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Reinforcement learning (RL) still suffers from the problem of sample inefficiency and struggles with the exploration issue, particularly in situations with long-delayed rewards, sparse rewards, and deep local optimum. Recently, learning from demonstration (LfD) paradigm was proposed to tackle this problem. However, these methods usually require a large number of demonstrations. In this study, we present a sample efficient teacher-advice mechanism with Gaussian process (TAG) by leveraging a few expert demonstrations. In TAG, a teacher model is built to provide both an advice action and its associated confidence value. Then, a guided policy is formulated to guide the agent in the exploration phase via the defined criteria. Through the TAG mechanism, the agent is capable of exploring the environment more intentionally. Moreover, with the confidence value, the guided policy can guide the agent precisely. Also, due to the strong generalization ability of Gaussian process, the teacher model can utilize the demonstrations more effectively. Therefore, substantial improvement in performance and sample efficiency can be attained. Considerable experiments on sparse reward environments demonstrate that the TAG mechanism can help typical RL algorithms achieve significant performance gains. In addition, the TAG mechanism with soft actor-critic algorithm (TAG-SAC) attains the state-of-the-art performance over other LfD counterparts on several delayed reward and complicated continuous control environments.

Cultivated peanut (Arachis hypogaeaL.) is a widely grown oilseed crop worldwide; however, the events leading to its origin and diversification are not fully understood. Here by combining chloroplast and whole-genome sequence data from a large germplasm collection, we show that the two subspecies of A. hypogaea(hypogaeaand fastigiata) likely arose from distinct allopolyploidization and domestication events. Peanut genetic clusters were then differentiated in relation to dissemination routes and breeding efforts. A combination of linkage mapping and genome-wide association studies allowed us to characterize genes and genomic regions related to main peanut morpho-agronomic traits, namely flowering pattern, inner tegument color, growth habit, pod/seed weight and oil content. Together, our findings shed light on the evolutionary history and phenotypic diversification of peanuts and might be of broad interest to plant breeders.

• Dual-functional PEEK was prepared via a combination of porous structure and metal-phenolic networks. • The functionalized PEEK exhibited enhanced bactericidal efficacy in acidic microenvironment. • "Superbug" methicillin-resistant Staphylococcus aureus can be effectively killed. • This dual-functional PEEK displayed desirable osseointegration capability in vivo. Polyetheretherketone (PEEK) has been recognized for its immense potential in hard tissue repair applications due to its mechanical properties resembling those of natural bones. However, the inherent bioinertness of pristine PEEK results in insufficient osseointegration. Moreover, implant-associated infection (IAI) has become a serious threat in orthopedic surgery. These risks usually lead to implant loosening, delayed healing, and even the failure of implantation, hampering many clinical applications of PEEK. In this study, we present a facile strategy to endow PEEK implants with enhanced osseointegration and pH-responsive antibacterial activity. Briefly, pristine PEEK was first treated with mixed acids to obtain a porous structure (referred to as SNPEEK), and then the metal-phenolic networks (MPN) coating was prepared using layer-by-layer (LbL) assembly consisting of Sr2+ and tannin acid (TA) (referred to as ST coating). The results demonstrated that the dual-functional PEEK displayed enhanced antibacterial activity in pH-responsive manner. At pH 7.4, the antibacterial ratios were 71.72% and 66.79% against Staphylococcus aureus (MSSA, ATCC 25,923) and methicillin-resistant Staphylococcus aureus (MRSA, ATCC BAA-40), respectively. Remarkably, at pH 5.5, the antibacterial activities significantly increased, resulting in killing ratios of 99.98% and 100%, respectively. Furthermore, the dual-functional PEEK promoted osteogenic differentiation of pre-osteoblasts (MC3T3-E1) and migration of human umbilical vascular endothelial cells (HUVECs). In addition, the dual-functional PEEK demonstrated effective anti-infection ability and desirable new bone formation ability in vivo compared to both pristine PEEK and SNPEEK implants. Overall, this study provides a promising strategy to endow PEEK implants with effective osseointegration and anti-infective ability, representing a prospective solution to address current clinical challenges associated with PEEK implants. [Display omitted] [ABSTRACT FROM AUTHOR]

Electrochemical CO2reduction on Cu-based catalysts is a promising technique to convert CO2to high-value C2and C3feedstocks. High carbon efficiency can be achieved in acidic electrolytes, but Cu-based catalysts show suppressed activity toward C2+formation in acidic conditions. Acid removes the oxygen-containing species on Cu, which are necessary for C–C coupling. In this work, a gas diffusion electrode (GDE)/Cu/Ni-N-C tandem configuration, in which Ni-N-C served as a CO2-to-CO catalyst, expressed a 5-time enhancement of C2+formation activity compared with GDE/Cu. Electrochemical measurements and finite element simulations indicate the improved C2+formation activity was due to the elevated local pH rather than the increased CO concentration in the Cu catalyst layer. The major function of the CO-formation catalyst in the tandem system working in an acidic condition is to modulate the local pH near the Cu catalyst instead of producing CO intermediate for Cu.

In many industrial scenarios, safety is a crucial factor to consider. In this article, we focus on the safe reinforcement learning problem that maximizes total rewards while enabling agents to avoid risks. We propose an intelligent fixed-horizon constrained policy learning (FHCPL) system, which allows agents to obtain high returns while maintaining risk avoidance behaviors. For discrete cases, a two-stage policy iteration algorithm, named fixed-horizon constrained policy iteration, is proposed, in which the safety of the learned policy is guaranteed. In the first stage, a policy that satisfies the safety constraint is obtained. In the second stage, a final learned policy that can get high returns while satisfying the safety constraint is reached. For continuous cases, we present the fixed-horizon constrained policy optimization algorithm. Empirical results demonstrate that, with the advantage of the fixed-horizon risk, the FHCPL achieves superior performance in terms of reward maximization and risk avoidance.

In autonomous driving, behavioral decision-making and trajectory planning remain huge challenges due to the large amount of uncertainty in environments and complex interaction relationships between the ego vehicle and other traffic participants. In this paper, we propose a novel fixed-horizon constrained reinforcement learning (RL) framework to solve decision-making and planning problems. Firstly, to introduce lane-level global navigation information into the lane state representation and avoid constant lane changes, we propose the constrained A-star algorithm, which can get the optimal path without constant lane changes. The optimality of the algorithm is also theoretically guaranteed. Then, to balance safety, comfort, and goal completion (reaching targets), we construct the planning problem as a constrained RL problem, in which the reward function is designed for goal completion, and two fixed-horizon constraints are developed for safety and comfort, respectively. Subsequently, a motion planning policy network (planner) with vectorized input is constructed. Finally, a dual ascent optimization method is proposed to train the planner network. With the advantage of being able to fully explore in the environment, the agent can learn an efficient decision-making and planning policy. In addition, benefiting from modeling the safety and comfort of the ego vehicle as constraints, the learned policy can guarantee the safety of the ego vehicle and achieve a good balance between goal completion and comfort. Experiments demonstrate that the proposed algorithm can achieve superior performance than existing rule-based, imitation learning-based, and typical RL-based methods.

As an emerging class of uncontrolled disinfection by-products, halobenzoquinones (HBQs) are 3 to 4 orders of magnitude more cytotoxic and genotoxic than regulated disinfection by-products. However, the formation of HBQs in different types of water sources is still unclear. In this study, 2,6-dichloro-1,4-benzoquinone (DCBQ) was selected as the representative species of HBQs to evaluate the formation characteristics during the chlorination of Yellow River diversion water, river water, south–north diversion water and mountain water. Principal component analysis and Pearson correlation analysis were carried out on the relationship between water quality characteristics and the formation of disinfection by-products in order to understand the formation potential of HBQs in each water source and the organic properties of disinfection by-product precursors such as HBQs. The results showed that different water sources have different capacities to form HBQs. The DCBQ formation potential (DCBQ-FP) of river water was the highest, followed by mountain water. The DCBQ-FP of Yellow River diversion water and south–north water diversion water was relatively the lowest. The DCBQ-FP was higher during the high temperature and high algal phase than during the low temperature and low turbidity phase. DCBQ precursors were mainly derived from algal-derived organic matter, low molecular neutrals (LMWN) during periods of high temperature and algal blooms. Aromatic compounds contribute significantly during the regular water quality period. The relationship with microbial metabolites (SMP) was high during periods of low temperature and low turbidity.

Background: Pathological myopia (PM) is closely associated with blinding ocular morbidities. Identifying biomarkers can provide clues on pathogeneses. This study aimed to identify metabolic biomarkers and underlying mechanisms in the vitreous humour (VH) of PM patients with complications. Methods: VH samples were collected from 39 PM patients with rhegmatogenous retinal detachment (RRD) (n= 23) or macular hole (MH)/myopic retinoschisis (MRS) (n= 16) and 23 controls (MH with axial length < 26 mm) who underwent surgical treatment. VH metabolomic profiles were investigated using ultra-performance liquid chromatography‒mass spectrometry. The area under the receiver operating characteristic curve (AUC) was computed to identify potential biomarkers for PM diagnosis. Results: Bioinformatics analysis identified nineteen and four metabolites altered in positive and negative modes, respectively, and these metabolites were involved in tryptophan metabolism. Receiver operating characteristic analysis showed that seventeen metabolites (AUC > 0.6) in the positive mode and uric acid in the negative mode represent potential biomarkers for PM with complications (AUC = 0.894). Pairwise and pathway analyses among the RRD-PM, MH/MRS-PM and control groups showed that tryptophan metabolism and uric acid were closely correlated with PM. Altered metabolites and pathways in our study were characterized by increased oxidative stress and altered energy metabolism. These results contribute to a better understanding of myopia progression with or without related complications. Conclusions: Our study provides metabolomic signatures and related immunopathological features in the VH of PM patients, revealing new insight into the prevention and treatment of PM and related complications.

A one-dimensional Cd(II) chain coordination polymer constructed by an electron-deficient viologen-anchored carboxylate ligand was successfully synthesized. Owing to the favorable stimuli-chromic properties of viologen, the title compound shows reversible photochromism, thermochromism, electrochromism, and naked-eye-detectable differentiable vapochromic response to different volatile amines. The chromic behaviors of it are ascribed to the formation of viologen radicals triggered by external stimuli. And the differentiated response to volatile amines is attributed to the size effect of the amines as well as the steric hindrance effect of forming α/β Cv–H···Naminesinteractions of the viologen unit to further affect the occurrence of electron transfer. Such an all-in-one crystalline material might have more practical applications in photoelectric, erasable inkless printing, light printing, and volatile amine detection fields.

ABSTRACTThe purpose of this study was to investigate the effects of different instructional sequences when learning Chinese as a foreign language. Six English-speaking individuals (two male adults, three female adults, and one male student) participated in this study. Combined listener instruction consisted of auditory-visual matching for textual stimuli (i.e., “Point to [name of Chinese character]) and visual-visual matching for textual and picture stimuli (i.e., “Match [name of Chinese character]). Combined speaker instruction consisted of textual and tacting responding in Chinese. The researcher taught six stimulus sets (a total of 30 Chinese vocabularies), with each set randomly assigned to either the Listener-Speaker or Speaker-Listener instructional sequence. Results indicated that four participants required fewer trials to criterion with Speaker-Listener instruction; the other two participants’ learning trials between the two instructional methods were comparable. Five participants demonstrated greater emergent listener responses for stimulus sets taught with combined speaker instruction than emergent speaker responses for stimulus sets taught with combined listener instruction. One participant’s emergent speaker and listener responses were at a high level and not differentiated between the two instructional methods.

Recently, disinfection by-products (DBPs) have received widespread attention, and the control and removal of DBPs from drinking water is crucial for ensuring water supply safety. Although conventional coagulation treatment can effectively remove DBPs, such as trihalomethanes (THMs) and haloacetic acids (HAAs), emerging disinfection by-products, such as halogenated benzoquinones (HBQs), pose a significant potential threat to the safety of drinking water. This article focuses on the study of two types of water sources, namely the Yellow River source and the South to North Water Diversion source. Queshan Reservoir water is selected as the representative water of the Yellow River source, and Nansihu Reservoir water is selected as the representative water of the South to North Water Diversion source. This study explores the efficiency of preoxidation–coagulation technology in removing precursors of DBPs and organic compounds from slightly polluted surface water and the effect of this technology on the generation of DBPs. It was found that preoxidation–coagulation had a positive effect on the removal of precursors of DBPs from the two types of water. The removal rates of precursors of DBPs from water ranged from 10% to 75%, with the highest removal rate of HBQ precursors reaching over 70%. Moreover, the organic matter removed by preoxidation–coagulation was mainly macromolecular organic matter, and the removal rates of macromolecular organic matter from both types of water sources were above 30%. The removal of small-molecule organic matter was limited. It is speculated that the removal of DBP precursors from water by preoxidation–coagulation is mainly achieved by controlling the content of macromolecular organic matter in the water. The results of this study provide a reference for future research on the removal of precursors of emerging DBPs from water.

In this paper, we propose a dynamic responsive policy for a quadrotor to traverse through narrow gaps based on deep reinforcement learning (RL). The policy provides agile and dynamically adjusted gap-traversing actions for the quadrotor in real-time by directly mapping the observed states of the quadrotor and gaps to motor thrusts. In contrast to existing optimization-based methods, our RL-based policy couples trajectory planning and control modules, which are strictly independent and computationally complex in previous works. Moreover, a safety-aware exploration is presented to reduce the collision risk and improve the safety of the policy, which also facilitates the transfer of the policy to real-world environments. Specifically, we formulate a safety reward on the state spaces of both position and orientation to inspire the quadrotor to traverse through the narrow gap at an appropriate attitude closer to the center of the gap. With the learned gap-traversing policy, we implement extensive simulations and real-world experiments to evaluate its performance and compare it with the related approaches. Our implementation includes several gap-traversing tasks with random positions and orientations, even if never trained specially before. All the performances indicate that our RL-based gap-traversing policy is transferable and more efficient in terms of real-time dynamic response, agility, time-consuming, and generalization.

Graphic Abstract:

Fish-inspired motion is an important research area with many applications in real-world tasks such as underwater vehicles or robotic fish control design. Owing to robust, smooth, and coordinated oscillatory signals generated by Central Pattern Generators (CPGs) for locomotion control of robots with multiple degrees of freedom, CPGs are the most versatile solution for robotic control systems, especially in robotic fish. However, tuning central pattern generator parameters is difficult for complex mechanical system designs. Besides, most current CPG-based methods only consider one aspect (e.g., speed), which widens the gap between theory and practice in robotic fish design. Also, it may affect the practical applicability of the designed motion model to a certain extent. This paper addresses this problem by constructing a multi-objective evolutionary design of a central pattern generator network to control the proposed biomimetic robotic fish. A new CPG model is proposed to help biomimetic robotic fish swim efficiently. In addition, an efficient multi-objective evolutionary algorithm proposed in our previous work is also applied to assist the biomimetic robotic fish in obtaining faster-swimming speed, good stability of the head, and higher propulsive efficiency simultaneously. Considering that the result of multi-objective optimization is a set of non-dominated solutions rather than a solution, a screening method based on fuzzy theory is adopted to assist decision-makers in selecting the most appropriate solution. Based on this, the control model of biomimetic robotic fish is constructed. The proposed control model is simulated and compared with seven well-known algorithms and a series of robotic fish designs. After that, the proposed control model is validated with extensive experiments on the actual biomimetic robotic fish. Simulations and experiments demonstrate the proposed control model’s effectiveness and good performance, especially when the control model has been applied to the real biomimetic robotic fish.

Obesity is an important independent risk factor for cardiovascular diseases, remaining an important health concern worldwide. Evidence shows that saturated fatty acid-induced inflammation in cardiomyocytes contributes to obesity-related cardiomyopathy. Dapagliflozin (Dapa), a selective SGLT2 inhibitor, exerts a favorable preventive activity in heart failure. In this study, we investigated the protective effect of Dapa against cardiomyopathy caused by high fat diet-induced obesity in vitro and in vivo. Cultured rat cardiomyocyte H9c2 cells were pretreated with Dapa (1, 2.5 μM) for 1.5 h, followed by treatment with palmitic acid (PA, 200 μM) for 24 h. We showed that Dapa pretreatment concentration-dependently attenuated PA-induced cell hypertrophy, fibrosis and apoptosis. Transcriptome analysis revealed that inhibition of PA-activated MAPK/AP-1 pathway contributed to the protective effect of Dapa in H9c2 cells, and this was confirmed by anti-p-cJUN fluorescence staining assay. Using surface plasmon resonance analysis we found the direct binding of Dapa with NHE1. Gain and loss of function experiments further demonstrated the role of NHE1 in the protection of Dapa. In vivo experiments were conducted in mice fed a high fat diet for 5 months. The mice were administered Dapa (1 mg·kg−1·d−1, i.g.) in the last 2 months. Dapa administration significantly reduced the body weight and improved the serum lipid profiles. Dapa administration also alleviated HFD-induced cardiac dysfunction and cardiac aberrant remodeling via inhibiting MAPK/AP-1 pathway and ameliorating cardiac inflammation. In conclusion, Dapa exerts a direct protective effect against saturated fatty acid-induced cardiomyocyte injury in addition to the lowering effect on serum lipids. The protective effect results from negative regulating MAPK/AP-1 pathway in a NHE1-dependent way. The current study highlights the potential of clinical use of Dapa in the prevention of obesity-related cardiac dysfunction.

We discovered a giant magnetoelasticity in soft matter with up to 5-fold enhancement of magnetomechanical coupling factors compared to that of rigid metal alloys without an externally applied magnetic field. A wavy chain analytical model based on the magnetic dipole-dipole interaction and demagnetizing field was established, fitting well to the experimental observation. To explore its potentials in electronic textiles, we coupled it with magnetic induction to invent a textile magnetoelastic generator (MEG), a new working mechanism for biomechanical energy conversion, featuring an intrinsic waterproofness, an ultralow internal impedance of approximately 20 Ω, and a high short-circuit current density of 1.37 mA/cm2, which is about four orders of magnitude higher than that of other textile generator counterparts. Meanwhile, assisted by machine learning, the textile MEG could continuously monitor the respiratory activities on heavily perspiring skin without any encapsulation, allowing a timely diagnosis of the respiration abnormalities in a self-powered manner. We foresee that this discovery can be extended to wide-range soft-matter systems, emerging as a compelling approach to develop electronic textiles for energy, sensing, and therapeutic applications.

We consider a degenerate chemotaxis model with two-species and two-stimuli in dimension d≥ 3 and find two critical curves intersecting at one point which separate the global existence and blow up of weak solutions to the problem. More precisely, above these curves (i.e. subcritical case), the problem admits a global weak solution obtained by the limits of strong solutions to an approximated system. Based on the second moment of solutions, initial data are constructed to make sure blow up occurs in finite time on and below these curves (i.e. critical and supercritical cases). In addition, the existence or non-existence of minimizers of free energy functional is discussed on the critical curves and the solutions exist globally in time if the size of initial data is small. We also investigate the crossing point between the critical lines in which a refined criteria in terms of the masses is given again to distinguish the dichotomy between global existence and blow up. We also show that the blow ups is simultaneous for both species.

The Kuroshio intrusion (KI) is a northwestward‐flowing branch of the Kuroshio Current, which enters the South China Sea (SCS) and regulates its temperature, salinity, and water mass exchanges. However, limited direct observations hinder our understanding of KI's mechanisms and responses to climate change. Here, we present a 60‐year bi‐monthly resolved coral oxygen isotope (δ18Oc) record from Dongsha Atoll, the northern SCS. The dry‐season (December–March) δ18Oc record reveals interannual to decadal variabilities of the KI. The impact of the East Asian winter monsoon (EAWM) on Dongsha δ18Oc was more pronounced during the 1970s and 1980s and after the early 2000s, while the influence of the El Niño‐Southern Oscillation (ENSO) on Dongsha δ18Oc was higher between the 1980s and 1990s. The Pacific Decadal Oscillation (PDO) may have a relatively minor effect on KI strength or may indirectly modulate KI strength through its influence on ENSO activities. Our Dongsha δ18Oc record highlight the importance of the EAWM, ENSO, and PDO in predicting future KI changes. The Kuroshio intrusion is a branch of the Kuroshio Current. It flows into the South China Sea and affects its temperature, salinity, and water movement. We however know very little how the Kuroshio intrusion responds to climate changes. Here we present a study on the chemical composition of a coral core from Dongsha Atoll in the northern South China Sea. Our study shows that the intrusion varies markedly over the past 60 years and is connected to changes in sea surface salinity. Stronger intrusions align with stronger East Asian winter monsoon intensity and El Niño events. Understanding how the Kuroshio intrusion reacts to climate change is important for effectively managing the potential impacts of global warming on the marine ecosystem. A 60‐year‐long coral oxygen isotope record from Dongsha Atoll, South China Sea reveals interannual to decadal variations in the Kuroshio intrusionStrong Kuroshio intrusion, corresponding to high sea surface salinity, is identifiable over the past 60 yearsThe Kuroshio intrusion variations are primarily driven by East Asian winter monsoon changes and also influenced by El Niño‐Southern Oscillation A 60‐year‐long coral oxygen isotope record from Dongsha Atoll, South China Sea reveals interannual to decadal variations in the Kuroshio intrusion Strong Kuroshio intrusion, corresponding to high sea surface salinity, is identifiable over the past 60 years The Kuroshio intrusion variations are primarily driven by East Asian winter monsoon changes and also influenced by El Niño‐Southern Oscillation

Terahertz (THz) computed tomography (THz CT) exhibits the potential to provide a wealth of data, surpassing that of THz tomographic imaging in applications such as detecting embedded defects, particularly defect evolution within a glass fiber-reinforced polymer. To realize high-resolution THz CT, a systematic approach guided by wave propagation simulation was employed. First, the front wave of the THz beam was fine-tuned to realize a beam diameter of <2 mm. To mitigate the strong refractive effect and minimize Fresnel reflection loss, a refractive-index-matching material was fabricated and utilized as a rounded enclosure for samples with sharp corners. To further improve the reconstruction resolution, a flat surface enclosure was applied to collect all incident beams at the detector. To realize comparable results to those of full-angle CT, a limited-angle CT approach was implemented, and the frequency range 0.1–3 THz was used in the image reconstruction study. The experimental and simulated images were used to validate the findings, and conductive and non-conductive defects measuring 200 µm were successfully visualized. Additionally, a custom-built user interface enabled us to visualize the field spatial distribution of the THz beam with respect to frequency.

Tetradentate chelates bearing tripodal arranged terpyridine and a functional pyrazole unit (i.e., L1-H and L2-H) were employed in preparation of Ir(III) complexes [Ir(L1)Cl2] (1) and [Ir(L2)Cl2] (2); subsequent chloride-to-bipyrazolate substitution gave [Ir(L1)(bipz)] (3) and [Ir(L2)(bipz)] (4). Single-crystal X-ray structural studies on 1and 3showed the possession of a tetradentate chelate, whereas the remaining cis-sites are occupied by either dual chlorides or the bipz chelate, respectively. Sky blue organic light-emitting diode with peak efficiencies (10.1%, 19.8 cd·A–1, and 20.4 lm·W–1) was successfully fabricated using 3(or 4) as dopant emitter, highlighting the potential application of this class of Ir(III) phosphor.

The microscopic structure of liquid methanol has been systematically investigated with Raman spectroscopy in a temperature range of 15−55 °C. The unbonded free −OH stretching vibrational band has been observed at ∼3660 cm−1in pure liquid. With the aid of depolarization measurements and theoretical calculations, four featured spectral components have been unambiguously identified and assigned to four well-defined vibrational modes of clusters in chain or ring forms. Furthermore, the cluster size distribution and its temperature dependence have been derived from the spectral fittings for the first time, which lead to the conclusion that the trimer, tetramer, and pentamer are the dominant clusters in liquid methanol, taking up more than 50% of total clusters.

The understanding of dynamic plasma proteome features in hybrid immunity and breakthrough infection is limited. A deeper understanding of the immune differences between heterologous and homologous immunization could assist in the future establishment of vaccination strategies. In this study, 40 participants who received a third dose of either a homologous BBIBP-CorV or a heterologous ZF2001 protein subunit vaccine following two doses of inactivated coronavirus disease 2019 vaccines and 12 patients with BA2.2 breakthrough infections were enrolled. Serum samples were collected at days 0, 28, and 180 following the boosting vaccination and breakthrough and then analyzed using neutralizing antibody tests and mass spectrometer–based proteomics. Mass cytometry of peripheral blood mononuclear cell samples was also performed in this cohort. The chemokine signaling pathway and humoral response markers (IgG2 and IgG3) associated with infection were found to be upregulated in breakthrough infections compared to vaccination-induced immunity. Elevated expression of IGKV, IGHV, IL-17 signaling, and the phagocytosis pathway, along with lower expression of FGL2, were correlated with higher antibody levels in the boosting vaccination groups. The MAPK signaling pathway and Fc gamma R-mediated phagocytosis were more enriched in the heterologous immunization groups than in the homologous immunization groups. Breakthrough infections can trigger more intensive inflammatory chemokine responses than vaccination. T-cell and innate immune activation have been shown to be closely related to enhanced antibody levels after vaccination and therefore might be potential targets for vaccine adjuvant design.

Multistimuli-responsive crystalline materials have a wide range of application prospects. However, development of new multistimuli-responsive materials remains full of challenge. In this work, taking a symmetrical modified extended viologen (ExV)-based carboxylate 1,1-bis(4-carboxybenzyl)-2,5-bipyridyl thiophene dichloride (H2L·Cl2) as a ligand and terephthalic acid (PTA) as an auxiliary ligand, a multistimuli-responsive crystalline 3D MOF material {[Cd2(L)(PTA)2]·3H2O}n(Cd-MOF-1) was constructed successfully. Cd-MOF-1shows distinctive photochromic and electrochromic properties, which can be attributed to the formation of viologen radicals induced by electron transfer (ET) under external photo/electricity stimuli. Furthermore, the title compound also displays photomodulable fluorescence and sensitive and distinguishable color response to propylamine (PA) vapor relative to other amine molecules. The distinguishable selectivity toward volatile amine vapors may be caused by the differences in the size or electron propelling capacity of the amines. In addition, the photochromic character of the title compound makes it suitable for ink-free erasable printing. This excellent multistimuli-responsive material may have more potential application values in the areas of photoelectric devices, light printing, volatile amine detection, etc. It is also helpful for us to further explore and develop MOF-based multistimuli responsive materials constructed by ExV derivatives.

Metal–organic framework (MOF) derived hybrid materials have been developed as an efficient non-noble-metal electrocatalysts for clean energy conversion systems. In this work, a Co-based MOF containing nitrogen and oxygen heteroatoms (Co-NOMOF) mixed with the thiomolybdate [Mo3S13]2−nanoclusters was used to prepare the N, S, O-doped carbon encapsulating Co9S8and MoS2(Co9S8/MoS2@NSOC) nanocomposite by one-step pyrolysis. The Co9S8/MoS2@NSOC nanocomposite exhibited remarkable catalytic performance for hydrogen evolution reaction (HER) with overpotential of 194 and 233 mV in 1 M KOH and 0.5 M H2SO4solution under 10 mA cm−2, respectively, which was ascribed to the multiheteroatom-doped hierarchical porous carbon matrix and the synergistic effect of intrinsic activity of Co9S8and MoS2. This work provides new opportunity for developing highly efficient non-precious metal electrochemical catalysts.

The efficacy of antidepressant therapy is frequently limited by challenges related to the potential to reach the brain. The development of new strategies to deliver more antidepressants to the brain so as to bypass the blood–brain barrier (BBB) is beneficial for the treatment of nervous system diseases, especially depression. Here, we have reported an unconventional strategy by the intranasal delivery of berberine with an in situthermoresponsive hydrogel as the holder in the nasal cavity to improve its antidepressant-like activity. A berberine/hydroxylpropyl-β-cyclodextrin (HP-β-CD) inclusion complex was first prepared to improve the solubility of berberine and loaded into a thermoresponsive hydrogel system of poloxamers. A radioactive tracer of 125I-labeled berberine was used to investigate brain targeting. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was performed to study the pharmacokinetic change in the hippocampus. Monoamine neurotransmitters were analyzed in a reserpine-induced depression model, and metabolomic analysis of the hippocampus was performed in a chronic unpredictable mild stress (CUMS)-induced depression model. The radioactive tracer analysis manifested that the thermoresponsive hydrogel administered intranasally could maintain a high concentration gradient of berberine to the brain, and the relative bioavailability of berberine was enhanced approximately by 110 times that of the oral berberine/HP-β-CD inclusion complex in the hippocampus. The thermoresponsive hydrogel system resulted in similar or better antidepressant-like efficacy even with a lower dosage in reserpine and CUMS-induced depression in rats. The pharmacometabolomics analysis revealed that in addition to increasing the hippocampal monoamine levels, berberine viaintranasal administration exhibited a unique mechanism by restoring the mitochondrial dysfunction as well as phospholipid and sphingolipid abnormalities as compared to intragastric (IG) administration. We consider this a safer and more effective strategy with a lower dosage than traditional oral drugs for the treatment of depression.

Using direct reinforcement learning (RL) to accomplish a task can be very inefficient, especially in robotic configurations where interactions with the environment are lengthy and costly. Instead, learning from expert demonstration (LfD) is an alternative approach to gain better performance in an RL setting, which also greatly improves sample efficiency. We propose a novel demonstration learning framework for actor-critic based algorithms. Firstly, we put forward an environment pre-training paradigm to initialize the model parameters without interacting with the target environment, which effectively avoids the cold start problem in deep RL scenarios. Secondly, we design a general-purpose LfD framework for most of the mainstream actor-critic RL algorithms that include a policy network and a value function like PPO, SAC, TRPO, A3C. Thirdly, we build a dedicated model training platform to perform the human-robot interaction and numerical experimentation. We evaluate the method in six Mujoco simulated locomotion environments and our robot control simulation platform. Results show that several epochs of pre-training can improve the agent’s performance over the early stage of training. Also, the final converged performance of the RL algorithm is also boosted by external demonstration. In general the sample efficiency is improved by 30% with the proposed method. Our demonstration pipeline makes full use of the exploration property of the RL algorithm, which is feasible for fast teaching robots in dynamic environments.

Macrobrachium rosenbergii, as an introduced species, is extensively cultured in China. In this study, 176 individuals from nine domestic strains in China, i.e., Florida (FD), Guangxi (GX), Hefu (HF), Myanmar (MD), “Nantaihu No. 2″ (NT), Thailand (TG), Taiwan (TW), “Shufeng No. 1″ (SF), and Zhengda (ZD), were collectedfor genome resequencing. We evaluated the genetic diversity, population structure and population history of nine cultured strains using SNP markers. We found that genetic diversity of the M. rosenbergiistrains was at a low level, among which FD and TG strains showed relatively higher genetic diversity, inferring that the genetic diversity of domestic populations decreased after artificial selection. Population genetic structure analysis showed that the individuals GX, HF, SF and NT strains were irregularly clustered together, and the ZD and TW strains exhibited the specific ancestors compared with other strains. The phylogenetic tree revealed that the individuals from TW, MD, ZD strains grouped into population-specific clusters. The principal components analysis (PCA) also showed that the nine strains were mixed together except the individuals from ZD and TW strains which were separated into specific subgroups. The Fst analysis showed that the Fst values detected from nine strains were less than 0.05, with the lowest Fst observed between SF and NT strains. In addition, two positively selected genes involved in metal transport and stress response were identified in the nine domestic strains by using selective sweep analyses with composite likelihood ratio (CLR), Fst, Pi, and Tajima’ Dmethods. The TreeMix phylogeny inferred four gene flow events among the nine strains, which occurred in the following directions: (1) from the common ancestor of ZD and TG to SF, (2) from SF to MD, (3) from SF to NT, and (4) from HF to GX. This study contributes to the better understanding genetic background and germplasm status of domestic M. rosenbergiistrains in China.

The air/liquid interface of aqueous methanol solutions, one of the earliest benchmark liquid interfaces ever studied by surface-selective sum frequency generation vibrational spectroscopy (SFG-VS), is known to display a turnover of SFG-VS intensities at the intermediate methanol concentrations, the origin of which has been under debate for the past 25 years. In this work, we discover that the hyperpolarizability of methanol, which was previously assumed to be a constant, in fact strongly depends on the bulk mole fractions of the methanol molecules. Furthermore, such concentration-dependence of the methanol hyperpolarizability is shown to play a critical role in the nonmonotonic changes of the methanol SFG-VS intensities as a function of the bulk mole fractions. By comparing the results from the molecular dynamics simulations and the newly interpreted SFG-VS spectra, a consistent surface model is obtained, showing that the average tilt angles of the asymmetrically oriented interfacial methanol molecules that actually contribute to the net SFG-VS signals are independent of the concentrations.