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High-precision collaborative observation is urgently needed due to the increasing demands of space science missions. Based on a conventional DFP (disturbance-free-payload) configuration, this paper presents a novel DFP that has great potential to deal with collaborative observation missions. The novel DFP system is developed, in which two or more payloads are installed via a non-contact unit and installed parallel configuration. Thus, the novel design is a multibody dynamics system. With the incorporation of the dynamics of the flexible umbilical between the PMs (payload modules) and SM (support module), the six-degrees-of-freedom multibody rigid–flexible dynamics of the whole system are derived. To verify the effectiveness of the novel DFP design in a collaborative observation mission, a multi-loop controller is designed for an inertial Earth collaborative observation mission. Simulation studies are conducted, which indicate that the proposed design can complete collaborative observation and achieve high precision.

Being the S-enantiomer of racemic ketamine, esketamine is found to be effective for sedation, analgesia, and treating depression. However, there is no comprehensive bibliometric analysis about esketamine research. In this study, we aimed to determine the scientific output and emerging topics related to esketamine.Esketamine-related articles and reviews that published between 2000 and 2020 were obtained from the Web of Science Core Collection database, using key word search of "esketamine" "esketamine hydrochloride", "s-ketamine", "S(+)-ketamine", "(S)-ketamine", or "(-)-ketamine". Various bibliographic elements were collected, including the annual number of publications, citation frequency, countries/regions, institutions, authors, journals, and keywords. Two sorts of scientometric software, namely VOS viewer and CiteSpace, were used to conduct bibliometric and knowledge-map analyses.A total of 683 publications were included in the current study. We found the number of publications in esketamine research field had increased annually since 2016. The United States was the leader in this field, with the highest publications number (162, 23.72%), total citations (3504/9713, 36.08%) and H-index (40). The most productive institution was Chiba University in Japan, and esketamine-related papers were mainly published in the journalThe past two decades have shown a marked increase in esketamine research. The United States maintained a top position worldwide, making the most significant contributions in the field of esketamine research. The contributions and collaborations of Asian countries have continuously increased and is a strong area of growth as well as development in recent years. Additionally, the emerging hotspots of esketamine research concentrate on clarifying its depression treatment effect.

A late-stage photoisomerization/cyclization union tactic, in conjunction with Type I Anion Relay Chemistry (ARC), permits enantioselective total syntheses and then biological evaluation of (+)-peniciketals A and B. The photochemical protocol was further showcased by an efficient three-step construction of the architecturally complex polycyclic skeleton found in (-)-diocollettines A. The mechanism and diastereoselectivity of the photochemical protocol have also been explored by both experiment and density functional theory calculations.

Polycystic ovary syndrome (PCOS) is a prevalent endocrine and metabolic disorder that affects premenopausal women. The etiology of PCOS is multifaceted, involving various genetic and epigenetic factors, hypothalamic–pituitary–ovarian dysfunction, androgen excess, insulin resistance, and adipose-related mechanisms. High-fat diets (HFDs) has been linked to the development of metabolic disorders and weight gain, exacerbating obesity and impairing the function of the hypothalamic–pituitary–ovarian axis. This results in increased insulin resistance, hyperinsulinemia, and the release of inflammatory adipokines, leading to heightened fat synthesis and reduced fat breakdown, thereby worsening the metabolic and reproductive consequences of PCOS. Effective management of PCOS requires lifestyle interventions such as dietary modifications, weight loss, physical activity, and psychological well-being, as well as medical or surgical interventions in some cases. This article systematically examines the pathological basis of PCOS and the influence of HFDs on its development, with the aim of raising awareness of the connection between diet and reproductive health, providing a robust approach to lifestyle interventions, and serving as a reference for the development of targeted drug treatments.

Background Relationships between iron-dependent ferroptosis and nerve system diseases have been recently revealed. However, the role of ferroptosis in neuropathic pain (NeP) remains to be elucidated. Thus, we aimed to investigate whether ferroptosis in spinal cord contributes to NeP induced by a chronic constriction injury (CCI) of the sciatic nerve. Methods Forty Sprague-Dawley rats received CCI or sham surgery, and were randomly assigned to the following four groups: sham group; CCI + LIP group; CCI + Veh group; and CCI group. Liproxstatin-1 or corn oil were separately injected intraperitoneally for three consecutive days after surgery in the CCI + LIP or CCI + Veh group. The mechanical and thermal hypersensitivities were tested after surgery. Biochemical and morphological changes related to ferroptosis in the spinal cord were also assessed. These included iron content, glutathione peroxidase 4 (GPX4) and anti-acyl-CoA synthetase long-chain family member 4 (ACSL4) expression, lipid peroxidation assays, as well as mitochondrial morphology. Results CCI-induced NeP was followed by iron accumulation, increased lipid peroxidation and dysregulation of ACSL4 and GPX4. Moreover transmission electron microscopy confirmed the presence of aberrant morphological changes on mitochondrial, such as mitochondria shrinkage and membrane rupture. Furthermore, the administration of liproxstatin-1 on CCI rats attenuated hypersensitivities, lowered the iron level, decreased spinal lipid peroxidation, restored the dysregulations in GPX4 and ACSL4 levels, and protected against CCI induced morphological changes in mitochondria. Conclusions Our findings indicated the involvement of ferroptosis in CCI induced NeP, and point to ferroptosis inhibitors such as liproxstatin-1 as potential therapies for hypersensitivity induced by peripheral nerve injury. Significance The spinal ferroptosis-like cell death was involved in the development of neuropathic pain resulted from peripheral nerve injury, and inhibition of ferroptosis by liproxstatin-1 could alleviate mechanical and thermal hypersensitivities. This knowledge suggested that ferroptosis could represent a potential therapeutic target for neuropathic pain.

Jingyi Du,* Yifan Deng,* Zhuolin Qiu, Guoliang Sun, Yue Guo, Ziqing Hei, Xiang Li Department of Anesthesiology, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xiang LiDepartment of Anesthesiology, The Third Affiliated Hospital of Sun Yat-sen University, Number 600, Tianhe Road, Guangzhou, 510630, People’s Republic of ChinaTel/ Fax +86 20 8525 3132Email lixiang27@mail.sysu.edu.cnPurpose: Cognitive impairment is a complication that most frequently happens in patients with chronic neuropathic pain and has limited effective therapy. The aim of this study was to explore the effects of curcumin on the cognitive deficit in rats with peripheral nerve injury induced-neuropathic pain.Methods: The neuropathic pain rat model was constructed using chronic constriction injury (CCI). The curcumin (60 mg/kg) or vehicle was intraperitoneally administered once a day, beginning at 14th day after surgery and continued for 14 consecutive days. The nociceptive threshold tests were measured by paw mechanical withdraw threshold (PMWT) and paw thermal withdrawal latency (PTWL), while the spatial memory abilities were evaluated by the Morris water maze test. The mean counts of bromodeoxyuridine (Brdu)/neuronal nuclei (NeuN) as well as Brdu/doublecortin (DCX) co-labeled cells were used to evaluate neurogenesis in the dentate gyrus of hippocampus. The ultrastructure of the synapse in hippocampal region was visualized using transmission electron microscopy (TEM).Results: Increased PMWT and PTWL, as well as relieved memory deficits, were found in CCI rats under curcumin administration. Moreover, curcumin treatment increased the number of newly born immature (BrdU/NeuN) and newly generated mature neurons (BrdU/DCX). The TEM examination revealed increased PSD thickness and shorter active zone length as well as narrowed synaptic cleft width in the hippocampal region of CCI rats after curcumin injection.Conclusion: Curcumin can alleviate CCI induced nociceptive behaviors and memory deficit. This effect might be associated with hippocampal neurogenesis and synaptic plasticity improvements, which indicated curcumin as a potential strategy for the cognitive impairment restoration under prolonged neuropathic pain condition.Keywords: curcumin, peripheral nerve injury, cognitive impairment, hippocampus neurogenesis

Introduction: Intracerebral hemorrhage (ICH) is known to trigger neuronal ferroptosis while forkhead box O3 (FOXO3) is implicated in ICH. This study aimed to determine the specific effect of FOXO3 on neuronal ferroptosis after ICH. Methods: The ICH mouse model was established through the injection of bacterial collagenase type IV and the cell model was established in Hemin-induced HT-22 cells. Subsequently, neurological functions, brain water content, and histopathological changes in mice were assessed. HT-22 cell activity was examined via cell counting kit-8 (CCK-8) method, and the levels of FOXO3, NADPH oxidase 4 (NOX4), and glutathione peroxidase 4 (GPX4) in brain tissues and HT-22 cells were measured. Fe2+ concentration and the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH) in the tissues and cells were examined. The binding relationship between FOXO3 and the NOX4 promoter region was determined via chromatin-immunoprecipitation (Ch-IP). Rescue experiments were designed to probe the role of NOX4 in the regulation of FOXO3 on neuronal ferroptosis. Results: FOXO3 was highly-expressed in ICH models while silencing FOXO3 alleviated brain damage, edema, and inflammatory infiltration in ICH mice. Meanwhile, silencing FOXO3 enhanced cell activity, diminished ROS and MDA activities and Fe2+ concentration, and elevated GSH and GPX4 levels in the tissues or cells. FOXO3 could bind to the NOX4 promoter and upregulate NOX4 transcription. NOX4 overexpression partially neutralized the repressive role of silencing FOXO3 in neuronal ferroptosis. Conclusion: Silencing FOXO3 attenuated ICH-induced neuronal ferroptosis via down-regulating NOX4 transcription levels, thus ameliorating post-ICH brain damage.

The enantioselective total syntheses of (+)-peniciketals A and B, two members of a family of architecturally complex spiroketals, have been achieved. Key synthetic transformations comprise Type I Anion Relay Chemistry (ARC) to construct the benzannulated [6,6]-spiroketal skeleton, a Negishi cross-coupling/olefin cross-metathesis reaction sequence to generate the trans-enone structure, and a late-stage large fragment union exploiting our recently developed photoisomerization/cyclization tactic.

Purpose: This study aimed to investigate the effect of transforming growth factor-β1 (TGF-β1) on the migration capacity of rat vascular smooth muscle cells (VSMCs) and its potential mechanism.Methods: Different concentrations of TGF-β1 were used to treat rat VSMCs. The migration capacity of cells was observed by wound healing assay and Transwell assay. Western Blotting and Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) were performed to examine the expression of EMT related gene.Results: In a certain concentration range, the migration ability of rat VSMCs was enhanced with the increase of TGF-β1 concentration. Meanwhile, TGF-β1 increased the expression of N-cadherin and Vimentin (mesenchymal markers), and decreased the expression of E-cadherin and β-catenin (epithelial markers) at both protein and mRNA levels. Conclusion: TGF-β1 promoted abnormal migration of rat VSMCs by regulating the expression of EMT related genes. This may be one of the mechanisms of in-stent restenosis (ISR) in coronary arteries.

The progress of space science and technology has ushered in a new era for humanity’s exploration of outer space. Recent studies have indicated that the aerospace special environment including microgravity and space radiation poses a significant risk to the health of astronauts, which involves multiple pathophysiological effects on the human body as well on tissues and organs. It has been an important research topic to study the molecular mechanism of body damage and further explore countermeasures against the physiological and pathological changes caused by the space environment. In this study, we used the rat model to study the biological effects of the tissue damage and related molecular pathway under either simulated microgravity or heavy ion radiation or combined stimulation. Our study disclosed that ureaplasma-sensitive amino oxidase (SSAO) upregulation is closely related to the systematic inflammatory response (IL-6, TNF-α) in rats under a simulated aerospace environment. In particular, the space environment leads to significant changes in the level of inflammatory genes in heart tissues, thus altering the expression and activity of SSAO and causing inflammatory responses. The detailed molecular mechanisms have been further validated in the genetic engineering cell line model. Overall, this work clearly shows the biological implication of SSAO upregulation in microgravity and radiation-mediated inflammatory response, providing a scientific basis or potential target for further in-depth investigation of the pathological damage and protection strategy under a space environment.

In this paper, the morphology and photoelectrochemical properties of hydrothermal synthesized chlorine-doped graphene quantum dots (Cl-GQDs) were analyzed by TEM, PL and UV–vis. The Cl-GQDs/In2O3 were synthesized by an ultrasonic treatment and the morphology, structure and composition, band gap and surface area were analyzed by different techniques. The effect of the mass percentage of Cl-GQDs on the photoelectrochemical (PEC) behavior of In2O3 was investigated, and the results showed that 3 wt% Cl-GQDs could effectively improve the separation of photogenerated carriers. Moreover, the photocurrent density of 3 wt% Cl-GQDs/In2O3 was about 10 times as large as that of pure In2O3. The cyclic voltammetry (CV) measurements of Cl-GQDs/In2O3 under dark and light were compared to further investigate the capacitive effect of Cl-GQDs, and the results indicated that Cl-GQDs could store photogenerated electrons, inhibiting the recombination of electron-hole pairs. This work was expected to be helpful for enhancing the PEC performance of In2O3 and extending the application of Cl-GQDs.

A hybrid energy storage system (HESS) consists of two or more types of energy storage components and the power electronics circuit to connect them. Therefore, the real-time capacity of this system highly depends on the state of the system and cannot be simply evaluated with traditional battery models. To tackle this challenge, an equivalent state of charge (ESOC) which reflects the remaining capacity of a HESS unit in a specific operation mode, is proposed in this paper. Furthermore, the proposed ESOC is applied to the control of the distributed HESS which contains several units with their own local targets. To optimally distribute the overall power target among these units, a sparse communication network-based hierarchical control framework is proposed. This framework considers the distributed control and optimal power distribution in the HESS from two aspects - the power output capability and the ESOC balance. Based on the primary droop control, the total power is allocated according to the maximum output capacity of each unit, and the secondary control is used to adjust the power from the perspective of ESOC balance. Therefore, each energy storage unit can be controlled to meet the local power demand of the microgrid. Simulation results based on MATLAB/Simulink verify the effectiveness of the application of the proposed equivalent SOC. National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [51877041] Published version This work was supported by the National Natural Science Foundation of China under Grant 51877041.

Drug–drug interactions (DDIs) are one of the major concerns in pharmaceutical research, and a number of computational methods have been developed to predict whether two drugs interact or not. Recently, more attention has been paid to events caused by the DDIs, which is more useful for investigating the mechanism hidden behind the combined drug usage or adverse reactions. However, some rare events may only have few examples, hindering them from being precisely predicted. To address the above issues, we present a few-shot computational method named META-DDIE, which consists of a representation module and a comparing module, to predict DDI events. We collect drug chemical structures and DDIs from DrugBank, and categorize DDI events into hundreds of types using a standard pipeline. META-DDIE uses the structures of drugs as input and learns the interpretable representations of DDIs through the representation module. Then, the model uses the comparing module to predict whether two representations are similar, and finally predicts DDI events with few labeled examples. In the computational experiments, META-DDIE outperforms several baseline methods and especially enhances the predictive capability for rare events. Moreover, META-DDIE helps to identify the key factors that may cause DDI events and reveal the relationship among different events.

Cells exposed with irradiation can induce different biological effects in non-irradiated cells due to the cell-cell interactions. Herein, we investigated the bystander effect of different types of irradiation including gamma irradiation (GR) and lithium heavy ion irradiation (LR) on the model human neuroblastoma cell line (SH-SY5Y). The gamma and lithium ion irradiation induced different bystander effects on the SH-SY5Y cell line. The bystander effect induced by gamma irradiation promoted the cell proliferation through activating the ERK and AKT signaling pathways, but it could slightly influence the cell cycle of non-irradiated SH-SY5Y cells. Whereas, the bystander effect induced by lithium heavy ion irradiation inhibited the cell proliferation, arrested the cell cycle and activated the process of pro-apoptosis. The findings of this study confirm the diversified bystander effects of various irradiation on the non-irradiated cells, therefore it highlights the importance of revised strategy for clinical radiotherapy and radioprotection to reduce the damages caused by bystander effects. Further, the in-depth mechanism research on the cell proliferation influenced by the bystander effect of radiation will also be useful to understand the biological effects of radiation.

A novel non-contact satellite for drag-free and attitude control is proposed in this paper. The non-contact satellite is separated into a payload module and a service module by non-contact Lorentz actuators. Instead of thrusters, the non-contact Lorentz actuators are used to exerted precise forces and torques, enabling drag-free and attitude control of the payload module, while the service module is designed to track the payload module to avoid collision. On the basis of this new design, the dynamics of drag-free and attitude control can be precisely modeled. Accordingly, a hierarchical control algorithm, consisting of an EKF-based estimation and rejection of environmental acceleration of payload module, attitude control of payload module, minimum norm allocation of non-contact Lorentz actuators, as well as collaborative control of service module, is systematically designed. A numerical simulation is then conducted to demonstrate the validity and effectiveness of the proposed design.

Ultrathin hybrid perovskites, with exotic properties and two-dimensional geometry, exhibit great potential in nanoscale optical and optoelectronic devices. However, it is still challenging for them to be compatible with high-resolution patterning technology toward miniaturization and integration applications, as they can be readily damaged by the organic solvents used in standard lithography processes. Here, a flexible three-step method is developed to make high-resolution multicolor patterning on hybrid perovskite, particularly achieved on a single nanosheet. The process includes first synthesis of precursor PbI

Diabetic neuropathic pain (DNP) is a highly prevalent complication of diabetes mellitus (DM) without effective treatments. The present study aimed to explore the effects of ferrostatin-1 (Fer-1) on mechanical hypersensitivity and spinal ferroptosis in rats with DM induced with streptozotocin (STZ). One week after STZ injection, the DM rats intraperitoneally received Fer-1 (2 μmol/kg) or a vehicle (1% DMSO) once daily for consecutive two weeks. The paw mechanical withdrawal thresholds (PMWT) were assessed weekly to investigate the nociceptive threshold. Biochemical and morphological alterations associated with spinal ferroptosis, including iron content, lipid peroxidation assays, the activities of anti-acyl-CoA synthetase long-chain family member 4 (ACSL4) and glutathione peroxidase 4 (GPX4), and mitochondrial morphology, were also evaluated. Decreased PMWT and significant changes in ferroptosis-associated markers, such as iron overload, lipid peroxidation, increased expression levels of ACSL4 and decreased expression levels of GPX4, and disrupted morphological features in mitochondria were found in rats with STZ-induced DM. These effects were significantly attenuated via intraperitoneal administration of the ferroptosis inhibitor Fer-1. Our findings indicated the involvement of iron-dependent ferroptosis in the spinal cords of rats with STZ-induced DM, and highlighted the effect of continuous administration of ferroptosis inhibitors such as Fer-1 on hypersensitivity in DM rats. These results suggest that inhibition of ferroptosis might be a potential therapeutic strategy in DNP treatment.

The detection of drug-drug interactions (DDIs) is a crucial task for drug safety surveillance, which provides effective and safe co-prescriptions of multiple drugs. Since laboratory researches are often complicated, costly and time-consuming, it's urgent to develop computational approaches to detect drug-drug interactions. In this paper, we conduct a comprehensive review of state-of-the-art computational methods falling into three categories: literature-based extraction methods, machine learning-based prediction methods and pharmacovigilance-based data mining methods. Literature-based extraction methods detect DDIs from published literature using natural language processing techniques; machine learning-based prediction methods build prediction models based on the known DDIs in databases and predict novel ones; pharmacovigilance-based data mining methods usually apply statistical techniques on various electronic data to detect drug-drug interaction signals. We first present the taxonomy of drug-drug interaction detection methods and provide the outlines of three categories of methods. Afterwards, we respectively introduce research backgrounds and data sources of three categories, and illustrate their representative approaches as well as evaluation metrics. Finally, we discuss the current challenges of existing methods and highlight potential opportunities for future directions.

Objectives: Pain and psychological disorders are the 2 most commonly occurring symptom clusters in patients with postherpetic neuralgia (PHN). This study aimed to investigate the risk factors for anxiety and depressive disorders in patients with PHN. Methods: Retrospectively, we examined the potential risk factors of anxiety and depression among patients with PHN from the clinic medical records of the Third Affiliated Hospital of Sun Yat-Sen University from 2017 to 2019. The Chinese version of the Hospital Anxiety and Depression Scale was used to assess anxiety and depression. Patients were retrospectively allocated to 2 groups – PHN with and without anxiety/depression – and compared to identify the differential patient characteristics. Results: Cases of 661 patients who were diagnosed with PHN were included. Anxiety and depression developed in 69.0% (456/661) and 65.8% (435/661) of the enrolled patients with PHN, respectively. Results of univariate regression analyses showed that female sex, magnitude of pain intensity, time from onset of rash and extent of spread of rashes were significantly associated with anxiety and depression in patients with PHN. Multivariate analysis revealed that both anxiety and depression states significantly correlated with female sex, magnitude of pain intensity, and extent of spread of rashes. Conclusions: Anxiety and depression were not uncommon in patients with PHN. Women with PHN who experience severe pain and develop extensive rashes have a high risk of developing anxiety and depressive disorders.

Neuropathic pain is clinically associated with the development of mental disorders. However, the early molecular changes possibly related to the late-set depressive consequence of neuropathic pain were obscure so far. In this genome-wide study, we aimed to characterize the molecular mechanisms at the early and late stages of neuropathic pain. The genetic data from anterior cingulate cortex (ACC) tissues of neuropathic pain mice in Gene Expression Omnibus database were analyzed by weighted gene co-expression network analysis. Modules with clinical significance were respectively distinguished for mice at two and eight weeks after operation. The genes that co-expressed in modules from two postoperative time points were obtained, and annotated by gene ontology and pathway enrichment analyses. Moreover, the hub genes were identified from the protein-protein interaction network, and their expression levels were validated by molecular biology experiments. Overall, two modules were respectively found to be associated with the neuropathic pain mice with and without depressive consequence. A total of 20 genes co-expressed in both modules, and MAPK signaling pathway was the most significant pathway for these genes. Furtherly, Dusp1, c-Fos and Gadd45β were identified as the hub genes. At two weeks after sciatic nerve cuffing, Gadd45β was significantly downregulated at both mRNA and protein levels in ACC and hippocampus, while the significant upregulation was only observed in mRNA and protein levels for c-Fos in ACC. This study firstly compared the gene expression profiles between neuropathic pain animals with and without depressive-like behavior, and we suggested the early changes in the activities of MAPK signaling pathway, c-Fos and Gadd45β might be related to late-onset depressive behavior induced by peripheral nerve injury.

An intelligent fault detection and classification for abnormal current data of transmission lines is proposed. According to the monthly report and the abnormal condition information stored in the system, four kinds of abnormal state data are chosen. By extracting three fault features of data, combining k-means algorithm and TSNE dimensionality reduction algorithm, fault categories can be clearly and intuitively distinguished, and the purpose of intelligent alarm for abnormal state current is realized.

Disturbance-Free-Payload is a novel spacecraft architecture proposed to achieve perfect vibration isolation performance of space applications. In this paper, the object under study is a DFP system in which a flexible umbilical connection between the support module (SM) and the payload module (PM) is introduced for data, power and fluid transfer. Bead model accounting for properties of mass and flexibility, is utilized to model the flexible umbilical. With incorporation of bead model, six degree-of-freedom multibody rigid-flexible dynamics for the DFP system is established via Newtonian mechanics. Along with rotational coupling between solar panels and SM, translational coupling, in particular, is taken into consideration since there is a stringent requirement on relative position between PM and SM. Based on the accurate motion equations of the DFP system, simulation studies are conducted to gain insight of the impact of umbilical connection and translational coupling on pointing performance of the DFP system. Simulation results validate effectiveness of DFP configuration in isolating vibrations transmitted from SM to PM. Besides, umbilical connection plays an important part in degrading pointing performance of PM whereas it exerts little impact on SM. Moreover, translational coupling leads to significant pointing performance degradation for both PM and SM.

In this paper, a three-dimensional (3D) impact-angle-control guidance law is proposed based on the approaches of nonsingular terminal sliding mode control and fixed-time convergence theory to intercept a maneuvering target. The guidance law is derived based on the coupled 3D engagement dynamics. To intercept the target with an expected impact angle, the nonsingular terminal sliding mode control is designed to ensure that the line-of-sight (LOS) angles and rates rapidly reach the desired values. Furthermore, the fixed-time convergence algorithm is proposed to guarantee that the LOS angles and rates are convergent in fixed time. The upper bound of the settling time can be obtained by presetting the parameters of the proposed guidance law, and it is independent of the initial conditions. The stability of the guidance system is proven via Lyapunov stability theory. The simulation results are presented to validate the efficiency and superiority of the proposed guidance law.

Multi-component union tactics in which three or more fragments are rapidly assembled are highly prized in the construction of architecturally complex natural products. Anion Relay Chemistry (ARC), a multi-component union tactic, has just such potential to elaborate structurally diverse scaffolds in a single operation with excellent stereochemical control. Conceptually, the ARC tactic can be divided into two main classes: “Through-Bond”, by the relay of negative charge through the bonding system of a molecule; and “Through-Space”, by the migration of negative charge across space by a transfer agent. “Through-Space” Anion Relay Chemistry, the focus of this Account, can be further subdivided into two types: Type I ARC, originated from Tietze-Schaumann-Smith coupling reaction, which for the first time permits controllable Brook rearrangements to construct unsymmetrical adducts, and as such has been successfully employed in the total syntheses of diverse natural products, including the mycoticins, bryostatin 1, spongistatins, rimocidin, indolizidine alkaloids, and enigmazole A; and Type II ARC, central to which is the design of novel bifunctional linchpins that enable rapid assembly of linear and cyclic fragments with diverse architectural features, ranging from polyols, spiroketals and polyenes to polypropionate scaffolds. Recently, the Type II ARC tactic has been exploited as the key construction tactic in the total syntheses of the spirastrellolides, the cryptocarya acetates, secu’amamine A, mandelalide A and nahuoic acid C(i) (B(ii)). This Account will present the evolution of both the Type I and Type II Anion Relay tactics, in conjunction with some prominent applications. [Image: see text]

A synchronous control of relative attitude and position is required in separated ultra-quiet spacecraft, such as drag-free, disturbance-free, and distributed spacecraft. Thus, a twistor-based synchronous sliding mode control is investigated in this paper to solve the control problem of relative attitude and position among separated spacecraft modules. The twistor-based control design and the stability proof are implemented using the Modified Rodrigues Parameter (MRP). To evaluate the effectiveness of the proposed control method, this paper presents a case study of separated spacecraft flying control considering the mass uncertainty and external disturbances. In addition, a simulation study of the Proportional-Derivative (PD) control is also presented for comparison. The results indicate that the twistor-based sliding mode controller can ensure global asymptotic stability. The states converge fast with ultra-precision and ultra-stability in both the attitude and position. Moreover, the proposed twistor-based sliding mode control system is robust to the mass uncertainty and external disturbances. Keywords: Distributed spacecraft, Gravitational wave detection, Synchronous control, Ultra-precision, Ultra-stability

In this work, a customized 3D ceramic printer was successfully designed and constructed. Three ceramic materials, alumina, Bioglass 45S5 (Bioglass), and zirconia were 3D printed into a C-ring shape by extruding the ceramic slurries. Once the 3D-printed specimens were in green state, a sintering process was performed. The microhardness values of the 3D-printed ceramic specimens were measured using a Vickers hardness tester. The hardness of the specimens increased from 37 ± 3 to 112 ± 5 HV0.2 for alumina, 23 ± 5 to 35 ± 1 HV0.2 for Bioglass, and 22 ± 5 to 31 ± 3 HV0.2 for zirconia, before and after the sintering process, respectively. These results, synthesis of slurries, the formation of specimens, and the mechanical properties, demonstrate the feasibility of 3D printing ceramic materials using a customized 3D ceramic printer.

Microwave-assisted catalysis offers great promise as an “intensified” technology for chemical processing. The present study investigates microwave-assisted direct conversion of methane with focus on the design and evaluation of microwave-sensitive H-(Fe)ZSM-5 catalysts for the existence of hotspot formation. Isomorphous substituted H-(Fe)ZSM-5 catalysts are tuned to identify key design parameters that control their microwave sensitivity. Increasing the amount of Al and Fe substitution in the zeolite lattice is found to result in higher microwave sensitivity due to improved dielectric properties and hence facilitated microwave heating of the catalyst bed. Comparison between the performance of these catalysts in a conventional thermally-heated (CH) fixed-bed and a microwave (MW) reactor allows identification of the effect of microwave irradiation on the catalyst activity. Methane conversion is drastically enhanced at MW conditions (from 3% at CH conditions to 40% at MW conditions), indicating accelerated methane activation over the metal site and hence suggesting a hot metal site despite much lower catalyst bulk temperature measured in the microwave reactor. The existence of metal hotspot formation is further supported by the reaction product distribution and spent catalyst analysis. At MW conditions, C2 (ethane and ethylene) and coke (mainly carbon nanotubes and nanofibers) selectivity are much higher at the cost of aromatics make compared to CH conditions. This can be explained by reduced aromatization activity at the Bronsted acid sites of the zeolite due to its lower relative temperature of the zeolite. The much-enhanced metal aggregation observed in the spent catalyst from the MW reactor along with the distribution of coke species further confirms the existence of selective heating (i.e. hotspot formation) occurring at the active metal site in the catalyst at MW conditions.

A convergent total synthesis of (−)-nahuoic acid Ci(Bii) (3), a novel cis-decalin polyketide, has been achieved. Key synthetic transformations include Type II Anion Relay Chemistry (ARC) to construct the polyol chain, a Ti-catalyzed asymmetric Diels–Alder reaction to generate the cis-decalin skeleton, and a late-stage large fragment union exploiting a Micalizio alkoxide-directed alkyne–alkene coupling tactic.

Based on 5 requirements which are essential for stable OAM mode transmission, we propose an OAM fiber family based on a structure of circular photonic crystal fiber (C-PCF). The proposed C-PCF in the family is made of pure silica, with a big round air hole at the center, several rings of air-hole array as the cladding, and a ring shaped silica area in between as the core where the OAM modes propagate. We also provide a design strategy with which the optimized C-PCF can be obtained with optimum number of high quality OAM modes (up to 42 OAM modes), large effective index separation for corresponding vector modes over a wide bandwidth, relative small and flat dispersion, and low nonlinear coefficient compared with a conventional single mode fiber. The designed fiber can be used in MDM communications and other OAM applications in fibers.

In this review article, the latest developments of the four most common additive manufacturing methods for metallic materials are reviewed, including powder bed fusion, direct energy deposition, binder jetting, and sheet lamination. In addition to the process principles, the microstructures and mechanical properties of AM-fabricated parts are comprehensively compared and evaluated. Finally, several future research directions are suggested.

Affective dimension prediction from multi-modal is becoming an increasingly attractive research field in artificial intelligence (AI) and human-computer interaction (HCI) . Previous works have shown that discriminative features from multiple modalities are of importance to accurately recognize emotional states. Recently, deep representations have proved to be effective for emotional state recognition. To investigate new deep spatial-temporal features and evaluate their effectiveness for affective dimension recognition, in this paper, we propose:~(1) combining a pre-trained 2D-CNN and a 1D-CNN for learning deep spatial-temporal features from video images and audio spectrograms; and~(2) a spatial-Temporal Graph Convolutional Networks (ST-GCN) adapted to facial landmarks graph. To evaluate the effectiveness of the proposed spatial-temporal features for affective dimension prediction, we propose Deep Bidirectional Long Short-Term Memory Networks (DBLSTM) model for single-modality prediction, early-fusion and late-fusion predictions. With respect to the liking dimension, we use the text modality for prediction. Experimental results, on the AVEC2019 CES dataset, show that our proposed spatial-temporal features and recognition model obtain promising results. On the development set, the obtained concordance correlation coefficient (CCC) is up to $0.724$ for arousal and $0.705$ for valence, and on the test set, the CCC is $0.513$ for arousal and $0.515$ for valence, which outperform the baseline system with corresponding CCC of $0.355$ and $0.468$ on arousal and valence, respectively.

International audience; The hydroxylation of phenols into polyphenols, which are valuable chemicals and pharmaceutical products, is a challenging reaction. The search for green synthetic processes has led to considering microorganisms and pure hydroxylases as catalysts for phenol hydroxylation. Herein, we report the structural and functional characterization of the flavin adenine dinucleotide (FAD)‐dependent 4‐hydroxyphenylacetate 3‐monooxygenase from Escherichia coli, named HpaB. It is shown that this enzyme enjoys a relatively broad substrate specificity, which allows the conversion of a number of non‐natural phenolic compounds, such as tyrosol, hydroxymandelic acid, coumaric acid, hydroxybenzoic acid and its methyl ester, and phenol, into the corresponding catechols. The reaction can be performed by using a simple chemical assay based on formate as the electron donor and the organometallic complex [Rh(bpy)Cp*(H2O)]2+ (Cp*: 1,2,3,4,5‐pentamethylcyclopentadiene, bpy: 2,2′‐bipyridyl) as the catalyst for FAD reduction. The availability of a crystal structure of HpaB in complex with FAD at 1.8 Å resolution opens up the possibility of the rational tuning of the substrate specificity and activity of this interesting class of phenol hydroxylases.

DFT exploration of 1,5- and 1,6-hydrogen atom transfers (HAT), radical addition, and relay to alkene is reported. The reactivity of 1,5- and 1,6-HAT are similar. We also explored reactions involving a multiple radical transferring process. Initially generated radicals undergo a multiple HAT process to form multiple bonds in a “relay” fashion, provided by exquisitely balanced rates.

Visible-light-induced generation of dithianyl and dioxolanyl radicals via selective hydrogen atom transfer (HAT) has been achieved. This radical relay tactic enables remote C(sp(3))—H functionalization to permit rapid access to polyol and spiroketal segments, and in turn has been exploited as a key synthetic construct in the total synthesis of the danshenspiroketallactones. The conformational stability of the danshenspiroketallactones has also been defined via experiments and DFT calculations.