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New method could jump-start creation of tiny medical devices for the body.

NIST Scientists Get Soft on 3D Printing

Illustration of a prospective biocompatible interface shows that hydrogels (green tubing), which can be generated by an electron or X-ray beam 3D printing process, act as artificial synapses or junctions, connecting neurons (brown) to electrodes (yellow). Image credit: A. Strelcov/NIST

Researchers at the National Institute of Standards and Technology (NIST) have developed a new method of 3D-printing gels and other soft materials. Published in a new paper, it has the potential to create complex structures with nanometer-scale precision. Because many gels are compatible with living cells, the new method could jump-start the production of soft tiny medical devices such as drug delivery systems or flexible electrodes that can be inserted into the human body.

A standard 3D printer makes solid structures by creating sheets of material — typically plastic or rubber — and building them up layer by layer, like a lasagna, until the entire object is created.

Using a 3D printer to fabricate an object made of gel is a “bit more of a delicate cooking process,” said NIST researcher Andrei Kolmakov. In the standard method, the 3D printer chamber is filled with a soup of long-chain polymers — long groups of molecules bonded together — dissolved in water. Then “spices” are added — special molecules that are sensitive to light. When light from the 3D printer activates those special molecules, they stitch together the chains of polymers so that they form a fluffy weblike structure. This scaffolding, still surrounded by liquid water, is the gel.

Typically, modern 3D gel printers have used ultraviolet or visible laser light to initiate formation of the gel scaffolding. However, Kolmakov and his colleagues have focused their attention on a different 3D-printing technique to fabricate gels, using beams of electrons or X-rays. Because these types of radiation have a higher energy, or shorter wavelength, than ultraviolet and visible light, these beams can be more tightly focused and therefore produce gels with finer structural detail. Such detail is exactly what is needed for tissue engineering and many other medical and biological applications. Electrons and X-rays offer a second advantage: They do not require a special set of molecules to initiate the formation of gels.

But at present, the sources of this tightly focused, short-wavelength radiation — scanning electron microscopes and X-ray microscopes — can only operate in a vacuum. That’s a problem because in a vacuum the liquid in each chamber evaporates instead of forming a gel.

Kolmakov and his colleagues at NIST and at the Elettra Sincrotrone Trieste in Italy, solved the issue and demonstrated 3D gel printing in liquids by placing an ultrathin barrier — a thin sheet of silicon nitride — between the vacuum and the liquid chamber. The thin sheet protects the liquid from evaporating (as it would ordinarily do in vacuum) but allows X-rays and electrons to penetrate into the liquid. The method enabled the team to use the 3D-printing approach to create gels with structures as small as 100 nanometers (nm) — about 1,000 times thinner than a human hair. By refining their method, the researchers expect to imprint structures on the gels as small as 50 nm, the size of a small virus.

Some future structures made with this approach could include flexible injectable electrodes to monitor brain activity, biosensors for virus detection, soft micro-robots, and structures that can emulate and interact with living cells and provide a medium for their growth.

“We’re bringing new tools — electron beams and X-rays operating in liquids — into 3D printing of soft materials,” said Kolmakov. He and his collaborators described their work in an article posted online Sept. 16 in ACS Nano.

Reference:

T. Gupta, et al. “Electron and X-ray Focus Beam Induced Crosslinking in Liquids: Toward Rapid Continuous 3D Nanoprinting of Soft Materials.“. ACS Nano (2020)

Source: NIST




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Xbox Series X restock for Cyber Monday: Where to buy the next-gen gaming system

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Cyber Monday is the next opportunity to score the in-demand Xbox Series X. Here’s when and where to find it at Target, Walmart, Best Buy and Amazon.

Image: Microsoft

Cyber Monday will offer new opportunities to buy the Xbox Series X gaming system at retailers in person and online. Amazon, Target, Best Buy, Walmart and GameStop are some of the key retailers that have been restocking the next-gen gaming console.

Microsoft’s Xbox Series X, which costs $500 and looks something like a skyscraper, debuted on Nov. 10 along with the $300 Xbox Series S, but it’s been in such high demand that it’s nearly impossible to snag a unit. Priced at $500, the Series X is the first major Xbox release since the Xbox One in 2013. Gamers are anxious to nab the Xbox Series X, because it’s new with blistering fast performance and load times, and an amazing frame rate. It can run games at 120 frames per second (fps), which is about double what the Xbox One could do. This kind of refresh rate makes games look unbelievably clear and also reduces any chances for motion sickness that some people experience when gaming with lower refresh rates.

When the Xbox Series X debuted, it was offered both in person and online, unlike the PS5, which was only sold online on its first day. But that hasn’t made it any easier to buy an Xbox. 

SEE: Guide to becoming a digital transformation champion (TechRepublic Premium)

Where to buy the Xbox Series X on Cyber Monday

Many retailers offered some stock on Black Friday, but are likely holding back additional restock units for Cyber Monday. This is the time to keep your finger on the refresh button and try to score a unit. Checking at unusual times such as 12:01 am and early in the morning around 4 am and 5 am seem to be fruitful. Because really, who needs sleep when it comes to buying a holiday gift, right?

At Best Buy, the Xbox Series X has been available periodically, and on Nov. 28, there were some units available, but for in-store purchases only. The retailer is also offering various bundles with additional games and accessories, such as one with the Xbox Series X with the Halo Infinite game for $560, or with the Xbox Series X console, an Xbox Game Pass Ultimate 3-month membership, a controller and a 1TB SSD Seagate storage expansion card for $783, or another with the Xbox Series X console, a $100 Xbox gift card and the 1TB SSD Seagate storage expansion card for $810, and a bundle with the Xbox Series X console and the Cyberpunk 2077 game for $560. Keep in mind that Best Buy is one of the retailers that likes to restock at midnight. 

On Twitter, some people reported that Walmart offered in-person stock of Xbox and PS5 for people shopping at the store, but it hasn’t been confirmed by Walmart. 

Amazon has offered the Xbox Series X for sale, but it’s the first place many people look, so it’s one of the toughest places to get lucky. 

GameStop has offered the Xbox Series X at regular intervals, and will likely restock on Cyber Monday. GameStop often bundles the Xbox and the PS5 with games and accessories such as headsets, so search for bundles as well as individual units. 

Target is offering online sales and curbside and in-store pickup of the Xbox. Refresh the page frequently to see if your regional stores have available inventory.

This article is being regularly updated with the latest information on Xbox Series X sales.

Also see

  • Raspberry Pi: A cheat sheet (TechRepublic)
  • Technology in education: The latest products and trends (free PDF) (TechRepublic)
  • How to securely erase hard drives (HDDs) and solid state drives (SSDs) (ZDNet)
  • Gift Guides for Techies (TechRepublic on Flipboard)

  • PS5 restock for Cyber Monday: When and where to buy the next-gen gaming console

    (TechRepublic)

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    Deep Smartphone Sensors-WiFi Fusion for Indoor Positioning and Tracking

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    While outdoor navigation services are widespread, there is no reliable and universal service for indoor positioning. A recent approach to tackle this problem has been recently published on arXiv.org. It employs a number of different sensors of a smartphone. Network sensors and observed landmarks allow estimating an absolute position. Then, motion and position sensors, such as accelerometer, gyroscope, and magnetometer, are used to estimate user displacement (an approach known as Pedestrian Dead Reckoning, PDR).

    Image credit: Mohammed Hassan via Pxhere, CC0 Public Domain

    Image credit: Mohammed Hassan via Pxhere, CC0 Public Domain

    A novelty of this paper is applying a deep learning approach to PDR. Convolutional and recurrent networks extract hidden correlations between different sensors, thus allowing them to cope with sensor noise. Moreover, barometer data is used to recognize the floor change. The system outperforms the International Conference on Indoor Positioning and Indoor Navigation challenge winner’s performance by a wide margin.

    We address the indoor localization problem, where the goal is to predict user’s trajectory from the data collected by their smartphone, using inertial sensors such as accelerometer, gyroscope and magnetometer, as well as other environment and network sensors such as barometer and WiFi. Our system implements a deep learning based pedestrian dead reckoning (deep PDR) model that provides a high-rate estimation of the relative position of the user. Using Kalman Filter, we correct the PDR’s drift using WiFi that provides a prediction of the user’s absolute position each time a WiFi scan is received. Finally, we adjust Kalman Filter results with a map-free projection method that takes into account the physical constraints of the environment (corridors, doors, etc.) and projects the prediction on the possible walkable paths. We test our pipeline on IPIN’19 Indoor Localization challenge dataset and demonstrate that it improves the winner’s results by 20% using the challenge evaluation protocol.

    Link: https://arxiv.org/abs/2011.10799




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    Moto G9 Plus Spotted on BIS Certification Site, Hints at India Launch: Report

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    Moto G9 Plus has reportedly been spotted on Indian BIS (Bureau of Indian Standards) certification website, hinting at a future launch in the country. The phone has already gone official in Brazil in September, and since then there has been no clarity on whether it will be launched in the Indian market or not. However, the fresh BIS listing raises hopes of an India launch in the future. The company has already launched Moto G9 model in the country, and Moto G9 Power is tipped to launch in the second week of December.

    MySmartPrice spotted the Moto G9 Plus listing on BIS site. The phone has been listed with model numbers XT2083-7 and XT2087-3 that are reportedly associated with Moto G9 Plus. There is no clarity on when the phone will be launched in the country, but the BIS certification does offer hope of its arrival in the imminent future. If we were to speculate, the phone could arrive alongside Moto G9 Power that is expected to launch in India sometime in the second week of December.

    Moto G9 Plus was launched in Brazil with a price tag of BRL 2,249.10 (roughly Rs. 31,000) for the lone 4GB + 128GB storage model. It should arrive in India within a similar price range. The phone was launched in the Brazilian market in Rose Gold and Blue Indigo colour options.

    Moto G9 Plus specifications

    As for specifications, we already know that Moto G9 Plus runs on Android 10 software and features a 6.8-inch full-HD+ Max Vision display. It is powered by the 2.2GHz Qualcomm Snapdragon 730G SoC, paired with 4GB of RAM and 128GB of internal storage.

    For photography, Moto G9 Plus has a quad rear camera setup that includes a 64-megapixel primary snapper, an 8-megapixel 118-degrees ultra-wide-angle shooter, a 2-megapixel macro camera, and a 2-megapixel depth sensor. At the front, there is a 16-megapixel selfie shooter.

    Moto G9 Plus has a 5,000mAh battery with 30W TurboPower fast charging support. Connectivity options include Bluetooth 5.0, Wi-Fi 802.11 ac, GPS, USB Type-C, and a 3.5mm audio jack. There is a side-mounted fingerprint sensor on board.


    Mi TV Stick vs Fire TV Stick Lite vs Mi Box 4K vs Fire TV Stick 4K: Which is the best budget streaming device for TVs in India? We discussed this on Orbital, our weekly technology podcast, which you can subscribe to via Apple Podcasts, Google Podcasts, or RSS, download the episode, or just hit the play button below.

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