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Category: biotech/medical – Page 1,262

About 99 percent of human genes are shared with chimpanzees. Only the small remainder sets us apart. However, we have one important difference: The brain of humans is three times as big as the chimpanzee brain.

During evolution our genome must have changed in order to trigger such brain growth. Wieland Huttner, Director and Research Group Leader a the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), and his team identified for the first time a gene that is only present in humans and contributes to the reproduction of basal brain stem cells, triggering a folding of the neocortex. The researchers isolated different subpopulations of stem cells and precisely identified, which are active in which cell type. In doing so, they noticed the gene ARHGAP11B: it is only found in humans and in our closest relatives, the Neanderthals and Denisova-Humans, but not in chimpanzees. This gene manages to trigger brain stem cells to form a bigger pool of stem cells. In that way, during brain development more neurons can arise and the cerebrum can expand. The cerebrum is responsible for cognitive functions like speaking and thinking.

Wieland Huttner’s researchers developed a method that isolates and identifies special subpopulations of brain stem cells from the developing human cerebrum. No one has managed to do this so far. The scientists first isolated different stem and progenitor cell types from fetal mice and human cerebrum tissue. In contrast to the big and folded human brain, the brain of mice is small and smooth. After the isolation, the researchers compared the genes that are active in the various cell types and were able to identify 56 genes that are only present in humans and which play a role in . “We noticed that the gene ARHGAP11B is especially active in basal brain stem cells. These cells are really important for the expansion of the neocortex during evolution,” says Marta Florio, PhD student in Wieland Huttner’s lab, who carried out the main part of the study.

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During fetal development of the mammalian brain, the cerebral cortex undergoes a marked expansion in surface area in some species, which is accommodated by folding of the tissue in species with most expanded neuron numbers and surface area. Researchers have now identified a key regulator of this crucial process.

Different regions of the are devoted to the performance of specific tasks. This in turn imposes particular demands on their development and structural organization. In the vertebrate , for instance, the – which is responsible for cognitive functions – is remarkably expanded and extensively folded exclusively in . The greater the degree of folding and the more furrows present, the larger is the surface area available for reception and processing of neural information. In humans, the exterior of the developing brain remains smooth until about the sixth month of gestation. Only then do superficial folds begin to appear and ultimately dominate the entire brain in humans. Conversely mice, for example, have a much smaller and smooth cerebral cortex.

“The mechanisms that control the expansion and folding of the brain during fetal development have so far been mysterious,” says Professor Magdalena Götz, a professor at the Institute of Physiology at LMU and Director of the Institute for Stem Cell Research at the Helmholtz Center Munich. Götz and her team have now pinpointed a major player involved in the molecular process that drives cortical expansion in the mouse. They were able to show that a novel nuclear protein called Trnp1 triggers the enormous increase in the numbers of nerve cells which forces the cortex to undergo a complex series of folds. Indeed, although the normal mouse brain has a smooth appearance, dynamic regulation of Trnp1 results in activating all necessary processes for the formation of a much enlarged and folded cerebral cortex.

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To an untrained observer, the electrical storm that takes place over the brain’s neural network seems a chaotic flurry of activity. But as neuroscientists understand it, the millions of neurons are actually engaged in a sort of tightly choreographed dance, a tango of excitatory and inhibitory neurons. How is this precise balance that makes normal function possible achieved during development? And how does it go wrong in diseases like epilepsy when brain activity goes out of control?

Focusing on the cerebral cortex, the part of the controlling thought, sensory awareness, and motor function, a group of Harvard Stem Cell Institute (HSCI) researchers in the Department of Stem Cell and Regenerative Biology (SCRB), led by Assistant Professor Paola Arlotta, has discovered that excitatory neurons control the positioning of inhibitory neurons in a process that is critically important for generating balanced circuitry and proper cortical response.

Professor Takao Hensch, a collaborator on the study in the Harvard Center for Brain Science, Department of Molecular & Cellular Biology (MCB), had previously shown that the maturation of this circuit balance triggers critical periods of brain development. Certain inhibitory cells appear particularly vulnerable to genetic or environmental factors in early life, contributing to mental illness, such as schizophrenia or autism spectrum disorders.

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“We put nanotubes inside of bacteria,” says Professor Ardemis Boghossian at EPFL’s School of Basic Sciences. “That doesn’t sound very exciting on the surface, but it’s actually a big deal. Researchers have been putting nanotubes in mammalian cells that use mechanisms like endocytosis, that are specific to those kinds of cells. Bacteria, on the other hand, don’t have these mechanisms and face additional challenges in getting particles through their tough exterior. Despite these barriers, we’ve managed to do it, and this has very exciting implications in terms of applications.”

Boghossian’s research focuses on interfacing artificial nanomaterials with biological constructs, including living cells. The resulting “nanobionic” technologies combine the advantages of both the living and non-living worlds. For years, her group has worked on the nanomaterial applications of single-walled carbon (SWCNTs), tubes of carbon atoms with fascinating mechanical and .

These properties make SWCNTs ideal for many novel applications in the field of nanobiotechnology. For example, SWCNTs have been placed inside to monitor their metabolisms using near-infrared imaging. The insertion of SWCNTs in mammalian cells has also led to new technologies for delivering therapeutic drugs to their intracellular targets, while in plant cells they have been used for genome editing. SWCNTs have also been implanted in living mice to demonstrate their ability to image biological tissue deep inside the body.

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A review paper by scientists at Zhejiang University summarized the development of continuum robots from the aspects of design, actuation, modeling and control. The new review paper, published on Jul. 26 in the journal Cyborg and Bionic Systems, provided an overview of the classic and advanced technologies of continuum robots, along with some prospects urgently to be solved.

“Some small-scale robots with new actuation methods are being widely investigated in the field of interventional surgical treatment or endoscopy, however, the characterization of mechanical properties of them is still different problem,” explained study author Haojian Lu, a professor at the Zhejiang University.

In order to realize the miniaturization of continuum robots, many cutting-edge materials have been developed and used to realize the actuation of robots, showing unique advantages. The continuum robots embedded with micromagnet or made of ferromagnetic composite material have accurate steering ability under an external controllable magnetic field; Magnetically soft continuum robots, on the other hand, can achieve small diameters, up to the micron scale, which ensures their ability to conduct targeted therapy in bronchi or in cerebral vessels.

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Summary: The TOB gene plays a significant role in reducing depression, anxiety, and fear in mouse models. The findings could have positive implications for developing new treatments for disorders associated with psychiatric stress.

Source: OIST

First characterized in Prof. Tadashi Yamamoto’s former lab in Japan in 1996, the gene Tob is well known for the role it plays in cancer. Previous research has also indicated that it has a hand in regulating the cell cycle and the body’s immune response.

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According to a study presented at ESC Congress 2022, short-term use of non-steroidal anti-inflammatory drugs (NSAIDs) is linked to a first-time hospitalization for heart failure in individuals with type 2 diabetes.

NSAIDs are the most common form of anti-inflammatory medication. The most popular NSAIDs include aspirin, ibuprofen (often known as Advil), and naproxen (known by the brand name Aleve and Naprosyn). However, despite their widespread use, these drugs can have side effects.

“In our study, approximately one in six patients with type 2 diabetes claimed at least one NSAID prescription within one year,” said first author Dr. Anders Holt of Copenhagen University Hospital, Denmark.” In general, we always recommend that patients consult their doctor before starting a new medication, and with results from this study, we hope to help doctors mitigate risk if prescribing NSAIDs.

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Animal studies on great apes have long been banned in Europe for ethical reasons. For the question pursued here, organoids (three-dimensional cell structures a few millimeters in size that are grown in the laboratory) are an alternative to animal experiments. These organoids can be produced from pluripotent stem cells, which then differentiate into specific cell types, such as nerve cells. In this way, the research team was able to produce both chimpanzee brain organoids and human brain organoids. “These brain organoids allowed us to investigate a central question concerning ARHGAP11B,” says Wieland Huttner of the MPI-CBG, one of the three lead authors of the study published in EMBO Reports.

“In a previous study we were able to show that ARHGAP11B can enlarge a primate brain. However, it was previously unclear whether ARHGAP11B had a major or minor role in the evolutionary enlargement of the human neocortex,” says Wieland Huttner. To clarify this, the ARGHAP11B gene was first inserted into brain ventricle-like structures of chimpanzee organoids. Would the ARGHAP11B gene lead to the proliferation of those brain stem cells in the chimpanzee brain that are necessary for the enlargement of the neocortex?

“Our study shows that the gene in chimpanzee organoids causes an increase in relevant brain stem cells and an increase in those neurons that play a crucial role in the extraordinary mental abilities of humans,” said Michael Heide, the study’s lead author, who is head of the Junior Research Group Brain Development and Evolution at the DPZ and employee at the MPI-CBG.

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Dielectric mirrors, also referred to as Bragg mirrors, reflect light nearly completely. Hence, they are suited for various applications, such as camera systems and sensor systems for microscopy and medical technologies. So far, such mirrors have been produced by complex processes in expensive vacuum devices. Researchers from Karlsruhe Institute of Technology (KIT) now are the first to print Bragg mirrors of high quality with inkjet printers. This may pave the way towards the digital manufacture of customized mirrors.

Research results are published in Advanced Materials (“Fabrication of Bragg Mirrors by Multilayer Inkjet Printing”).

Bragg mirrors are produced by applying several thin layers of materials onto a carrier. The resulting optical mirror specifically reflects the light of a certain wavelength. Reflectivity of a Bragg mirror depends on the materials, the number of layers applied, and their thicknesses. So far, Bragg mirrors have been produced in expensive vacuum production facilities. KIT researchers now were the first to print them on different carriers. This largely facilitates production.

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Testing of the trains started four years ago, and their initial implementation date was meant to be in 2021. The pandemic squashed that timeline, but late last month Alstom, the French company making the trains, announced the start of passenger service.

Five Coradia iLint trains started carrying passengers in August, and nine more will replace the diesel trains currently running on a route in Bremervörde, Lower Saxony by the end of this year.

The only byproducts from the trains’ operation are steam and water; any heat created is used to help power their heating and air conditioning systems. They have a range of 1,000 kilometers (621 miles), meaning they can run on a single tank of hydrogen for a full day. Their maximum speed is 140 kilometers per hour (87 miles per hour), but their average speeds are lower than this.

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