in space. We present a review of experimental studies on the formation and evolution of COMs in the solid state, i.e., within ices of astrophysical interest, devoting special attention to the in situ detection and analysis techniques commonly used in laboratory astrochemistry. We discuss their main strengths and weaknesses and provide a perspective view on novel techniques, which may help in overcoming the current experimental challenges.


Author(s):  
Henry S. Slayter

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.


2019 ◽  
Vol 3 (5) ◽  
pp. 435-443 ◽  
Author(s):  
Addy Pross

Despite the considerable advances in molecular biology over the past several decades, the nature of the physical–chemical process by which inanimate matter become transformed into simplest life remains elusive. In this review, we describe recent advances in a relatively new area of chemistry, systems chemistry, which attempts to uncover the physical–chemical principles underlying that remarkable transformation. A significant development has been the discovery that within the space of chemical potentiality there exists a largely unexplored kinetic domain which could be termed dynamic kinetic chemistry. Our analysis suggests that all biological systems and associated sub-systems belong to this distinct domain, thereby facilitating the placement of biological systems within a coherent physical/chemical framework. That discovery offers new insights into the origin of life process, as well as opening the door toward the preparation of active materials able to self-heal, adapt to environmental changes, even communicate, mimicking what transpires routinely in the biological world. The road to simplest proto-life appears to be opening up.


Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
N Pandita ◽  
A Varghese ◽  
M Mantri ◽  
Y Kachwala
Keyword(s):  

Planta Medica ◽  
2013 ◽  
Vol 79 (05) ◽  
Author(s):  
ADC Abergas ◽  
MCQ Aleria ◽  
ZJS Alimagno ◽  
KNC Batac ◽  
AFM De Lara ◽  
...  

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