Negative corona discharge strategy for efficient quantum dot light-emitting diodes.

In colloid quantum dot light-emitting diodes (QLEDs), the control of interface states between ZnO and quantum dots (QDs) plays a vital role. We present a straightforward and efficient method using a negative corona discharge to modify the QD film, creating a dipole moment at the interface of QDs and magnesium-doped ZnO (ZnMgO) for balanced charge carrier distribution within the QDs. This process boosts external quantum efficiencies in red, green, and blue QLEDs to 17.71%, 14.53%, and 9.04% respectively. Notably, optimized devices exhibit significant enhancements, especially at lower brightness levels (1000 to 10,000 cd·m-2), vital for applications in mobile displays, TV screens, and indoor lighting.

Data-Driven Controlled Synthesis of Oriented Quasi-Spherical CsPbBr3 Perovskite Materials.

Controlled synthesis of lead-halide perovskite crystals is challenging yet attractive because of the pivotal role played by the crystal structure and growth conditions in regulating their properties. This study introduces data-driven strategies for the controlled synthesis of oriented quasi-spherical CsPbBr3, alongside an investigation into the synthesis mechanism. High-throughput rapid characterization of absorption spectra and color under ultraviolet illumination was conducted using 23 possible ligands for the synthesis of CsPbBr3 crystals. The links between the absorption spectra slope (difference in the absorbance at 400 nm and 450 nm divided by a wavelength interval of 50 nm) and crystal size were determined through statistical analysis of more than 100 related publications. Big data analysis and machine learning were employed to investigate a total of 688 absorption spectra and 652 color values, revealing correlations between synthesis parameters and properties. Ex situ characterization confirmed successful synthesis of oriented quasi-spherical CsPbBr3 perovskites using polyvinylpyrrolidone and Acacia. Density functional theory calculations highlighted strong adsorption of Acacia on the (110) facet of CsPbBr3. Optical properties of the oriented quasi-spherical perovskites prepared with these data-driven strategies were significantly improved. This study demonstrates that data-driven controlled synthesis facilitates morphology-controlled perovskites with excellent optical properties.

New insights into the proton pumping mechanism of ba3 cytochrome c oxidase: the functions of key residues and water.

As the terminal oxidase of cell respiration in mitochondria and aerobic bacteria, the proton pumping mechanism of ba3-type cytochrome c oxidase (CcO) of Thermus thermophiles is still not fully understood. Especially, the functions of key residues which were considered as the possible proton loading sites (PLSs) above the catalytic center, as well as water located above and within the catalytic center, remain unclear. In this work, molecular dynamic simulations were performed on a set of designed mutants of key residues (Asp287, Asp372, His376, and Glu126II). The results showed that Asp287 may not be a PLS, but it could modulate the ability of the proton transfer pathway to transfer protons through its salt bridge with Arg225. Maintaining the closed state of the water pool above the catalytic center is necessary for the participation of inside water molecules in proton transfer. Water molecules inside the water pool can form hydrogen bond chains with PLS to facilitate proton transfer. Additional quantum cluster models of the Fe-Cu metal catalytic center are established, indicating that when the proton is transferred from Tyr237, it is more likely to reach the OCu atom directly through only one water molecule. This work provides a more profound understanding of the functions of important residues and specific water molecules in the proton pumping mechanism of CcO.

LSD1-Based Reversible Inhibitors Virtual Screening and Binding Mechanism Computational Study.

As one of the crucial targets of epigenetics, histone lysine-specific demethylase 1 (LSD1) is significant in the occurrence and development of various tumors. Although several irreversible covalent LSD1 inhibitors have entered clinical trials, the large size and polarity of the FAD-binding pocket and undesired toxicity have focused interest on developing reversible LSD1 inhibitors. In this study, targeting the substrate-binding pocket of LSD1, structure-based and ligand-based virtual screenings were adopted to expand the potential novel structures with molecular docking and pharmacophore model strategies, respectively. Through drug-likeness evaluation, ADMET screening, molecular dynamics simulations, and binding free energy screening, we screened out one and four hit compounds from the databases of 2,029,554 compounds, respectively. Generally, these hit compounds can be divided into two categories, amide (Lig2 and Comp2) and 1,2,4-triazolo-4,3-α-quinazoline (Comp3, Comp4, Comp7). Among them, Comp4 exhibits the strongest binding affinity. Finally, the binding mechanisms of the hit compounds were further calculated in detail by the residue free energy decomposition. It was found that van der Waals interactions contribute most to the binding, and FAD is also helpful in stabilizing the binding and avoiding off-target effects. We believe this work not only provides a solid theoretical foundation for the design of LSD1 substrate reversible inhibitors, but also expands the diversity of parent nucleus, offering new insights for synthetic chemists.

The Canonical Wnt Signaling Pathway Inhibits the Glucocorticoid Receptor Signaling Pathway in the Trabecular Meshwork.

Glucocorticoid-induced glaucoma is a secondary open-angle glaucoma. About 40% of the general population may develop elevated intraocular pressure on prolonged glucocorticoid treatment secondary to damages in the trabecular meshwork (TM), a tissue that regulates intraocular pressure. Therefore, identifying the key molecules responsible for glucocorticoid-induced ocular hypertension is crucial. In this study, Dickkopf-related protein 1 (Dkk1), a canonical Wnt signaling inhibitor, was found to be elevated in the aqueous humor and TM of glaucoma patients. At the signaling level, Dkk1 enhanced glucocorticoid receptor (GR) signaling, whereas Dkk1 knockdown or Wnt signaling activators decreased GR signaling in human TM cells as indicated by luciferase assays. Similarly, activation of the GR signaling inhibited Wnt signaling. At the protein level, glucocorticoid-induced extracellular matrix was inhibited by Wnt activation using Wnt activators or Dkk1 knockdown in primary human TM cells. In contrast, inhibition of canonical Wnt signaling by ß-catenin knockdown increased glucocorticoid-induced extracellular matrix proteins. At the physiological level, adenovirus-mediated Wnt3a expression decreased glucocorticoid-induced ocular hypertension in mouse eyes. In summary, Wnt and GR signaling inhibit each other in the TM, and canonical Wnt signaling activators may prevent the adverse effect of glucocorticoids in the eye.

Discovery of cinnamamide-barbiturate hybrids as a novel class of Nrf2 activator against myocardial ischemia/reperfusion injury.

Myocardial ischemia/reperfusion (MI/R) has been a challenge for global public health. Activation of nuclear factor erythroid-2-related factor 2 (Nrf2) signaling could attenuate MI/R injury by maintaining cell redox balance and reducing oxidative damage. Cinnamamide derivatives have been proven to be a class of potential Nrf2 activators and cardioprotective agents. The development of novel cinnamamide derivatives to combat oxidative stress in cardiomyocytes is highly desirable. In this study, twenty-three cinnamamide-barbiturate hybrids were studied. Cell-based assays showed that most of the compounds exhibited excellent protective activity against H2O2-induced oxidative injury in H9c2 cells. Notably, compound 7w, which had the highest activity and low cytotoxicity, was demonstrated to remarkably reduce intracellular ROS accumulation by activating the mRNA expression of Nrf2 and its downstream antioxidant gene HO-1, indicating a novel promising antioxidant and Nrf2 activator. The probable binding mode between protein Keap1 and compound 7w was also studied via molecule docking. Furthermore, we found that the administration of compound 7w could significantly reduce the cardiac infarct size and improve the cardiac function against MI/R injury in rats, as well as decrease cardiac oxidative stress. Taken together, we report, for the first time, that cinnamamide-barbiturate hybrids are a novel class of potential cardioprotective agents. The excellent cardioprotective action of such compounds rely on enhancing the endogenous antioxidative system by upregulating the Nrf2 signaling pathway in vitro and in vivo against MI/R damage. These findings provide a new perspective for designing cinnamamide-barbiturate hybrids as a novel class of Nrf2 activator against cardiovascular diseases.

Prediction-Based Human-Robot Collaboration in Assembly Tasks Using a Learning from Demonstration Model.

Most robots are programmed to carry out specific tasks routinely with minor variations. However, more and more applications from SMEs require robots work alongside their counterpart human workers. To smooth the collaboration task flow and improve the collaboration efficiency, a better way is to formulate the robot to surmise what kind of assistance a human coworker needs and naturally take the right action at the right time. This paper proposes a prediction-based human-robot collaboration model for assembly scenarios. An embedded learning from demonstration technique enables the robot to understand various task descriptions and customized working preferences. A state-enhanced convolutional long short-term memory (ConvLSTM)-based framework is formulated for extracting the high-level spatiotemporal features from the shared workspace and predicting the future actions to facilitate the fluent task transition. This model allows the robot to adapt itself to predicted human actions and enables proactive assistance during collaboration. We applied our model to the seats assembly experiment for a scale model vehicle and it can obtain a human worker's intentions, predict a coworker's future actions, and provide assembly parts correspondingly. It has been verified that the proposed framework yields higher smoothness and shorter idle times, and meets more working styles, compared to the state-of-the-art methods without prediction awareness.

An Anti-UAV Long-Term Tracking Method with Hybrid Attention Mechanism and Hierarchical Discriminator.

To prevent unmanned aerial vehicles (UAVs) from threatening public security, anti-UAV object tracking has become a critical issue in industrial and military applications. However, tracking UAV objects stably is still a challenging issue because the scenarios are complicated and the targets are generally small. In this article, a novel long-term tracking architecture composed of a Siamese network and re-detection (SiamAD) is proposed to efficiently locate UAV targets in diverse surroundings. Specifically, a new hybrid attention mechanism module is exploited to conduct more discriminative feature representation and is incorporated into a Siamese network. At the same time, the attention-based Siamese network fuses multilevel features for accurately tracking the target. We further introduce a hierarchical discriminator for checking the reliability of targeting, and a discriminator-based redetection network is utilized for correcting tracking failures. To effectively catch up with the appearance changes of UAVs, a template updating strategy is developed in long-term tracking tasks. Our model surpasses many state-of-the-art models on the anti-UAV benchmark. In particular, the proposed method can achieve 13.7% and 16.5% improvements in success rate and precision rate, respectively, compared with the strong baseline SiamRPN++.

Nitro-Carbazole Based Oxime Esters as Dual Photo/Thermal Initiators for 3D Printing and Composite Preparation.

A series of Type I photoinitiators (PIs) based on a nitrocarbazole scaffold are developed and examined for the first time as photoinitiators for visible light photopolymerization. Three oxime esters (OXE-M, OXE-V, OXE-P) varying by the terminal groups (acetyl, acryloyl and benzoyl) attached via the oxime ester group are originally prepared. As a result of this, the three PIs exhibit excellent photoinitiation abilities in the presence of acrylate monomers upon LED@ 405 nm irradiation. Markedly, OXE-M exhibits a better performance than the benchmark Type I phosphine-oxide (diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide TPO). Chemical mechanisms supporting the polymerization process with these PIs are investigated by steady state photolysis, molecular orbital calculations and real-time Fourier transformed infrared spectroscopy. After the cleavage of N─O bond and decarboxylation, free radicals are generated to initiate the free radical polymerization efficiently. Free radical photopolymerization of OXE-M is applied in direct laser write and 3D printing. Interestingly, OXE-M exhibits thermal initiation behaviors in monomers and can be used as dual photo and thermal initiators. The highly opaque feature of carbon fibers makes it difficult for light penetration, so dual photo/thermal curing are used here to prepare carbon fiber composites.

Development and clinical application of a rapid SARS-CoV-2 antibody test strip: A multi-center assessment across China.

BACKGROUND: The ongoing coronavirus disease 19 (COVID-19) is posing a threat to the public health globally. Serological test for SARS-CoV-2 antibody can improve early diagnosis of COVID-19 and serves as a valuable supplement to RNA detection. METHOD: A SARS-CoV-2 IgG/IgM combined antibody test strip based on colloidal gold immunochromatography assay was developed, with both spike protein and nucleocapsid protein of SARS-CoV-2 antigen used for antibody detection. From 3 medical institutions across China, serum or plasma of 170 patients with confirmed COVID-19 diagnosis and 300 normal controls were collected and tested with the strip. Sensitivity, specificity, kappa coefficient, receiver operating characteristic (ROC) curve, and area under the curve (AUC) were analyzed. Positive rates in different medical centers, age group, gender, and different disease course were compared. RESULTS: 158 out 170 samples from confirmed COVID-19 patients had positive results from the test, and 296 out of 300 samples from normal controls had negative results. The kit was 92.9% sensitive and 98.7% specific. The positive rate was 77.3% during the first week after disease onset, but reached 100% since day 9. AUC and kappa coefficient were 0.958 and 0.926, respectively, which showed the consistency of the test results with the standard diagnosis. Age or gender caused little variations in the kit sensitivity. CONCLUSION: The rapid, easy-to-use SARS-CoV-2 IgG/IgM combined antibody test kit has a superior performance, which can help with accurate diagnosis and thus timely treatment and isolation of COVID-19 patients, that contributes to the better control of the global pandemic.

A Two-Stage, Intelligent Bearing-Fault-Diagnosis Method Using Order-Tracking and a One-Dimensional Convolutional Neural Network with Variable Speeds.

When performing fault diagnosis tasks on bearings, the change of any bearing's rotation speed will cause the frequency spectrum of bearing fault characteristics to be blurred. This makes it difficult to extract stable fault features based on manual or intelligent methods, resulting in a decrease in diagnostic accuracy. In this paper, a two-stage, intelligent fault diagnosis method (order-tracking one-dimensional convolutional neural network, OT-1DCNN) is proposed to deal with the problem of fault diagnosis under variable speed conditions. Firstly, the order tracking algorithm is used to resample the monitoring data obtained under different rotation speeds. Then, the one-dimensional convolutional neural network is adopted to extract features of the fault data. Finally, the fault type of collected data can be obtained by fully connected networks based on the features extracted. In the time domain, while the proposed algorithm only relies on the fault data collected under one speed as the training dataset, it is capable of doing fault diagnosis under different speed conditions. In the condition with the largest difference in speed with each dataset, the accuracy of the proposed method is higher than the baseline methods by 0.54% and 11.00%-on CWRU dataset and our own dataset respectively. The results show that the proposed method performs well in dealing with the fault diagnosis under the condition of variable speeds.

Novel Photoinitiators Based on Benzophenone-Triphenylamine Hybrid Structure for LED Photopolymerization.

In this study, a new generation of photoinitiator (PI) based on hybrid structures combining benzophenone and triphenylamine is proposed. Remarkably, these photoinitiators (noted monofunctional benzophenone-triphenylamine (MBP-TPA) and trifunctional benzophenone-triphenylamine (TBP-TPA)) are designed and developed for the photopolymerization under light-emitting diodes (LEDs). Benzoyl substituents connected with triphenylamine moiety contribute to the excellent absorption properties which results in both high final conversions and polymerization rates in free radical photopolymerization (FRP). Remarkably, TBP-TPA owning trifunctional benzophenone group exhibits a better Type II PI behavior than well-known 2-isopropylthioxanthone for photopolymerization under LED@365 and 405 nm irradiation. FRP and cationic photopolymerization of TBP-TPA-based systems are applied on 3D printing experiments, and good profiles of the 3D patterns are observed. The high molecular weight of TBP-TPA associated with it trifunctional character can also be very interesting for a better migration stability of PIs that is a huge challenge. The development of this new generation of photoinitiators based on benzophenone hybrid structures is a real breakthrough. It reveals that the novel versatile photoinitiators based on benzophenone-triphenylamine hybrid structures have great potentials for future industrial applications (e.g., 3D printing, composites, etc.).

Physical Distancing Measures and Walking Activity in Middle-aged and Older Residents in Changsha, China, During the COVID-19 Epidemic Period: Longitudinal Observational Study.

BACKGROUND: Physical distancing measures taken to contain COVID-19 transmission may substantially reduce physical activity levels and cause individuals to adopt a more sedentary lifestyle. OBJECTIVE: The objective of this study is to determine if there was any change in daily steps, an important component of daily physical activity, and examine risk factors for frequent low daily steps during the COVID-19 epidemic. METHODS: We used data collected from the Step Study, a population-based longitudinal study of walking activity among residents aged ≥40 years in Changsha, China. Daily steps were collected via a smartphone linked to WeChat, a social networking platform. We plotted mean daily steps and the prevalence of low daily steps (≤1500 steps/day) 30 days before (reference period) and 30 days after (epidemic period) January 21, 2020 (date of the first COVID-19 case diagnosed in Changsha), and compared it with the same corresponding period from 2019. We examined the association of risk factors with the prevalence of frequent low daily steps (≤1500 steps/day for ≥14 days) using logistic regression. RESULTS: Among 3544 participants (mean age 51.6 years; n=1226 females, 34.6%), mean daily steps dropped from 8097 to 5440 and the prevalence of low daily steps increased from 3% (2287/76,136 person-day) to 18.5% (12,951/70,183 person-day) during the reference and epidemic periods, respectively. No such phenomenon was observed during the corresponding period in 2019. Older age (P for interaction=.001) and female sex (P for interaction<.001) were both associated with a higher prevalence of frequent low daily steps and were more pronounced during the epidemic period. More education was associated with a lower prevalence of frequent low daily steps during the reference period but not the epidemic period (P for interaction=.34). Body mass index or comorbidity were not associated with frequent low daily steps during either period. CONCLUSIONS: Daily steps of Changsha residents aged ≥40 years dropped significantly during the COVID-19 period, especially among older adults and females. Although successful physical distancing, measured by the rapid downward trend in daily step counts of residents, played a critical role in the containment of the COVID-19 epidemic, our findings of an increase in the prevalence of frequent low daily steps raise concerns about unintended effects on physical activity.

Decellularization methods for developing porcine corneal xenografts and future perspectives.

Corneal transplantation is the only option to cure corneal opacities. However, there is an imbalance between supply and demand of corneal tissues in the world. To solve the problem of corneal shortage, corneal xenotransplantation studies have been implemented in the past years using porcine corneas. The corneal xenografts could come from (a) wild-type pigs, (b) genetically engineered pigs, (c) decellularized porcine corneas, and (d) decellularized porcine corneas that are recellularized with human corneal cells, eventually with patients' own cells, as in all type of xenografts. All approaches except, the former would reduce or mitigate recipient immune responses. Although several techniques in decellularization have been reported, there is still no standardized protocol for the complete decellularization of corneal tissue. Herein, we reviewed different decellularization methods for porcine corneas based on the mechanism of action, decellularization efficacy, biocompatibility, and the undesirable effects on corneal ultrastructure. We compared 9 decellularization methods including: (a) sodium dodecyl sulfate, (b) triton x-100, (c) hypertonic saline, (d) human serum with electrophoresis, (e) high hydrostatic pressure, (f) freeze-thaw, (h) nitrogen gas, (h) phospholipase A2 , and (i) glycerol with chemical crosslinking methods. It appears that combined methods could be more useful to perform efficient corneal decellularization.

[Lung cancer screening with low-dose spiral CT in a unit staff: Results of the baseline screening].

OBJECTIVE: To analyze the incidence and imaging characteristics of pulmonary nodules in a unit staff.
 Methods: Low-dose spiral CT (LDCT) scan were performed in 1 372 staffs ≥45 years old in a certain unit during the physical examination. The clinical and imaging data were collected to analyze the detection rate, imaging characteristics, and postoperative pathological conditions of pulmonary nodules.
 Results: The total detection rate for pulmonary nodules was 30.39% (417/1 372). The detected nodules were mainly single (227 cases), solid (343 cases), <5 mm in diameter (261 cases), and Lung-Reporting and Data System (Lung-RADS) category 2 nodules (340 cases). The single nodules were mostly found in the right upper lung (74 cases, 32.60%). The detection rate of pulmonary nodules tended to decrease but the detection rate of category 4 nodules increased with the increasing age (P<0.05), while the gender had no significant influence on the detection rate (P>0.05). Compared with the Lung-RADS category 3 nodules, the proportions of nodules in subsolid state, with irregular shape, lobulation sign, and vascular penetration in the Lung-RADS category 4 were increased (all P<0.05). Among them, 11 patients received surgical therapy, including 10 women. Postoperative pathology confirmed lung adenocarcinoma in 9 patients (2.16%), including 8 women, all non-smokers.
 Conclusion: The nodules in subsolid state with vascular penetration, irregular shape and lobulation sign tend to be malignant. Lung cancer screening with low-dose spiral CT in female non-smokers should be emphasized.

Zinc-finger-nucleases mediate specific and efficient excision of HIV-1 proviral DNA from infected and latently infected human T cells.

HIV-infected individuals currently cannot be completely cured because existing antiviral therapy regimens do not address HIV provirus DNA, flanked by long terminal repeats (LTRs), already integrated into host genome. Here, we present a possible alternative therapeutic approach to specifically and directly mediate deletion of the integrated full-length HIV provirus from infected and latently infected human T cell genomes by using specially designed zinc-finger nucleases (ZFNs) to target a sequence within the LTR that is well conserved across all clades. We designed and screened one pair of ZFN to target the highly conserved HIV-1 5'-LTR and 3'-LTR DNA sequences, named ZFN-LTR. We found that ZFN-LTR can specifically target and cleave the full-length HIV-1 proviral DNA in several infected and latently infected cell types and also HIV-1 infected human primary cells in vitro. We observed that the frequency of excision was 45.9% in infected human cell lines after treatment with ZFN-LTR, without significant host-cell genotoxicity. Taken together, our data demonstrate that a single ZFN-LTR pair can specifically and effectively cleave integrated full-length HIV-1 proviral DNA and mediate antiretroviral activity in infected and latently infected cells, suggesting that this strategy could offer a novel approach to eradicate the HIV-1 virus from the infected host in the future.

Progressively Learning to Reach Remote Goals by Continuously Updating Boundary Goals.

Training an effective policy on complex goal-reaching tasks with sparse rewards is an open challenge. It is more difficult for the task of reaching remote goals (RRG), as the unavailability of the original rewards and large Wasserstein distance between the distributions of desired goals and initial states make existing methods for common goal-reaching tasks inefficient or even completely ineffective. In this article, we propose progressively learning to reach remote goals by continuously updating boundary goals (PLUB), which solves RRG tasks by reducing the Wasserstein distance between the distributions of boundary goals and desired goals. Specifically, the concept of boundary goal is introduced, which is the set of the closest achieved goals for each desired goal. In addition, to reduce the computational complexity caused by the Wasserstein distance, the closest moving distance is introduced, which is its upper bound, and also the expectation of the distance between the desired goal and the closest boundary goal. By selecting the appropriate intermediate goal from all boundary goals and continuously updating boundary goals, both the closest moving distance and the Wasserstein distance can be reduced. As a result, RRG tasks degenerate into common goal-reaching tasks that can be efficiently solved by a combination of hindsight relabeling and the learning from demonstrations (LfD) method. Extensive experiments on several robotic manipulation tasks demonstrate that PLUB can bring substantial improvements over the existing methods.

Minimally Invasive Corneal Neurotization: 10-Year Update in Technique Including Novel Donor Transfer of the Great Auricular Nerve.

SUMMARY: Corneal anesthesia, caused by lack of corneal innervation, is a rare but devastating condition that can lead to neurotrophic keratopathy, corneal ulceration, scarring, and blindness. Minimally invasive corneal neurotization enables transfer of regional donor sensory nerves to the cornea to provide sensation and ocular protection. The authors provide an update on technical advances and modifications that have refined the surgery over the past 10 years, as well as step-by-step intraoperative videos of corneal neurotization, noting its critical steps, pitfalls, and caveats. The videos illustrate the novel technique of using the greater auricular nerve with a sural nerve graft extension as the donor nerve for the procedure. The steps and considerations depicted will allow surgeons to carry out corneal neurotization efficiently, safely, and effectively.