scholarly journals Highly tunable properties in pressure-treated two-dimensional Dion–Jacobson perovskites

2020 ◽  
Vol 117 (28) ◽  
pp. 16121-16126 ◽  
Author(s):  
Lingping Kong ◽  
Gang Liu ◽  
Jue Gong ◽  
Lingling Mao ◽  
Mengting Chen ◽  
...  
Keyword(s):  
3D Structure ◽  
Three Dimensional ◽  
Strain Engineering ◽  
Ex Situ ◽  
Light Absorber ◽  
Absorber Material ◽  
Order Of Magnitude ◽  
Condensed Matters ◽  
Novel Structures

The application of pressure can achieve novel structures and exotic phenomena in condensed matters. However, such pressure-induced transformations are generally reversible and useless for engineering materials for ambient-environment applications. Here, we report comprehensive high-pressure investigations on a series of Dion–Jacobson (D-J) perovskites A′An−1PbnI3n+1[A′ = 3-(aminomethyl) piperidinium (3AMP), A = methylammonium (MA),n= 1, 2, 4]. Our study demonstrates their irreversible behavior, which suggests pressure/strain engineering could viably improve light-absorber material not only in situ but also ex situ, thus potentially fostering the development of optoelectronic and electroluminescent materials. We discovered that the photoluminescence (PL) intensities are remarkably enhanced by one order of magnitude at mild pressures. Also, higher pressure significantly changes the lattices, boundary conditions of electronic wave functions, and possibly leads to semiconductor–metal transitions. For (3AMP)(MA)3Pb4I13, permanent recrystallization from 2D to three-dimensional (3D) structure occurs upon decompression, with dramatic changes in optical properties.

Potential Applications of Bacterial Cellulose in Environmental and Pharmaceutical Sectors

2020 ◽  
Vol 26 (45) ◽  
pp. 5793-5806
Author(s):  
Mazhar Ul-Islam ◽  
Salman Ul-Islam ◽  
Sumayia Yasir ◽  
Atiya Fatima ◽  
Md. Wasi Ahmed ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
3D Structure ◽  
Three Dimensional ◽  
Base Material ◽  
Advanced Materials ◽  
Ex Situ ◽  
Potential Applications ◽  
Wide Readership ◽  
Water Filters

Biopolymers and their composites have been extensively investigated in recent years for multiple applications, especially in environmental, medical, and pharmaceutical fields. Bacterial cellulose (BC) has emerged as a novel biomaterial owing to its nontoxic, high-liquid absorbing and holding capacity, drug-carrying ability, and pollutant absorbing features. Additionally, its web-shaped three-dimensional (3D) structure and hydrogen bonding sites have incited a combination of various nanoparticles, polymers, and other materials with BC in the form of composites. Such BC-based composites have been developed through in-situ, ex-situ, and solution casting methods for targeted applications, such as air and water filters, controlled drug delivery systems, wound dressing materials, and tissue regeneration. This review details the production and development of BCbased composites with different materials and by various methods. It further describes various applications of BC-based composites in the environmental and pharmaceutical sectors, with specific examples from the recent literature. This review could potentially appeal a wide readership in these two emerging fields, where novel and advanced materials for different applications have been developed on a regular basis using BC as the base material.

Detection, Averaging, and 3D Reconstruction of Biological Specimens on Hypercubes (Transputer-based) Computers

1990 ◽  
Vol 48 (1) ◽  
pp. 454-455
Author(s):  
Jose-Maria Carazo ◽  
I. Benavides ◽  
S. Marco ◽  
J.L. Carrascosa ◽  
E.L. Zapata
Keyword(s):  
3D Reconstruction ◽  
3D Structure ◽  
Three Dimensional ◽  
Software Tools ◽  
Mapping Method ◽  
Computer Architectures ◽  
Parallel Computer ◽  
Reconstruction Process ◽  
Computing Power ◽  
Order Of Magnitude

Obtaining the three-dimensional (3D) structure of negatively stained biological specimens at a resolution of, typically, 2 - 4 nm is becoming a relatively common practice in an increasing number of laboratories. A combination of new conceptual approaches, new software tools, and faster computers have made this situation possible. However, all these 3D reconstruction processes are quite computer intensive, and the middle term future is full of suggestions entailing an even greater need of computing power. Up to now all published 3D reconstructions in this field have been performed on conventional (sequential) computers, but it is a fact that new parallel computer architectures represent the potential of order-of-magnitude increases in computing power and should, therefore, be considered for their possible application in the most computing intensive tasks.We have studied both shared-memory-based computer architectures, like the BBN Butterfly, and local-memory-based architectures, mainly hypercubes implemented on transputers, where we have used the algorithmic mapping method proposed by Zapata el at. In this work we have developed the basic software tools needed to obtain a 3D reconstruction from non-crystalline specimens (“single particles”) using the so-called Random Conical Tilt Series Method. We start from a pair of images presenting the same field, first tilted (by ≃55°) and then untilted. It is then assumed that we can supply the system with the image of the particle we are looking for (ideally, a 2D average from a previous study) and with a matrix describing the geometrical relationships between the tilted and untilted fields (this step is now accomplished by interactively marking a few pairs of corresponding features in the two fields). From here on the 3D reconstruction process may be run automatically.

scholarly journals Tunable In Situ 3D-Printed PVDF-TrFE Piezoelectric Arrays

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5032
Author(s):  
Alec Ikei ◽  
James Wissman ◽  
Kaushik Sampath ◽  
Gregory Yesner ◽  
Syed N. Qadri
Keyword(s):  
3D Printing ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Mechanical Strain ◽  
Pressure Sensors ◽  
Strain Ratio ◽  
Ex Situ ◽  
Order Of Magnitude ◽  
3D Printed

In the functional 3D-printing field, poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) has been shown to be a more promising choice of material over polyvinylidene fluoride (PVDF), due to its ability to be poled to a high level of piezoelectric performance without a large mechanical strain ratio. In this work, a novel presentation of in situ 3D printing and poling of PVDF-TrFE is shown with a d33 performance of up to 18 pC N−1, more than an order of magnitude larger than previously reported in situ poled polymer piezoelectrics. This finding paves the way forward for pressure sensors with much higher sensitivity and accuracy. In addition, the ability of in situ pole sensors to demonstrate different performance levels is shown in a fully 3D-printed five-element sensor array, accelerating and increasing the design space for complex sensing arrays. The in situ poled sample performance was compared to the performance of samples prepared through an ex situ corona poling process.

scholarly journals In situ structure of virus capsids within cell nuclei by correlative light and cryo-electron tomography

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Swetha Vijayakrishnan ◽  
Marion McElwee ◽  
Colin Loney ◽  
Frazer Rixon ◽  
David Bhella
Keyword(s):  
Electron Microscopy ◽  
Structure Determination ◽  
Electron Tomography ◽  
3D Structure ◽  
Three Dimensional ◽  
Cell Nuclei ◽  
Nuclear Egress ◽  
Virus Capsids ◽  
Cryo Electron Tomography

Abstract Cryo electron microscopy (cryo-EM), a key method for structure determination involves imaging purified material embedded in vitreous ice. Images are then computationally processed to obtain three-dimensional structures approaching atomic resolution. There is increasing interest in extending structural studies by cryo-EM into the cell, where biological structures and processes may be imaged in context. The limited penetrating power of electrons prevents imaging of thick specimens (> 500 nm) however. Cryo-sectioning methods employed to overcome this are technically challenging, subject to artefacts or involve specialised and costly equipment. Here we describe the first structure of herpesvirus capsids determined by sub-tomogram averaging from nuclei of eukaryotic cells, achieved by cryo-electron tomography (cryo-ET) of re-vitrified cell sections prepared using the Tokuyasu method. Our reconstructions confirm that the capsid associated tegument complex is present on capsids prior to nuclear egress. We demonstrate that this method is suited to both 3D structure determination and correlative light/electron microscopy, thus expanding the scope of cryogenic cellular imaging.

Thermal stability of RuO2, BaxSr1−xTiO3/RuO2, and BaxSr1−xTiO3/Pt/Ti/SiO2on Si(100)

2000 ◽  
Vol 15 (9) ◽  
pp. 1955-1961 ◽  
Author(s):  
T. S. Kang ◽  
Y. S. Kim ◽  
Jung Ho Je
Keyword(s):  
Thermal Stability ◽  
Three Dimensional ◽  
Interface Roughness ◽  
Ex Situ ◽  
X Ray ◽  
Good Thermal Stability ◽  
X Ray Scattering ◽  
Thermal Stability Of ◽  
Ray Scattering

The thermal stability of RuO2/Si(100) films in air was studied using ex situ synchrotron x-ray scattering. The (110) textured RuO2 film showed good thermal stability due to the low surface and strain energies. However, the RuO2 films of high strain and surface energies were transformed to three-dimensional islands during annealing up to 800 °C. We also studied, during the post annealing process, the interface roughness of BaxSr1−xTiO3 (BST)/RuO2/Si(100) and BST/Pt/Ti/SiO2/Si(100) structures comparatively, using in situ synchrotron x-ray scattering. The interfaces of the BST/RuO2/Si were thermally stable up to 500 °C, and the deterioration of the interfaces above 500 °C was attributed to the crystallization of amorphous BST film. Meanwhile, the interfaces of the BST/Pt/Ti/SiO2/Si were significantly degraded even at the low temperature of 350 °C, mainly due to the formation of the Pt–Ti alloy and the Ti oxidation.

scholarly journals Integration of Multiple Resolution Data in 3D Chromatin Reconstruction Using ChromStruct

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 338
Author(s):  
Claudia Caudai ◽  
Monica Zoppè ◽  
Anna Tonazzini ◽  
Ivan Merelli ◽  
Emanuele Salerno
Keyword(s):  
Spatial Organization ◽  
Local Level ◽  
3D Structure ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Rna Seq ◽  
Chromosome Conformation ◽  
Experimental Protocols ◽  
Easy Integration

The three-dimensional structure of chromatin in the cellular nucleus carries important information that is connected to physiological and pathological correlates and dysfunctional cell behaviour. As direct observation is not feasible at present, on one side, several experimental techniques have been developed to provide information on the spatial organization of the DNA in the cell; on the other side, several computational methods have been developed to elaborate experimental data and infer 3D chromatin conformations. The most relevant experimental methods are Chromosome Conformation Capture and its derivatives, chromatin immunoprecipitation and sequencing techniques (CHIP-seq), RNA-seq, fluorescence in situ hybridization (FISH) and other genetic and biochemical techniques. All of them provide important and complementary information that relate to the three-dimensional organization of chromatin. However, these techniques employ very different experimental protocols and provide information that is not easily integrated, due to different contexts and different resolutions. Here, we present an open-source tool, which is an expansion of the previously reported code ChromStruct, for inferring the 3D structure of chromatin that, by exploiting a multilevel approach, allows an easy integration of information derived from different experimental protocols and referred to different resolution levels of the structure, from a few kilobases up to Megabases. Our results show that the introduction of chromatin modelling features related to CTCF CHIA-PET data, histone modification CHIP-seq, and RNA-seq data produce appreciable improvements in ChromStruct’s 3D reconstructions, compared to the use of HI-C data alone, at a local level and at a very high resolution.

scholarly journals Computer Microvision for MEMS

2000 ◽  
Vol 8 (5) ◽  
pp. 32-35 ◽  
Author(s):  
Dennis M. Freeman
Keyword(s):  
Inner Ear ◽  
3D Structure ◽  
Three Dimensional ◽  
Ccd Camera ◽  
Optical Microscope ◽  
Sensory Cells ◽  
Mems Devices ◽  
Microscopy Technique ◽  
Stroboscopic Illumination

Computer Microvision is a microscopy technique originally developed to study sound-induced motions of sensory cells in the inner ear - motions that are on the order of picometers-i.e., smaller than the radius of a hydrogen atom. Three-dimensional micrornovies of inner ear cells moving in response to sound were analyzed to quantify motions with nanometer precision. Recently we have adapted the technique for in situ measurement of motions of micro-electron mechanical (MEMS) devices.In Computer Microvision systems, images of MEMS are magnified with an optical microscope and projected onto a CCD camera. Stroboscopic illumination is used to obtain stopaction images of the moving structures. Stop-action images from multiple focal planes provide information about 3D structure and 3D motion. Image analysis algorithms determine motions of all visible structures with nanometer accuracy. The system can measure motions at frequencies as high as 5 MHz with nanometer resolution, i.e., well below the wavelength of light.

scholarly journals Cryoelectron tomography of radial spokes in cilia and flagella

2011 ◽  
Vol 195 (4) ◽  
pp. 673-687 ◽  
Author(s):  
Gaia Pigino ◽  
Khanh Huy Bui ◽  
Aditi Maheshwari ◽  
Pietro Lupetti ◽  
Dennis Diener ◽  
...  
Keyword(s):  
Local Control ◽  
Tetrahymena Thermophila ◽  
3D Structure ◽  
Three Dimensional ◽  
3D Reconstructions ◽  
Specific Location ◽  
Radial Spokes ◽  
Similarities And Differences ◽  
Cilia And Flagella

Radial spokes (RSs) are ubiquitous components in the 9 + 2 axoneme thought to be mechanochemical transducers involved in local control of dynein-driven microtubule sliding. They are composed of >23 polypeptides, whose interactions and placement must be deciphered to understand RS function. In this paper, we show the detailed three-dimensional (3D) structure of RS in situ in Chlamydomonas reinhardtii flagella and Tetrahymena thermophila cilia that we obtained using cryoelectron tomography (cryo-ET). We clarify similarities and differences between the three spoke species, RS1, RS2, and RS3, in T. thermophila and in C. reinhardtii and show that part of RS3 is conserved in C. reinhardtii, which only has two species of complete RSs. By analyzing C. reinhardtii mutants, we identified the specific location of subsets of RS proteins (RSPs). Our 3D reconstructions show a twofold symmetry, suggesting that fully assembled RSs are produced by dimerization. Based on our cryo-ET data, we propose models of subdomain organization within the RS as well as interactions between RSPs and with other axonemal components.

scholarly journals Process Monitoring Dataset from the Additive Manufacturing Metrology Testbed (AMMT): Overhang Part X4

2020 ◽  
Vol 125 ◽  
Author(s):  
Brandon Lane ◽  
Ho Yeung
Keyword(s):  
Computed Tomography ◽  
Additive Manufacturing ◽  
Real Time ◽  
Process Monitoring ◽  
Three Dimensional ◽  
Ex Situ ◽  
Web Page ◽  
X Ray ◽  
X Ray Computed

This document provides details on the files available in the dataset “Overhang Part X4” pertaining to a three-dimensional (3D) additive manufacturing (AM) build performed on the Additive Manufacturing Metrology Testbed (AMMT) by Ho Yeung and Brandon Lane on June 28, 2019. The files include the input command files, materials data, in-situ process monitoring data, and metadata. This data is one of a set of “AMMT Process Monitoring Datasets”, as part of the Metrology for Real-Time Monitoring of Additive Manufacturing project at the National Institute of Standards and Technology (NIST). Ex-situ part characterization data, including X-ray computed tomography (XCT) measurements, will be provided as it is made available. Readers should refer to the AMMT datasets web page for updates.

scholarly journals An in-memory computing architecture based on two-dimensional semiconductors for multiply-accumulate operations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yin Wang ◽  
Hongwei Tang ◽  
Yufeng Xie ◽  
Xinyu Chen ◽  
Shunli Ma ◽  
...  
Keyword(s):  
Three Dimensional ◽  
High Capacity ◽  
Random Access ◽  
High Energy ◽  
Ex Situ ◽  
Analog Computation ◽  
Electrical Characteristics ◽  
Access Memory ◽  
Multi Level

AbstractIn-memory computing may enable multiply-accumulate (MAC) operations, which are the primary calculations used in artificial intelligence (AI). Performing MAC operations with high capacity in a small area with high energy efficiency remains a challenge. In this work, we propose a circuit architecture that integrates monolayer MoS2 transistors in a two-transistor–one-capacitor (2T-1C) configuration. In this structure, the memory portion is similar to a 1T-1C Dynamic Random Access Memory (DRAM) so that theoretically the cycling endurance and erase/write speed inherit the merits of DRAM. Besides, the ultralow leakage current of the MoS2 transistor enables the storage of multi-level voltages on the capacitor with a long retention time. The electrical characteristics of a single MoS2 transistor also allow analog computation by multiplying the drain voltage by the stored voltage on the capacitor. The sum-of-product is then obtained by converging the currents from multiple 2T-1C units. Based on our experiment results, a neural network is ex-situ trained for image recognition with 90.3% accuracy. In the future, such 2T-1C units can potentially be integrated into three-dimensional (3D) circuits with dense logic and memory layers for low power in-situ training of neural networks in hardware.

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