91 research outputs found
Static and dynamic crushing of novel porous crochet-sintered metal and its filled composite tube
© 2018 Elsevier Ltd A novel porous crochet-sintered metal (PCSM) is fabricated by rolling a crocheted porous cloth and subsequent vacuum sintering using a continual single super-fine soft 304 rope twisted by 49 fibers as raw material. This work investigates the quasi-static and dynamic axial crushing response of PCSMs and their filled composite tubes. The pore structures of PCSMs are formed by inter-crocheted and multiple inter-locked rope skeletons and metallurgical bonds. The PCSMs have almost no initial impact effects with a high crushing force efficiency. Filling the PCSMs changes the deformation model of 6063 tube, improves the static crashworthiness parameters of 6063 tube by 8–25% with almost no increasing initial impact effect, and doesn't always play a positive role in dynamic absorption. Porosity has obvious influence on the quasi-static and dynamic behavior and crashworthiness of PCSMs and their filled composite tube, and the effect of porosity on dynamic crashworthiness of composite tube is greater than that on quasi-static crashworthiness of composite tube. The PCSMs and their composite tubes show great potential for application in energy absorbers. The method of filling PCSM into bare tube is possible to improve the energy absorption ability of thin-walled tube with almost no increase in the initial peak force
A duplication-free quantum neural network for universal approximation
The universality of a quantum neural network refers to its ability to
approximate arbitrary functions and is a theoretical guarantee for its
effectiveness. A non-universal neural network could fail in completing the
machine learning task. One proposal for universality is to encode the quantum
data into identical copies of a tensor product, but this will substantially
increase the system size and the circuit complexity. To address this problem,
we propose a simple design of a duplication-free quantum neural network whose
universality can be rigorously proved. Compared with other established
proposals, our model requires significantly fewer qubits and a shallower
circuit, substantially lowering the resource overhead for implementation. It is
also more robust against noise and easier to implement on a near-term device.
Simulations show that our model can solve a broad range of classical and
quantum learning problems, demonstrating its broad application potential.Comment: 15 pages, 10 figure
Ensemble-learning error mitigation for variational quantum shallow-circuit classifiers
Classification is one of the main applications of supervised learning. Recent
advancement in developing quantum computers has opened a new possibility for
machine learning on such machines. Due to the noisy performance of near-term
quantum computers, error mitigation techniques are essential for extracting
meaningful data from noisy raw experimental measurements. Here, we propose two
ensemble-learning error mitigation methods, namely bootstrap aggregating and
adaptive boosting, which can significantly enhance the performance of
variational quantum classifiers for both classical and quantum datasets. The
idea is to combine several weak classifiers, each implemented on a shallow
noisy quantum circuit, to make a strong one with high accuracy. While both of
our protocols substantially outperform error-mitigated primitive classifiers,
the adaptive boosting shows better performance than the bootstrap aggregating.
The protocols have been exemplified for classical handwriting digits as well as
quantum phase discrimination of a symmetry-protected topological Hamiltonian,
in which we observe a significant improvement in accuracy. Our
ensemble-learning methods provide a systematic way of utilising shallow
circuits to solve complex classification problems.Comment: 14 pages, 6 figure
Topological chiral kagome lattice
Chirality, a fundamental structural property of crystals, can induce many
unique topological quantum phenomena. In kagome lattice, unconventional
transports have been reported under tantalizing chiral charge order. Here, we
show how by deforming the kagome lattice to obtain a three-dimensional (3D)
chiral kagome lattice in which the key band features of the non-chiral 2D
kagome lattice - flat energy bands, van Hove singularities (VHSs), and
degeneracies - remain robust in both the = 0 and planes in momentum
space. Given the handedness of our kagome lattice, degenerate momentum points
possess quantized Chern numbers, ushering in the realization of Weyl fermions.
Our 3D chiral kagome lattice surprisingly exhibits 1D behavior on its surface,
where topological surface Fermi arc states connecting Weyl fermions are
dispersive in one momentum direction and flat in the other direction. These 1D
Fermi arcs open up unique possibilities for generating unconventional non-local
transport phenomena at the interfaces of domains with different handedness, and
the associated enhanced conductance as the separation of the leads on the
surface is increased. Employing first-principles calculations, we investigate
in-depth the electronic and phononic structures of representative materials
within the ten space groups that can support topological chiral kagome
lattices. Our study opens a new research direction that integrates the
advantages of structural chirality with those of a kagome lattice and thus
provides a new materials platform for exploring unique aspects of correlated
topological physics in chiral lattices.Comment: 7 pages, 4 figure
Investigating the L-Glu-NMDA receptor-H2S-NMDA receptor pathway that regulates gastric function in rats’ nucleus ambiguus
BackgroundIn previous investigations, we explored the regulation of gastric function by hydrogen sulfide (H2S) and L-glutamate (L-Glu) injections in the nucleus ambiguus (NA). We also determined that both H2S and L-Glu have roles to play in the physiological activities of the body, and that NA is an important nucleus for receiving visceral sensations. The purpose of this study was to explore the potential pathway link between L-Glu and H2S, resulting in the regulation of gastric function.MethodsPhysiological saline (PS), L-glutamate (L-Glu, 2Â nmol), NaHS (2Â nmol), D-2-amino-5-phopho-novalerate (D-AP5, 2Â nmol) + L-Glu (2Â nmol), aminooxyacetic acid (AOAA, 2Â nmol) + L-Glu (2Â nmol), D-AP5 (2Â nmol) + NaHS (2Â nmol) were injected into the NA. A balloon was inserted into the stomach to observe gastric pressure and for recording the changes of gastric smooth muscle contraction curve. The gastric fluid was collected by esophageal perfusion and for recording the change of gastric pH value.ResultsInjecting L-Glu in NA was found to significantly inhibit gastric motility and promote gastric acid secretion in rats (p < 0.01). On the other hand, injecting the PS, pre-injection N-methyl-D-aspartate (NMDA) receptor blocker D-AP5, cystathionine beta-synthase (CBS) inhibitor AOAA and re-injection L-Glu did not result in significant changes (p > 0.05). The same injection NaHS significantly inhibit gastric motility and promote gastric acid secretion in rats (p < 0.01), but is eliminated by injection D-AP5 (p > 0.05).ConclusionThe results indicate that both exogenous L-Glu and H2S injected in NA regulate gastric motility and gastric acid secretion through NMDA receptors. This suggests that NA has an L-Glu-NMDA receptor-CBS-H2S pathway that regulates gastric function
Optical Data Transmission ASICs for the High-Luminosity LHC (HL-LHC) Experiments
We present the design and test results of two optical data transmission ASICs
for the High-Luminosity LHC (HL-LHC) experiments. These ASICs include a
two-channel serializer (LOCs2) and a single-channel Vertical Cavity Surface
Emitting Laser (VCSEL) driver (LOCld1V2). Both ASICs are fabricated in a
commercial 0.25-um Silicon-on-Sapphire (SoS) CMOS technology and operate at a
data rate up to 8 Gbps per channel. The power consumption of LOCs2 and LOCld1V2
are 1.25 W and 0.27 W at 8-Gbps data rate, respectively. LOCld1V2 has been
verified meeting the radiation-tolerance requirements for HL-LHC experiments.Comment: 9 pages, 12 figure
The 120Gbps VCSEL Array Based Optical Transmitter (ATx) Development for the High-Luminosity LHC (HL-LHC) Experiments
The integration of a Verticle Cavity Surface-Emitting Laser (VCSEL) array and
a driving Application-Specific Integrated Circuit (ASIC) in a custom optical
array transmitter module (ATx) for operation in the detector front-end is
constructed, assembled and tested. The ATx provides 12 parallel channels with
each channel operating at 10 Gbps. The optical transmitter eye diagram passes
the eye mask and the bit-error rate (BER) less than 1E-12 transmission is
achieved at 10 Gbps/ch. The overall insertion loss including the radiation
induced attenuation is sufficiently low to meet the proposed link budget
requirement.Comment: 10 pages, 9 figure
Segmental Membranous Glomerulopathy in Adults
Introduction: The clinicopathological features of segmental membranous glomerulopathy (SMGN) have not been well characterized. The aim of this study was to investigate the prevalence and clinicopathological features of SMGN in adults.
Methods: Adult patients with biopsy-confirmed SMGN in the native kidney at our center between January 2017 to September 2020 were identified. The clinicopathological features of SMGN were collected. The glomerular deposition of IgG subclasses, M-type phospholipase A2 receptor 1 (PLA2R), thrombospondin type 1 domain-containing 7A (THSD7A) and neural epidermal growth factor-like 1 protein (NELL1) were tested. Clinical and pathologic features were comparable between NELL1-positive and NELL1-negative SMGN.
Results: A total of 167 patients with biopsy-proven SMGN were enrolled. During the same period, 32,640 (33.0%) out of 98,939 renal biopsies were diagnosed with membranous nephropathy (MN) in adults. SMGN accounted for 0.17% of total kidney biopsies and 0.51% of MN in adults. One hundred and fifty (89.8%) cases were isolated SMGN and 17 (10.2%) cases were complicated with other kidney disease. Clinically, the median age of isolated SMGN patients was 41.5 years, with female (74%) predominance, and 33.1% had full nephrotic syndrome. Pathologically, IgG1 was the dominant subclass (92.5%), followed by IgG4 (45.0%). PLA2R and THSD7A staining were done in 142 and 136 isolated SMGN cases, respectively. In which, all the cases showed negative. NELL1 staining was done in 135 isolated SMGN cases, 58 cases (43.0%) showed positive. Fifty-eight patients (41.1%) had diffuse (≥90%) foot process effacement, 119 patients (83.8%) had either stage I (38.0%) or stage II (45.8%) membranous alterations in patients with SMGN. Most patients with NELL1-positive SMGN were female. Patients with NELL1-positive SMGN were more likely with lower prevalence of full nephrotic syndrome than NELL1-negative SMGN.
Conclusions: SMGN is a relatively rare pathological type. Majority of patients with isolated SMGN were female, with a median age of 41.5 years, 33.1% had full nephrotic syndrome, absence of PLA2R and THSD7A, 43.0% with NELL1-positive, and mainly stage I or II MN (83.8%). NELL1 is the major target antigen of SMGN in adults
Cracking the Code:Enhancing Molecular Tools for Progress in Nanobiotechnology
Nature continually refines its processes for optimal efficiency, especially within biological systems. This article explores the collaborative efforts of researchers worldwide, aiming to mimic nature’s efficiency by developing smarter and more effective nanoscale technologies and biomaterials. Recent advancements highlight progress and prospects in leveraging engineered nucleic acids and proteins for specific tasks, drawing inspiration from natural functions. The focus is developing improved methods for characterizing, understanding, and reprogramming these materials to perform user-defined functions, including personalized therapeutics, targeted drug delivery approaches, engineered scaffolds, and reconfigurable nanodevices. Contributions from academia, government agencies, biotech, and medical settings offer diverse perspectives, promising a comprehensive approach to broad nanobiotechnology objectives. Encompassing topics from mRNA vaccine design to programmable protein-based nanocomputing agents, this work provides insightful perspectives on the trajectory of nanobiotechnology toward a future of enhanced biomimicry and technological innovation.</p
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