Quickly grasping the surrounding environment's information and the location of the vehicle is the key to achieving automatic driving. However, accurate and robust localization and mapping are still ...challenging for field vehicles and robots due to the characteristics of emptiness, terrain changeability, and Global Navigation Satellite System (GNSS)-denied in complex field environments. In this study, an LVI-SAM-based lidar, inertial, and visual fusion using simultaneous localization and mapping (SLAM) algorithm was proposed to solve the problem of localization and mapping for vehicles in such open, bumpy, and Global Positioning System (GPS)-denied field environments. In this method, a joint lidar front end of pose estimation and correction was designed using the Super4PCS, Iterative Closest Point (ICP), and Normal Distributions Transform (NDT) algorithms and their variants. The algorithm can balance localization accuracy and real-time performance by carrying out lower-frequency pose correction based on higher-frequency pose estimation. Experimental results from the complex field environment show that, compared with LVI-SAM, the proposed method can reduce the translational error of localization by about 4.7% and create a three-dimensional point cloud map of the environment in real time, realizing the high-precision and high-robustness localization and mapping of the vehicle in complex field environments.
Astragalus mongolicus Bunge is used in traditional Chinese medicine and is thus cultivated in bulk. The cultivation of A. mongolicus requires a large amount of nitrogen fertilizer, increasing the ...planting cost of medicinal materials and polluting the environment. Isolation and screening of plant growth-promoting rhizobacteria (PGPR) and exploring the nitrogen fixation potential of A. mongolicus rhizosphere microorganisms would effectively reduce the production cost of A. mongolicus. This study used A. mongolicus roots and rhizosphere soil samples from Longxi County of Gansu Province, Jingle County, and Hunyuan County of Shanxi Province, China, to isolate and identify nitrogen-fixing bacteria. Through nitrogen fixation efficiency test, single strain inoculation test, and plant growth-promoting characteristics, three strains, Bacillus sp. J1, Arthrobacter sp. J2, and Bacillus sp. G4 were selected from 86 strains of potential nitrogen-fixing bacteria, which were the most effective in promoting the A. mongolicus growth and increasing the nitrogen, phosphorus, and potassium content in plants. The antagonistic test showed that these bacteria could grow smoothly under the co-culture conditions. The J1, J2, and G4 strains were used in a mixed inoculum and found to enhance the biomass of A. mongolicus plants and the accumulation of the main medicinal components in the field experiment. Mixed bacterial agent inoculation also increased bacterial diversity and changed the structure of the bacterial community in rhizosphere soil. Meanwhile, the relative abundance of Proteobacteria increased significantly after inoculation, suggesting that Proteobacteria play an important role in plant growth promotion. These findings indicate that specific and efficient PGPRs have a significant promoting effect on the growth of A. mongolicus, while also having a positive impact on the structure of the host rhizosphere bacteria community. This study provides a basis for developing a nitrogen-fixing bacterial fertilizer and improving the ecological planting efficiency of A. mongolicus.
Surface coating has been widely used to ameliorate the surface properties of Ti alloys. In this study, high-power pulsed magnetically controlled sputtering technology was used to successfully prepare ...a nano-CrN/TiN multi-layered coating on the surface of a TC4 Ti alloy. The surface of the obtained coating was uniform, dense, and free of obvious defects. With the decrease in modulation period, the optimal growth of the nano-CrN/TiN multi-layered coating was changed from a (220) crystal surface to (111) and a (200) crystal surface. Compared to the single-layered CrN or TiN coating, the nano-multi-layered coating had higher hardness and lower wear rate. Furthermore, the hardness and the wear resistance increased with the decrease in the modulation period. This presented an optimal modulation period of 6 nm. Meanwhile, the resistance of the obtained coating to high-temperature oxidation at 800 °C was also significantly improved.
To explore potential risk factors of preoperative cognitive dysfunction in adult patients with moyamoya disease (MMD) and discuss significance of moyamoya vessels.
The author reviewed adult MMD ...patients harboring no parenchymal infarction or hemorrhage underwent a standardized neuropsychological assessment test battery from December 2018 to May 2019. The authors defined patients with cognitive dysfunction as cognitive impairment shown on 3 or more neuropsychological tests. According to the presence of cerebral angiography, arterial stenosis, moyamoya vessels, and compensatory arteries were conducted. Univariate and multivariate analyses were performed to identify predictors for cognitive dysfunction before surgery. Subgroup analyses by onset type and Suzuki stage were carried out to identify specific predictors for preoperative cognitive dysfunction.
In total, 29 of 92 (31.52%) patients had cognitive dysfunction. Multivariate analysis showed that moyamoya vessels generating from left hemisphere was recognized as independent predictor for cognitive dysfunction (P = 0.025, OR 95%CI, 0.085 0.012-0.874). For patients in left ICA-moyamoya subgroup, 19 of 45 (42.22%) cases with sparse moyamoya vessels had cognitive dysfunction (P = 0.031), while 22 (91.67%) of patients with dense moyamoya vessels had normal cognition (P = 0.004). Moyamoya vessels arising from ophthalmic artery had no significant association with cognitive dysfunction (P = 0.111). Multivariate analysis found that moyamoya vessels originating from left ICA was recognized as independent predictors for preoperative cognitive dysfunction (P = 0.048, OR 95%CI, 0.394 0.132-0.926).
Moyamoya vessels arising from left hemisphere was a risk factor for the preoperative cognitive dysfunction in adult patients with MMD, with the denser moyamoya vessels, the less cognitive dysfunction. The current study offers a new perspective of moyamoya vessels and supporting data for choosing MMD candidates on cerebral revascularization.
Objective This study aims to investigate the clinical and pathological characteristics, treatment approaches, and prognosis of gallbladder neuroendocrine carcinoma (GB-NEC). Methods Retrospective ...analysis was conducted on the clinical data of 37 patients with GB-NEC admitted to Shanxi Cancer Hospital from January 2010 to June 2023. The study included an examination of their general information, treatment regimens, and overall prognosis. Results Twelve cases, either due to distant metastasis or other reasons, did not undergo surgical treatment and received palliative chemotherapy (Group 1). Two cases underwent simple cholecystectomy (Group 2); four patients underwent palliative tumor resection surgery (Group 3), and nineteen patients underwent radical resection surgery (Group 4). Among the 37 GB-NEC patients, the average pre-surgery CA19-9 level was 113.29 + or - 138.45 U/mL, and the median overall survival time was 19 months (range 7.89-30.11 months). Of these, 28 cases (75.7%) received systemic treatment, 25 cases (67.6%) underwent surgical intervention, and 16 cases (64.0%) received postoperative adjuvant treatment, including combined radiochemotherapy or chemotherapy alone. The median overall survival time was 4 months (0.61-7.40 months) for Group 1 (n = 12), 8 months for Group 2 (n = 2), 21 months (14.67-43.33 months) for Group 3 (n = 4), and 19 months (range 7.89-30.11 months) for Group 4 (n = 19). A significant difference in median overall survival time was observed between Group 1 and Group 4 (P = 0.004). Conclusion Surgery remains the primary treatment for GB-NEC, with radical resection potentially offering greater benefits to patient survival compared to other therapeutic options. Postoperative adjuvant therapy has the potential to extend patient survival, although the overall prognosis remains challenging. Keywords: Clinical features, Gallbladder neuroendocrine carcinoma, Survival time, Surgical treatment
As the level of weightlifting competition continues to improve, athletes need to continuously improve their athletic performance to achieve better results. However, we often see in training that some ...excellent weightlifters are often interrupted due to sports injuries, and their special ability and competitive level cannot be improved. How to effectively prevent sports injuries and reduce the incidence of sports injuries is a topic that needs to be grasped in the current sports team training process. The national weightlifting team attaches great importance to the role of technology in training and competitions. During the Tokyo Olympic preparation period, the concept of technology to help the Olympics has been fully implemented in the national weightlifting team. New training equipment, new monitoring methods, and new recovery methods have added more guarantees to the preparation of the national weightlifting team, improving athletes' competitive performance, reducing the risk of sports injuries, and ensuring the safety and health of athletes.
The motivation of this research is to review all methods used in data compression of collected data in monitoring the condition of equipment based on the framework of edge computing. Since a large ...amount of signal data is collected when monitoring conditions of mechanical equipment, namely, signals of running machines are continuously transmitted to be crunched, compressed data should be handled effectively. However, this process occupies resources since data transmission requires the allocation of a large capacity. To resolve this problem, this article examines the monitoring conditions of equipment based on edge computing. First, the signal is pre-processed by edge computing, so that the fault characteristics can be identified quickly. Second, signals with difficult-to-identify fault characteristics need to be compressed to save transmission resources. Then, different types of signal data collected in mechanical equipment conditions are compressed by various compression methods and uploaded to the cloud. Finally, the cloud platform, which has powerful processing capability, is processed to improve the volume of the data transmission. By examining and analyzing the monitoring conditions and signal compression methods of mechanical equipment, the future development trend is elaborated to provide references and ideas for the contemporary research of data monitoring and data compression algorithms. Consequently, the manuscript presents different compression methods in detail and clarifies the data compression methods used for the signal compression of equipment based on edge computing.
With the steady progress of the Healthy China and the rural revitalization strategy, the development of health services in new rural areas has become a “concentric circle” . This is not only a ...practical need for building a healthy China but also an essential requirement for the Party and the State to implement rural revitalization. At present, the development of health services in new rural areas faces numerous challenges, such as a lack of medical resources, a lack of health knowledge dissemination, and backward medical service levels. The integration of medical vocational colleges in their actual efforts to assist the development of health services in rural areas is not only an important manifestation of vocational education serving society but also significantly contributes to further assisting the implementation of the rural revitalization strategy.
ObjectMoyamoya disease (MMD) is a common and chronic progressive stenotic-occlusive cerebrovascular disease in Eastern Asia. To evaluate the hemispheric haemodynamic status of adult patients with ...MMD, we explored the potential risk factors of hemispheric perfusion alterations with CT perfusion (CTP) and DSA.MethodsWe retrospectively reviewed 44 male and 44 female (176 hemispheres) adult patients with MMD who had both DSA and CTP. Data on cerebral blood perfusion (CBF), cerebral blood volume (CBV), mean transmit time (MTT), time to peak (TTP) of cerebral hemisphere and cerebellum were gathered and difference of relative haemodynamic parameters between different subgroups were assessed with independent sample t analysis, one-way analysis of variance and general linear regression analysis.ResultsParameters in regional CBF (rCBF) of frontal, temporal lobe and basal ganglia in female was more superior than male. rCBF, regional MTT (rMTT) and regional TTP (rTTP) in adult MMD patients with haemorrhage were superior than the ischaemic. With the increase of age, significant difference could be seen in rCBF and rCBV of thalamus. However, with progress of arterial stenosis, significant difference could only be obsevrved in rCBV, rMTT and rTTP, whereas rCBF had no significant difference. For increase of moyamoya vessels, significant decrease of rCBF could be seen in temporal and parietal lobe. With the increase of compensatory artery numbers, no significant difference could be seen in rCBF parameters (p>0.05).ConclusionsIn adult MMD patients, age, gender and clinical type were potential risk factors for the change of cerebral perfusion. When arterial stenosis is worsened, moyamoya vessels could alter perfusion of temporal and parietal lobe, but not frontal lobe. Extracranial/intracranial compensatory arteries could maintain microcirculation stability in frontal lobe and basal ganglia, indicating that the protection from extracranial compensatory arteries, a theoretic base for surgery treatment if necessary.
Dispersive soil, which has the characteristics of low erosion resistance and high dispersibility in water, is the main reason for the channel slope failure that happened in the planning area of the ...Western Alkaline Treatment project in Jilin Province. Therefore, the study focused on the improvement of dispersive soil. In this research, pinhole test and crumb test were conducted on the soil under varying percentages of alum (1%, 1.5%, 2%, 2.5%, and 3%). Results indicated that alum can reduce the dispersivity of soil distinctly, and the optimal content of alum was 2.5%. This research also investigated the durability of 2.5%-alum-improved dispersive soil for dispersibility under the condition of freeze-thaw cycle. The soil samples with 2.5% alum content were subjected to pinhole test, crumb test, double hydrometer test, and percentage of exchangeable sodium ion test under the different number of freeze-thaw cycles. The results showed that the 2.5%-alum-improved soil was unaffected by the number of freeze-thaw cycles, which illustrated that alum can be used to improve soil dispersivity in engineering practice.
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