Long-range 3D Research Articles

Cyber-enhanced canine suit with wide-view angle for three-dimensional LiDAR SLAM for indoor environments

Understanding the topographical information of the disaster site can enhance the efficiency and safety of search and rescue missions. This study describes the development of a cyber-enhanced canine suit for three-dimensional (3D) simultaneous localization and mapping within indoor environments. The suit’s weight was approximately 3.0 kg and was compatible with large dogs (>30.0 kg). It could collect dense, wide view-angle, and long-range 3D point clouds. The collected point clouds were processed offline to create 3D maps. The suit was equipped with a protective cover that could prevent physical damage to the light imaging detection and ranging (LiDAR) sensor from collision. The protective cover was designed to (a) eliminate any effects on the performance of the 3D LiDAR and (b) sustain the stress from the impact at the velocity of 20.0 m/s with no physical damage. Additionally, the canine suit was also modified for better fitting and stability of the LiDAR on a wider range of dog bodies. The performance of the suit was demonstrated on real dogs in four different scenarios in areas with different space sizes, dog gait patterns, and ground layouts. The space size and position errors observed did not exceed 0.80% and 1.13%, respectively.

Super-enhancers in transcriptional regulation and genome organization.

Gene expression is precisely controlled in a stage and cell-type-specific manner, largely through the interaction between cis-regulatory elements and their associated trans-acting factors. Where these components aggregate in promoters and enhancers, they are able to cooperate to modulate chromatin structure and support the engagement in long-range 3D superstructures that shape the dynamics of a cell's genomic architecture. Recently, the term ‘super-enhancer’ has been introduced to describe a hyper-active regulatory domain comprising a complex array of sequence elements that work together to control the key gene networks involved in cell identity. Here, we survey the unique characteristics of super-enhancers compared to other enhancer types and summarize the recent advances in our understanding of their biological role in gene regulation. In particular, we discuss their capacity to attract the formation of phase-separated condensates, and capacity to generate three-dimensional genome structures that precisely activate their target genes. We also propose a multi-stage transition model to explain the evolutionary pressure driving the development of super-enhancers in complex organisms, and highlight the potential for involvement in tumorigenesis. Finally, we discuss more broadly the role of super-enhancers in human health disorders and related potential in therapeutic interventions.

HSN: Hybrid Segmentation Network for Small Cell Lung Cancer Segmentation

Small cell lung cancer (SCLC) is one of the most common types of malignant tumors, characterized by rapid growth and early metastasis spread. Early and accurate diagnosis of SCLC is vital for improved survival. Accurate cancer segmentation helps doctors understand the location and size of cancer and make better diagnostic decisions. However, manual segmentation of lung cancers from large amounts of medical images is a time-consuming and challenging task. In this paper, we propose a hybrid segmentation network (referred to as HSN) based on convolutional neural network (CNN) to automatically segment SCLC from computed tomography (CT) images. The design philosophy of our model is to combine a lightweight 3D CNN to learn long-range 3D contextual information and a 2D CNN to learn fine-grained semantic information, which is essential for accurate cancer segmentation. We propose a hybrid features fusion module to effectively fuse the 2D and 3D features and to jointly train these two CNNs. We utilize a generalized Dice loss function to tackle the severe class imbalance problem in data. A dataset consists of 134 CT scans was constructed to evaluate our model. Our model achieved high performances with a mean Dice score of 0.888, a mean sensitivity score of 0.872 and a mean precision of 0.909, outperforming the other state-of-the-art 2D and 3D CNN methods by a large margin.

Unusual Interplay between Superconductivity and Field-Induced Charge Order in YBa_{2}Cu_{3}O_{y}.

We present a detailed study of the temperature (T) and magnetic field (H) dependence of the electronic density of states (DOS) at the Fermi level, as deduced from specific heat and Knight shift measurements in underdoped YBa_{2}Cu_{3}O_{y}. We find that the DOS becomes field independent above a characteristic field H_{DOS}, and that the H_{DOS}(T) line displays an unusual inflection near the onset of the long-range 3D charge-density wave order. The unusual S shape of H_{DOS}(T) is suggestive of two mutually exclusive orders that eventually establish a form of cooperation in order to coexist at low T. On theoretical grounds, such a collaboration could result from the stabilization of a pair-density wave state, which calls for further investigation in this region of the phase diagram.

Eye-safe fiber laser for long-range 3D imaging applications.

We report an all-fiber Er/Yb master oscillator power amplifier at 1.55μm, delivering 135μJ pulses with 6ns duration (full width at half-maximum) at 100kHz pulse repetition frequency, limited by stimulated Brillouin scattering. The output contains <1% amplified spontaneous emission and has a beam quality of M2=1.1. By seeding with a high-power distributed-feedback laser diode, only two fiber amplification stages are needed, which represents a low overall system complexity compared to reported sources of similar performance. With an optical-to-optical efficiency of 29% and a robust alignment-free design, the source is well suited for field applications in 3D imaging with a several-kilometer range, and we present results from using it in an in-house-developed scanning lidar system.

Long-range 3D imaging of highly dynamic objects using the intensity ratios of partial beams of reflected laser light

The procedural aspects of obtaining long-range three-dimensional images of highly dynamic objects using the ratios of partial beam intensities of the reflected laser light are considered. Alongside with the object images, the proposed method simultaneously provides the data on the object relief with high resolution on a set of surface points during a single-pulse location cycle. The high resolving power and speed of the method ensure the efficiency of its application to detecting and recognition of remote highly dynamic objects, including low-dimensional ones, by their 3D characteristics.

Targeted in situ genome-wide profiling with high efficiency for low cell numbers.

Cleavage under targets and release using nuclease (CUT&RUN) is an epigenomic profiling strategy in which antibody-targeted controlled cleavage by micrococcal nuclease releases specific protein-DNA complexes into the supernatant for paired-end DNA sequencing. As only the targeted fragments enter into solution, and the vast majority of DNA is left behind, CUT&RUN has exceptionally low background levels. CUT&RUN outperforms the most widely used chromatin immunoprecipitation (ChIP) protocols in resolution, signal-to-noise ratio and depth of sequencing required. In contrast to ChIP, CUT&RUN is free of solubility and DNA accessibility artifacts and has been used to profile insoluble chromatin and to detect long-range 3D contacts without cross-linking. Here, we present an improved CUT&RUN protocol that does not require isolation of nuclei and provides high-quality data when starting with only 100 cells for a histone modification and 1,000 cells for a transcription factor. From cells to purified DNA, CUT&RUN requires less than a day at the laboratory bench and requires no specialized skills.

3D Long-Range Triplet Migration in a Water-Stable Metal-Organic Framework for Upconversion-Based Ultralow-Power in Vivo Imaging.

Triplet-triplet annihilation upconversion (TTA-UC) has gained increasing attention because it allows for harvesting of low-energy photons in the solar spectrum with high efficiency in relevant applications including solar cells and bioimaging. However, the utilization of conventional TTA-UC systems for low-power bioapplications is significantly hampered by their general incompatibility and low efficiency in aqueous media. Herein we report a metal-organic framework (MOF) as a biocompatible nanoplatform for TTA-UC to realize low-power in vivo imaging. Our MOF consists of a porphyrinic sensitizer in an anthracene-based Zr-MOF as a TTA-UC platform. In particular, closely aligned chromophores in the MOF facilitate a long-range 3D triplet diffusion of 1.6 μm allowing efficient energy migration in water. The tunable ratio between sensitizer and annihilator by our synthetic method also allows an optimization of the system for maximized TTA-UC efficiency in water at a very low excitation power density. Consequently, the low-power imaging of lymph node in a live mouse was successfully demonstrated with an excellent signal-to-noise ratio (SNR > 30 at 5 mW cm-2).

Increasing local density and purity of molecules/bacteria on a sensing surface from diluted blood using 3D hybrid electrokinetics.

We present a long-range and selective nanocolloid/molecular/bacteria concentrator based on 3D hybrid AC electrokinetics (ACEK) that includes AC dielectrophoresis (DEP) and biased AC electroosmosis (ACEO). Through a convergency comb-shaped electrode design, this long-range ACEO allows the effective transport of a high number of targets into the centre of the detection zone. In the proposed 3D hybrid electrokinetics model, 3D ACEO provides long-range transportation, and the 3D DEP provides an effective separation mechanism. Thus, detection targets ranging from nanoscale to micrometers could be selectively concentrated long-range from diluted blood. The proposed design was used for selectively concentrating nanocolloids and bacteria in the diluted blood sample, respectively. Compared to a 3D short-range dipolar electrode configuration, the detection limit of long-range 3D convergency tripolar electrode configuration is one order of magnitude higher. The result also shows that the 3D hybrid ACEK demonstrated a higher purity of any plane above the electrode, which compared positively to the same design of a 2D hybrid ACEK. The concentration factor of the proposed 3D hybrid electrokinetics device increased by several orders of local density and raised the local purity at least 6 orders (from 0.05% to greater than 99.9%). The chip is capable of making a DNA/protein/bacterial aggregate characterized by high local density and purity for further molecular and bacteria detection/analysis.

Cation Exchange in Dynamic 3D Porous Magnets: Improvement of the Physical Properties.

We report two novel three-dimensional porous coordination polymers (PCPs) of formulas Li4{Mn4[Cu2(Me3mpba)2]3}·68H2O (2) and K4{Mn4[Cu2(Me3mpba)2]3}·69H2O (3) obtained-via alkali cation exchange in a single-crystal to single-crystal process-from the earlier reported anionic manganese(II)-copper(II) PCP of formula Na4{Mn4[Cu2(Me3mpba)2]3}·60H2O (1) [Me3mpba(4-) = N,N'-2,4,6-trimethyl-1,3-phenylenebis(oxamate)]. This postsynthetic process succeeds where the direct synthesis in solution from the corresponding building blocks fails and affords significantly more robust PCPs with enhanced magnetic properties [long-range 3D magnetic ordering temperatures for the dehydrated phases (1'-3') of 2.0 (1'), 12.0 (2'), and 20.0 K (3')]. Changes in the adsorptive properties upon postsynthetic exchange suggest that the nature, electrostatic properties, mobility, and location of the cations within the framework are crucial for the enhanced structural stability. Overall, these results further confirm the potential of postsynthetic methods (including cation exchange) to obtain PCPs with novel or enhanced physical properties while maintaining unaltered their open-framework structures.

Engineering Gyroid-Structured Functional Materials via Templates Discovered in Nature and in the Lab.

In search of optimal structures for functional materials fabrication, the gyroid (G) structure has emerged as a promising subject of widespread research due to its distinct symmetry, 3D interconnected networks, and inherent chiral helices. In the past two decades, researchers have made great progress fabricating G-structured functional materials (GSFMs) based on G templates discovered both in nature and in the lab. The GSFMs demonstrate extraordinary resonance when interacting with light and matter. The superior properties of GSFMs can be divided into two categories based on the dominant structural properties, namely, dramatic optical performances dominated by short-range symmetry and well-defined texture, and effective matter transport due to long-range 3D interconnections and high integrity. In this review, G templates suitable for fabrication of GSFMs are summarized and classified. State-of-the-art optical applications of GSFMs, including photonic bandgap materials, chiral devices, plasmonic materials, and matamaterials, are systematically discussed. Applications of GSFMs involved in effective electron transport and mass transport, including electronic devices, ultrafiltration, and catalysis, are highlighted. Existing challenges that may hinder the final application of GSFMS together with possible solutions are also presented.

Vision-Based Long-Range 3D Tracking, applied to Underground Surveying Tasks

To address the need of highly automated positioning systems in underground construction, we present a long-range 3D tracking system based on infrared optical markers. It provides continuous 3D position estimation of static or kinematic targets with low latency over a tracking volume of 12 m x 8 m x 70 m (width x height x depth). Over the entire volume, relative 3D point accuracy with a maximal deviation ≤ 22 mm is ensured with possible target rotations of yaw, pitch = 0 − 45° and roll = 0 − 360°. No preliminary sighting of target(s) is necessary since the system automatically locks onto a target without user intervention and autonomously starts tracking as soon as a target is within the view of the system. The proposed system needs a minimal hardware setup, consisting of two machine vision cameras and a standard workstation for data processing. This allows for quick installation with minimal disturbance of construction work. The data processing pipeline ensures camera calibration and tracking during on-going underground activities. Tests in real underground scenarios prove the system’s capabilities to act as 3D position measurement platform for multiple underground tasks that require long range, low latency and high accuracy. Those tasks include simultaneously tracking of personnel, machines or robots.

Magnetic relaxation versus 3D long-range ordering in {Dy₂Ba(α-fur)₈}n furoate polymers.

A novel Dy-complex formulated as {[Dy2Ba(α-C4H3OCOO)8·(H2O)4]·2H2O}n, {Dy2Ba(α-fur)8}n, has been synthesized, structurally characterized, and magnetically and thermally investigated as a function of field and temperature, down to 85 mK. The α-furoate ligands consolidate 1D zig-zag chains formed by Dy2 dimers separated by Ba ions. Ab initio calculations were used to determine the easy anisotropy axis direction, the gyromagnetic tensor components and the energy levels of each Dy. The heat capacity and susceptibility measurements allowed us to conclude that intradimer and interdimer interactions are ferromagnetic and of the same order, J'/k(B) ≈ J''/k(B) = +0.55 K. In the absence of an applied magnetic field, the dynamic relaxation of the magnetization occurs through the fast (τ(T) ~ 10(-5) s) spin-reversal of each of the individual Dys through a quantum tunneling (QT) process. A long-range 3D ordered state is achieved at T(N) = 0.25 K, in which the ferromagnetically coupled zig-zag chains (J'/k(B) ≈ J''/k(B) = +0.528(1) K) running along the c-axis are antiferromagnetically coupled to the adjacent chains (J'''/k(B) = -0.021(1) K). Critical slowing down of the QT time constant is observed when the temperature approaches T(N). Under the application of a magnetic field, the QT relaxation is replaced by an Orbach process (with energy barrier U/k(B) = 68 K and τ0 ~ 10(-9) s at H = 2 kOe) and a very slow (τ(s) ∼ 0.2 s) relaxation process. We propose and demonstrate the proof of concept of a spintronic device, in which two different relaxation rates can be selected, and on/off switched by magnetic field biasing. The dynamical behavior of this compound is compared with another furoate to discuss the effect of competitive interactions.

Power-Law Dependence of Low-Temperature Magnetic Specific Heat for Hole-Doped Delafossite CuCr1-xMgxO2

Delafossite CuCrO2 is one of the canonical frustrated compounds having an S 1⁄4 3=2 antiferromagnetic triangular lattice (ATL), wherein a nonmagnetic Cu layer (Cuþ; S 1⁄4 0) and a magnetic CrO2 layer (Cr 3þ; S 1⁄4 3=2) are alternatively stacked. Because of various application possibilities, such as in transparent conductor, as thermoelectric material, and as multiferroic material, its magnetic, transport, thermal, structural, and ferroelectric properties have been widely studied. To explore novel phenomena in geometrically frustrated compounds, the effects of various substitutions on the physical properties have also been investigated. Among them, the substitution of nonmagnetic Mg2þ for magnetic Cr3þ is intriguing, because it produces itinerant holes and dramatically reduces the resistivity, which nontrivially affects the 120 Neel state. In spite of the distinct disorder being introduced into the magnetic state and the antiferromagnetic (AF) correlation being suppressed by the Mg substitution, the Neel temperature (TN) increases and the peak of magnetic specific heat (Cmag) at TN becomes sharper (Fig. 1), indicating the promotion of the AF transition. These effects of the Mg substitution on Cmag around TN are in marked contrast to those of the isovalent substitution, such as Al substitution for Cr and Ag for Cu, which clearly suppresses the Neel state owing to the introduced chemical randomness and the enhanced two-dimensional (2D) nature. Although the recent elastic and inelastic neutron scattering measurements seem to indicate that the Mg substitution slightly modulates the longer range magnetic interactions, the realized 120 Neel state below TN for CuCr1 xMgxO2 is almost identical to that for CuCrO2. On the other hand, the measurements of magnetization and magnetoresistance indicate that the itinerant holes doped by the Mg substitution seem to produce some ferromagnetic (FM) interaction between the localized spins. The perturbated FM interaction should compete with the AF exchange interaction, which should suppress the Neel order. However, the AF transition is clearly promoted, as shown in Fig. 1. According to the recent PES and XAS measurements, the spectra of Cr4þ are not observed but the spectrum of Cr3þ is modulated by the Mg substitution, indicating that the Cr ion for CuCr0:97Mg0:03O2 is trivalent. Then, CuCr1 xMgxO2 with x 0:03 is regarded as approximately an S 1⁄4 3=2 spin system so that the orbital degree of freedom of Cr4þ is absent. Therefore, although the microscopic mechanism has not been established, the unconventional promotion of the AF transition should be attributed to the doped itinerant holes having FM interaction with localized spins, since the spin dilution simply blurs the AF transition. To elucidate the origin of the unconventional promotion of the AF transition by the hole doping more clearly, it is necessary to understand the magnetic ground state correctly. In this short note, we report on the power-law dependence of the low-temperature (low-T ) Cmag of CuCr1 xMgxO2 without an enhancement of low-T Cmag by Mg substitution. These behaviors are due to the mixture of the effect of chemical randomness producing the 2D diffuse liquid like component and that of hole doping suppressing the low-energy excitation of long-range anisotropic 3D AF magnons. Figure 2(a) shows a summary of Cmag=T vs ðT=5Þ 1 at low temperatures below 5K for CuCr1 xMgxO2 together with those for the isovalent substituted compounds such as Cu1 xAgxCrO2 and CuCr1 xAlxO2, where is the coefficient of the T -linear component and is the exponent of the power-law dependence of Cmag summarized in Fig. 2(b). Although the values are much enhanced by the heavy Al substitution, those for CuCrO2, 7) CuCr1 xMgxO2, 7) and Cu1 xAgxCrO2 are about 1mJ/K mol, which is comparable to the experimental and fitting errors. The observed finite values are perhaps due to the spin glass component. It should be emphasized that, as shown in Fig. 2(b), for CuCr1 xMgxO2 gradually decreases from 3 with an increase in x, as observed in Cu1 xAgxCrO2 and CuCr1 xAlxO2, although the change around TN with the Mg substitution is quite different from those for the isovalent substituted compounds (Fig. 1). The decrease in seems to indicate the appearance of the same 2D diffuse spin liquid like state as those of Cu1 xAgxCrO2 and CuCr1 xAlxO2. However, in contrast to the isovalent compounds, the low-T Cmag for CuCr1 xMgxO2 seems to be not enhanced but rather suppressed by the Mg substitution. Furthermore, as shown in Fig. 2(b), the change in upon the Mg substitution is more dramatic than that upon the Al substitution in spite of the introduction of similar spin defects. 0 5 10 15

Spin-glass in the spinel-type CuCrTiS4

It is difficult to find a typical compound to understand the spin-glass (SG). Only a few model compounds for the SG have been investigated; Fe0.50Mn0.50TiO3 as a short-range interacting three-dimensional (3D) Ising SG, Dy0.103Y0.897Ru2Si2 as a long-range 3D Ising SG, and AgMn as a long-range 3D Heisenberg SG. A spinel-type compound CuCrTiS4 will be provided in this study as a realistic candidate for a short-range interacting 3D Heisenberg SG. This CuCrTiS4 can cause a SG phase below T g = 7.91 K, which is obtained by a random non-magnetic 50% substitution of Ti for Cr on B-sites in the ferromagnetic mother spinel CuCr2S4. The localized magnetic moment of CuCrTiS4 comes from Cr3+ with S = 3/2, where a valence state of Cu+Cr3+Ti4+S4 2− is built up. Experimental data will be focused only on the static properties of dc magnetization M(T) under various magnetic fields, without any dynamical magnetic feature. The spin-glass phase transition T g is well defined at low field, nevertheless hardly in higher fields than approximately 40 Oe. An appearance of the field dependence of M(T) of CuCrTiS4 is similar to that of Fe0.50Mn0.50TiO3 with the short-range Ising SG, and also these of AgMn and CuMn with the long-range interacting Heisenberg SGs. This general nature in M(T) seems to originate from the common mechanism under magnetic fields for all the spin-glasses.

Magnetic Order and Transitions in the Spin-web Compound Cu3TeO6

The spin-web compound Cu3TeO6, belongs to an intriguing group of materials where magnetism is governed by 3d9 copper Cu2+ ions. This compound has been sparsely experimentally studied and we here present the first investigation of its local magnetic properties using muon-spin relaxation/rotation ({\mu}+SR). Our results show a clear long-range 3D magnetic order below TN as indicated by clear zero-field (ZF) muon-precessions. At TN = 61.7 K a very sharp transition is observed in the weak transverse-field (wTF) as well as ZF data. Contrary to suggestions by susceptibility measurements and inelastic neutron scattering, we find no evidence for either static or dynamic (on the time-scale of {\mu}+SR) spin-correlations above TN.

A non-template hydrothermal route to uniform 3D macroporous films with switchable optical properties

Here we report the direct synthesis of long-range uniform 3D macroporous film on the surface of glass via a non-template strategy by reacting silica with a mixture solution of HCl and H 2O 2 under hydrothermal conditions. The size of macropores can be tuned from 1 μm to 7 μm by changing the hydrothermal temperature. Followed by the impregnation or release of water, the 3D porous films showed a high-contrast optical switchable property. The maximum optical transmittance modulation of these 3D porous films was up to 50% over the visible and near IR wavelength range. Furthermore, liquid-induced optical switching device were designed as a sandwich structure. The average transmittance of the device was varied between 62.3% (from 350 to 1100 nm) at the transparent state and 13.2% (from 350 to 1100 nm) at the opaque state, respectively. Such a wide modulation range of optical transmittance is suitable for application of this porous film to energy saving smart windows.

3D Hierarchically Ordered Composite Block Copolymer Hollow Sphere Arrays by Solution Wetting

Hierarchically ordered 3D arrays of block copolymer hollow spheres have been fabricated by using solution wetting of silica inverse colloidal crystals. Subsequent drying and annealing in the molten state yield nanopatterned shells due to the microphase separation of the block copolymers. The shell thickness can be controlled by properly selecting the polymer solution concentration, and the nanostructures inside the shells can be manipulated by varying molecular weights and/or compositions of the block copolymers. This versatile strategy can be readily applied to fabricate patterned metal (gold and palladium) nanoparticles inside the shells of the highly ordered hollow spheres. Thus, the locally ordered nanostructures of block copolymers are integrated into long-range 3D order defined by the silica inverse colloidal crystal templates, promising convenient fabrication of highly integrated devices.

Digital Preservation of a Historical Building – the 3D as-built Scan of Don Nan-Kuan House

AbstractThis study presents an effort in building archiving for the digital preservation of Chinese architecture. A historical architecture, Don Nan-Kuan House, was scanned. In order to retrieve shapes those are more accurate than traditional manual measurements. A long-range 3D laser scanner was used. Difficulty in measuring asbuilt forms was solved under the size of a building. The integration of measurements from outdoors and environments was also achieved to clarify the spatial interrelationship through as-built sections. This research helped us identify the most errorprone measurements done by traditional approach. To represent the special characteristics of as-built 3D building form, the preservation includes the application of as-built data in architecture, the information application of digital data in virtual reality, and the Internet display of large 3D data sets.

Long-range 2D and 3D self-organizations of Co nanocrystals: A new challenge for a new physics

The ability to grow long-range 2D and 3D organizations of metallic nanocrystals allows the emergence of unexpected physical properties. Here magnetic, structural and mechanical intrinsic properties due to the ordering of cobalt nanocrystals at the mesoscopic scale are discovered. Analogy between nanocrystals ordered in the supra-crystal and atoms in the bulk phase or in a nanocrystal related to the ordering concept is proposed. Notre savoir faire en matière de croissance d'organisations à 2D et 3D sur longue distance de nanocristaux métalliques permet l'émergence de propriétés physiques inattendues. Ici, nous montrons des propriétés intrinsèques magnétique, structurale et mécanique dues à l'organisation à l'échelle mésoscopique des nanocristaux de cobalt. Nous proposons une analogie entre les nanocristaux ordonnés dans le supra-cristal et les atomes dans la phase massive ou dans le nanocristal, relative au concept d'ordre.