DAILY NEWS ANALYSIS

Chola Dynasty

• A recently released movie centered on a made-up history of the Chola kingdom in the tenth century.
• The Cholas are renowned for their progressiveness, the architectural wonders and temples they built, the historical period's social structure, and the naming of cities after women.

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The Cholas' reign:

Sphere of influence

• Currently existing Tamil Nadu, Kerala, and portions of Andhra Pradesh and Karnataka made up the Chola kingdom.
• It is one of the dynasties with the longest reigns in recorded history.

Geographic range:

• The lush Kaveri River Valley served as the Cholas' home base.
• South of the Tungabhadra, they united peninsular India and controlled it as one state for three centuries.
• The southernmost point of the Chola holdings was the Maldives, and the northernmost point was the banks of the Godavari River in Andhra Pradesh.
• Capital and significant locations: Thanjavur served as their early capital, followed by Gangaikonda Cholapuram.
• Madurai and Kanchipuram were regarded as the regional capitals where sporadic court proceedings took place.

Establishment of the dynasty:

• Vijaylaya, a Pallava monarch who was called a "feudatory," started the dynasty.
• Vijaylaya built the groundwork for a dynasty that would control a significant portion of southern India while being a relatively minor player in the area among giants.
• The Rajaraja I dynasty rose to power as a military, economic, and cultural force under Rajaraja I and his successors Rajendra I, Rajadhiraja I, Rajendra II, Virarajendra, and Kulothunga Chola I.
• The dynasty continued to rule various lands up until the 13th century CE as one of the Three Crowned Kings of Tamilakam, with the Chera and Pandya.
• Other strong dynasties in the area rose and fell during the Chola period (about the 9th to 12th century AD), including the Rashtrakutas of the Deccan, who overthrew the Cholas, and the Chalukyas of the Andhra Pradesh region, with whom the Cholas repeatedly engaged in war.
• Agriculture and canals under the Cholas: Tamil Nadu had significant agricultural growth during the imperial Chola Dynasty's dominion, particularly in the Kaveri Basin.
• The majority of the Kaveri River's canals date from this time.
• Trade: Although the scope of this dominance is debatable, the Cholas had close relations with commercial organizations, which enabled them to launch great naval expeditions.
• A powerful army and navy: The Chola dynasty was most notable for its maritime prowess, which allowed them to extend their conquests as far as Malaysia and the Sumatra islands of Indonesia.
• Because of the dominance, for a while the Bay of Bengal was transformed into a "Chola lake."
• The dynasty rose to prominence in South Asia and South-East Asia as a military, economic, and cultural force.
• The 9th and 10th centuries were a turbulent time when countries frequently went to war with one another, therefore the Cholas had good reason to maintain a formidable army and navy.

Design & Culture:

• Temple construction: The Pallava dynasty, which was influenced by the Amaravati school of design, is how the Cholas traditionally built their temples.
• The two splendid temples of Thanjavur and Gangaikondacholapuram are examples of how the Chola architecture has developed to maturity and majesty.
• Brihadeeswara Temple: At the time it was constructed, the majestic Brihadeeswara temple in Thanjavur, India, was the biggest structure there.
• The extensive administrative and financial procedures pertaining to the temple's daily management are etched on the walls of this temple.

Temple of Airavateswara:

• Rajaraja II commissioned the construction of the beautiful Airavateswara temple at Darasuram near Thanjavur, which is a fine example of the stage of architectural development attained in the 12th century CE.

Sculptures:

• The sculptures and bronzes produced during the Chola era are equally noteworthy.
• Chola kings and queens ordered several pieces of art and sculpture, including the well-known bronze Nataraja statues.
• Bronzes from the Chola era were produced utilizing the lost wax method.
• In the past, the Rashtrakutas constructed the Kailasanatha temple in Aurangabad, Maharashtra, which at the time was the largest monolithic edifice (made from a single rock).
• Blots on the Chola history include the slaughter of people, especially Brahmans and children, and the sacking and plundering of Chalukyan cities like Kalyani.
• Anuradhapura, the former seat of the Sri Lankan kings, was destroyed.

Read Also: Nobel Prize in Chemistry 2022

Nanomaterials' role in resolving environmental problems

• The application of contemporary technology, such as nanomaterials or Carbon Dots (CD), may provide remedies for environmental problems like water contamination.
• The integrity of the aquatic environment has been harmed by the entry of poisonous and hazardous contaminants into waterbodies as a result of modern society's urbanisation.
• New technological advancements like nanotechnology offer creative answers for effective and sustainable environmental remediation.

Nanotechnology: What is it?

• About: The study of physical phenomena and creation of novel materials and devices with physical sizes between 1 and 100 nanometers constitute the field of nanotechnology (nm).
• Almost every aspect of our life is impacted by nanotechnology, including manufacturing, electronics, computers, and information technology, as well as industries including agriculture, medicine, the environment, and energy storage.
• India's involvement in nanotechnology has been marked by a broad group of stakeholders, each with their own goals and responsibilities.
• Currently, government-led initiatives are the main drivers of nanotechnology in India. Participation by the industry only lately began.
• With a few notable exceptions, public universities and research institutions are where the majority of nanotechnology research and development is conducted.

About Describe Carbon Dots (CDs):

• One of the newest members of the family of carbon nanomaterials are Carbon Dots (CDs).
• They have an average diameter of fewer than 10 nanometers and were found in 2004.
• The outstanding optical characteristics of CDs vary uniquely depending on the synthesis precursor.
• Because they make good electron donors and acceptors, they are becoming more and more sought-after as candidates in applications including sensing and bioimaging.
• Bioimaging refers to techniques that allow non-invasive real-time visualisation of biological processes.
• Additionally, CDs are reasonably priced, very biocompatible, and environmentally benign.

Role of CDs in Managing Environmental Issues

Pollution Detection:

• For the identification of environmental contaminants using fluorescence and colorimetry, CDs are a fantastic option.
• Because of their strong fluorescence emission, they are frequently utilised as fluorescent nanoprobes for pollution detection.
• They also make it possible to use the colorimetric approach to detect contaminants that change colour.
• Contaminant Adsorption: The technology's compact size and high specific surface area enable the provision of numerous surfaces as adsorption sites.
• Water Treatment: Since CDs are promising nano-fillers in the construction of thin-film nanocomposite membranes, where they can create chemical interactions with other chemicals, they can also be effective for water treatment.
• Waste from water hyacinths was used to make CDs; these CDs fluoresced green when exposed to UV light. They have also been shown to be luminous sensors for troublesome pesticides in aquatic bodies.
• Pollutant Degradation: By offering a cutting-edge method for subsequent-generation photocatalysis, the technique can also be helpful for pollutant degradation.
• The term "photocatalysis" refers to chemical reactions that utilise light and a semiconductor.
• Carbon dots serve as a photosensitizer, whereas organic contaminants in contaminated water can operate as electron and hole transporting agents.
• Antimicrobial: Physical/mechanical destruction, oxidative stress, photocatalytic activity, and suppression of bacterial metabolism are the principal antimicrobial mechanisms of CDs.
• Under visible or natural light, CDs in contact with the bacteria cell could effectively produce reactive oxygen species.
• Deoxyribnucleioc acid (DNA) or ribonucleic acid (RNA) damage from this can lead to the death of bacteria.

What is Carbon Dot Green Synthesis Categorization?

• In general, "top-down" and "bottom-up" approaches can be used to synthesise carbon dots.
• The top-down strategy uses laser ablation, arc discharge, and chemical or electrochemical oxidation to reduce massive carbon structures into quantum-sized carbon dots.
• In the bottom-up approach, CDs are created by pyrolyzing, carbonising, hydrothermally processing, or microwave-assisted synthesising small molecule precursors.

Read Also : SYNTHETIC BIOLOGY

Nobel Prize 2022 in Medicine/Physiology

• Svante Pääbo, a Swedish biologist, just received the 2022 Nobel Prize for Physiology or Medicine for his work on the genomes of extinct hominins and human evolution.
• David Julius and Ardem Patapoutian, two American scientists, received the award in 2021 for their work identifying the receptors for temperature and touch.

What are Svante Paabo's Research's Key Highlights?

• Human development and the nearest living relatives of modern humans, the Neanderthals, evolved outside of Africa and lived in Europe and Western Asia from about 400,000 years ago until 30,000 years ago, when they went extinct. Homo sapiens first appeared in Africa about 300,000 years ago.
• Neanderthal genome sequencing: It has been discovered that ancient gene sequences from our extinct ancestors have an impact on the physiology of modern people.
• For instance, the Denisovan variant of the gene EPAS1, which is widespread among modern Tibetans, gives an advantage for life at high altitudes.
• Other instances include Neanderthal genes that influence how our immune systems react to various pathogens.
• Denisova's discovery: In the Denisova cave in southern Siberia, a fragment of a finger bone that was 40,000 years old was found in 2008.
• This bone's DNA was sequenced, which resulted in the identification of a previously unidentified hominin that was given the name Denisova.
• Coexistence of Different Human Species: The Neanderthals and Denisovans, who are the progenitors of modern humans, coexisted with them for around 20,000 years, during which time they not only interacted but also interbred.
• Approximately 1-4% of the genome in contemporary humans of European or Asian descent is Neanderthal-derived.
• Additionally, there had been gene exchange between Denisova and Homo sapiens. Populations in Melanesia and other regions of South East Asia, where people have up to 6% Denisova DNA, are where this association was initially discovered.

Novel Approach:

• Ancient DNA is extremely fragmented and contaminated with fungi and bacteria, making it difficult to amplify and sequence. DNA tends to deteriorate and undergo chemical modification over time.
• Pääbo made the decision to research Neanderthal mitochondrial DNA as a result.
• The organelle inside the cell known as the mitochondria, or the "powerhouse of the cell," has its own DNA.
• The mitochondrial genome exists in thousands of copies despite being tiny and only holding a small portion of the genetic material in the cell. This raises the likelihood of its sequencing being successful.
• Importance: The conceptual innovation is crucial to comprehending human evolution.
• Paleogenomics is the study and analysis of the genes of ancient or extinct creatures, and it has grown as a result of Dr. Pääbo's research.

Neanderthals: Who were they?

• Before going extinct some 30,000 years ago, Neanderthals, the closest relatives of modern humans, inhabited throughout Europe, West Asia, and even southern Siberia and the Middle East.

Read Also: Nobel Prize in Chemistry 2022

Nobel Prize in Chemistry 2022

• The Nobel Prize in Chemistry for 2022 has been given to Carolyn R. Bertozzi, Morten Meldal, and K. Barry Sharpless "for the creation of Click Chemistry and Bioorthogonal Chemistry."

• Sharpless (who won a second time) developed the term "click chemistry" and put a lot of effort into it.
• Independent of Sharpless, Meldal developed a unique chemical structure called a "triazole," which has a wide range of important uses.
• Bertozzi then advanced by creating "bioorthogonal" click reactions, which could function inside living creatures (a term she coined).
• Benjamin List and David MacMillan received the 2021 Nobel Prize in Chemistry for their work on asymmetric organocatalysis.

What have Nobel Prize winners done for click chemistry?

Idea (Invented by Sharpless):

• In a simple form of chemistry known as "Click Chemistry," molecular building blocks can come together easily and swiftly. It is a type of straightforward chemistry that is trustworthy, where reactions happen rapidly and undesirable byproducts are avoided.
• Barry Sharpless developed the idea of "click chemistry" around the year 2000. He discovered that it is simpler to link smaller molecules with entire carbon frameworks than it is to force carbon atoms, the building blocks of organic matter, to bond with one another.
• The key concept is to select straightforward reactions between molecules that have a "stronger intrinsic motivation" to bond together, leading to a quicker and less wasteful process.
• Meaning: Chemists frequently attempt to replicate the intricate chemical molecules seen in nature, and this has implications for the field of medicine, including how to identify and neutralise pathogens in cells. But this procedure could be difficult and drawn out.
• Although the reliable way of creating molecules known as click chemistry cannot produce precise replicas of natural molecules, it will be possible to find molecules that perform the same activities.

(Meldal and Sharpless) Azide - Alkyne Cycloaddition

• The copper catalysed azide-alkyne cycloaddition was the crowning achievement of click chemistry in the 2000s, and it was produced independently by Meldal and Sharpless.
• A triazole, a stable ring-shaped chemical structure that is a popular building block in medicines, dyes, and agricultural compounds, was discovered by Meldal to be produced when copper ions were added to a reaction between an alkyne and an acyl halide. By including copper ions, the reaction may be controlled to produce only one chemical.
• The triazole was created by combining the azide with the alkyne. Azide is an organic molecule with a N3 (Nitride Ion) ion, whereas an alkyne is a hydrocarbon with at least one triple bond in the carbon atom.
• Today, the discovery of pharmaceuticals, the mapping of Deoxyribonucleic Acid (DNA), and the production of materials that are more suited for their intended use are only a few applications for this straightforward and efficient chemical reaction.

(Bertozzi) Bioorthogonal Reactions

• These processes take place inside living things without interfering with the cell's regular chemistry.
• Further advancements in a variety of biomedical fields, including molecular bioimaging, targeted delivery, in situ drug activation, research on cell-nanomaterial interactions, biosensing, etc., may result from its application in conjunction with nanotechnology.
• Researchers have enhanced the targeting of cancer drugs by using bioorthogonal processes.
• The origin of Bertozzi's Cancer Fighting Click Chemistry?

Finding Glycans

• In order to make glycans more visible, Carolyn R. Bertozzi intended to attach fluorescent molecules to them. Glycans are a difficult-to-find form of carbohydrate present on the surface of cells that are essential to the immune system.
• The same azide that Meldal and Sharpless both employed was chosen by Bertozzi. The azide is safe to introduce in living things and avoids reacting with other cell components.
• She created a different click chemistry process in 2004 that operated without poisonous copper and was secure for use in live cells.
• The work of Bertozzi is being used to discover glycans on the surface of tumour cells and to disarm their defence systems that render immune cells ineffective.
• Clinical trials for this treatment are now being conducted on patients with advanced cancer. Additionally, scientists have started creating "clickable antibodies" that can be used to track tumours and precisely administer radiation dosages to cancer cells.

Read Also: Nobel Prize 2022 in Medicine/Physiology