Intelligent Drilling and Coring Technologies for Unmanned Interplanetary Exploration

The robotic technology, especially the intelligent robotics that can autonomously conduct numerous dangerous and uncertain tasks, has been widely applied to planetary explorations. Similar to terrestrial mining, before landing on planets or building planetary constructions, a drilling and coring activity should be first conducted to investigate the in-situ geological information. Given the technical advantages of unmanned robotics, utilizing an autonomous drill tool to acquire the planetary soil sample may be the most reliable and cost-effective solution. However, due to several unique challenges existed in unmanned drilling and coring activities, such as long-distance time delay, uncertain drilling formations, limited sensor resources, etc., it is indeed necessary to conduct researches to improve system’s adaptability to the complicated geological formations. Taking drill tool’s power consumption and soil’s coring morphology into account, this chapter proposed a drilling and coring characteristics online monitoring method to investigate suitable drilling parameters for different formations. Meanwhile, by applying pattern recognition techniques to classify different types of potential soil or rocks, a drillability classification model is built accurately to identify the current drilling formation. By combining suitable drilling parameters with the recognized drillability levels, a closed-loop drilling strategy is established finally, which can be applied to future interplanetary exploration

Inversion of thermal properties of lunar soil from penetration heat of projectile using a 2D axisymmetric model and optimized PSO algorithm

The thermophysical parameters of lunar soil can be inferred from the temperature field during the invasion process of reconnaissance projectile. This paper adopts a two-dimensional axisymmetric model to reconstruct the projectile invasion process. An optimized particle swarm optimization method is then used to retrieve the thermophysical parameters of lunar soil. When the reconnaissance projectile penetrates the lunar interior, it rubs against the lunar soil and generates heat, which diffuses between the projectile body and the lunar soil. The sensors inside the reconnaissance projectile measure the temperature variation of the projectile body to inverse the thermophysical parameters. This paper carried out physical modeling of the penetration process of reconnaissance projectile. A two-dimensional axisymmetric simulation model is constructed for the physical process, and the adaptive inertial weight particle swarm algorithm is adopted. The inversion experiment of lunar soil thermophysical parameters based on the simulation model shows that the inversion error is less than 10%, which verifies the feasibility of this method

Baicalin-modified polyethylenimine for miR-34a efficient and safe delivery

The security and efficiency of gene delivery vectors are inseparable for the successful construction of a gene delivery vector. This work provides a practical method to construct a charge-regulated, hydrophobic-modified, and functionally modified polyethylenimine (PEI) with effective gene delivery and perfect transfection performance through a condensation reaction, named BA-PEI. The carrier was shown to possess a favorable compaction of miRNAs into positively charged nanoparticles with a hydrodynamic size of approximately 100 nm. Additionally, BA-PEI possesses perfect degradability, which benefits the release of miR-34a from the complexes. In A549 cells, the expression level of the miR-34a gene was checked by Western blotting, which reflects the transfection efficiency of BA-PEI/miR-34a. When miR-34a is delivered to the cell, the perfect anti-tumor ability of the BA-PEI/miR-34a complex was systematically evaluated with the suppressor tumor gene miR-34a system in vitro and in vivo. BA-PEI-mediated miR-34a gene transfection is more secure and effective than the commercial transfection reagent, thus providing a novel approach for miR-34a-based gene therapy

Drilling load modeling and validation based on the filling rate of auger flute in planetary sampling

Some type of penetration into a subsurface is required in planetary sampling. Drilling and coring, due to its efficient penetrating and cuttings removal characteristics, has been widely applied in previous sampling missions. Given the complicated mechanical properties of a planetary regolith, suitable drilling parameters should be matched with different drilling formations properly. Otherwise, drilling faults caused by overloads could easily happen. Hence, it is necessary to establish a drilling load model, which is able to reveal the relationships among drilling loads, an auger’s structural parameters, soil’s mechanical properties, and relevant drilling parameters. A concept for the filling rate of auger flute (FRAF) is proposed to describe drilling conditions. If the FRAF index under one group of drilling parameters is less than 1, this means that the auger flute currently removes cuttings smoothly. Otherwise, the auger will be choked with compressed cuttings. In drilling operations, the drilling loads on the auger mainly come from the conveyance action, while the drilling loads on the drill bit primarily come from the cutting action. Experiments in one typical lunar regolith simulant indicate that the estimated drilling loads based on the FRAF coincide with the test results quite well. Based on this drilling load model, drilling parameters have been optimized

Mechanical Characteristics of Lunar Regolith Drilling and Coring and Its Crawling Phenomenon: Analysis and Validation

The collection of lunar regolith with complete stratigraphic information is the key to analyzing the evolution and composition of the moon. To keep each sample’s stratification for further analysis, a sampling method called flexible-tube coring has been adopted for Chinses lunar explorations. Given the uncertain physical properties of lunar regolith, drilling force and core lift force should be adjusted immediately in piercing process. Otherwise, only a small amount of core could be sampled, and overload drilling faults could occur correspondingly. Due to the fact that the cored regolith is inevitably connected to the flexible tube, coring characteristics may have a great influence on both lifting force and sampling quantity. To comprehend the regolith coring characteristics, a flexible-tube coring motion mechanics model was established and verified to acquire the lifting force results accurately. Herein, the judgment conditions for the flexible tube crawling phenomenon are proposed. Finally, the accuracy of the model is verified by comparing it with the Chang’e V telemetry data. This article provides theoretical support for the design and regulation improvement of Chang’e VI drilling and coring in the future

Suppression of the HSF1-mediated proteotoxic stress response by the metabolic stress sensor AMPK.

Numerous extrinsic and intrinsic insults trigger the HSF1-mediated proteotoxic stress response (PSR), an ancient transcriptional program that is essential to proteostasis and survival under such conditions. In contrast to its well-recognized mobilization by proteotoxic stress, little is known about how this powerful adaptive mechanism reacts to other stresses. Surprisingly, we discovered that metabolic stress suppresses the PSR. This suppression is largely mediated through the central metabolic sensor AMPK, which physically interacts with and phosphorylates HSF1 at Ser121. Through AMPK activation, metabolic stress represses HSF1, rendering cells vulnerable to proteotoxic stress. Conversely, proteotoxic stress inactivates AMPK and thereby interferes with the metabolic stress response. Importantly, metformin, a metabolic stressor and popular anti-diabetic drug, inactivates HSF1 and provokes proteotoxic stress within tumor cells, thereby impeding tumor growth. Thus, these findings uncover a novel interplay between the metabolic stress sensor AMPK and the proteotoxic stress sensor HSF1 that profoundly impacts stress resistance, proteostasis, and malignant growth. EMBO J 2015 Feb 3; 34(3):275-93

Research on the Principle of a New Flexible Screw Conveyor and Its Power Consumption

A new screw conveyor with flexible discrete spiral blades is proposed to solve the problem of particle material gathering between the screw and the tube wall in the traditional screw conveyor. With a theoretical analysis, the power consumption model of the screw conveyor with flexible discrete spiral blades is built. Then, its practicability is verified by simulation and experimental testing. The simulation results show that the increase of the spiral angle will raise the transportation speed of the particles. The diameter of the flexible blades raises with the increase of the power consumption of the screw conveyor. The experimental testing verified the analysis and simulation results

Data_Sheet_1_Efficacy and safety of roxadustat for the treatment of anemia in non-dialysis chronic kidney disease patients: A systematic review and meta-analysis of randomized double-blind controlled clinical trials.pdf

ObjectiveTo evaluate the efficacy and safety of roxadustat in the treatment of anemia in non-dialysis-dependent chronic kidney disease (NDD-CKD) patients.Materials and methodsFor this systematic review and meta-analysis, we searched for randomized controlled trials (RCTs) of anemia in NDD-CKD patients to assess the efficacy and safety of roxadustat. The primary efficacy endpoint was the proportion of patients who achieved a hemoglobin (Hb) response. Secondary efficacy endpoints were hepcidin, serum iron, serum ferritin (SF), total iron-binding capacity (TIBC), transferrin saturation (TAST), and low-density lipoprotein (LDL). In addition, adverse events (AEs) were compared. Meta-analyses were performed using Revman 5.4 software. The quality of the evidence was assessed using the Cochrane risk of bias tool. This study was conducted under a pre-established protocol registered with PROSPERO (registration number: CRD42021252331).ResultsSeven studies enrolled 4,764 patients, of whom 2,730 received roxadustat and 2,034 received placebo. The results of this meta-analysis showed that roxadustat increased Hb levels [weighted mean difference (WMD) = 1.43, 95% CI: 1.17 to 1.68, P 2 = 95%], and Hb response [relative ratio (RR) = 8.12, 95% CI: 5.80 to 11.37, P 2 = 61%]. In addition, roxadustat significantly increased transferrin TAST. During the treatment period in patients with anemia, the AEs of roxadustat compared with placebo was not statistically significant.ConclusionRoxadustat can improve anemia in NDD-CKD patients by increasing Hb levels and regulating iron metabolism, but does not increase the incidence of AEs.Systematic review registration[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021252331].</p