Micromechanical testing and property upscaling of planetary rocks:A critical review

Knowledge of the mechanical behavior of planetary rocks is indispensable for space explorations.The scarcity of pristine samples and the irregular shapes of planetary meteorites make it difficult to obtain representative samples for conventional macroscale rock mechanics experiments(macro-RMEs).This critical review discusses recent advances in microscale RMEs(micro-RMEs)techniques and the upscaling methods for extracting mechanical parameters.Methods of mineralogical and microstructural analyses,along with non-destructive mechanical techniques,have provided new opportunities for studying planetary rocks with unprecedented precision and capabilities.First,we summarize several mainstream methods for obtaining the mineralogy and microstructure of planetary rocks.Then,nondestructive micromechanical testing methods,nanoindentation and atomic force microscopy(AFM),are detailed reviewed,illustrating the principles,advantages,influencing factors,and available testing results from literature.Subsequently,several feasible upscaling methods that bridge the micro-measurements of meteorite pieces to the strength of the intact body are introduced.Finally,the potential applications of planetary rock mechanics research to guiding the design and execution of space missions are environed,ranging from sample return missions and planetary defense to extraterrestrial construction.These discussions are expected to broaden the understanding of the microscale mechanical properties of planetary rocks and their significant role in deep space exploration.

Microplastics in sediment of the Three Gorges Reservoir:abundance and characteristics under different environmental conditions

Freshwater microplastic pollution is an urgent issue of global concern,and research on the distribution in reservoirs is lacking.We investigated the microplastic pollution levels in wet sediments collected from the Three Gorges Reservoir,the largest reservoir of China.Results show that microplastics were ubiquitous in the sediments of the Three Gorges Reservoir,and their abundance ranged from 59 to 276 pp/kg(plastic particles per kg,dry weight).Economic development and total population were important factors affecting the spatial heterogeneity of microplastic abundance,and the contribution of large cities along the reservoir to microplastic pollution should be paid with more attention.Fibrous microplastics were the most abundant type of microplastic particles in reservoir sediments,whereas polystyrene,polypropylene,and polyamide were the main types of polymers.The apparent spatial heterogeneity in morphology and color of microplastics is attributed to different anthropogenic or landbased pollution sources.Moreover,the accumulation of microplastics near the inlet of tributaries reflects the role of potential contributors of tributaries.More importantly,multiple bisphenols(BPs)and heavy metals detected at the microplastic surfaces indicate that microplastics can act as carriers of these pollutants in the environment in the same way as sediments did,which may alter the environmental fate and toxicity of these pollutants.Therefore,we conclude that the Three Gorges Reservoir had been contaminated with microplastics,which posed a stress risk for organisms who ingest them along with their associated pollutants(BPs,heavy metals).

YOLOv5ST:A Lightweight and Fast Scene Text Detector

Scene text detection is an important task in computer vision.In this paper,we present YOLOv5 Scene Text(YOLOv5ST),an optimized architecture based on YOLOv5 v6.0 tailored for fast scene text detection.Our primary goal is to enhance inference speed without sacrificing significant detection accuracy,thereby enabling robust performance on resource-constrained devices like drones,closed-circuit television cameras,and other embedded systems.To achieve this,we propose key modifications to the network architecture to lighten the original backbone and improve feature aggregation,including replacing standard convolution with depth-wise convolution,adopting the C2 sequence module in place of C3,employing Spatial Pyramid Pooling Global(SPPG)instead of Spatial Pyramid Pooling Fast(SPPF)and integrating Bi-directional Feature Pyramid Network(BiFPN)into the neck.Experimental results demonstrate a remarkable 26%improvement in inference speed compared to the baseline,with only marginal reductions of 1.6%and 4.2%in mean average precision(mAP)at the intersection over union(IoU)thresholds of 0.5 and 0.5:0.95,respectively.Our work represents a significant advancement in scene text detection,striking a balance between speed and accuracy,making it well-suited for performance-constrained environments.

A versatile humanoid robot platform for dexterous manipulation and human-robot collaboration

Humanoid robots have attracted much attention by virtue of their compatibility with human environments.However,biped humanoids with immense promise still cannot function steadily and reliably in real-world settings in the current state.Hence,rationally combining a humanoid robot with different stable mobile platforms is a favoured solution for diverse scenarios.Here,a new versatile humanoid robot platform,aiming to provide a generic solution that can be flexibly deployed in diverse scenarios,for example,indoors and fields is presented.Versatile humanoid robot platform incorporates multimodal perception,and extensible interfaces on hardware and software,allowing it to be rapidly integrated with different mobile platforms and end-effectors,only through easyto-assemble interfaces.Additionally,the platform has achieved impressive integration,lightness,dexterity,and strength in its class,with human-like size and rich perception,targeted to have human-intelligent manipulation skills for human-engineered environments.Overall,this article elaborates on the reasoning behind the design choices,and outlines each subsystem.Lastly,the essential performance of the platform is successfully demonstrated in a set of experiments with precise and dexterous manipulation,and human–robot collaboration requirements.

Head-to-head comparison of 7 high-sensitive human papillomavirus nucleic acid detection technologies with the SPF10 LiPA-25 system

Background:The SPF10 LiPA-25 system for human papillomavirus(HPV)detection with high analytical perfor-mance is widely used in HPV vaccine clinical trials.To develop and evaluate more valent HPV vaccines,other comparable methods with simpler operations are needed.Methods:The performance of the LiPA-25 against that of other 7 assays,including 4 systems based on reverse hybridization(Bohui-24,Yaneng-23,Tellgen-27,and Hybribio-16)and 3 real-time polymerase chain reaction(PCR)assays(Hybribio-23,Bioperfectus-21,and Sansure-26),was evaluated in selected 1726 cervical swab and 56 biopsy samples.A total of 15 HPV genotypes(HPV 6,11,16,18,31,33,35,39,45,51,52,56,58,59,and 66)were considered for comparison for each HPV type.Results:Among the swab samples,compared to LiPA-25,compatible genotypes were observed in 94.1%of samples for Hybribio-23,92.8%for Yaneng-23,92.6%for Bioperfectus-21,92.4%for Hybribio-16,91.3%for Sansure-26,89.7%for Bohui-24,and 88.0%for Tellgen-27.The highest overall agreement of the 15 HPV genotypes combined was noted for Hybribio-23(κ=0.879,McNemar’s test:P=0.136),followed closely by Hybribio-16(κ=0.877,P<0.001),Yaneng-23(κ=0.871,P<0.001),Bioperfectus-21(κ=0.848,P<0.001),Bohui-24(κ=0.847,P<0.001),Tellgen-27(κ=0.831,P<0.001),and Sansure-26(κ=0.826,P<0.001).Additionally,these systems were also highly consistent with LiPA-25 for biopsy specimens(all,κ>0.897).Conclusions:The levels of agreement for the detection of 15 HPV types between other 7 assays and LiPA-25 were all good,and Hybribio-23 was most comparable to LiPA-25.The testing operation of HPV genotyping should also be considered for vaccine and epidemiological studies.

Partial aging can counter-intuitively couple with sulfidation to improve the reactive durability of zerovalent iron

Sulfated zero-valent iron(SZVI)has shown promising applications in wastewater treatment.However,the rapid decline in the reactivity of SZVI with time limits its real practice.To mediate this problem,partial aging was proposed to improve the reactive durability of SZVI.Taking Cr(VI)as the target contaminant,we found that the aged ZVI(AZVI)gradually lost reactivity as aging time increased from 0.5 to 2 d.Counter-intuitively,the partially aged SZVI(ASZVI)showed greater reactivity than SZVI when exposed to oxygenated water for a period ranging from 0.5 to 14 d.In addition,the ASZVI with 0.5 d of aging time(ASZVI-0.5)not only maintained reactivity in successive runs but also increased the Cr(VI)removal capacity from 9.1 mg/g by SZVI to 19.1 mg/g by ASZVI-0.5.Correlation analysis further revealed that the electron transfer from the Fe0 core to the shell was mediated by the conductive FeS and FeS2 in the subshell of ASZVI.Meanwhile,the lepidocrocite and magnetite on the surface of ASZVI facilitated Cr(VI)adsorption and subsequent electron transfer for Cr(VI)reduction.Moreover,the iron(hydr)oxide shell could retain the conductive FeS and FeS2 in the subshell,allowing ASZVI to reduce Cr(VI)efficiently and sustainably.In general,partial aging can enhance the reactive durability of ZVI when coupled with sulfidation and this synergistic effect will be beneficial to the application of SZVI-based technology for wastewater treatment.

Cross-scale mechanical softening of Marcellus shale induced by CO_(2)-water-rock interactions using nanoindentation and accurate grain-based modeling

Mechanical softening behaviors of shale in CO_(2)-water–rock interaction are critical for shale gas exploitation and CO_(2)sequestration.This work investigated the cross-scale mechanical softening of shale triggered by CO_(2)-water–rock interaction.Initially,the mechanical softening of shale following 30 d of exposure to CO_(2)and water was assessed at the rock-forming mineral scale using nanoindentation.The mechanical alterations of rock-forming minerals,including quartz,muscovite,chlorite,and kaolinite,were analyzed and compared.Subsequently,an accurate grain-based modeling(AGBM)was proposed to upscale the nanoindentation results.Numerical models were generated based on the real microstructure of shale derived from TESCAN integrated minerals analyzer(TIMA)digital images.Mechanical parameters of shale minerals determined by nanoindentation served as input material properties for AGBMs.Finally,numerical simulations of uniaxial compression tests were conducted to investigate the impact of mineral softening on the macroscopic Young’s modulus and uniaxial compressive strength(UCS)of shale.The results present direct evidence of shale mineral softening during CO_(2)-water–rock interaction and explore its influence on the upscale mechanical properties of shale.This paper offers a microscopic perspective for comprehending CO_(2)-water-shale interactions and contributes to the development of a cross-scale mechanical model for shale.

Size,morphology,and composition of lunar samples returned by Chang'E-5 mission

This study focuses on the physical and chemical properties of surficial lunar regolith(LR)samples returned from the Moon by the Chang’E-5(CE-5)mission.Insights regarding the effect of a new sampling geological site on the surficial lunar sample CE5 C0400 were illustrated using nondestructive techniques such as laser diffractometry coupled with image analysis,X-ray computed tomography,and field emission scanning electron microscopy equipped with energy dispersive spectroscopy,and Xray diffraction combined with Rietveld refinement.From the characterization analyses,the CE-5 sampling site in the northeastern Oceanus Procellarum on the Moon yields a unique collection of relatively regular-shaped and fine basalt-dominated particles.The median grain size D_(50) is(55.24±0.96)μm,falling within the relatively low end of the range of the Apollo lunar returned samples.The coefficient of uniformity C_(u)of 15.1 and the coefficient of curvature C_(c)of 1.7 could classify CE5 C0400 to be well-graded.The minerals in CE5 C0400 comprise approximately 44.5%pyroxene,30.4%plagioclase,3.6%olivine,and6.0%ilmenite.There is a relatively low content of approximately 15.5%glass phase in the CE-5 lunar sample.From the results,we deduce that the CE-5 LR structure could have mainly resulted from micrometeoroid impacts to achieve such a high level of maturity.

A prospective cohort study on the relationship between vancomycin steady-state trough concentration and efficacy and safety in Chinese adults

Clinical guidelines recommend a steady-state vancomycin(VCM)trough concentration(SVTC)of 10–15 mg/L for regular infections and 15–20 mg/L for severe infections.However,clinical trials have shown that increasing SVTC is not beneficial for efficacy,and instead it leads to nephrotoxicity.To verify whether increasing the SVTC results in improved clinical outcomes with sustainable adverse effects,we prospectively determined its correlation with clinical efficacy and safety.The participants included patients hospitalized with Gram-positive bacterial infections from March 2017 through October 2018.The patients were classified into group I(SVTC<10 mg/L),II(10≤SVTC≤20 mg/L),or III(SVTC>20 mg/L).Clinical,microbiological,and laboratory data were collected.Clinical outcomes between group I and II were matched after propensity score matching(PSM).A total of 331 patients were included in this study.Clinical failure occurred in 59(29%)of 204 patients on day 14,with no significant difference between groups I and II(P=0.535).Infection recurred at 28 d in 62(30%)of 204 patients,and no significant difference in infection recurrence was observed between both the groups(log-rank,P=0.674).Except for a significant increase in the incidence of acute kidney injury in group II,no significant difference was observed between two groups for any clinical results.The incidence of adverse events in groups I and II was significantly lower than that in group III(P<0.001).SVTC had an applicable cut-off point at 14.55 mg/L.SVTC was not correlated with VCM clinical efficacy,while it was a good indicator of nephrotoxicity.

Development of two TaqMan real-time reverse transcription-PCR assays for the detection of severe acute respiratory syndrome coronavirus-2

The outbreak of coronavirus disease 2019(COVID-19)in Wuhan,China,was caused by a novel coronavirus(CoV),named severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).The rapid detection of viral nucleic acids is critical for the early identification of infected cases.We have developed two TaqMan real-time reverse transcription-PCR assays to detect SARS-CoV-2.The designed primers target the nucleocapsid(N)and open reading frame(ORF)1b gene regions,where the probes discriminate SARS-CoV-2 from other human and animal CoVs.The sensitivities are one genomic copy per reaction for theN gene assay and ten copies for the ORF 1b gene assay.The overall linear detection ranges are 1–10^(6)and 10–10^(6)copies per reaction for the N gene assay and the ORF 1b gene assay,respectively.Surveillance of 23 suspected COVID-19 patients demonstrated that SARS-CoV-2 could be detected from 100%(23/23)and 62.5%(16/23)of clinical specimens by the N gene assay and the ORF 1b gene assay,respectively.All of the samples not detected by the ORF 1b gene assay were throat swabs,indicating a lower viral load in the upper respiratory tract and the relatively lower sensitivity of the ORF 1b gene assay.The assays developed in the present study offer alternative diagnostic tests for COVID-19.

Mechanical design and analysis of a novel variable stiffness actuator with symmetrical pivot adjustment

The safety of human-robot interaction is an essential requirement for designing collaborative robotics.Thus,this paper aims to design a novel variable stiffiiess actuator(VSA)that can provide safer physical human-robot interaction for collaborative robotics.VS A follows the idea of modular design,mainly including a variable stiffiiess module and a drive module.The variable stiffiiess module transmits the motion from the drive module in a roundabout maimer,making the modularization of VS A possible.As the key component of the variable stiffiiess module,a stiffness adjustment mechanism with a symmetrical structure is applied to change the positions of a pair of pivots in two levers linearly and simultaneously,which can eliminate the additional bending moment caused by the asymmetric structure.The design of the doubledeck grooves in the lever allows the pivot to move freely in the groove,avoiding the geometric constraint between the parts.Consequently,the VSA stiffiiess can change from zero to infinity as the pivot moves from one end of the groove to the other.To facilitate building a manipulator in the future,an expandable electrical system with a distributed structure is also proposed.Stiffiiess calibration and control experiments are performed to evaluate the physical performance of the designed VSA.Experiment results show that the VSA stiffiiess is close to the theoretical design stiffness.Furthermore,the VSA with a proportional-derivative feedback plus feedforward controller exhibits a fast response for stiffiiess regulation and a good performance for position tracking.

Ultra-robust stretchable electrode for e-skin:In situ assembly using a nanofiber scaffold and liquid metal to mimic water-to-net interaction

The development of stretchable electronics could enhance novel interface structures to solve the stretchability-conductivity dilemma,which remains a major challenge.Herein,we report a nano-liquid metal(LM)-based highly robust stretchable electrode(NHSE)with a self-adaptable interface that mimics water-tonet interaction.Based on the in situ assembly of electrospun elastic nanofiber scaffolds and electrosprayed LM nanoparticles,the NHSE exhibits an extremely low sheet resistance of 52 mΩsq^(-1).It is not only insensitive to a large degree of mechanical stretching(i.e.,350%electrical resistance change upon 570%elongation)but also immune to cyclic deformation(i.e.,5%electrical resistance increases after 330000 stretching cycles with 100%elongation).These key properties are far superior to those of the state-of-the-art reports.Its robustness and stability are verified under diverse circumstances,including long-term exposure to air(420 days),cyclic submersion(30000 times),and resilience against mechanical damages.The combination of conductivity,stretchability,and durability makes the NHSE a promising conductor/electrode solution for flexible/stretchable electronics for applications such as wearable on-body physiological signal detection,human-machine interaction,and heating e-skin.

Outcome comparison of pyrotinib with current standard of care in the second/third line setting in advanced non-small cell lung cancer patients with HER2 mutation

To the Editor:In recent years,impressive outcomes have been achieved in patients harboring human epidermal growth factor receptor 2(HER2)mutations,which accounts for 1%to 4%of cases in non-small cell lung cancer(NSCLC).

多系统平滑肌功能障碍综合征合并窗型动脉导管未闭手术治疗一例

收治1例诊断为多系统平滑肌功能障碍综合征合并窗型动脉导管未闭的女性3岁患儿,基因检测发现存在主动脉平滑肌肌动蛋白α2(ACTA2)基因c.536G>A(p.R179H)杂合突变,心血管影像学检查提示窗型动脉导管未闭、肺动脉高压。在院期间予抗感染、平喘、降肺高压治疗改善症状后行动脉导管未闭关闭术+肺动脉成形术。术后恢复良好,门诊规律随访。多系统平滑肌功能障碍综合征是一种全身性疾病,合并窗型动脉导管未闭的患儿可通过手术治疗消除主-肺动脉分流去改善患儿心功能并降低肺动脉压力。手术前后的肺动脉压力评估及监测尤为重要。

Dihydroartemisinin increased the abundance of Akkermansia muciniphila by YAP1 depression that sensitizes hepatocellular carcinoma to anti-PD-1 immunotherapy

The effect of anti-programmed cell death 1(anti-PD-1)immunotherapy is limited in patients with hepatocellular carcinoma(HCC).Yes-associated protein 1(YAP1)expression increased in liver tumor cells in early HCC,and Akkermansia muciniphila abundance decreased in the colon.The response to anti-PD-1 treatment is associated with A.muciniphila abundance in many tumors.However,the interaction between A.muciniphila abundance and YAP1 expression remains unclear in HCC.Here,anti-PD-1 treatment decreased A.muciniphila abundance in the colon,but increased YAP1 expression in the tumor cells by mice with liver tumors in situ.Mechanistically,hepatocyte-specific Yap1 knockout(Yap1^(LKO))maintained bile acid homeostasis in the liver,resulting in an increased abundance of A.muciniphila in the colon.Yap1 knockout enhanced anti-PD-1 efficacy.Therefore,YAP1 inhibition is a potential target for increasing A.muciniphila abundance to promote anti-PD-1 efficacy in liver tumors.Dihydroartemisinin(DHA),acting as YAP1 inhibitor,increased A.muciniphila abundance to sensitize anti-PD-1 therapy.A.muciniphila by gavage increased the number and activation of CD8^(+)T cells in liver tumor niches during DHA treatment or combination with anti-PD-1.Our findings suggested that the combination anti-PD-1 with DHA is an effective strategy for liver tumor treatment.

Straightforward construction of hollow polyoxometalate-based metal-organic framework via pseudo-homoepitaxial growth

Hollow structures are significant for shortening diffusion path and promoting active center exposure.Single-crystalline hollow polyoxometalate-based metal-organic frameworks(POM@MOFs)with increased adsorption performance and catalytic activity were synthesized through a straightforward pseudo-homoepitaxial growth strategy within only 1.5 min.The strategy ingeniously exploits favorable characteristics of well-matched lattice/structure but acid stability difference between MOF and POM@MOF to construct a pseudo-homoepitaxial structure.Specifically,the MOF single crystals are used as seeds to perform epitaxial growth of the lattice/structure-matched POM@MOF under appropriate conditions.Interestingly,the MOF seeds collapse spontaneously during epitaxial growth,affording regular hollow POM@MOF single crystals.Because the acid stability of the POM@MOF is much higher than that of the MOF,it is speculated that the hollow structure formation may be related to the acid released from the epitaxial POM@MOF growth.And the pseudo-homoepitaxial POM@MOF growth strategy based on structural matching but stability difference avoids additional template removal process in conventional hollow MOF preparation and ensures hollow single crystal construction.

Mechanical design,modeling,and identification for a novel antagonistic variable stiffness dexterous finger

This study traces the development of dexterous hand research and proposes a novel antagonistic variable stiffness dexterous finger mechanism to improve the safety of dexterous hand in unpredictable environments,such as unstructured or man-made operational errors through comprehensive consideration of cost,accuracy,manufacturing,and application.Based on the concept of mechanical passive compliance,which is widely implemented in robots for interactions,a finger is dedicated to improving mechanical robustness.The finger mechanism not only achieves passive compliance against physical impacts,but also implements the variable stiffness actuator principle in a compact finger without adding supererogatory actuators.It achieves finger stiffness adjustability according to the biologically inspired stiffness variation principle of discarding some mobilities to adjust stiffness.The mechanical design of the finger and its stiffness adjusting methods are elaborated.The stiffness characteristics of the finger joint and the actuation unit are analyzed.Experimental results of the finger joint stiffness identification and finger impact tests under different finger stiffness presets are provided to verify the validity of the model.Fingers have been experimentally proven to be robust against physical impacts.Moreover,the experimental part verifies that fingers have good power,grasping,and manipulation performance.

Ultra-conformable liquid metal particle monolayer on air/water interface for substrate-free E-tattoo

Gallium-based liquid metal has gained significant attention in conformal flexible electronics due to its high electrical conductivity,intrinsic deformability,and biocompatibility.However,the fabrication of large-area and highly uniform conformal liquid metal films remains challenging.Interfacial self-assembly has emerged as a promising method,but traditional approaches face difficulties in assembling liquid metal particles.Here,we realized the multi-size universal self-assembly(MUS)for liquid metal particles with various diameters(<500μm).By implementing a z-axis undisturbed interfacial material releasing strategy,the interference of gravitational energy on the stability of floating particles is avoided,enabling the fabrication of ultra-conformable monolayer films with large areas(>100 cm^(2))and high floating yield(50–90%).Moreover,the films can be conformally transferred onto complex surfaces such as human skin,allowing for the fabrication of substrate-free flexible devices.This eliminates interference from traditional substrate mechanical responses,making the liquid metal e-tattoo more user-friendly.

Advances in Space Robots

1.Main Text Space robots are a type of specialized robots that assist and replace humans in conducting scientific experiments,external vehicular activities,space exploration,and other activities in space.Space robots are gradually changing traditional modes of space transportation,on-orbit construction,on-orbit maintenance,and planetary exploration.It is one of the important enabling means for future unmanned and manned space missions.The development of space robots presents the design,fabrication,and control challenges,as such devices will operate in space where the environment differs greatly from Earth.