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Robots are playing an increasingly important role in engineering applications. Soft robots have promising applications in several fields due to their inherent advantages of compliance, low density, and soft interactions. A soft gripper based on bio-inspiration is proposed in this study. We analyze the cushioning and energy absorption mechanism of human fingertips in detail and provide insights for designing a soft gripper with a variable stiffness structure. We investigate the grasping modes through a large deformation modeling approach, which is verified through experiments. The characteristics of the three grasping modes are quantified through testing and can provide guidance for robotics manipulation. First, the adaptability of the soft gripper is verified by grasping multi-scale and extremely soft objects. Second, a cushioning model of the soft gripper is proposed, and the effectiveness of cushioning is verified by grasping extremely sharp objects and living organisms. Notably, we validate the advantages of the variable stiffness of the soft gripper, and the results show that the soft robot can robustly complete assemblies with a gap of only 0.1 mm. Owing to the unstructured nature of the engineering environment, the soft gripper can be applied in complex environments based on the abovementioned experimental analysis. Finally, we design the soft robotics system with feedback capture based on the inspiration of human catching behavior. The feasibility of engineering applications is initially verified through fast capture experiments on moving objects. The design concept of this robot can provide new insights for bionic machinery. [ABSTRACT FROM AUTHOR]

Key message: Imbalanced chromosomes and cell cycle arrest, along with down-regulated genes in DNA damage repair and sperm cell differentiation, caused pollen abortion in synthetic allodiploid Brassica juncea hybrids. Interspecific hybridization is considered to be a major pathway for species formation and evolution in angiosperms, but the occurrence of pollen abortion in the hybrids is common, prompting us to recheck male gamete development in allodiploid hybrids after the initial combination of different genomes. Here, we investigated the several key meiotic and mitotic events during pollen development using the newly synthesised allodiploid B. juncea hybrids (AB, 2n = 2× = 18) as a model system. Our results demonstrated the partial synapsis and pairing of non-homologous chromosomes concurrent with chaotic spindle assembly, affected chromosome assortment and distribution during meiosis, which finally caused difference in genetic constitution amongst the final tetrads. The mitotic cell cycle arrest during microspore development resulted in the production of anucleate pollen cells. Transcription analysis showed that sets of key genes regulating cyclin (CYCA1;2 and CYCA2;3), DNA damage repair (DMC1, NBS1 and MMD1), and ubiquitin–proteasome pathway (SINAT4 and UBC) were largely downregulated at the early pollen meiosis stages, and those genes involved in sperm cell differentiation (DUO1, PIRL1, PIRL9 and LBD27) and pollen wall synthesis (PME48, VGDH11 and COBL10) were mostly repressed at the late pollen mitosis stages in the synthetic allodiploid B. juncea hybrids (AB). In conclusion, this study elucidated the related mechanisms affecting pollen fertility during male gametophyte development at the cytological and transcriptomic levels in the synthetic allodiploid B. juncea hybrids. [ABSTRACT FROM AUTHOR]

Multiple surface treatment methods for titanium alloy prostheses, widely used in orthopedics, are available; however, these can affect bone integration and regeneration efficiency. In this study, through cell and animal experiments, we devised seven bone implant categories of Ti6Al4V based on surface preparation and post-processing technology (polishing, grit-blasting, fine titanium spraying, coarse titanium spraying, electron beam melting [EBM] printing, selective laser melting [SLM] printing, and post-processed SLM printing) and imaged each microscopic surface structure with a scanning electron microscope (SEM). Mechanical testing revealed excessive post-processing damaged the mechanical properties of the implants. In vitro, human bone marrow mesenchymal stem cells (hBMSCs) were cultured with implants, and the morphology of the cells adhering to the implant surface was observed using SEM and confocal laser scanning microscopy. Cell Counting Kit-8 (CCK-8) semi-quantitatively determined cell activity, indirectly reflecting the proliferation of hBMSCs. Alizarin red and alkaline phosphatase experiments assessed osteogenic differentiation. In vivo, experiments utilized the New Zealand rabbit femoral condyle bone defect model to assess bone regeneration and integration using micro-computed tomography, Van Giesen staining, and Masson staining. We found that 3D-printed implants with regular pore structures were more conducive to hBMSC osteogenic differentiation, while the presence of metal powder on NPT-SLM-printed implants hindered such differentiation. The post-treatment SLM scaffold surface may have some residual semi-melted powder; however, these powder residues have no significant effect on cell activity and differentiation. Surface treatment (grit-blasting and titanium spraying) of planar structures can enhance hBMSC adhesion but does not necessarily promote their differentiation. The framework structure of 3D printing may affect the osteogenic differentiation of hBMSCs, and for SLM-printed implants, excessive pursuit of a "powderless" state will damage the mechanical properties of the implant. [ABSTRACT FROM AUTHOR]

Human epidermal growth factor receptor 2 (HER2) gene amplification helps identify breast cancer patients who may respond to targeted anti-HER2 therapy. This study aims to develop an automated method for quantifying HER2 fluorescence in situ hybridization (FISH) signals and improve the working efficiency of pathologists. An Aitrox artificial intelligence (AI) model based on deep learning was constructed, and a comparison between the AI model and traditional manual counting was performed. In total, 918 FISH images from 320 consecutive invasive breast cancers were analysed and automatically classified into 5 groups according to the 2018 ASCO/CAP guidelines. The overall classification accuracy was 85.33% (157/184) with a mean average precision of 0.735. In Group 5, the most common group, the consistency was as high as 95.90% (117/122), while the consistency was low in the other groups due to the limited number of cases. The causes of this inconsistency, including clustered HER2 signals, coarse CEP17 signals and some section quality problems, were analysed. The developed AI model is a reliable tool for evaluating HER2 amplification statuses, especially for breast cancer in Group 5; additional cases from multiple centres could further improve the accuracy achieved for other groups. [ABSTRACT FROM AUTHOR]

Morphological parameters of knee joint are related to race and nationality. At present, knee prosthesis come from white male population. Due to the mismatch between the prosthesis and other ethnic groups, the prosthesis life span is reduced, revision surgery and the patients' economic burden are increased. There is no data of the Mongolian ethnic group. In order to treat patients more accurately, we measured the Mongolian data of the femoral condyle. A total of 122 knee joints were scanned in 61 volunteers (21 males and 40 females) with an average age of 23.259 ± 1.395 years. The Mimics software was used to reconstruct the 3D image and measure the data of each line. The data were analyzed by statistical methods such as t test, and P < 0.05 was taken as the significant. 122 normal femoral condyle data were obtained. The mean transverse diameter of femoral condyle is 76.472 ± 5.952 mm, medial condyle is 29.259 ± 11.461 mm, and the sagittal diameter of the medial condyle was 56.758 ± 4.163 mm. The transverse diameter of the lateral femoral condyle is 29.388 ± 3.157 mm, the sagittal diameter of the lateral condyle is 58.937 ± 3.527 mm and the femoral plane rate is 1.264 ± 0.072. (1) There was no statistical significance in the left and right knee joint data (P > 0.05). (2) The different genders data of femoral condyle were statistically significant (P < 0.05). (3) Compared with other nationalities and races, the data of femoral condyle are different. (4) There are differences between femoral surface ratio and mainstream prosthesis data. [ABSTRACT FROM AUTHOR]

To understand the natural gas characteristics of multi-thin coal seam, this study selected the desorbed gas of coal seams in different layers of Well A in the Wujiu depression, Hailar Basin in northeast Inner Mongolia. The results show that the heavy hydrocarbon content of desorbed gas increases significantly with the increasing depth. Methane carbon (δ13C1) and ethane carbon (δ13C2) isotope values are vertically become heavier downwards, while the δ 13 C CO 2 values did not change significantly. The kerogen is close to the III−II mixed type with the source rocks mainly deposited in a shore/shallow lake or braided-river delta front, and the gas produced has certain characteristics of oil associated gas. However, the characteristics of oil associated gas produced by the organic formed in the shallow-water environment (braided-river delta plain) are not obvious. The sandstone pore and fracture systems interbedded with multi-thin coal seam are well developed. And it is conducive to the migration of methanogenic micro-organisms to coal seams via groundwater, making it easier to produce biogenic gas under this geological condition. During the burial evolution of coal-bearing strata in the study area, when the burial depth reaches the maximum, there are significant differences in the paleotemperature experienced by different vertical coal seams, caused by a high-paleogeothermal gradient, increasing the δ13C2 of desorbed gas with increasing depth. The above research indicates that there is less biogenic gas in the multi-thin coal seams with relatively developed mudstone, and the multi-thin coal seams with relatively developed sandstones have obvious biogenic gas characteristics. Therefore, for the exploration and development of biogenic gas in low-rank multi-thin coal seams, it is necessary to give priority to the layer with high sandstone content. [ABSTRACT FROM AUTHOR]

Using first-principles calculations, we studied the electronic properties of graphdiyne (GDY) nanosheet and its Si-doped counterpart, SiGDY. Both GDY and SiGDY sheet surfaces were examined for acetaminophen (AP) drug adsorption using adsorption energy, charge transfer, and change in electrical conductivity (as indicators). As shown in this study, pure GDY has little affinity for AP. In specific, only 7.83 percent of the GDY surface's bandwidth energy changed after AP adsorption. On SiGDY, AP has a gaseous energy value of − 18.75 kcal/mol, as well as an aqueous energy value of − 49.39 kcal/mol. The water-phase solubility of the prescribed medications is determined using their solvation energy value. These charges are transferred between AP and the SiGDY sheet, which is extremely positively charged, giving AP the necessary binding energy. After AP adsorption, the electrical conductivity of SiGDY was increased by approximately 19.01 percent. [ABSTRACT FROM AUTHOR]

Sensitive detection of local acoustic vibrations at the nanometer scale has promising potential applications involving miniaturized devices in many areas, such as geological exploration, military reconnaissance, and ultrasound imaging. However, sensitive detection of weak acoustic signals with high spatial resolution at room temperature has become a major challenge. Here, we report a nanometer-scale system for acoustic detection with a single molecule as a probe based on minute variations of its distance to the surface of a plasmonic gold nanorod. This system can extract the frequency and amplitude of acoustic vibrations with experimental and theoretical sensitivities of 10 pm Hz−1/2 and 10 fm Hz−1/2, respectively. This approach provides a strategy for the optical detection of acoustic waves based on molecular spectroscopy without electromagnetic interference. Moreover, such a small nano-acoustic detector with 40-nm size can be employed to monitor acoustic vibrations or read out the quantum states of nanomechanical devices. .Sensitive detection of weak acoustic signals at nanometer scale is challenging. Here, the authors present an acoustic detection system based on a single molecule as a probe, where frequency and amplitude of acoustic vibrations can be extracted from its minute variations in distance to the surface of a plasmonic gold nanorod. [ABSTRACT FROM AUTHOR]

To integrate driver experience and heterogeneous vehicle platform characteristics in a motion-planning algorithm, based on the driver-behavior-based transferable motion primitives (MPs), a general motion-planning framework for offline generation and online selection of MPs is proposed. Optimal control theory is applied to solve the boundary value problems in the process of generating MPs, where the driver behaviors and the vehicle motion characteristics are integrated into the optimization in the form of constraints. Moreover, a layered, unequal-weighted MP selection framework is proposed that utilizes a combination of environmental constraints, nonholonomic vehicle constraints, trajectory smoothness, and collision risk as the single-step extension evaluation index. The library of MPs generated offline demonstrates that the proposed generation method realizes the effective expansion of MP types and achieves diverse generation of MPs with various velocity attributes and platform types. We also present how the MP selection algorithm utilizes a unique MP library to achieve online extension of MP sequences. The results show that the proposed motion-planning framework can not only improve the efficiency and rationality of the algorithm based on driving experience but can also transfer between heterogeneous vehicle platforms and highlight the unique motion characteristics of the platform. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) have attracted much attention due to their excellent photoelectric properties and potential applications. Although previous studies have shown that almost all organic molecules can be converted into CDs via chemical carbonization, the mechanism of the conversion process remains unclear. The hydrothermal/solvothermal method commonly used to prepare CDs is complicated and leads to the generation of many by-product CDs with similar structures. Considering that the purification of the synthesized by-products is difficult, the process of CDs formation cannot be readily analyzed and understood. Herein, we use ethanol as a carbon source to synthesize white-emitting CDs (W-CDs). Column chromatography separation shows that the synthesized W-CDs are composed of blue-, cyan-, and yellow-emitting CDs that fluoresce at wavelengths corresponding to the three emission centers of W-CDs. Although the samples have similar graphitic structure, they exhibit different surface states due to variations in the degree of oxidation and carbonization. Therefore, the red-shift in their emission peaks is attributed to an increased degree of carbonization in their polymer structure. Theoretical calculations verify the experimental results, and the prepared CDs are successfully used to develop multi-color and white light-emitting diodes (LEDs). [ABSTRACT FROM AUTHOR]

Carbon dots (CDs), as a kind of carbon nanomaterials, have attracted widespread attention due to their unique structure and excellent optical properties, and they are low-cost, environmentally friendly and biocompatible. However, the development of near-infrared (NIR) emission CDs remains a challenge. In this study, we successfully prepared CDs with a maximum emission of 714 nm using citric acid as the carbon source, thiourea and ammonium fluoride as the dopant source, and N,N-dimethylformamide as the solvent. The quantum yield (QY) is as high as 22.64%. Interestingly, the prepared CDs self-oxidize in the presence of oxygen, resulting in a blue shift of their emission. Therefore, they can be used to prepare white light-emitting diodes (WLEDs) without adding other fluorescent substances. Notably, the work presented herein constitutes the first report of WLEDs preparation from single CDs. [ABSTRACT FROM AUTHOR]

The phase state of shale oil has a significant impact on its mobility. The mineral and organic matter in shale reservoirs play an important role in oil phase. This study attempts to evaluate the properties of shale oils in different phase states and to investigate how these differences are related to initial shale composition. Samples from the first member of the Qingshankou (Q1) Formation were analyzed using X-ray diffraction, total organic carbon content, rock pyrolysis solvent extraction and group component separation. Subsequently, fluorescence techniques were used to quantitatively determine the content and properties of the free oil (FO), the adsorbed oil associated with carbonate (ACO), and the adsorbed oil associated with silicate and clay-organic complexes (AKO). The results showed that non-hydrocarbons and asphaltenes are the primary fluorescing compounds on shale grain. FO is the dominant phase in the Q1 Formation. The quantitative grain fluorescence on extraction (QGF-E) and total scanning fluorescence (TSF) spectra of ACO and AKO show a significant redshift compared to the FO. The TSF spectra of FO have a characteristic skew to the left and a single peak distribution, suggesting a relatively light hydrocarbon component. The TSF spectra of ACO show a skew to the right and an even, double-peaked distribution. The TSF spectra of AKO show a single peak with a skew to the right, indicating that ACO and AKO hydrocarbons are heavier than FO hydrocarbons. In summary, enrichment of carbonate minerals in shale may result in mis-identification of "sweet spots" when using QGF. The normalized fluorescence intensity of QGF-E and TSF are effective indexes allowing oil content evaluation. As an additional complicating factor, hydrocarbon fractionation occurs during generation and expulsion, leading to a differentiation of oil composition. And FO has high relatively light hydrocarbon content and the strongest fluidity. [ABSTRACT FROM AUTHOR]

A planar metamaterial structure has been designed to obtain surface plasmon-induced-transparency (PIT) effect, which is composed of a nanodisk sandwiched between double rods. From theoretical perspective, the three-level plasmonic system has been utilized to analyze the near-field coupling mechanism. Besides, the simulation results show that PIT resonance can be tailored by structure parameters. Particularly, when the length of the rods is more than twice of the diameter of the disk, two PIT windows are generated simultaneously, based on the coupling between the bright mode of the nanodisk and two multipole dark modes of rods. Furthermore, a metamaterial structure, composed by a disk and two pairs of nanorods, is suggested to achieve the polarization-independent plasmon-induced-transparency effect. As a result, this work shows great application prospect in the area of compact optical devices, such as multiband tunable filters, plasmonic switches, and slow light devices. [ABSTRACT FROM AUTHOR]

Real-time precise point positioning (PPP) based on open-access real-time service (RTS) of the international GNSS service (IGS) has attracted increasing attention in recent years. For offshore applications, the receiving of RTS corrections becomes a major obstacle due to lack of internet-based infrastructures. Short-message communication (SMC) is a particular technique of BeiDou navigation satellite system (BDS), which can provide bidirectional communication between users in a cost-effective way. However, the limited bandwidth and frequency of BDS SMC make it impossible to directly broadcast IGS RTS corrections with BDS SMC. An offshore real-time PPP technique is proposed based on IGS RTS corrections with a single set of BDS SMC devices for communication. RTS orbit corrections in the along-track, cross-track and radial directions, the clock correction and the code bias correction of each satellite are together converted into an equivalent range correction on the basis of user approximate position and will-be-used code observation types. The range corrections within 1 min are fitted into a first-order polynomial. Only the range and range-rate corrections at the reference time are broadcast with BDS SMC. In addition, different from broadcasting corrections of all satellites in the IGS RTS, corrections of only visible satellites are encoded into a BDS SMC correction message to further reduce the data size. The encoding strategy of BDS SMC correction message and a detailed procedure of the offshore real-time PPP technique are presented. The land-simulated and offshore experiment results show that the proposed technique can meet the demands of high-precision offshore applications. [ABSTRACT FROM AUTHOR]

A multilayer coal bed methane system with a complex superimposed relationship developed vertically in the Gujiao block. Taking the cumulative thickness of mudstone between neighbouring coal seams and open faults as object of research, the key strata for the division of different CBM systems was defined. The connection of an open fault for the fluid pressure system and the spatial distribution of the CBM system were analysed. The results showed that the porosity of compact mudstone is extremely low. When the mudstone thickness of the roof and floor increases, the gas content increases. Taking the Lijiashe and Wangzhimao faults as the boundary lines, the fluid pressure gradient between the Shanxi and Taiyuan formations is less than 0.08 MPa /100 m in the northern fracture zone, such as the Zhenchengdi, the Xiqu, the Tunlan, and the northern Dongqu well fields. The vertical gas units of different strata may belong to the same CBM system. The structure is simple in the southern Lijiashe fault. The vertical gas units in the southern Lijiashe fault belong to different CBM systems. Combined with the minimum thickness of the mudstone layer (2 m) and coal seam (0.5 m) standards, the spatial distribution of CBM systems was analysed. [ABSTRACT FROM AUTHOR]

The formation environment of the main coal seam in Shengli coal mine is analyzed, and the effect of coal ash parameters on the coal-forming environment is mainly discussed according to gray component parameters combined with other coal quality test analysis data. Results show that the hydrodynamic conditions of the main coal during coal accumulation have a general pattern of strong northeast and weak southwest, and lakeside swamp is generally in the retrograde process from south to north. The No.5 coal seam is a water entry cycle, and the No.5lower coal is a water withdrawal cycle. The No.6 thick coal seam is formed in the peat swamp environment where the water is shallow and the groundwater activity is weak. The input of terrestrial debris material was most abundant in the formation period of No.5lower coal, followed by No.5 coal, and that in No.6 coal is the least. Vertically, the peat swamp environment changed from weak reduction to weak oxidation to strong reducing environment. The ash yield was low to high to low from bottom to top. The organic sulfur is the main type of sulfur in the main coal seam. The weaker the hydrodynamic condition, the higher the organic sulfur content in the reduction environment, while lower organic sulfur content in the oxidation environment. The peat swamp water of No.5lower coal is medium alkaline, and the peat swamp water of No.5 and No. 6 coals is weakly alkaline or acidic. [ABSTRACT FROM AUTHOR]

The competition between attraction and diffusion determines the kinetics of non-equilibrium aggregation process. The formation of silver nanoclusters through non-equilibrium aggregation of silver atoms in solution was simulated by molecular dynamics as a model system to study the influence of the competition between attraction and diffusion on the aggregation process by varying concentration and temperature. It has been found that the aggregation time decreases monotonically with increasing concentration of silver atoms because of increasing attraction, while initially decreasing and then increasing with increasing temperature because of the competition between accelerated attractive motion and increasing diffusive motion of silver atoms. A mean field approximation was employed to develop a phenomenological model describing the mechanism of temperature dependence of aggregation time. [ABSTRACT FROM AUTHOR]

Network coding is vulnerable to pollution attacks, which prevent receivers from recovering the source message correctly. Most existing schemes against pollution attacks either bring significant redundancy to the original message or require a high computational complexity to verify received blocks. In this paper, we propose an efficient scheme against pollution attacks based on probabilistic key pre-distribution and homomorphic message authentication codes (MACs). In our scheme, each block is attached with a small number of MACs and each node can use these MACs to verify the integrity of the corresponding block with a high probability. Compared to previous schemes, our scheme still leverages a small number of keys to generate MACs for each block, but more than doubles the detection probability.Meanwhile, our scheme is able to efficiently restrict pollution propagation within a small number of hops. Experimental results show that our scheme is more efficient in verification than existing ones based on public-key cryptography. [ABSTRACT FROM AUTHOR]