Effect of diagenetic variation on the static and dynamic mechanical behavior of coral reef limestone

Coral reef limestone at different depositional depths and facies differ remarkably on the textural and mineralogical characteristics,owing to the complex sedimentary diagenesis.To explore the effects of pore structure and mineral composition associated with diagenetic variation on the mechanical behavior of reef limestone,a series of quasi-static and dynamic compression tests along with microscopic examinations were performed on the reef limestone at shallow and deep burial depths.It is revealed that the shallow reef limestone(SRL)is classified as a porous aragonite-type carbonate rock with high porosity(55.3±3.2)%and pore connectivity.In comparison,the deep reef limestone(DRL)is mainly composed of dense calcite-type calcium carbonate with low porosity(4.9±1.6)%and pore connectivity.The DRL strengthened and stiffened by the tight grain framework consistently displays much higher values of the dynamic compressive strength,elastic modulus,brittleness index,and specific energy absorption than those of the SRL.The gap between two types of limestone further increases with an increase in strain rate.It appears that the failure pattern of SRL is dominated by the inherent defects like weak bonding interfaces and growth lines,revealed by the intricate fracturing network and mixed failure.Likewise,although the preexisting megapores in DRL may affect the crack propagation on pore tips to a certain distance,it hardly alters the axial splitting failure of DRL under impacts.The stress wave propagation and attenuation in SRL is primarily controlled by the reflection and diffusion caused by plenty mesopores,as well as an energy dissipation in layer-wise pore collapse and adjacent grain crushing,while the stress wave in DRL is highly hinged on the insulation and diffraction induced by the isolated megapores.This process is accompanied by the energy dissipation behavior of inelastic deformation resulted from the pore-emanated microcracking.

Protein arginine methyltransferase-6 regulates heterogeneous nuclear ribonucleoprotein-F expression and is a potential target for the treatment of neuropathic pain

Protein arginine methyltransferase-6 participates in a range of biological functions,particularly RNA processing,transcription,chromatin remodeling,and endosomal trafficking.However,it remains unclear whether protein arginine methyl transferase-6 modifies neuropathic pain and,if so,what the mechanisms of this effect.In this study,protein arginine methyltransferase-6 expression levels and its effect on neuropathic pain were investigated in the spared nerve injury model,chronic constriction injury model and bone cancer pain model,using immunohistochemistry,western blotting,immunoprecipitation,and label-free proteomic analysis.The results showed that protein arginine methyltransferase-6 mostly co-localized withβ-tubulinⅢin the dorsal root ganglion,and that its expression decreased following spared nerve injury,chronic constriction injury and bone cancer pain.In addition,PRMT6 knockout(Prmt6~(-/-))mice exhibited pain hypersensitivity.Furthermore,the development of spared nerve injury-induced hypersensitivity to mechanical pain was attenuated by blocking the decrease in protein arginine methyltransferase-6 expression.Moreover,when protein arginine methyltransferase-6 expression was downregulated in the dorsal root ganglion in mice without spared nerve injury,increased levels of phosphorylated extracellular signal-regulated kinases were observed in the ipsilateral dorsal horn,and the response to mechanical stimuli was enhanced.Mechanistically,protein arginine methyltransferase-6 appeared to contribute to spared nerve injury-induced neuropathic pain by regulating the expression of heterogeneous nuclear ribonucleoprotein-F.Additionally,protein arginine methyltransfe rase-6-mediated modulation of hete rogeneous nuclear ribonucleoprotein-F expression required amino atids 319 to 388,but not classical H3R2 methylation.These findings indicated that protein arginine methyltransferase-6 is a potential therapeutic target fo r the treatment of peripheral neuro pathic pain.

Enhancing the Goos-Hänchen shift based on quasi-bound states in the continuum through material asymmetric dielectric compound gratings

Quasi-bound state in the continuum(QBIC)resonance is gradually attracting attention and being applied in Goos-Hänchen(GH)shift enhancement due to its high quality(Q)factor and superior optical confinement.Currently,symmetry-protected QBIC resonance is often achieved by breaking the geometric symmetry,but few cases are achieved by breaking the material symmetry.This paper proposes a dielectric compound grating to achieve a high Q factor and high-reflection symmetry-protectede QBIC resonance based on material asymmetry.Theoretical calculations show that the symmetry-protected QBIC resonance achieved by material asymmetry can significantly increase the GH shift up to-980 times the resonance wavelength,and the maximum GH shift is located at the reflection peak with unity reflectance.This paper provides a theoretical basis for designing and fabricating high-performance GH shift tunable metasurfaces/dielectric gratings in the future.

Vault predicting after implantable collamer lens implantation using random forest network based on different features in ultrasound biomicroscopy images

AIM:To analyze ultrasound biomicroscopy(UBM)images using random forest network to find new features to make predictions about vault after implantable collamer lens(ICL)implantation.METHODS:A total of 450 UBM images were collected from the Lixiang Eye Hospital to provide the patient’s preoperative parameters as well as the vault of the ICL after implantation.The vault was set as the prediction target,and the input elements were mainly ciliary sulcus shape parameters,which included 6 angular parameters,2 area parameters,and 2 parameters,distance between ciliary sulci,and anterior chamber height.A random forest regression model was applied to predict the vault,with the number of base estimators(n_estimators)of 2000,the maximum tree depth(max_depth)of 17,the number of tree features(max_features)of Auto,and the random state(random_state)of 40.0.RESULTS:Among the parameters selected in this study,the distance between ciliary sulci had a greater importance proportion,reaching 52%before parameter optimization is performed,and other features had less influence,with an importance proportion of about 5%.The importance of the distance between the ciliary sulci increased to 53% after parameter optimization,and the importance of angle 3 and area 1 increased to 5% and 8%respectively,while the importance of the other parameters remained unchanged,and the distance between the ciliary sulci was considered the most important feature.Other features,although they accounted for a relatively small proportion,also had an impact on the vault prediction.After parameter optimization,the best prediction results were obtained,with a predicted mean value of 763.688μm and an actual mean value of 776.9304μm.The R²was 0.4456 and the root mean square error was 201.5166.CONCLUSION:A study based on UBM images using random forest network can be performed for prediction of the vault after ICL implantation and can provide some reference for ICL size selection.

Visual Feedback Disturbance Rejection Control for an Amphibious Bionic Stingray Under Actuator Saturation

Dear Editor,This letter is concerned with visual feedback disturbance rejection control for an amphibious bionic stingray subject to actuator saturation with internal and external disturbances. A visual feedback control method is designed for a dynamic nonlinear system on yaw angle of the amphibious bionic stingray via a finite-time extended-stateobserver,which is proved to achieve finite-time stability via a Lyapunov method. Finally, simulation results verify the effectiveness on the visual feedback control method.

Study on the thermal deformation behavior and microstructure of FGH96 heat extrusion alloy during two-pass hot deformation

The change rules associated with hot deformation of FGH96 alloy were investigated by isothermal two-pass hot deformation tests in the temperature range 1050–1125°C and at strain rates ranging from 0.001 to 0.1 s^(-1) on a Gleeble 3500 thermo-simulation machine. The results showed that the softening degree of the alloy between passes decreases with increasing temperature and decreasing strain rates. The critical strain of the first-pass is greater than that of the second-pass. The true stress–true strain curves showed that single-peak dynamic recrystallization, multi-peak dynamic recrystallization, and dynamic response occur when the strain rate is 0.1, 0.01, and 0.001 s^(-1), respectively. The alloy contains three different grain structures after hot deformation: partially recrystallized tissue, completely fine recrystallized tissue, coarse-grained grains. The small-angle grain boundaries increase with increasing temperature. Increasing strain rates cause the small-angle grain boundaries to first increase and then decrease.

A Review of Smart Materials for the Boost of Soft Actuators,Soft Sensors,and Robotics Applications

With the advance of smart material science,robotics is evolving from rigid robots to soft robots.Compared to rigid robots,soft robots can safely interact with the environment,easily navigate in unstructured fields,and be minimized to operate in narrow spaces,owning to the new actuation and sensing technologies developed by the smart materials.In the review,different actuation and sensing technologies based on different smart materials are analyzed and summarized.According to the driving or feedback signals,actuators are categorized into electrically responsive actuators,thermally responsive actuators,magnetically responsive actuators,and photoresponsive actuators;sensors are categorized into resistive sensors,capacitive sensors,magnetic sensors,and optical waveguide sensors.After introducing the principle and several robotic prototypes of some typical materials in each category of the actuators and sensors.The advantages and disadvantages of the actuators and sensors are compared based on the categories,and their potential applications in robotics are also presented.

Antigenicity of tissues and organs from GGTA1/CMAH/β4GalNT2 triple gene knockout pigs

Clinical xenotransplantations have been hampered by human preformed antibody-mediated damage of the xenografts.To overcome biological incompatibility between pigs and humans,one strategy is to remove the major antigens[Gal,Neu5 Gc,and Sd(a)]present on pig cells and tissues.Triple gene(GGTAI,CMAH,and β4 GalNT2)knockout(TKO)pigs were produced in our laboratory by CRISPR-Cas9 targeting.To investigate the antigenicity reduction in the TKO pigs,the expression levels of these three xenoantigens in the cornea,heart,liver,spleen,lung,kidney,and pancreas tissues were examined.The level of human IgG/IgM binding to those tissues was also investigated,with wildtype pig tissues as control.The results showed that aGal,Neu5 Gc,and Sd(a)were markedly positive in all the examined tissues in wildtype pigs but barely detected in TKO pigs.Compared to wildtype pigs,the liver,spleen,and pancreas of TKO pigs showed comparable levels of human IgG and IgM binding,whereas corneas,heart,lung,and kidney of TKO pigs exhibited significantly reduced human IgG and IgM binding.These results indicate that the antigenicity of TKO pig is significantly reduced and the remaining xenoantigens on porcine tissues can be eliminated via a gene targeting approach.

Catalysis-based specific detection and inhibition of tyrosinase and their application

Tyrosinase is an important enzyme in controlling the formation of melanin in melanosome,and plays a key role in the pigmentation of hair and skin.The abnormal expression or activation of tyrosinase is associated with several diseases such as albinism,vitiligo,melanoma and Parkinson disease.Excessive deposition of melanin could cause diseases such as freckles and brown spots in the human body,and it is also closely related to browning of fruits and vegetables and insect molting.Detecting and inhibiting the activity of tyrosinase is of extraordinary value in the progress of diagnosis and treatment of these diseases.Therefore,many selective optical detection probes and small molecular inhibitors have been developed,and have made significant contributions to the basic and clinical research on these diseases.In this paper,the detection and inhibition of tyrosinase and their application in whitening products are reviewed,with special emphasis on development of fluorescent probes and inhibitors.Hopefully,this review will help design more efficient and sensitive tyrosinase probes and inhibitors,as well as shed light on novel treatment of diseases such as melanoma.

Distribution of glycerol dialkyl glycerol tetraethers in Tibetan hot springs

Isoprenoidal glycerol dialkyl glycerol tetraethers （iGDGTs） from the Gulu hot springs （23--83.6 ℃, pH 〉 7） and Yangbajing hot springs （80-128 ℃, pH 〉 7） were analyzed in order to investigate the distribution of archaeal lipids among different hot springs in Tibet. A soil sample from Gulu was incubated at different temperatures and analyzed for changes in iGDGTs to help evaluate whether surrounding soil may contribute to the iGDGTs in hot springs. The sources of bacterial GDGTs （bGDGTs） in these hot springs were also investigated. The results revealed different profiles ofiGDGTs between Gulu and Yangbajing hot springs. Core iGDGTs and polar iGDGTs also presented different patterns in each hot spring. The PCA analysis showed that the structure of polar iGDGTs can be explained by three factors and suggested multiple sources of these compounds. Bivariate correlation analysis showed significant positive correlations between polar and core bGDGTs, suggesting the in situ production of bGDGTs in the hot springs. Furthermore, in the soil incubation experiment, temperature had the most significant influence on concentration of bGDGTs rather than iGDGTs, and polar bGDGTs had greater variability than core bGDGTs with changing temperature. Our results indicated that soil input had little influence on the composition of GDGTs in Tibetan hot springs.

Strengthened Monitoring of H5 Avian Influenza Viruses in External Environment in Hubei, 2018

The contamination status of H5 avian influenza viruses and distribution of subtypes of H5N1 and H5N6 in poultry-related environment of Hubei areas were investigated.Urban and rural live poultry markets,poultry farms,intensive livestock farms and other monitoring types of 103 counties in 17 cities were selected in Hubei.Wiping samples from cage surface,wiping samples from chopping board,fecal specimens and other environmental samples were collected and tested by real-time RT-PCR using primers and probes of influenza A,avian influenza of H5,N1 and N6 from December 2017 to March 2018.The avian influenza virus positive rate was compared among different monitoring sites,samples,time and regions.Totally,7132 environmental samples were collected in 1634 monitoring points with a positive rate of 2.24%.The positive rate of H5 avian influenza virus was the highest in urban and rural live poultry markets(3.44%,x^2=61.329,P<0.05)in 6 monitoring sites and wiping samples from chopping board(5.46%,x^2=67.072,P<0.05)in 6 sample types.H5N6 avian influenza viruses were detected more in eastern than western Hubei,and H5N6 avian influenza viruses were detected only in Xiangyang city of western Hubei.There were important high-risk places of human infection with H5 avian influenza virus in urban and rural live poultry markets and the poultry slaughtering plants.H5N6 has been the predominant subtype of H5 avian influenza viruses in the eastern and western Hubei and H5N6 avian influenza viruses were still present in a few areas of Hubei.Outbreaks of human H5N1 and H5N6 avian influenza remain at risk in Hubei province.

音乐治疗对肿瘤科住院患者化疗期间焦虑水平的影响

目的评估音乐疗法在减少肿瘤患者的焦虑和重要参数方面的有效性。方法收集湘潭市中心医院2019年1月—2020年11月住院的需要化疗治疗的肿瘤患者,采用随机分组的方法分为两组(试验组和对照组),其中,试验组实施音乐治疗干预+常规护理,对照组实施常规护理干预,使用状态-特质焦虑量表(state-trait anxiety inventory,STAI)作为数据收集工具,对受试者的人口统计学及临床数据进行信息收集,采用t检验用于验证组内和组间统计学检验。结果研究被分为试验组与对照组,在进行研究干预后,试验组及对照组的所有参与者(100%)测量的焦虑水平下降。试验组进行干预后的平均STAI评分较干预前下降(10.55±5.31)分,两组之间对比,差异有统计学意义(P<0.05)。对照组在第二次测量的STAI评分较第一次测量的平均下降(2.85±1.42)分。结论音乐已被证明是一种有效的非干预性治疗资源,在肿瘤化疗中可改善患者的焦虑评分。

A Novel Composite Skin Graft Technique with Fat Derivatives

Skin grafting,although a relatively classic and well-known technique,still has multiple disadvantages such as secondary contracture of the skin graft,sunken depression,poor elasticity,and color mismatch.Adding adipose tissues significantly improved the graft appearance compared to traditional skin grafting methods.Herein,we report two cases of modified skin graft procedures,both showing positive outcomes.In case 1,a mechanically processed fat-derived product was injected into the lower half of the skin graft area.In case 2,left upper eyelid blepharoplasty was performed,and the orbital fat strip was transferred and placed under the recipient area on the right side.Hair growth was observed only in case 1,whereas the extent of sunken depression was significantly reduced in both cases.Compared to traditional skin grafting methods,adding fat components to the skin graft recipient area improved the appearance and blood supply,together with enhancing the regenerative rate.

Gigahertz-rate-switchable wavefront shaping through integration of metasurfaces with photonic integrated circuit

Achieving spatiotemporal control of light at high speeds presents immense possibilities for various applications in communication,computation,metrology,and sensing.The integration of subwavelength metasurfaces and optical waveguides offers a promising approach to manipulate light across multiple degrees of freedom at high speed in compact photonic integrated circuit(PIC)devices.Here,we demonstrate a gigahertz-rate-switchable wavefront shaping by integrating metasurface,lithium niobate on insulator photonic waveguides,and electrodes within a PIC device.As proofs of concept,we showcase the generation of a focus beam with reconfigurable arbitrary polarizations,switchable focusing with lateral focal positions and focal length,orbital angular momentum light beams as well as Bessel beams.Our measurements indicate modulation speeds of up to the gigahertz rate.This integrated platform offers a versatile and efficient means of controlling the light field at high speed within a compact system,paving the way for potential applications in optical communication,computation,sensing,and imaging.

A mitochondria-targeted H_(2)S-activatable fluorogenic probe for tracking hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury(HIRI)is the cause of postoperative hepatic dysfunction and failure,and even death.As an important biological effector molecule,hydrogen sulfide(H_(2)S)of mitochondria as a gasotransmitter that is usually used to protect against acute HIRI injury.However,the exact relationship between HIRI and mitochondrial H_(2)S remains tangled due to the lack of an effective analytical method.Herein,we have fabricated a mitochondria-targeted H_(2)S-activatable fluorogenic probe(Mito-GW)to explore the stability of mitochondrial H_(2)S and track the changes of mitochondrial H_(2)S during the HIRI.By virtue of pyridinium electropositivity and its amphiphilicity,Mito-GW could accumulate in mitochondria.It goes through an analyte-prompted immolation when reacts with H_(2)S,resulting in the releasing of the fluorophore(GW).Therefore,the extent of Mito-GW conversion to GW can be used to evaluate the changes of mitochondrial H_(2)S level in living cells and tissues.As proof-of-principle,we have used MitoGW to demonstrate the mitochondria H_(2)S-levels increase and then decrease during HIRI in vitro and in vivo.Our research highlights the tremendous potential of Mito-GW as a mitochondrial H_(2)S fluorogenic probe in elucidating the pathogenesis of HIRI,providing a powerful tool for promoting future research on hepatology.

简化老年综合评估在老年膀胱癌患者保留膀胱的三联治疗中应用价值

目的评估简化老年综合评估(CGA)分级在老年膀胱癌患者保留膀胱的三联治疗中的应用价值.方法纳入2021年1月-2023年1月湘潭市中心医院放疗科收治的65岁及以上的老年膀胱癌患者为研究对象,根据CGA标准将患者分为适合组、不适合组和虚弱组,分别接受不同治疗方案.结果32例患者中男性28例,女性4例,中位年龄75岁.适合组14例(43.75%)接受顺铂和/或吉西他滨同步放化疗,不适合组10例(31.25%)接受卡培他滨同步放化疗,虚弱组8例(25.00%)接受放疗联合支持治疗.三组患者最常见的不良反应为1-2级.所有患者均完成治疗,其中由于毒副反应导致的放疗完成总时间延长仅2例(6.25%).三组患者的客观缓解率分别为78.57%、60.00%和37.50%;疾病控制率分别为92.86%、80.00%和75.00%;临床完全缓解率分别为50.00%、40.00%和12.50%.结论基于CGA的分级系统选择合适的治疗方案,可以降低治疗毒性,提高患者治疗耐受性.老年膀胱癌患者保留膀胱的三联治疗中进行CGA评估具有临床可行性.

Spin-decoupled meta-coupler empowered multiplexing and multifunction of guided wave radiation

Employing couplers to convert guided waves into free-space modes and flexibly control their wavefront is one of the key technologies in chip-integrated displays and communications.Traditional couplers are mainly composed of gratings,which have limitations in footprint,bandwidth,as well as controllability.Though the resonant/geometric metasurface newly emerges as a promising interface for bridging guided waves with free-space ones,it either relies on complex optimizations of multiple parameters,or is subject to the locked phase response of opposite spins,both of which hinder the functional diversity and practical multiplexing capability.Here,we propose and experimentally demonstrate an alternative with a spin-decoupled meta-coupler,simultaneously integrating triple functions of guided wave radiation,polarization demultiplexing,and dual-channel wavefront manipulation into a single device.By endowing polarization-dependent functionalities into a pure geometric metasurface,the out-coupled left-handed and right-handed circular polarization guided waves intelligently identify the predesigned phase modulation and reconstruct desired wavefronts,like bifocal focusing and holography multiplexing,with a polarization extinction ratio over 13.4 dB in experiments.We envision that the robust,broadband,and multifunctional meta-coupler could pave a way for the development of versatile multiplexed waveguide-based devices.

Spectral tomographic imaging with aplanatic metalens

Tomography is an informative imaging modality that is usually implemented by mechanical scanning,owing to the limited depth-of-field(DOF)in conventional systems.However,recent imaging systems are working towards more compact and stable architectures;therefore,developing nonmotion tomography is highly desirable.Here,we propose a metalens-based spectral imaging system with an aplanatic GaN metalens(NA=0.78),in which large chromatic dispersion is used to access spectral focus tuning and optical zooming in the visible spectrum.After the function of wavelength-switched tomography was confirmed on cascaded samples,this aplanatic metalens is utilized to image microscopic frog egg cells and shows excellent tomographic images with distinct DOF features of the cell membrane and nucleus.Our approach makes good use of the large diffractive dispersion of the metalens and develops a new imaging technique that advances recent informative optical devices.

Modification mechanism of caking and coking properties of Shenmu subbituminous coal by low-temperature rapid pyrolysis treatment

Shenmu(SM)subbituminous coal without caking property was treated by low-temperature rapid pyrolysis(LTRP)to modify its caking and coking properties.The treated samples were characterized by Fourier transform infrared spectrometry,vitrinite reflectance,and X-ray diffraction to determine the modification mechanism.Moreover,caking index(G)and coking indices(mechanical strength,coke reactivity,and coke strength after reaction)were employed to evaluate caking and coking properties,respectively.The results showed that SM coal was gradually upgraded with increasing processing temperature.Furthermore,the G values for the treated samples were significantly higher than that for SM coal,and G reached the maximum value at 450℃,implying the modification of caking property and the existence of an optimum temperature(450℃).Additionally,laboratory coking determinations showed that LTRP increased the mechanical strength of coke and coke strength after reaction and decreased coke reactivity when the treated coals were used in the coal blends instead of raw SM coal.Overall,LTRP treatment is effective to improve the caking and coking properties of SM coal.A mechanism was proposed for the modification.Suitable upgrading degree with suitable molecular masses and some releasable hydrogen-rich donor species present within the coal,which dominate the development of caking property,is important.

Skill Learning for Human-Robot Interaction Using Wearable Device

With the accelerated aging of the global population and escalating labor costs, more service robots are needed to help people perform complex tasks. As such, human-robot interaction is a particularly important research topic. To effectively transfer human behavior skills to a robot, in this study, we conveyed skill-learning functions via our proposed wearable device. The robotic teleoperation system utilizes interactive demonstration via the wearable device by directly controlling the speed of the motors. We present a rotation-invariant dynamicalmovement-primitive method for learning interaction skills. We also conducted robotic teleoperation demonstrations and designed imitation learning experiments. The experimental human-robot interaction results confirm the effectiveness of the proposed method.