Artificial synapses can boost neuromorphic computing to overcome the inherent limitations of von Neumann architecture. As a promising memristor candidate, ferroelectric tunnel junctions (FTJ) enable ...the authors to successfully emulate spike‐timing‐dependent synapses. However, the nonlinear and asymmetric synaptic weight update under repeated presynaptic stimulation hampers neuromorphic computing by favoring the runaway of synaptic weights during learning. Here, the authors demonstrate an FTJ whose conductivity varies linearly and symmetrically by judiciously combining ferroelectric domain switching and oxygen vacancy migration. The artificial neural network based on this FTJ‐synapse achieves classification accuracy of 96.7% during supervised learning, which is the closest to the maximum theoretical value of 98% achieved to date. This artificial synapse also demonstrates stable unsupervised learning in a noisy environment for its well‐balanced spike‐timing‐dependent plasticity response. The novel concept of controlling ionic migration in ferroelectric materials paves the way toward highly reliable and reproducible supervised and unsupervised learning strategies.
By combining ferroelectric domain switching and oxygen vacancy migration, a ferroelectric tunnel junction artificial synapse with intrinsic nonlinearity as low as 0.13–0.17 and symmetric weight updating is developed, which greatly improved the classification accuracy of neural network hardware in supervised learning to 96.7% and enhanced robustness to noise during unsupervised learning.
Deep Transfer Bug Localization Huo, Xuan; Thung, Ferdian; Li, Ming ...
IEEE transactions on software engineering,
07/2021, Letnik:
47, Številka:
7
Journal Article
Recenzirano
Many projects often receive more bug reports than what they can handle. To help debug and close bug reports, a number of bug localization techniques have been proposed. These techniques analyze a bug ...report and return a ranked list of potentially buggy source code files. Recent development on bug localization has resulted in the construction of effective supervised approaches that use historical data of manually localized bugs to boost performance. Unfortunately, as highlighted by Zimmermann et al., sufficient bug data is often unavailable for many projects and companies. This raises the need for cross-project bug localization - the use of data from a project to help locate bugs in another project. To fill this need, we propose a deep transfer learning approach for cross-project bug localization. Our proposed approach named TRANP-CNN extracts transferable semantic features from source project and fully exploits labeled data from target project for effective cross-project bug localization. We have evaluated TRANP-CNN on curated high-quality bug datasets and our experimental results show that TRANP-CNN can locate buggy files correctly at top 1, top 5, and top 10 positions for 29.9, 51.7, 61.3 percent of the bugs respectively, which significantly outperform state-of-the-art bug localization solution based on deep learning and several other advanced alternative solutions considering various standard evaluation metrics.
Macrophages are highly heterogeneous and exhibit a diversity of functions and phenotypes. They can be divided into pro‐inflammatory macrophages (M1) and anti‐inflammatory macrophages (M2). Diabetic ...wounds are characterized by a prolonged inflammatory phase and difficulty in healing due to the accumulation of pro‐inflammatory (M1) macrophages in the wound. Therefore, hydrogel dressings with macrophage heterogeneity regulation function hold great promise in promoting diabetic wound healing in clinical applications. However, the precise conversion of pro‐inflammatory M1 to anti‐inflammatory M2 macrophages by simple and biosafe approaches is still a great challenge. Here, an all‐natural hydrogel with the ability to regulate macrophage heterogeneity is developed to promote angiogenesis and diabetic wound healing. The protocatechuic aldehyde hybridized collagen‐based all‐natural hydrogel exhibits good bioadhesive and antibacterial properties as well as reactive oxygen species scavenging ability. More importantly, the hydrogel is able to convert M1 macrophages into M2 macrophages without the need for any additional ingredients or external intervention. This simple and safe immunomodulatory approach shows great application potential for shortening the inflammatory phase of diabetic wound repair and accelerating wound healing.
An all‐natural hydrogel composed of small molecules pro‐catechol and collagen is developed to promote diabetic wound healing by modulating macrophage heterogeneity. The hydrogel exhibits good bioadhesive, antibacterial, and reactive oxygen species scavenging abilities. In vitro and in vivo experiments show that the hydrogel is able to promote the conversion of pro‐inflammatory (M1) macrophages to anti‐inflammatory (M2) macrophages and the expression of anti‐inflammatory factors.
Dysfunction of the circadian rhythm is one of most common nonmotor symptoms in Parkinson's disease (PD), but the molecular role of the circadian rhythm in PD is unclear. We here showed that ...inactivation of brain and muscle ARNT‐like 1 (BMAL1) in 1‐methyl‐4‐phenyl‐1,2,4,5‐tetrahydropyridine (MPTP)‐treated mice resulted in obvious motor functional deficit, loss of dopaminergic neurons (DANs) in the substantia nigra pars compacta (SNpc), decrease of dopamine (DA) transmitter, and increased activation of microglia and astrocytes in the striatum. Time on the rotarod or calorie consumption, and food and water intake were reduced in the Bmal1−/− mice after MPTP treatment, suggesting that absence of Bmal1 may exacerbate circadian and PD motor function. We observed a significant reduction of DANs (~35%) in the SNpc, the tyrosine hydroxylase protein level in the striatum (~60%), the DA (~22%), and 3,4‐dihydroxyphenylacetic acid content (~29%), respectively, in MPTP‐treated Bmal1−/− mice. Loss of Bmal1 aggravated the inflammatory reaction both in vivo and in vitro. These findings suggest that BMAL1 may play an essential role in the survival of DANs and maintain normal function of the DA signaling pathway via regulating microglia‐mediated neuroinflammation in the brain.
Multifunctional nanomaterials with simple structure and good biosafety, integrating multimodal imaging and therapeutic functions, can facilitate the development of clinical cancer treatments. Here, a ...simple but powerful pure bismuth based nanoparticle (Gd-PEG-Bi NPs) was developed from pure Bi NPs and gadolinium-diethylenetriaminepentaacetic acid-bis-tetradecylamide, which not only shows high quality MRI/CT/PAI triple-modal imaging, but can also be a potent photothermal therapy agent under the guidance of the triple-modal imaging. The Gd-PEG-Bi NPs showed good stability and excellent biocompatibility. In vitro and in vivo study demonstrated that Gd-PEG-Bi NPs have ultrahigh X-ray attenuation coefficient, short T1 relaxation time in MRI, and strong PAI signal. Following the imaging diagnosis, the excellent light-to-heat conversion efficiency of Gd-PEG-Bi NPs was capable of suppressing the tumor growth effectively under near-infrared laser radiation in vivo. Such multifunctional nanoparticles were ideal candidates for cancer diagnosis and treatment.
Display omitted
•A simple and powerful pure bismuth based nanoparticle was developed.•The pure bismuth based nanoparticle showed excellent light-to-heat conversion efficiency.•The bismuth nanoparticle can provide MRI/CT/PAI multimodal imaging and photothermal therapy.
The pH‐dependent surface‐enhanced Raman spectra of two typical surface sensor molecules p‐mercaptobenzoic acid (PMBA) and p‐mercaptopyridine (PMPY) were simulated by density functional theory ...calculations. First, the acid dissociation constants and individual surface Raman spectra of PMBA and PMPY were computed and compared with experimental results. It was found that acid dissociation constants calculated by the hybrid implicit‐explicit model and surface‐enhanced Raman scattering (SERS) spectra simulated by the explicit model most closely coincide with experimental results. Then, the pH‐dependent SERS spectra of PMBA and PMPY were obtained by overlaying the SERS of individual acid species and base species multiplied by their molar fractions, which were calculated from the acid dissociation constants. During the deprotonation process of PMBA, the Raman intensity from COOH stretching decreases and the Raman intensity from COO− stretching increases. During the protonation process of PMPY, the ν8a mode undergoes a significant blueshift and the relative Raman intensity of ν7a mode decreases. At last, pH calibration curves of PMBA and PMPY were obtained according to the simulated pH‐dependent Raman spectra, in which the logarithmic value of relative Raman intensity of characteristic peaks varies almost linearly with solution pH.
The pH‐dependent surface‐enhanced Raman spectra of two typical surface sensor molecules p‐mercaptobenzoic acid and p‐mercaptopyridine were simulated by density functional theory calculations.
Planting at an optimum density and supplying adequate nitrogen（N） to achieve higher yields is a common practice in crop production, especially for maize（Zea mays L.）; however, excessive N fertilizer ...supply in maize production results in reduced N use efficiency（NUE） and severe negative impacts on the environment. This research was conducted to determine the effects of increased plant density and reduced N rate on grain yield, total N uptake, NUE, leaf area index（LAI）, intercepted photosynthetically active radiation（IPAR）, and resource use efficiency in maize. Field experiments were conducted using a popular maize hybrid Zhengdan 958（ZD958） under different combinations of plant densities and N rates to determine an effective approach for maize production with high yield and high resource use efficiency. Increasing plant density was clearly able to promote N absorption and LAI during the entire growth stage, which allowed high total N uptake and interception of radiation to achieve high dry matter accumulation（DMA）, grain yield, NUE, and radiation use efficiency（RUE）. However, with an increase in plant density, the demand of N increased along with grain yield. Increasing N rate can significantly increase the DMA, grain yield, LAI, IPAR, and RUE. However, this increase was non-linear and due to the input of too much N fertilizers, the efficiency of N use at NCK（320 kg ha~（–1）） was low. An appropriate reduction in N rate can therefore lead to higher NUE despite a slight loss in grain production. Taking into account both the need for high grain yield and resource use efficiency, a 30% reduction in N supply, and an increase in plant density of 3 plants m~（–2）, compared to LD（5.25 plants m~（–2））, would lead to an optimal balance between yield and resource use efficiency.
Background Our previous study reported that recombinant human epidermal growth factor (rhEGF)-triggered EGFR internalization promoted radioresistance. Here, we aimed to evaluate the effect of rhEGF ...on the skin protection of rectal and anal cancer patients receiving radiotherapy. Methods One hundred and ninety-three rectal and anal cancer patients who received radiotherapy were prospectively enrolled from January 2019 to December 2020. To perform self-controlled study, the left and right pelvic skin area (separated by midline) were randomly assigned to the rhEGF and control side. The association between radiation dermatitis and factors including rhEGF, the dose of radiotherapy and tumor distance from anal edge were analyzed. Results Among 193 enrolled patients, 41 patients (21.2%) did not develop radiation dermatitis, and 152 patients (78.8%) suffered radiation dermatitis on at least one side of pelvic skin at the end of radiotherapy. For the effect on radiation dermatitis grade, rhEGF had improved effect on 6 (4.0%) patients, detrimental effect on 2 (1.3%) patients, and no effect on 144 (94.7%) patients. Whereas for the effect on radiation dermatitis area, rhEGF showed improved effect on the radiation dermatitis area of 46 (30.2%) patients, detrimental effect on 15 (9.9%) patients, and no effect on 91 (59.9%) patients. The radiation dermatitis area of rhEGF side was significantly smaller than that of control side (P = 0.0007). Conclusions rhEGF is a skin protective reagent for rectal and anal cancer patients receiving radiotherapy. Trial registration Chinese Clinical Trial Registry identifier: ChiCTR1900020842; Date of registration: 20/01/2019. Keywords: rhEGF, Radiation dermatitis, Rectal and anal cancer, Clinical trial
A boron dipyrromethene (BODIPY)-based fluorescent probe bearing a tellurium atom was developed for fast and selective detection of hypochlorite (ClO−). Its molecular structure was firstly determined ...by X-ray diffraction analysis, indicating that the divalent tellurium formed a relatively small angle of 96.6(8)o and thus its electrons were easily oxidized. This probe could fast respond to ClO− and a strong green fluorescence appeared, attributing to oxidation of the tellurium and thereby inhibition of photoinduced electron transfer of the tellurium to the BODIPY. A linear fluorescence change was observed in the ClO−-concentration range of 0–8 μM with a detection limit of 0.12 μM. This probe was found to be applicable in a broad pH range (4–12). Confocal fluorescence microscopy imaging in RAW264.7 and HepG2 cells showed a remarkable green fluorescence enhancement with ClO−. This change could be also observed with phorbol myristate acetate-induced HClO. These results demonstrated that this probe could be an efficient fluorescent probe for ClO− detection in living cells.
Herein, we report the synthesis and X-ray crystal structure of a new tellurium-containing boron dipyrromethene-based fluorescent probe for fast and selective detection of ClO− in solutions and cells. Display omitted
•A OFF-ON BODIPY-based fluorescent probe for ClO− was developed.•Its molecular structure was determined by X-ray diffraction analysis.•A strong green fluorescence was immediately observed with addition of ClO−.•This remarkable change was also seen in living cells upon exposure to exogenous and endogenous HClO.
The nanomaterials for non-enzymatic electrochemical sensors are usually pre-synthesized and coated onto electrodes by
ex situ
methods. In this work, amorphous cobalt-nickel sulfide (CoNiS) ...nanoparticles were facilely prepared on copper foam (CF) by the
in situ
successive ionic layer adsorption and reaction (SILAR) method, and as-prepared CoNiS/CF was studied as an electrode for non-enzymatic glucose sensing. It was analyzed by field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDAX) and X-ray photoelectron spectroscopy (XPS). The electrochemical performance was investigated by cyclic voltammetry (CV) and chronoamperometry (CA). This binary sulfide electrode showed better performance toward glucose oxidation compared to the corresponding single sulfide and showed a wide linear range of 0.005 to 3.47 mM, a high sensitivity of 2298.7 μA mM
−1
cm
−2
and a low detection limit of 2.0 μM. The sensor exhibited high sensitivity and good repeatability and stability and was able to detect glucose in an actual sample. This work provides a simple and fast
in situ
electrode preparation method for a high-sensitivity glucose sensor.
CoNiS/CF was prepared by a simple SILAR method for glucose sensor, which exhibited high sensitivity, good repeatability, and stability, and was able to detect glucose in real sample.
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