Science & Technology

PARAM-1: India’s Foundational LLM

Context: In July 2025, the government-backed BharatGen released PARAM-1, a bilingual Large Language Model (LLM) built from scratch to reflect India’s linguistic and cultural realities, focusing on Hindi and English.

Relevance of the Topic: Prelims: Key Features of PARAM-1.

Foundational AI

Foundational AI: Large-scale AI models trained on very large datasets and over which numerous specific applications can be built, including generative AI.
Large Language Models (LLMs) are a type of Foundational AI model trained with vast datasets with at least one billion or more parameters. E.g., AI-powered tools like ChatGPT, Gemini, Perplexity, DeepSeek, Grok.
Small Language Models (SLMs) are compact AI systems typically having fewer than 1 billion parameters (ranges from millions to a few billion parameters). Cheaper to run and maintain, and ideal for specific use cases.

In its mission to build open source Large Language Models (LLMs) for Indian researchers and developers, BharatGen, the government-backed AI Initiative, has released a LLM called PARAM-1.

About PARAM-1

PARAM-1 is a 2.9-billion parameter bilingual foundational AI model developed by the BharatGen team.
It reflects India’s linguistic and cultural realities- with 25% of its training data in Hindi and the rest in carefully curated English.

Key Features:

Bilingual focus: Trained in Hindi and English, incorporating government documents, literary works, educational and community content.
Script-aware Tokeniser:
- Tokeniser is the first step in how a language model processes text. It breaks sentences into smaller units, or tokens, which the model can interpret.
- Standard tokenisers (built for English) perform poorly on Indian scripts, splitting words into too many fragments.
- PARAM-1 addresses this with a script-aware tokeniser that recognises Hindi and other Indic scripts, creating fewer and more meaningful tokens. This improves both accuracy and efficiency.
Three-phase training focuses on language fluency, factual consistency, and long-context understanding. This allows the model to gradually develop fluency, retain factual information, and improve performance on tasks that require reading and reasoning over longer texts.
India-centric evaluation: Tested on Indian benchmarks like MILU (competitive exam questions) and SANSKRITI (cultural knowledge), besides global ones like MMLU and ARC.

Limitations:

Currently supports only Hindi and English, excluding India’s wider linguistic diversity. Raises concerns over the model’s inclusivity, especially in a country where linguistic identity often intersects with regional politics and access to services.

Molecular Imaging: Caltech’s Angstrom-Scale Microscope

Context: Scientists at the California Institute of Technology (Caltech) have developed a breakthrough imaging technique that enables real-time filming of Brownian motion (molecular motions). This imaging technique indirectly detects molecules by observing their interactions with light and tapping into Brownian motion.

Relevance of the Topic: Prelims: Basic idea about working of Microscope; Brownian motion; Applications of high-resolution Molecular Imaging.

Conventional Microscope

Conventional light microscopes work by using visible light to magnify and resolve small objects or structures.
Limitations:
- Conventional microscopes are invasive (disturb or damage the sample being studied) either physically, chemically, or by introducing heat or radiation.
- Have limited fields of view. They can not distinguish individual molecules, which are around tens of Angstroms in size (1 Angstrom = 0.0000000001 m).

Brownian Motion:

Brownian motion is the random movement of particles in a fluid (liquid or air) due to their collisions with other atoms or molecules. The more massive a particle, the slower its Brownian motion.
Examples of Brownian Motion include:
- The motion of pollen grains on still water
- Movement of dust motes in a room (although largely affected by air currents)
- Diffusion of pollutants in the air
- Diffusion of calcium through bones
- Movement of "holes" of electrical charge in semiconductors.

Breakthrough Imaging Technique

The breakthrough imaging technique utilises Brownian motion, ultrafast lasers, and light-matter interaction to indirectly detect and visualise molecular behaviour by observing their interactions with light.
Their technique taps into the Brownian motion of particles. By measuring how fast a molecule changes the properties of light, researchers could determine its size.
- The more massive a particle, the slower its Brownian motion.
- Small molecules spin fast and disturb the light more than larger ones. This fact allows the size estimation of molecules by observing their interaction with light.
Benefits of the Microscope: Non-invasive; Can help visualise molecular sizes in real-time at the Angstrom scale (higher resolution). No existing technique till date has achieved this level of detail.

Significance: This new imaging technique could help better visualise processes and transform biomedical research, disease detection, drug design, and nanomaterial fabrication.

Applications of high-resolution Molecular Imaging:

Early detection of diseases (like cancer, cardiovascular, neurodegenerative) by visualising specific biomarkers associated with disease progression.
Drug design and targeted drug delivery: Help researchers visualise delivery of drugs to specific tissues or cells, and optimise the design of nanocarriers for improved therapeutic outcomes.
Efficient electronics: Observing the movement of electrons, and manipulating it to design more efficient electronic devices.
Nanomaterial fabrication: Helps understand molecular processes in nanomaterial synthesis.

Also Read: Nobel Prize in Physics for Attosecond Physics

Vitamin D deficiency linked to Neurodevelopmental Issues

Context: A major study published in The Lancet Psychiatry has found a potential link between neonatal vitamin D levels and the risk of developing neurodevelopmental disorders such as schizophrenia, ADHD, and Autism.

Relevance of the Topic: Prelims: India’s Vitamin D Problem; Vitamin D.

Vitamin D deficiency linked to Neurodevelopmental Issues

Researchers from Denmark used dried blood spot samples (Danish Neonatal Screening Biobank) from over 88,000 individuals born between 1981 and 2005.
From these samples, the team measured levels of:
- 25-hydroxyvitamin D or 25(OH)D which is the standard marker of vitamin D status.
- Vitamin D-binding protein which carries vitamin D in the blood and prolongs its activity.

Key Findings of the Study:

Babies with higher vitamin D levels were less likely to be diagnosed with schizophrenia, ADHD, or autism.
Newborns with levels about 12.6 nmol/l higher than average had an 18% lower risk of schizophrenia, an 11% lower risk of ADHD, and a 7% lower risk of autism.
Vitamin D-binding protein levels were also linked to schizophrenia risk.
Researchers found no strong link between low vitamin D levels at birth (neonatal vitamin D) and the risk of depression or bipolar disorder later in life.

Limitations of the Study:

Nearly all participants were of European Ancestry.
In a smaller non-European group, the results were less consistent, possibly due to lower vitamin D levels, smaller sample size, and/or genetic diversity.

Gene variants may influence both vitamin D and neurodevelopment, a phenomenon known as pleiotropy.
Vitamin D measured only at birth- the study could not pinpoint a critical window during pregnancy.

India’s Vitamin D Problem

India has a high Vitamin D deficiency rate despite abundant sunlight.
A study conducted at AIIMS Rishikesh between 2017 and 2018 found that 74% of infants and 85.5% of their mothers were deficient in vitamin D, with nearly half experiencing severe deficiency.
A 2024 study conducted in the Bundelkhand region of India found a strong positive correlation between mothers’ and their infants’ vitamin D levels and interpreted it to mean babies born to vitamin D-deficient mothers were very likely to be deficient themselves.
However, findings also suggest that timely supplementation in deficient mothers can remarkably improve both maternal and neonatal levels.

Vitamin D insufficiency is not just an individual issue: it is a biological legacy passed from one generation to the next, shaping not just bones but brains too. India must move from reactive treatment to proactive care through awareness, screening, and timely supplementation.

Apache AH-64E Helicopters

Context: In a significant fillip to modernisation of military aviation capabilities, the Indian Army received the first batch of three Apache AH-64E helicopters from the US at the Hindon airbase.

Relevance of the Topic:Prelims: Key facts about Apache AH-64E Helicopters.

Apache AH-64E Helicopters

The AH-64E Apache is one of the world's most advanced multi-role combat helicopters.
Manufactured by: Boeing, the US.

Key Features:

Warhead: The choppers are fitted with:
- Hellfire air-to-surface anti tank missile
- Stinger air-to-air missiles
- 70 mm Hydra rockets
- 30 mm automatic cannons
Advanced Technology: AH-64E incorporates 26 new technologies to enhance battlefield performance. These include:
- Advanced Digital Connectivity
- Joint Tactical Information Distribution System
- Powerful T700-GE-701D engines with enhanced transmissions
- Improved rotor blades made of composite materials
- Ability to control unmanned aerial vehicles (UAVs) mid-flight (allowing manned-unmanned teaming in real time).
Sensors & Radar: Equipped with Longbow Fire Control Radar:
- capable of simultaneously tracking up to 128 targets and engaging up to 16 at once
- Fire-and-forget capability when combined with Hellfire missiles
- All weather operation capability.

Significance: The induction of Apache combat helicopters strengthen India’s operational capabilities against Pakistan along the Western Border and high-altitude areas.

Can approach enemy troops covertly with relative stealth and launch as close range attack
Capability to operate in hostile airspace with threats from ground.
Capability to destroy enemy tanks, armoured personnel carriers and fortified positions in mountainous terrain.
Provides cover to army tanks and infantry during battle.

Armed Forces and Apache Helicopters

The Indian Air Force (IAF) has 22 Apache Helicopters which are used for air defence and deep-strike roles targeting enemy radar installations and command posts.
The Indian Army intends to use its fleet for close air support, tank-busting missions and battlefield dominance during armoured engagements. India signed a Rs 5691 crore deal in 2020 for 6 Apaches, specifically for the Indian Army.

Key Facts:

In early 2025, the Ministry of Defence signed a Rs 62,700 crore (approximately $7.3 billion) contract with Hindustan Aeronautics Limited (HAL) for 156 ‘Prachand’ Light Combat Helicopters, underscoring the increasing role of rotorcraft in India’s war-fighting doctrine.
These helicopters- 66 for the IAF and 90 for the Indian Army- will be delivered over the next five years. This would be a significant development unfolding on the Eastern front.

MiG-21 Fighter Jets to Retire

Context: After protecting the skies for more than six decades, the MiG-21 Bison fighter jets of the Indian Air Force are set to retire in September 2025. The plans are to replace them with indigenously developed Tejas Mk1A fighter aircraft.

Relevance of the Topic:Prelims: Key facts about MiG-21 Fighter Jets.

MiG-21 Fighter Jets: India’s First Supersonic Fighter

MiG-21 is a single-engine supersonic jet fighter and interceptor aircraft.
Developed by: Mikoyan-Gurevich Design Bureau in the former Soviet Union.
Induction: First procured in 1963 into the Indian Air Force (IAF). They formed the backbone of the Air Force till the mid-2000s, when the Su-30MKIs were inducted.
Initially developed as an interceptor, the supersonic jet was eventually upgraded to perform as a multi-role combat aircraft, including ground attacks.
With a maximum speed of 2230 kilometres per hour, the jet carries one 23mm twin-barrel cannon with four R-60 close combat missiles.
Key Role: They have played key roles in the wars with Pakistan (1965 and 1971), Kargil War (1999), Balakot air strikes (2019), and the most-recent Operation Sindoor (2025).

Variants of MiG-21 Fighter Jets:

Over the years, India procured more than 700 MiG-21 aircraft of different variants. Many were domestically built by Hindustan Aeronautics Ltd. They include- Type 74 or MiG 21F; Type 76 or MiG 21PF; Type 77 or MiG 21FL; Type 96 or MiG 21M; Type 75 or MiG 21 Bis (upgraded Type 96); and MiG-21 Bison.

MiG-21 Fighter Jets to Retire

The Air Force currently has two MiG-21 squadrons, or 36 aircrafts, that are operated by the squadrons stationed at the Nal airbase in Rajasthan.
- Indian Air Force (IAF) has 31 fighter squadrons as against the sanctioned strength of 42 squadrons. It is significantly below the optimal readiness requirements.
- The phase out of two MIG-21 squadrons has been long extended due to the delayed deliveries of LCA-Mk1A (Tejas fighter aircraft). After the phased out, the combat strength of the Air Force will drop to 29 squadrons.

Controversy:

The MiG-21 aircrafts have been involved in several accidents, leading to the deaths of 170 pilots and 40 civilians. They were once termed “Flying Coffin”.

Also Read: Race for Fighters: the IAF’s dilemma

How GLP-1 Drugs Work?

Context: Two GLP-1 drugs- Novo Nordisk’s semaglutide and Eli Lilly’s tirzepatide, are now available in the Indian market.

Mounjaro, Ozempic, Wegovy, Semaglutide, Tirzepatide belong to a class of glucagon-like peptide-1 (GLP-1) receptor agonists, originally developed to treat diabetes and obesity.

Relevance of the Topic:Prelims: Key facts about GLP-1 Drugs.

What are GLP-1 Drugs?

GLP-1 is an incretin hormone and a neurotransmitter naturally secreted from the small intestine and hindbrain in the human body, after one eats a meal. It travels to the pancreas, where it helps to regulate blood sugar by increasing insulin and decreasing glucagon.
GLP-1 RA (glucagon-like peptide-1 receptor agonists) are a new class of drugs that mimic naturally-occurring gut hormones called incretin (GLP-1 is one such incretin). Thus, they regulate appetite and digestion, helping users feel full faster and consume fewer calories.
Semaglutide and Tirzepatide both mimic the action of GLP-1. Tirzepatide additionally also mimics the action of another hormone called GIP (glucose-dependent insulinotropic polypeptide).

How GLP-1 Drugs Work?

GLP-1 drugs impact centres in the brain associated with control of hunger and satiety, to effectively tell us that we have had enough to eat and need to stop eating. They work by:

improving the secretion of insulin that allows more of the glucose in the bloodstream to enter cells where it can be used for energy.
inhibiting the secretion of the hormone glucagon that stimulates the liver to release stored glucose into the bloodstream.
slowing down the emptying of the stomach so that the glucose levels in the bloodstream does not spike.
reducing appetite by signalling to the brain that one is satiated.

The drugs can be self-administered by the patient once a week via subcutaneous injection (similar to insulin). Semaglutide is also available as an oral tablet.

Utility of GLP-1 Drugs:

Weight loss: Extremely effective for weight-loss helping people lose on an average 15% to 20% of their body weight, equivalent to otherwise lost with bariatric surgeries.
Diabetes: GLP-1 drugs infusion significantly increases insulin levels and lowers glucose levels in diabetic patients.
Alzheimer’s: Some evidence shows that the drugs are associated with lower risk of Alzheimer’s and Dementia.
Other Conditions: Found to be effective and are being studied for conditions including- cardiovascular diseases, kidney disease, non-alcoholic fatty liver disease, and obstructive sleep apnoea. Studies have shown a 69% reduction in heart failure events.

Potential Side Effects of GLP-1 Drugs:

Common side effects include- nausea, vomiting, acidity, burping, hiccups, diarrhoea, abdominal pain, and appetite loss.
Rarer complications include- pancreatitis, retinal changes (necessitating eye exams), and increased risk of medullary thyroid carcinoma, especially for those with a family history.

Confined field trials on Genetically Modified (GM) Maize

Context: Punjab Agricultural University (PAU) is set to begin confined field trials of genetically modified (GM) Maize in the ongoing kharif season.

PAU has received approval from the Review Committee on Genetic Manipulation (RCGM), under the Department of Biotechnology, along with formal consent from the Punjab state government.

Relevance of the Topic: Prelims: Key facts about GM crops; GM Maize; Regulations related to GM crops.

Confined Field Trials of GM Maize

PAU will conduct confined field-trials of two varieties of transgenic Maize in collaboration with Bayer Crop Science Limited (formerly Monsanto).
GM Maize has been genetically engineered with both herbicide-tolerant (HT) and insect-resistant Bacillus thuringiensis (BT) traits.
- Herbicide-tolerant (HT) Maize: To study weed-control efficacy in herbicide-tolerant maize hybrids with the application of Glyphosate-K salt.
- Insect-resistant (IR) Maize: To study the efficacy of insect-protected maize hybrids against targeted lepidopteran pests (stem borer; fall armyworm).
Confined field trials are small-scale field experiments to address the biosafety requirements and evaluate the performance of specific traits in genetically engineered plants.

Criticism of Confined field trials of GM Maize trials:

Anti-GMO activists have expressed strong opposition to the project. The concerns include-

Unintended environmental consequences including the risk of gene flow into nearby farms or wild varieties. Trials pose risks of genetic contamination and long-term ecological damage.
Risk of potential long-term health risks associated with GM food products.
Introduction of GM crops in India (even for research or confined trials) sets a dangerous precedent, particularly in Punjab where agricultural ecology is already under stress. Glyphosate-tolerant Maize trails are controversial as glyphosate (a herbicide) is currently banned in Punjab due to its negative impacts on human health and the environment.
Lack of transparency and insufficient public consultation. Bayer’s involvement has been questioned given the global controversies surrounding GM seed patent enforcement.

The organisations have demanded transparency on the scientific basis for the approval and raised concerns over biosafety violations in previous GM crop trials at PAU.

PAU Maintains that:

Trials were permitted only after receiving clearance from the Government of India’s Review Committee on Genetic Manipulation (RCGM), under the Department of Biotechnology.
Biosafety Research Level 1 (BRL-I) trials (preliminary) and Advanced level II (BRL-II) trials would be carried out under strict standard operating procedures, with mandatory permission from state-level committees.

Review Committee on Genetic Manipulation (RCGM) is the regulatory authority for BRL-1 trials (size limited to no more than one acre/trial site location).

Genetic Engineering Appraisal Committee (GEAC) is the regulatory authority for Biosafety Research Level II (BRL- II) trials (size is generally limited to no more than 2.5 acres/trial site location).

What are GM Crops?

Genetically Modified (GM) crops are plants that have had their DNA modified (altered) through genetic engineering.
- It involves inserting new DNA into the genome of a plant.
- The seeds produced by these plants will inherit the new DNA.
E.g., BT cotton is a genetically modified variety of cotton that contains genes from the bacterium Bacillus thuringiensis.

Benefits of GM crops:

Genetic modification is done to transfer a particular trait to the plant in order to:
- Increased the yield of a crop
- Increased nutritional content of a crop
- Developing resistance to:
  - Abiotic stresses like temperature, salinity or herbicide-resistant
  - Biotic stresses like insect-resistant crops.

Regulations related to GM crops:

Genetically Modified Organisms (GMOs) and their products are regulated under the “Rules for the Manufacture, Use, Import, Export and Storage of Hazardous Microorganisms/ Genetically Engineered Organisms or Cells, 1989.”
The rules are notified under the Environment (Protection) Act, 1986. These rules regulate the use, research, and commercialisation of GMOs, especially for environmental and biosafety concerns.
The commercial cultivation and the field trials of GM crops require clearance from the Genetic Engineering Appraisal Committee (GEAC) under the Ministry of Environment, Forest and Climate Change.
After the GEAC clearance, the state governments have the power to approve (or reject) the field trials of particular GM crops in their respective states.

Status of GM crops in India

BT cotton is the only GM crop that is commercially allowed for cultivation in India from 2002.
Field trials of GM Mustard (DMH-11) were approved by GEAC in 2022, but its commercial release is still pending.

Valuable Lessons from Axiom-4 Mission

Context: The safe return of Group Captain Shubhanshu Shukla from the International Space Station as part of the Axiom-4 Mission, where he was the pilot among the four-member crew, marks a watershed moment for India’s space programme.

Relevance of the Topic:Prelims: Key facts about Axiom-4 Mission. Mains: Significance of Axiom-4 Mission.

Axiom-4 Mission

Axiom-4 Mission is a private spaceflight organised by Axiom Space launched aboard the SpaceX Dragon spacecraft in June 2025.
The crew spent 18 days aboard the International Space Station (ISS) and conducted various experiments in the microgravity environment.
The mission was conducted in collaboration with NASA, Axiom Space, ESA, and other international partners.

Successful Homecoming:

Axiom-4 Mission returned to Earth with their SpaceX Dragon capsule splashing down off the San Diego coast in the US.
The astronauts will undergo a rehabilitation programme for about a week under the supervision of flight surgeons to help him adapt back to gravity.
The crew completed 320 orbits of earth. They also completed over 60 research activities.

Valuable Lessons from Axiom-4 Mission

Invaluable lessons for Gaganyaan Mission: Group Captain Shukla of IAF is selected as one of the astronauts on India’s Gaganyaan Mission. The mission provides an invaluable blueprint for streamlining complex operational flows in the upcoming Gaganyaan Mission. This includes-
- Pre-flight preparations and launch sequences to in-orbit activities, docking procedures, and the critical re-entry and recovery phases.
- Intricacies of communication protocols, real-time decision-making under pressure, and robust contingency planning.
Blueprint for Astronaut Selection and Training: Participation in Axiom-4 Mission led to fairly detailed exposure of training procedures to Group Captain Shukla. This experience provides a rich case study in-
- Crew training and preparation: Globally, commercial astronauts are from various professional backgrounds (not necessarily career military pilots) rigorously trained and seamlessly integrated into a complex mission profile.
- Refinement of India’s training methodologies and astronaut selection: This includes incorporating best practices for physiological adaptation to microgravity and psychological conditioning for isolation. Both simulation-based drills and real-time problem-solving scenarios can enhance the preparedness of Indian Vyomnauts.
Paves way for International Crewed Mission Coordination: While ISRO’s approach to space exploration and research has been largely national, the global landscape of human spaceflight is becoming increasingly collaborative and driven by the commercial sector. The mission showcases the efficiency and necessity of international collaboration, where diverse expertise works together towards shared objectives.
Private-sector Engagement in Space Sector:
- Axiom-4’s reliance on established commercial launch and crew vehicles (like Space X’s Falcon 9 and Crew Dragon) highlights increasing reliability and capability of private-sector space transportation and collaboration.
- This could inspire India to explore strategic partnerships with the private sector in India and globally for certain sub-systems or specific commercial methodologies.
- This mission’s success (viability and profitability) can encourage more Indian companies to invest in space infrastructure, services, and human spaceflight support. This could lead to a thriving ecosystem of Indian suppliers, manufacturers, and service providers for future missions.
Encourages the Younger Generation to pursue STEM Education.

As the global space community becomes more interconnected, Axiom-4 Mission highlights the benefits of pooling resources, expertise, and technological capabilities.

The participation of one of its astronaut candidates in Axiom-4 will enrich Gaganyaan Mission in terms of planning and execution, and serve as a stepping stone in building operations infrastructure for future programs like commercial space flights and Bhartiya Antariksha Station.

Also Read: ISRO’s Experiments in Axiom-4 Mission

Patriot Missile System

Context: Germany is considering funding the US-made Patriot Air Defence Systems for Ukraine amid ongoing Russian missile and drone attacks.

Relevance of the Topic: Prelims: Key facts about Patriot Missile System.

Ukraine has repeatedly asked Western allies for more air defences to protect critical infrastructure and civilians from frequent missile and drone attacks. Ukrainian officials maintain that Patriot systems are vital to defend against long-range attacks by Russia.

What is the Patriot Missile System?

Petriot (Phased Array Tracking Radar for Intercept on Target) is a mobile surface-to-air defence system.
Developed by: United States
It is used to detect, track, and shoot down incoming missiles, aircraft, and drones.
It is considered one of the most advanced air defence systems in the US arsenal, and has been in service since the 1980s.

How does the Patriot work?

The system has different capabilities depending on the type of interceptor used.
The earlier PAC-2 interceptor uses a blast-fragmentation warhead that detonates in the vicinity of a target.
The PAC-3 family of missiles uses more accurate technology that hits the target directly.
According to NATO, the system’s radar range exceeds 150 km.

Global Usage:

The system is used in 19 countries including: The US, Germany, Poland, Ukraine, Japan, Qatar, Saudi Arabia, and Egypt.
In 2025, the US transferred about 90 Patriot interceptors from Israel to Ukraine.

Cost of the System:

A newly produced single Patriot battery costs over $1 billion, including $400 million for the system and $690 million for the missiles in a battery.
Patriot interceptors are estimated to cost $4 million.

Stem Cell Therapy ‘ ZIMISLECEL’ shows promise in Type-1 Diabetes

Context: ZIMISLECEL, a new allogeneic stem cell-derived islet cell therapy, has shown promise in a recent study involving people with Type-1 Diabetes.

Relevance of the Topic: Prelims: ZIMISLECEL; Type-1 DiabetesMains: Potential use cases of Stem Cell Therapy.

About Diabetes

Diabetes is a lifelong condition that causes a person's blood glucose (sugar) level to become too high. The hormone insulin (produced by the pancreas) is responsible for controlling the amount of glucose in the blood.
Type-1 Diabetes (insulin-dependent) is an autoimmune condition in which the body’s immune system mistakenly destroys insulin-making cells (islets cells) in the pancreas. It is characterised by deficient insulin production, and the person requires daily administration of insulin. For decades, managing T-1D has relied on insulin therapy alone.

ZIMISLECEL: Stem Cell-derived Islet Cell Therapy

Zimislecel is an investigational stem cell-derived islet therapy for Type-1 Diabetes.
Scientists made Zimislecel by growing islets from pluripotent stem cells in the lab. These stem cells were matured into functioning islets and infused into the liver in the patients with severe, long-standing Type-1 Diabetes.
Early trials show that these stem cell-derived islet cells began producing insulin again, improving blood sugar control and preventing dangerous lows.

Results of the Trials:

The early-stage trial aimed to assess the safety and efficacy of Zimislecel in restoring islet function in affected individuals.
- Within 90 days, all participants were producing C-peptide, a marker of insulin production, with levels more than doubling by day 365.
- Blood sugar control improved and 83% of participants treated no longer required insulin after one year.
- To prevent their bodies from rejecting the transplanted cells, they were placed on an immunosuppressive regimen.
Phase 3 trials of Zimislecel are underway with 50 participants from around the world and will be followed for five years.

The therapy is still underdevelopment and may have cost considerations and the side-effects related to life-long immunosuppression.

What are Stem Cells?

Stem cells are undifferentiated cells with the potential to develop into specialised cell types in the body. They can self-renew which makes them valuable for therapeutic applications.
Stem cell therapy utilises stem cells to promote the repair, regeneration, or replacement of damaged or diseased tissues within the body.

Types of Stem Cells:

Totipotent: Most versatile, with potential to differentiate into all different cell types of an organism and extraembryonic cells (including placenta and umbilical cord). Only found in fertilised eggs (zygote).
Pluripotent: Derived from inner cell mass of a blastocyst (an early-stage embryo). Can give rise to all different cell types in the body (except extraembryonic cells). E.g., Embryonic stem cells and induced pluripotent stem cells (genetically reprogrammed to the pluripotent state from adult cells).
Multipotent: More specialised than pluripotent stem cells and can differentiate into limited range of cell types within a specific tissue or organ. E.g., Hematopoietic stem cells (give rise to various blood cell types), mesenchymal stem cells (can differentiate into bone, cartilage, fat cell etc.)

Unipotent: Most specialised type of stem cells, can only renew themselves and differentiate into one specific cell type. E.g., Stem cells in skin that can only differentiate into another skin cell.

Also Read: HC permits Stem Cell Therapy for two kids with autism

ASTRA: Beyond Visual Range Air to Air Missile

Context: Recently, Defence Research and Development Organisation (DRDO) and the Indian Air Force (IAF) carried out a successful flight test of the Beyond-Visual-Range Air-to-Air missile (BVRAAM) Astra missile from Su-30 Mk-I platform off the coast of Odisha.

Relevance of the Topic: Prelims: Key facts about Astra Missiles.

About Astra Missile

Astra is a Beyond-Visual-Range Air-to-Air missile (BVRAAM) with a range exceeding 100 kms.
Developed by: Defence Research and Development Organisation (DRDO)
It is equipped with an art guidance and navigation system and indigenous Radio Frequency (RF) Seeker that provides it the ability to strike with high accuracy.
- One of the key technological achievements of the recent test was the validation of the Radio Frequency (RF) seeker.
- RF seeker detects and tracks the target using radio waves ensuring accurate terminal guidance.
The missile (Astra Mk1) has already been inducted into service with the IAF. It is integrated in Su-30 Mk-I fighter aircraft; integration is underway in Tejas Mk1A fighter, and will be integrated in future in AMCA, Rafale etc.

Variants of Astra Missile

1. Astra Mk1:

First-ever BVRAAM indigenously developed by India.
Astra Mk-1 is 3.6 m long, and weighs 154 kg.
Uses a single-pulse rocket motor with solid propellant that can propel the missile to a speed of Mach 4.5.
It uses mid-course inertial guidance driven by a fibre-optic gyroscope.
The maximum range is 110 km in head-on chase and 20 km in tail chase.
The missile could be launched from different altitudes.

2. Astra Mk2:

It has a projected range of 140-160 km. Astra Mk-2 uses a dual-pulse rocket motor which dramatically increases its range and kill probability.

It incorporates upgraded guidance algorithms and an indigenous radio frequency (RF) seeker.
The missile is slated to achieve operational readiness by 2026.

3. Astra Mk3 (Gandiva missile):

India and Russia are working together to build the future Astra Mk-3 missile powered by a solid fuel ducted ramjet (SFDR) engine.
Projected Range: 350 kms. This would put the Astra Mk3 in the same league as the world’s most advanced air-to-air missiles.

Successful Trials

The test launches were carried out against high-speed unmanned aerial targets at different ranges, target aspects and launch platform conditions. The missiles destroyed the targets with pinpoint accuracy.

Significance of the Test

Validates critical defence technology: Traditionally, India relied on imported RF seekers, which incurred high costs and also exposed supply chains to geopolitical uncertainties. The test validates the indigenous RF seeker which is a critical defence technology.
Reinforces reliance on Astra missiles: Re-establishes the accuracy and reliable performance of Astra weapon system. It reinforces India’s growing technological edge in aerial warfare systems.

India’s successful test of the Astra missile with an indigenous RF seeker places it along the list of a few nations, like the US, Russia, France, and China, with advanced BVRAAM programs developed entirely within national borders.

Akash Prime Air Defence System

Context: Indian Army has carried out successful trials of the indigenously developed Akash Prime Air Defence System at an altitude of over 15,000 feet in the Ladakh sector. The test was successful and the missile has met the country’s critical air defence requirements for high-altitude.

Relevance of the Topic:Prelims: Key facts about Akash Prime Air Defence System; Akash Missile Defence System.

Akash Missile Defence System

Indigenously developed by: Defence Research and Development Organisation (DRDO)
Medium-range Mobile Surface-to-Air missile (SAM) designed to neutralise aerial threats such as fighter jets, drones, cruise missiles, and air-to-surface missiles.
Operates on a command-guidance system with datalink for mid-course corrections and switches to active radar homing in the terminal phase.
Propelled by an integrated ramjet-rocket engine allowing it to maintain supersonic speeds (Mach 1.8 to 2.5) throughout its flight.
Range extends up to 25-45 km, with the ability to intercept targets at altitudes up to 20 km.
The missile carries a 60 kg high-explosive, pre-fragmented warhead, detonated by a digital proximity fuse for maximum impact.
Supported by a sophisticated radar network. Real time multi-sensor data processing enables simultaneous engagement of multiple targets from any direction.
- Rajendra Phased Array Radar can track up to 64 targets and guide eight missiles simultaneously.
- 3D Central Acquisition Radar (3D CAR) provides long-range surveillance and target acquisition.

Akash has evolved over the years, with variants like Akash-1 (25 km range), Akash-NG (up to 30 km with improved guidance), and Akash Prime (up to 35 km).

Akash Prime Air Defence System

The system can operate at heights up to 4500 metres and is capable of targeting objects at a range of around 25 to 30 kilometres.
Compared to the existing Akash system, Akash Prime includes an indigenous active Radio Frequency (RF) seeker for improved target accuracy. The RF seeker enables the missiles to detect, track, and home in on targets with greater precision in extreme weather and terrain.
The modification allows its reliable use in cold temperatures and high-altitude conditions.

Akash’s integration with advanced command-and-control systems like Integrated Air Command and Control System (IACCS) enables real-time threat neutralisation. The upgraded variant (Akash Prime) will enhance the Air Defence potential in high-altitude frontiers and improve the operational effectiveness.