18 research outputs found
SpikeBERT: A Language Spikformer Trained with Two-Stage Knowledge Distillation from BERT
Spiking neural networks (SNNs) offer a promising avenue to implement deep
neural networks in a more energy-efficient way. However, the network
architectures of existing SNNs for language tasks are too simplistic, and deep
architectures have not been fully explored, resulting in a significant
performance gap compared to mainstream transformer-based networks such as BERT.
To this end, we improve a recently-proposed spiking transformer (i.e.,
Spikformer) to make it possible to process language tasks and propose a
two-stage knowledge distillation method for training it, which combines
pre-training by distilling knowledge from BERT with a large collection of
unlabelled texts and fine-tuning with task-specific instances via knowledge
distillation again from the BERT fine-tuned on the same training examples.
Through extensive experimentation, we show that the models trained with our
method, named SpikeBERT, outperform state-of-the-art SNNs and even achieve
comparable results to BERTs on text classification tasks for both English and
Chinese with much less energy consumption
Dissecting the regulation and function of ATP at the single-cell level.
Regulation of cellular ATP level is critical for diverse biological processes and may be defective in diseases such as cancer and mitochondrial disorders. While mitochondria play critical roles in ATP level regulation, we still lack a systematic and quantitative picture of how individual mitochondrial-related genes contribute to cellular ATP level and how dysregulated ATP levels may affect downstream cellular processes. Advances in genetically encoded ATP biosensors have provided new opportunities for addressing these issues. ATP biosensors allow researchers to quantify the changes of ATP levels in real time at the single-cell level and characterize corresponding effects at the cellular, tissue, and organismal level. Along this direction, several recent single-cell studies using ATP biosensors, including the work by Mendelsohn and colleagues, have started to uncover the principles for how genetic and nongenetic parameters may modulate ATP levels to affect cellular functions and human health
Certified Robustness to Text Adversarial Attacks by Randomized [MASK]
Very recently, few certified defense methods have been developed to provably guarantee the robustness of a text classifier to adversarial synonym substitutions. However, all the existing certified defense methods assume that the defenders have been informed of how the adversaries generate synonyms, which is not a realistic scenario. In this study, we propose a certifiably robust defense method by randomly masking a certain proportion of the words in an input text, in which the above unrealistic assumption is no longer necessary. The proposed method can defend against not only word substitution-based attacks, but also character-level perturbations. We can certify the classifications of over 50% of texts to be robust to any perturbation of five words on AGNEWS, and two words on SST2 dataset. The experimental results show that our randomized smoothing method significantly outperforms recently proposed defense
methods across multiple datasets under different attack algorithms
Research trends of worldwide ophthalmologic randomized controlled trials in the 21st century: A bibliometric study
Background: Randomized controlled trials (RCTs) are often considered the gold standard and the cornerstone for clinical practice. However, bibliometric studies on worldwide RCTs of ophthalmology published in the 21st century have not been reported in detail yet. This study aims to perform a bibliometric study and visualization analysis of worldwide ophthalmologic RCTs in the 21st century. Methods: Global ophthalmologic RCTs from 2000 to 2022 were searched in the Web of Science Core Collection. The number of publications, country/region, institution, author, journal, and research hotspots of RCTs were analyzed using HistCite, VOSviewer, CiteSpace, and Excel software. Results: 2366 institutions and 90 journals from 83 countries/regions participated in the publication of 1769 global ophthalmologic RCTs, with the United States leading in the number of volumes and research field, and the Moorfields Eye Hospital contributing to the most publications. Ophthalmology received the greatest number of publications and co-citations. Jeffrey S. Heier owned the most publications and Jost B. Jonas owned the most co-citations. The knowledge foundations of global ophthalmologic RCTs were mainly retinopathy, glaucoma, dry eye disease (DED), and cataracts, and anti-vascular endothelial growth factor (VEGF) therapy (ranibizumab), topical ocular hypotensive medication, laser trabeculoplasty. Anti-VEGF therapy for age-related macular degeneration (AMD), DME (diabetic macular edema), and DED, the use of new diagnostic tools, and myopia were the hottest research highlights. Anti-VEGF therapy, prompt laser, triamcinolone, and verteporfin photodynamic therapy for AMD, DME, and CNV (choroidal neovascularization), DED, myopia, and open-angle glaucoma were the research hotspots with the longest duration. The future research hotspots might be DED and the prevention and control of myopia. Conclusions: Overall, the number of global ophthalmologic RCTs in the 21st century was keeping growing, there was an imbalance between the regions and institutions, and more efforts are required to raise the quantity, quality, and global impact of high-quality clinical evidence in developing countries/regions
Adaptive mesh refinement based numerical simulation of detonation initiation in supersonic combustible mixtures using a hot jet
The open-source program AMROC, implementing a block-structured adaptive mesh refinement method, was adopted for the fine structure numerical simulation of detonation
initiation in supersonic combustible mixtures. Simulations were conducted on a nested parallel LINUX compute system. The initiation process was specified as three stages and their respective flow field characteristics were analyzed. Results indicate that a hot jet under specific conditions can have a similar effect as a pneumatic oblique bevel for inducing periodical shock-induced detonative combustion by a bow shock. The interaction of bow-shock-induced combustion with
the local detonation wave, produced by the reflection shock on the upper wall, can create a structure with two triple-wave points. The hot jet not only plays a role in the detonation initiation, but also is found to act as a stabilizing control mechanism for detonation propagation. In our simulations, the detonation wave propagates in an overdriven state initially and achieves self-sustaining motion after the shutdown of the hot jet. Subsequently, the final pisiform structure of typical stable Chapman-Jouguet detonation cells is formed
Single-Channel Blind Signal Separation of the MHD Linear Vibration Sensor Based on Singular Spectrum Analysis and Fast Independent Component Analysis
An MHD vibration sensor, as a new type of sensor used for vibration measurements, meets the technical requirements for the low-noisy measurement of acceleration, velocity, and micro-vibration in spacecraft during their development, launch, and orbit operations. A linear vibration sensor with a runway type based on MHD was independently developed by a laboratory. In a practical test, its output signal was mixed with a large amount of noise, in which the continuous narrowband interference was particularly prominent, resulting in the inability to efficiently carry out the real-time detection of micro-vibration. Considering the high interference of narrowband noise in linear vibration signals, a single-channel blind signal separation method based on SSA and FastICA is proposed in this study, which provides a new strategy for linear vibration signals. Firstly, the singular spectrum of the linear vibration signal with noise was analyzed to suppress the narrowband interference in the collected signal. Then, a FastICA algorithm was used to separate the independent signal source. The experimental results show that the proposed method can effectively separate the useful linear vibration signals from the collected signals with low SNR, which is suitable for the separation of the MHD linear vibration sensor and other vibration measurement sensors. Compared with EEMD, VMD, and wavelet threshold denoising, the SNR of the separated signal is increased by 10 times on average. Through the verification of the actual acquisition of the linear vibration signal, this method has a good denoising effect
Photocatalytic Overall Water Splitting Reaction Feature on Photodeposited Ni<i><sub>x</sub></i>P/γ-Ga<sub>2</sub>O<sub>3</sub> Nanosheets
Solar light-driven overall water splitting for hydrogen
production
is an ideal solution to climate warming and energy shortage issues.
Obtaining a highly efficient and stable photocatalyst remains a major
challenge at present. Herein, NixP/γ-Ga2O3 nanosheets, which were synthesized from NiCl2, NaH2PO2, and home-made γ-Ga2O3 nanosheets by the photodeposition method under
254 UV irradiation for 30 min, are found as a highly active and durable
photocatalyst for pure water splitting into H2 and O2 without a sacrificial reagent. The H2 production
rate is as high as 5.5 mmol·g–1·h–1 under 125 W high-pressure mercury lamp irradiation,
which is 3.4 and 2.5 times higher than that on the pristine γ-Ga2O3 nanosheets and Pt/γ-Ga2O3 nanosheets, respectively, and is 2.0 times higher than that
on the 0.5 wt % Ni2P/γ-Ga2O3 reported previously. However, the O2 evolution rate is
much less than the H2 evolution rate in the initial reaction
stage. On prolonging the irradiation time, H2 evolution
declines, while O2 evolution increases until it reaches
its stoichiometric value corresponding to H2. The reason
for the photocatalytic behavior of NixP/γ-Ga2O3 is studied and the corresponding
mechanism is suggested. The absent or low oxygen evolution in the
initial reaction stage is because the dioxygen generated from water
oxidation by the photogenerated holes is wholly or partially captured
by the surface oxygen vacancies to form the surface peroxide bonds
(−O–O−). Once the oxygen vacancies are eliminated
by the photogenerated O2, the overall water splitting reaction
would reach the steady state. Thereafter, H2 production
decreases from 5.5 to 2.0 mmol·g–1·h–1, but the O2 evolution gradually approaches
the corresponding stoichiometric value, especially for the photocatalyst
treated with H2O2 for 24 h
Engineering MMP‑2 Activated Nanoparticles Carrying B7-H3 Bispecific Antibodies for Ferroptosis-Enhanced Glioblastoma Immunotherapy
Administration of bispecific antibodies (biAbs) in tumor
therapy
is limited by their short half-life and off-target toxicity. Optimized
strategies or targets are needed to overcome these barriers. B7-H3
(CD276), a member of the B7 superfamily, is associated with poor survival
in glioblastoma (GBM) patients. Moreover, a dimer of EGCG (dEGCG)
synthesized in this work enhanced the IFN-γ-induced ferroptosis
of tumor cells in vitro and in vivo. Herein, we prepared recombinant anti-B7-H3×CD3 biAbs and constructed
MMP-2-sensitive S-biAb/dEGCG@NPs to offer a combination treatment
strategy for efficient and systemic GBM elimination. Given their GBM
targeted delivery and tumor microenvironment responsiveness, S-biAb/dEGCG@NPs
displayed enhanced intracranial accumulation, 4.1-, 9.5-, and 12.3-fold
higher than that of biAb/dEGCG@NPs, biAb/dEGCG complexes, and free
biAbs, respectively. Furthermore, 50% of GBM-bearing mice in the S-biAb/dEGCG@NP
group survived longer than 56 days. Overall, S-biAb/dEGCG@NPs can
induce GBM elimination by boosting the ferroptosis effect and enhancing
immune checkpoint blockade (ICB) immunotherapy and may be successful
antibody nanocarriers for enhanced cancer therapy