Emulation of photonic synapses through photo‐recordable devices has aroused tremendous discussion owing to the low energy consumption, high parallel, and fault‐tolerance in artificial neuromorphic ...networks. Nonvolatile flash‐type photomemory with short photo‐programming time, long‐term storage, and linear plasticity becomes the most promising candidate. Nevertheless, the systematic studies of mechanism behind the charge transfer process in photomemory are limited. Herein, the physical properties of APbBr3 perovskite quantum dots (PQDs) on the photoresponsive characteristics of derived poly(3‐hexylthiophene‐2,5‐diyl) (P3HT)/PQDs‐based photomemory through facile A‐site substitution approach are explored. Benefitting from the lowest valance band maximum and longest exciton lifetime of FAPbBr3 quantum dot (FA‐QDs), P3HT/FA‐QDs‐derived photomemory not only exhibits shortest photoresponsive characteristic time compared to FA0.5Cs0.5PbBr3 quantum dots (Mix‐QDs) and CsPbBr3 quantum dots (Cs‐QDs) but also displays excellent ON/OFF current ratio of 2.2 upon an extremely short illumination duration of 1 ms. Moreover, the device not only achieves linear plasticity of synapses by optical potentiation and electric depression, but also successfully emulates the features of photon synaptic such as pair‐pulse facilitation, long‐term plasticity, and multiple spike‐dependent plasticity and exhibits extremely low energy consumption of 3 × 10−17 J per synaptic event.
Engineering of minimum photo‐recording time in poly(3‐hexylthiophene)/APbBr3 perovskite quantum dots‐based photomemory via facile an A‐site substitution approach is demonstrated. poly(3‐hexylthiophene‐2,5‐diyl)/FAPbBr3 quantum dot‐derived photomemory displays an extremely short programming time of 1 ms and enables the extremely low energy consumption of 3 × 10−17 J per synaptic event on the application of photonic synapse.
Hepatitis B virus (HBV) chronically infects 250 million people worldwide, resulting in nearly one million deaths annually. Studies in recent years have significantly improved our knowledge on the ...mechanisms of HBV persistence. HBV uses multiple pathways to harness host innate immunity to enhance its replication. It can also take advantage of the developing immune system and the not-yet-stabilized gut microbiota of young children to facilitate its persistence, and use maternal viral e antigen to educate immunity of the offspring to support its persistence after vertical transmission. The knowledge gained from these recent studies paves the way for the development of new therapies for the treatment of chronic HBV infection, which has so far been very challenging.
HBV frequently causes chronic infection after vertical transmission but mostly self-limited acute infection after horizontal transmission.
HBV harnesses type I interferon immune response to enhance its own replication.
HBV persistence is affected by the age of infection, size of viral inoculum, and gut microbiota.
Maternal HBeAg can train Kupffer cells of the offspring, likely in utero, to suppress HBV-specific CD8+ T cells in the presence of HBeAg after birth.
Mixed‐cation hybrid perovskite nanocrystal (HPNC) with high crystallinity, color purity, and tunable optical bandgap offers a practical pathway toward next‐generation displays. Herein, a two‐step ...modified hot‐injection combined with cation compositional engineering and surface treatment to synthesize high‐purity cesium/formamidinium lead bromide HPNCs(Cs1‐xFAxPbBr3) is presented. The optimized Cs0.5FA0.5PbBr3 light‐emitting devices (LEDs) exhibit uniform luminescence of 3500 cd m−2 and a prominent current efficiency of 21.5 cd A−1. As a proof of concept, a self‐healing polymer (SHP) integrated with white LED backlight and laser prototypes exhibited 4 h autonomous self‐healing through the synergistic effect of weak reversible imine bonds and stronger H‐bonds. First, the SHP‐HPNCs‐initial and SHP‐HPNCs‐cut possess high long‐term stability and dramatically suppressed lead leakage as low as 0.6 ppm along with a low leakage rate of 1.11 × 10−5 cm2 and 3.36 × 10−5 cm2 even over 6 months in water. Second, the Cs0.5FA0.5PbBr3 HPNCs and SHP‐induced shattered–repaired perovskite glass substrate show the lowest lasing threshold values of 1.24 and 8.58 µJ cm−2, respectively. This work provides an integrative and in‐depth approach to exploiting SHP with intrinsic and entropic self‐healing capabilities combined with HPNCs to develop robust and reliable soft‐electronic backlight and laser applications.
Novel post‐synthesis cesium/formamidinium (Cs/FA) mixed‐cation perovskite nanocrystals possess high structural and optoelectronic properties for integration in self‐healing polymer composites. Entropic‐driven self‐healing not only enhances white backlight display performance, but also sustains the working performance of a shattered–repaired glass substrate laser, thereby representing potentially major advances in optoelectronics and photonics applications.
In contrast to horizontal transmission of hepatitis B virus (HBV) between adults, which often leads to self-limited acute infection, vertical transmission of HBV from mother to child often leads to ...chronic infection. However, the mechanisms linking vertical transmission with chronic infection are not known. We developed a mouse model to study the effect of maternal HBV infection on HBV persistence in offspring and found that HBV carried by the mother impaired CD8+ T cell responses to HBV in her offspring, resulting in HBV persistence. This impairment of CD8+ T cell responses was mediated by hepatic macrophages, which were predisposed by maternal HBV e antigen (HBeAg) to support HBV persistence by upregulation of inhibitory ligand PD-L1 and altered polarization upon restimulation with HBeAg. Depletion of hepatic macrophages led to CD8+ T cell activation and HBV clearance in the offspring, raising the possibility of targeting macrophages to treat chronic HBV patients.
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•Developed a mouse model to study effect of maternal HBV on persistence in offspring•The CTL response to HBV is impaired in the offspring of HBV-positive mothers•Depletion of macrophages in offspring restores the CTL response for HBV clearance•Maternal HBeAg enhances PD-L1 expression in macrophages of offspring to suppress CTLs
Children born to mothers who carry HBV often become chronic HBV carriers. By developing a mouse model to study this vertical transmission, Ou and colleagues find that maternal HBV e antigen conditions macrophages of the offspring to suppress the CTL response to HBV, resulting in HBV persistence in the offspring.
Novel transparent conductive electrodes (TCEs) with copper (Cu)/silver (Ag) core/shell nanofibers (NFs) containing random, aligned, and crossed structures were prepared using a combination of ...electrospinning (ES) and chemical reduction. The ES process was used to prepare continuous copper nanofibers (Cu-NFs), which were used as core materials and were then immersed in silver ink (Ag ink) to form a protective layer of Ag to protect the Cu-NFs from oxidation. The Ag shell layer protected the Cu-NFs against oxidation and enhanced their conductivity. Such Cu/Ag core/shell webs can be easily transferred on the flexible matrix and can be applied in TCEs. The metal NF webs of different structures exhibited various degrees of conductivity and followed the order random type > crossed type > aligned type; however, the order with respect to transmittance (T) was inverse. The aligned nanowire networks exhibited a high T of over 80%, and the random ones exhibited a low sheet resistance of less than 102 Ω/sq (the best value is 7.85 Ω/sq). The present study demonstrated that TCEs based on Cu/Ag core/shell NF webs have considerable flexibility, transparency, and conductivity and can be applied in novel flexible light-emitting diode devices and solar cells in the future.
This paper develops Deep Neural Network (DNN) models that can recognize stroke gaits. Stroke patients usually suffer from partial disability and develop abnormal gaits that can vary widely and need ...targeted treatments. Evaluation of gait patterns is crucial for clinical experts to make decisions about the medication and rehabilitation strategies for the stroke patients. However, the evaluation is often subjective, and different clinicians might have different diagnoses of stroke gait patterns. In addition, some patients may present with mixed neurological gaits. Therefore, we apply artificial intelligence techniques to detect stroke gaits and to classify abnormal gait patterns. First, we collect clinical gait data from eight stroke patients and seven healthy subjects. We then apply these data to develop DNN models that can detect stroke gaits. Finally, we classify four common gait abnormalities seen in stroke patients. The developed models achieve an average accuracy of 99.35% in detecting the stroke gaits and an average accuracy of 97.31% in classifying the gait abnormality. Based on the results, the developed DNN models could help therapists or physicians to diagnose different abnormal gaits and to apply suitable rehabilitation strategies for stroke patients.
Objectives
This study aimed to evaluate the feasibility of automatic Stanford classification of classic aortic dissection (AD) using a 2-step hierarchical neural network.
Methods
Between 2015 and ...2019, 130 arterial phase series (57 type A, 43 type B, and 30 negative cases) in aortic CTA were collected for the training and validation. A 2-step hierarchical model was built including the first step detecting AD and the second step predicting the probability (0–1) of Stanford types. The model’s performance was evaluated with an off-line prospective test in 2020. The sensitivity and specificity for Stanford type A, type B, and no AD (Sens
A, B, N
and Spec
A, B, N
, respectively) and Cohen’s kappa were reported.
Results
Of 298 cases (22 with type A, 29 with type B, and 247 without AD) in the off-line prospective test, the Sens
A
, Sens
B
, and Sens
N
were 95.45% (95% confidence interval CI, 77.16–99.88%), 79.31% (95% CI, 60.28–92.01%), and 93.52% (95% CI, 89.69–96.25%), respectively. The Spec
A
, Spec
B
, and Spec
N
were 98.55% (95% CI, 96.33–99.60%), 94.05% (95% CI, 90.52–96.56%), and 94.12% (95% CI, 83.76–98.77%), respectively. The classification rate achieved 92.28% (95% CI, 88.64–95.04%). The Cohen’s kappa was 0.766 (95% CI, 0.68–0.85;
p
< 0.001).
Conclusions
Stanford classification of classic AD can be determined by a 2-step hierarchical neural network with high sensitivity and specificity of type A and high specificity in type B and no AD.
Key Points
•
The Stanford classification for aortic dissection is widely adopted and divides it into Stanford type A and type B based on the ascending thoracic aorta dissected or not
.
•
The 2-step hierarchical neural network for Stanford classification of classic aortic dissection achieved high sensitivity (95.45%) and specificity (98.55%) of type A and high specificity in type B and no aortic dissection (94.05% and 94.12%, respectively) in 298 test cases
.
•
The 2-step hierarchical neural network demonstrated moderate agreement (Cohen’s kappa: 0.766, p < 0.001) with cardiovascular radiologists in detection and Stanford classification of classic aortic dissection in 298 test cases
.
Transferring exogenous mitochondria has therapeutic effects on damaged heart, liver, and lung tissues. Whether this protective effect requires the symbiosis of exogenous mitochondria in host cells ...remains unknown. Here xenogenic mitochondria derived from a hamster cell line were applied to ischemic rat brains and rat primary cortical neurons. Isolated hamster mitochondria, either through local intracerebral or systemic intra-arterial injection, significantly restored the motor performance of brain-ischemic rats. The brain infarct area and neuronal cell death were both attenuated by the exogenous mitochondria. Although internalized mitochondria could be observed in neurons and astrocytes, the low efficacy of mitochondrial internalization could not completely account for the high rate of rescue of the treated neural cells. We further illustrated that disrupting electron transport or ATPase synthase in mitochondria significantly attenuated the protective effect, suggesting that intact respiratory activity is essential for the mitochondrial potency on neural protection. These results emphasize that nonsymbiotic extracellular mitochondria can provide an effective cell defense against acute injurious ischemic stress in the central nervous system.
Previous studies indicated that hepatitis C virus (HCV) perturbs the autophagic pathway to induce the accumulation of autophagosomes in cells. To understand the role of autophagosomes in the HCV life ...cycle, we established a stable Huh7 hepatoma cell line that contained an HCV subgenomic RNA replicon and also expressed a GFP-LC3 fusion protein. The GFP-LC3 protein is localized to autophagosomes during autophagy and served as a convenient marker for autophagosomes. Our results indicate that the silencing of the expression of LC3 or Atg7, two protein factors critical for the formation of autophagosomes, suppresses the replication of HCV RNA. Confocal microscopy studies revealed the localization of HCV NS5A and NS5B proteins, which are two important components of the HCV RNA replication complex, and nascent HCV RNA to autophagosomes. The association of the HCV RNA replication complex with the autophagosomal membranes was further confirmed by co-immunoprecipitation and immunoelectron microscopy studies. Interestingly, inhibition of Class III PI3K activity had no effect on the autophagosomes induced by HCV. These results indicate that HCV induces autophagosomes via a Class III PI3K-independent pathway and uses autophagosomal membranes as sites for its RNA replication.
Hepatitis C virus (HCV) induces autophagosomes in its host cells.
The HCV RNA replication complex colocalizes with autophagosomes, which are induced by HCV via a Class III PI3K-independent pathway.
HCV induces autophagosomes and uses their membranes for its RNA replication.
The perturbation of the autophagic pathway by HCV may have important consequences in HCV pathogenesis.
Out-of-hospital cardiac arrest (OHCA) is associated with a poor prognosis and a highly variable survival rate. Few studies have focused on outcomes in rural and urban groups while also evaluating ...underlying diseases and prehospital factors for OHCAs.
To investigate the relationship between the patient's underlying disease and outcomes of OHCAs in urban areas versus those in rural areas.
We reviewed the emergency medical service (EMS) database for information on OHCA patients treated between January 2015 and December 2019, and collected data on pre-hospital factors, underlying diseases, and outcomes of OHCAs. Univariate and multivariate logistic regression analyses were used to evaluate the prognostic factors for OHCA.
Data from 4225 OHCAs were analysed. EMS response time was shorter and the rate of attendance by EMS paramedics was higher in urban areas (p < 0.001 for both). Urban area was a prognostic factor for >24-h survival (odds ratio OR = 1.437, 95% confidence interval CI: 1.179–1.761). Age (OR = 0.986, 95% CI: 0.979–0.993). EMS response time (OR = 0.854, 95% CI: 0.811–0.898), cardiac arrest location (OR = 2.187, 95% CI: 1.707–2.795), attendance by paramedics (OR = 1.867, 95% CI: 1.483–2.347), and prehospital defibrillation (OR = 2.771, 95% CI: 2.154–3.556) were independent risk factors for survival to hospital discharge, although the influence of an urban area was not significant (OR = 1.211, 95% CI: 0.918–1.584).
Compared with rural areas, OHCA in urban areas are associated with a higher 24-h survival rate. Shorter EMS response time and a higher probability of being attended by paramedics were noted in urban areas. Although shorter EMS response time, younger age, public location, defibrillation by an automated external defibrillator, and attendance by Emergency Medical Technician-paramedics were associated with a higher rate of survival to hospital discharge, urban area was not an independent prognostic factor for survival to hospital discharge in OHCA patients.
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