Acute encephalitis outbreak in India linked to Chandipura virus
BETWEEN early June and August 15, the Union Ministry of Health and Family Welfare reported 245 cases of acute encephalitis syndrome (AES) with 82 deaths (a case fatality rate, or CFR, of 33 per cent), the WHO reported. Chandipura virus (CHPV) infection has been confirmed in 64 of the 245 cases, 61 of them from Gujarat and 3 from Rajasthan. To date, no human-to-human transmission has been reported. CHPV is endemic in India, which sees regular outbreaks. However, the current outbreak is the largest in the past 20 years, the report said.
CHPV is a member of the Rhabdoviridae family and is known to cause sporadic cases and outbreaks of AES in western, central, and southern parts of India, especially during the monsoon season. It is transmitted by vectors such as sandflies, mosquitoes, and ticks. The CFR from CHPV infection is high (56-75 per cent, as reported in previous outbreaks), and there is no specific treatment or vaccine available.
A total of 43 districts in India have currently reported AES cases. In 2003, a large outbreak of AES was reported in Andhra Pradesh, with 329 suspected cases and 183 deaths; a study suggests that this was due to CHPV.
According to the WHO, the disease affects mostly children under 15 and can present itself as a febrile illness that may progress to convulsions, coma, and death in some cases. In children, it can lead to high mortality within 48-72 hours of the onset of symptoms. Survival can be increased with early access to care and intensive supportive care, the WHO said. To prevent further spread of CHPV, the WHO has recommended vector control and protection against vector bites.
A sandfly, one of the vectors that transmits the Chandipura virus, the pathogen that causes acute encephalitis syndrome. | Photo Credit: Google Images
More export controls on quantum computing technologies
THE Bureau of Industry and Security (BIS) of the US Department of Commerce has published a new interim final rule (IFR) on advanced semiconductor manufacturing and computing technologies, quantum computing in particular, to align its export control regulations with those of its allies, including Japan. This worldwide rule, which came into effect on September 6, is a supplement to the final rule that the BIS published on October 25, 2023, titled “Implementation of Additional Export Controls: Certain Advanced Computing and Semiconductor Manufacturing Items; Supercomputer and Semiconductor End Use”. The aim is “to protect U.S. national security interests by restricting the People’s Republic of China’s military modernization efforts and degrading its ability to violate human rights”.
The following are some of the specific items included in the new IFR:
• Quantum computing items: quantum computers, related equipment, components, materials, software, and technology that can be used in the development and maintenance of quantum computers.
• Advanced semiconductor manufacturing equipment: tools and machines that are essential for the production of advanced semiconductor devices.
• Gate-all-around field-effect transistor technology: technology that produces or develops high-performance computing chips that can be used in supercomputers.
• Additive manufacturing items: equipment, components, and related technology and software designed to produce metal or metal alloy components.
The IFR has also established a new Licence Exception Implemented Export Controls (IEC) so that countries may meet the terms of IEC by implementing equivalent national controls, which would eliminate the need to submit licence applications for those items. India is not one of the countries that can use this licence exception.
In the wake of the US’ move, the Dutch government put in place on September 6 strict controls on export outside the EU of the semiconductor manufacturing equipment made by the Dutch multinational corporation ASML.
Also Read | New IISc supercapacitor can store and also release energy
A photo-chargeable supercapacitor showed a 3,000 per cent rise in capacitance under light compared with the dark. | Photo Credit: Santilata Sahoo
Shining light on a new supercapacitor
CAPACITORS are electrostatic devices that store energy as charges on two metal plates called electrodes. Supercapacitors are upgraded versions of capacitors; they exploit electrochemical phenomena to store more energy. Now, researchers at the Department of Instrumentation and Applied Physics (IAP), Indian Institute of Science (IISc), and collaborators have designed a supercapacitor that can be charged by shining light on it, a press release from the IISc said. The development was reported in Journal of Materials Chemistry A.
The electrodes of the new supercapacitor are made of zinc oxide (ZnO) nanorods grown directly on fluorine doped tin oxide, which is transparent. This allows light to fall on the optically active ZnO nanorods, which charges the supercapacitor. Two electrolytes—a liquid and a semi-solid gel—were used as the conducting medium between the electrodes.
The capacity for storing charges (capacitance) is inversely proportional to the distance between the electrodes. In electrostatic capacitors, it is difficult to maintain a small distance between electrodes. However, in a supercapacitor the electrodes’ charges attract the electrolyte’s oppositely charged ions, resulting in the formation of a charge layer—called an electric double layer— just atoms away from each other. This results in the high capacitance of supercapacitors, said Pankaj Chauhan of the group.
When the researchers shone UV light on their supercapacitor, they noticed a capacitance that was several times higher than previously ever reported for supercapacitors. They also noticed two unusual properties. First, while capacitance generally decreases as the voltage increases, they found that their supercapacitor’s capacitance under light illumination actually increased with increasing voltage. It has been termed “necking behaviour”.
Second, the energy stored within a supercapacitor typically decreases when it is charged faster because the ions in the electrolyte do not move fast enough to respond to the increased charging rate. However, with the liquid electrolyte, the team found that the energy stored in the supercapacitor increased upon fast charging under UV light. A.M. Rao, of Clemson University, US, and a co-author of the study, said that these findings could lead to the development of simultaneously fast-charging and energy-dense supercapacitors.
Supercapacitors, Abha Misra of the IAP said, could potentially replace the solar cells used in street lights. They have high power density, so they can release charge more quickly than batteries. They can also be used to power chips in electronic devices like cell phones. “We have miniaturised supercapacitors to micron scale so that they can be integrated along with these microelectronic chips,” Misra added.
