Archive for the ‘chemistry’ category: Page 160

May 12, 2022

Photosynthesis used to power a microprocessor for over six months

Posted by in categories: chemistry, energy

System represents a breakthrough in the real-life applicability of biophotovotaic devices.

Microprocessors can be powered using photosynthetic microorganisms in ambient light without the need for an external power source, new research shows. Led by Emre Ozer from Arm and Christopher Howe from the University of Cambridge, researchers in the UK, Italy and Norway introduced cyanobacteria Synechocystis sp. PCC6803 into an aluminium–air battery to create a biophotovoltaic device. The device is a similar size to an AA battery, is made from durable and mainly recyclable materials and does not require a dedicated light source to function. It is the first reported bioelectrochemical system capable of continuously powering a microprocessor outside of laboratory-controlled conditions.

‘We decided that we didn’t want to operate the system with a dedicated source of energy. We needed to prove that we can operate under ambient light, and we were able to do it,’ comments Paolo Bombelli, one of the lead researchers from the University of Cambridge.

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May 11, 2022

Design of effective self-powered SnS2/halide perovskite photo-detection system based on triboelectric nanogenerator

Posted by in categories: chemistry, health, internet, nanotechnology, robotics/AI, wearables

On account of the improvement the Internet of things (IoTs) and smart devices, our lives have been noticeably facilitated in the past few years. Machines and devices are becoming more ingenious with the help of artificial intelligence and various sensors1,2. So, integrated circuits are necessary to provide convenient and effectual communication3 Since the first report on TENG by Wang’s group in 20124, triboelectric systems have been recognized as a proper choice to harvest and convert the energy from the environment5,6. Photodetectors, as one of the most significant types of sensors that can precisely convert incident light into electrical signals have attracted increasing attention in recent years. Various applications including photo-sensors, spectral analysis7,8, environment monitoring9, communication devices10, imaging11, take advantage of narrow band or broad band photodetectors from ultraviolet to terahertz wavelenght. Literature reviews show that the heterojunction/heterostructure based on 2D/3D materials have been widely used in PD applications. In fact, to attain high performance of PDs based heterojunction, the built-in electrical field is needed to suppress the photogenerated recombination and stimulating collection12. Although, Si based PDs offer reliably high performance results, their complexity and expensive manufacturing process have limited their expansion and adoptability for industrial purposes13,14,15. Hence, most available PDs are designed based on external power supplies such as electrochemical batteries for signal production and processing, their design not only increases the sensor’s dimension and weight, but also creates limitations for sensor maintenances16 which is not proper in the IoTs. In 2014, ZH Lin et al. and Zheng et al. represented an investigation on the self-powered PD based on TENG system3,17, and since then, self-driven PDs have been extensively investigated2,5,9,18,19,20. These devices can find potential applications in health monitoring systems such as heart checking21 and health protection from some detrimental radiation such as high levels of UV radiance22.

But in the other hand, even though TENGs could be promise for using in wearable electronics, they still inevitably have limitations in power generation, sensing range, sensitivity, and also the sensing domain for the intrinsic limitations of electrification23,24,25. Moreover, due to high voltage, low current, and alternating current output of the TENGs, they cannot be used in order to supply power to electronic devices effectively without using power management circuits (PMCs) based on the LC modules. There are several reports that describe the importance of the impedance matching of the TENG and PMC units for better energy storage efficiency of the pulsed-TENG26,27. Without using the PMC unit, there are some challenges as a result of synching the TENG, as the power supply, and the consumption element such as the PD device. These challenges include the process of matching the resistance of the device and the impedance of the TENG to achieve effective performance of the self-powered system6,28.

In this study an efficient battery-free photodetector based on bulk heterojunction SnS2 nanosheets and perovskite materials has been designed and powered employing three different TENGs (GO paper/ Kapton, FTO/Kapton and hand/ FTO). In the first step for circuit designing to have better performance of the photodetector in coupling with TENG, the effect load resistance amount in the circuit on the impedance matching the TENG and the inner resistance of the photodetector, has been investigated through output current amplitude. The investigation, shows that to achieve the high amount of the photocurrent, the load resistance should be positioned in both critical zone of the out-put voltage of the TENG and the resistance range of high power density production of the TENG. In the second step, for investigation the effect of the dark resistance of the photodetector on out-put current of the self-powered photodetector, a device with very lower initial resistance (All-oxide Cu2O/ZnO photodetector) has been used with and without different load resistance in the circuit; in this regard, it is concluding that the initial resistance is too important to have proper design impedance matching circuit.

May 10, 2022

Researchers find new function performed by almost half of brain cells

Posted by in categories: biotech/medical, chemistry, health, neuroscience

* Astrocytes play a variety of roles with neurons, but until now, scientists did not know that these cells carry electrical impulses.

* Applying new technology, Tufts University scientists recently discovered in mice that astrocytes are electrically active like neurons. Astrocytes play a variety of roles with neurons, but until now, scientists did not know that these cells carry electrical impulses.

Neurotransmitters are chemical messengers that facilitate the transfer of electrical signals between neurons and support the blood-brain barrier. Scientists have long understood that astrocytes control these substances to support neuronal health.

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May 9, 2022

Electron Motion Tracked in a Quantum State of Matter Using X-Ray Pulses Less Than a Millionth of a Billionth of a Second Long

Posted by in categories: biological, chemistry, quantum physics, solar power, sustainability

Less than a millionth of a billionth of a second long, attosecond X-ray pulses allow researchers to peer deep inside molecules and follow electrons as they zip around and ultimately initiate chemical reactions.

Scientists at the Department of Energy’s SLAC National Accelerator Laboratory devised a method to generate X-ray laser bursts lasting hundreds of attoseconds (or billionths of a billionth of a second) in 2018. This technique, known as X-ray laser-enhanced attosecond pulse generation (XLEAP), enables researchers to investigate how electrons racing about molecules initiate key processes in biology, chemistry, materials science, and other fields.

“Electron motion is an important process by which nature can move energy around,” says SLAC scientist James Cryan. “A charge is created in one part of a molecule and it transfers to another part of the molecule, potentially kicking off a chemical reaction. It’s an important piece of the puzzle when you start to think about photovoltaic devices for artificial photosynthesis, or charge transfer inside a molecule.”

May 8, 2022

Using Sound To Control Enzymatic Reactions

Posted by in categories: chemistry, energy, physics

Unhackneyed compartmentalization generated by audible sound allows the enzyme reactions to be controlled spatiotemporally.

Spatiotemporal regulation of multistep enzyme reactions through compartmentalization is essential in studies that mimic natural systems such as cells and organelles. Until now, scientists have used liposomes, vesicles, or polymersomes to physically separate the different enzymes in compartments, which function as ‘artificial organelles’. But now, a team of researchers led by Director KIM Kimoon at the Center for Self-assembly and Complexity within the Institute for Basic Science in Pohang, South Korea successfully demonstrated the same spatiotemporal regulation of chemical reactions by only using audible sound, which is completely different from the previous methods mentioned above.

Although sound has been widely used in physics, materials science, and other fields, it has rarely been used in chemistry. In particular, audible sound (in the range of 20–20,000 Hz) has not been used in chemical reactions so far because of its low energy. However, for the first time, the same group from the IBS had previously successfully demonstrated the spatiotemporal regulation of chemical reactions through a selective dissolution of atmospheric gases via standing waves generated by audible sound back in 2020.

May 7, 2022

Scientists engineer new tools to electronically control gene expression

Posted by in categories: biotech/medical, chemistry

Researchers, led by experts at Imperial College London, have developed a new method that allows gene expression to be precisely altered by supplying and removing electrons.

This could help control biomedical implants in the body or reactions in large ‘bioreactors’ that produce drugs and other useful compounds. Current stimuli used to initiate such reactions are often unable to penetrate materials or pose risk of toxicity—electricity holds the solution.

Gene expression is the process by which are ‘activated’ to produce new molecules and other downstream effects in cells. In organisms, it is regulated by regions of the DNA called promoters. Some promoters, called inducible promoters, can respond to different stimuli, such as light, chemicals and temperature.

May 4, 2022

Physicist designs magnetic thrust engine that could rocket us to the Red Planet

Posted by in categories: chemistry, physics, satellites, sustainability

Circa 2021

With SpaceX continuing the testing phase for Starship and enthusiasm spreading for an actual crewed flight to Mars, an interesting magnetic thrust rocket concept conceived by physicist Fatima Ebrahimi at the US Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) might make the mission much more cost effective.

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May 2, 2022

Could the blueprint for life have been generated in asteroids?

Posted by in categories: biotech/medical, chemistry, genetics

Using new analyses, scientists have just found the last two of the five informational units of DNA and RNA that had yet to be discovered in samples from meteorites. While it is unlikely that DNA could be formed in a meteorite, this discovery demonstrates that these genetic parts are available for delivery and could have contributed to the development of the instructional molecules on early Earth. The discovery, by an international team with NASA researchers, gives more evidence that chemical reactions in asteroids can make some of life’s ingredients, which could have been delivered to ancient Earth by meteorite impacts or perhaps the infall of dust.

All DNA and RNA, which contains the instructions to build and operate every living being on Earth, contains five informational components, called nucleobases. Until now, scientists scouring had only found three of the five. However, a recent analysis by a team of scientists led by Associate Professor Yasuhiro Oba of Hokkaido University, Hokkaido, Japan, identified the final two nucleobases that have eluded scientists.

Nucleobases belong to classes of organic molecules called purines and pyrimidines, which have a wide variety. However, it remains a mystery why more types haven’t been discovered in meteorites so far.

Apr 29, 2022

Towards practical and robust DNA-based data archiving using the yin–yang codec system

Posted by in categories: chemistry, computing, information science

The yin-yang codec transcoding algorithm is proposed to improve the practicality and robustness of DNA data storage.

Given these results, YYC offers the opportunity to generate DNA sequences that are highly amenable to both the ‘writing’ (synthesis) and ‘reading’ (sequencing) processes while maintaining a relatively high information density. This is crucially important for improving the practicality and robustness of DNA data storage. The DNA Fountain and YYC algorithms are the only two known coding schemes that combine transcoding rules and screening into a single process to ensure that the generated DNA sequences meet the biochemical constraints. The comparison hereinafter thus focuses on the YYC and DNA Fountain algorithms because of the similarity in their coding strategies.

The robustness of data storage in DNA is primarily affected by errors introduced during ‘writing’ and ‘reading’. There are two main types of errors: random and systematic errors. Random errors are often introduced by synthesis or sequencing errors in a few DNA molecules and can be redressed by mutual correction using an increased sequencing depth. System atic errors refer to mutations observed in all DNA molecules, including insertions, deletions and substitutions, which are introduced during synthesis and PCR amplification (referred to as common errors), or the loss of partial DNA molecules. In contrast to substitutions (single-nucleotide variations, SNVs), insertions and deletions (indels) change the length of the DNA sequence encoding the data and thus introduce challenges regarding the decoding process. In general, it is difficult to correct systematic errors, and thus they will lead to the loss of stored binary information to varying degrees.

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Apr 26, 2022

Fertility crisis: Is modern life making men infertile? — BBC REEL

Posted by in categories: biotech/medical, chemistry

We all know man-made chemicals are damaging ecosystems across the planet. But could certain chemicals also be negatively affecting human fertility?

Dr Shanna Swan, an environmental and reproductive epidemiologist at Mount Sinai Hospital in New York and the author of Count Down, predicts that current trends could not continue much longer without threatening human survival.

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